rnd-20040322-B-src
[rocksndiamonds.git] / src / game.c
index 4e6cdf9fd1903ce197d7a2b95537ee7bc62d5457..6fc7f7bdc7dbd196ecfd616c94935a282f716466 100644 (file)
 
 /* for Explode() */
 #define EX_PHASE_START         0
-#define EX_NO_EXPLOSION                0
-#define EX_NORMAL              1
-#define EX_CENTER              2
-#define EX_BORDER              3
+#define EX_TYPE_NONE           0
+#define EX_TYPE_NORMAL         (1 << 0)
+#define EX_TYPE_CENTER         (1 << 1)
+#define EX_TYPE_BORDER         (1 << 2)
+#define EX_TYPE_CROSS          (1 << 3)
+#define EX_TYPE_SINGLE_TILE    (EX_TYPE_CENTER | EX_TYPE_BORDER)
 
 /* special positions in the game control window (relative to control window) */
 #define XX_LEVEL               37
@@ -59,7 +61,8 @@
 #define YY_KEYS                        123
 #define XX_SCORE               15
 #define YY_SCORE               159
-#define XX_TIME                        29
+#define XX_TIME1               29
+#define XX_TIME2               30
 #define YY_TIME                        194
 
 /* special positions in the game control window (relative to main window) */
@@ -73,7 +76,8 @@
 #define DY_KEYS                        (DY + YY_KEYS)
 #define DX_SCORE               (DX + XX_SCORE)
 #define DY_SCORE               (DY + YY_SCORE)
-#define DX_TIME                        (DX + XX_TIME)
+#define DX_TIME1               (DX + XX_TIME1)
+#define DX_TIME2               (DX + XX_TIME2)
 #define DY_TIME                        (DY + YY_TIME)
 
 /* values for initial player move delay (initial delay counter value) */
 
 #define GET_NEW_PUSH_DELAY(e)  (   (element_info[e].push_delay_fixed) + \
                                 RND(element_info[e].push_delay_random))
+#define GET_NEW_DROP_DELAY(e)  (   (element_info[e].drop_delay_fixed) + \
+                                RND(element_info[e].drop_delay_random))
 #define GET_NEW_MOVE_DELAY(e)  (   (element_info[e].move_delay_fixed) + \
                                 RND(element_info[e].move_delay_random))
 #define GET_MAX_MOVE_DELAY(e)  (   (element_info[e].move_delay_fixed) + \
                                    (element_info[e].move_delay_random))
 
-#define ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, condition)            \
+#define GET_TARGET_ELEMENT(e, ch)                                      \
+       ((e) == EL_TRIGGER_ELEMENT ? (ch)->actual_trigger_element :     \
+        (e) == EL_TRIGGER_PLAYER  ? (ch)->actual_trigger_player : (e))
+
+#define ELEMENT_CAN_ENTER_FIELD_BASE_X(x, y, condition)                        \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (condition)))
+
+#define ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, condition)             \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
+                                       (condition)))
+
+#define ELEMENT_CAN_ENTER_FIELD_BASE_3(e, x, y, condition)             \
+               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
+                                       (condition)))
+
+#define ELEMENT_CAN_ENTER_FIELD_BASE_4(e, x, y, condition)             \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
                                        (condition) ||                  \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
                                        (DONT_COLLIDE_WITH(e) &&        \
-                                        IS_FREE_OR_PLAYER(x, y))))
+                                        IS_PLAYER(x, y) &&             \
+                                        !PLAYER_ENEMY_PROTECTED(x, y))))
 
-#define ELEMENT_CAN_ENTER_FIELD_GENERIC_2(x, y, condition)             \
+#if 0
+#define ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, condition)            \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (condition)))
+                                       (condition) ||                  \
+                                       (DONT_COLLIDE_WITH(e) &&        \
+                                        IS_PLAYER(x, y) &&             \
+                                        !PLAYER_ENEMY_PROTECTED(x, y))))
+#endif
 
 #define ELEMENT_CAN_ENTER_FIELD(e, x, y)                               \
-       ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, 0)
+       ELEMENT_CAN_ENTER_FIELD_BASE_4(e, x, y, 0)
+
+#if 1
+#define SATELLITE_CAN_ENTER_FIELD(x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(EL_SATELLITE, x, y, 0)
+#else
+#define SATELLITE_CAN_ENTER_FIELD(x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_X(x, y, Feld[x][y] == EL_ACID)
+#endif
+
+#if 0
+#define ENEMY_CAN_ENTER_FIELD(e, x, y) (IN_LEV_FIELD(x, y) && IS_FREE(x, y))
+#endif
+
+#define ENEMY_CAN_ENTER_FIELD(e, x, y)                                 \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
+
+#if 1
+
+#define YAMYAM_CAN_ENTER_FIELD(e, x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_3(e, x, y, Feld[x][y] == EL_DIAMOND)
+
+#define DARK_YAMYAM_CAN_ENTER_FIELD(e, x, y)                           \
+       ELEMENT_CAN_ENTER_FIELD_BASE_3(e, x,y, IS_FOOD_DARK_YAMYAM(Feld[x][y]))
+
+#define PACMAN_CAN_ENTER_FIELD(e, x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_3(e, x, y, IS_AMOEBOID(Feld[x][y]))
+
+#define PIG_CAN_ENTER_FIELD(e, x, y)                                   \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, IS_FOOD_PIG(Feld[x][y]))
+
+#define PENGUIN_CAN_ENTER_FIELD(e, x, y)                               \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, (Feld[x][y] == EL_EXIT_OPEN ||\
+                                                IS_FOOD_PENGUIN(Feld[x][y])))
+#define DRAGON_CAN_ENTER_FIELD(e, x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
 
-#define ELEMENT_CAN_ENTER_FIELD_OR_ACID(e, x, y)                       \
-       ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, (Feld[x][y] == EL_ACID))
+#define MOLE_CAN_ENTER_FIELD(e, x, y, condition)                       \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, (condition))
 
-#define ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(x, y)                                \
-       ELEMENT_CAN_ENTER_FIELD_GENERIC_2(x, y, (Feld[x][y] == EL_ACID))
+#define SPRING_CAN_ENTER_FIELD(e, x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
 
-#define ENEMY_CAN_ENTER_FIELD(x, y) (IN_LEV_FIELD(x, y) && IS_FREE(x, y))
+#else
 
-#define YAMYAM_CAN_ENTER_FIELD(x, y)                                   \
+#define YAMYAM_CAN_ENTER_FIELD(e, x, y)                                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
                                        Feld[x][y] == EL_DIAMOND))
 
-#define DARK_YAMYAM_CAN_ENTER_FIELD(x, y)                              \
+#define DARK_YAMYAM_CAN_ENTER_FIELD(e, x, y)                           \
                (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
                                        IS_FOOD_DARK_YAMYAM(Feld[x][y])))
 
-#define PACMAN_CAN_ENTER_FIELD(x, y)                                   \
+#define PACMAN_CAN_ENTER_FIELD(e, x, y)                                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
                                        IS_AMOEBOID(Feld[x][y])))
 
-#define PIG_CAN_ENTER_FIELD(x, y)                                      \
+#define PIG_CAN_ENTER_FIELD(e, x, y)                                   \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
                                        IS_FOOD_PIG(Feld[x][y])))
 
-#define PENGUIN_CAN_ENTER_FIELD(x, y)                                  \
+#define PENGUIN_CAN_ENTER_FIELD(e, x, y)                               \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
                                        IS_FOOD_PENGUIN(Feld[x][y]) ||  \
-                                       Feld[x][y] == EL_EXIT_OPEN ||   \
-                                       Feld[x][y] == EL_ACID))
+                                       Feld[x][y] == EL_EXIT_OPEN))
 
-#if 0
-#if 1
-#define MAZE_RUNNER_CAN_ENTER_FIELD(x, y)                              \
-               (IN_LEV_FIELD(x, y) && IS_FREE(x, y))
-#else
-#define MAZE_RUNNER_CAN_ENTER_FIELD(x, y)                              \
+#define DRAGON_CAN_ENTER_FIELD(e, x, y)                                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       IS_FOOD_DARK_YAMYAM(Feld[x][y])))
-#endif
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID)))
+
+#define MOLE_CAN_ENTER_FIELD(e, x, y, condition)                       \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID) ||      \
+                                       (condition)))
+
+#define SPRING_CAN_ENTER_FIELD(e, x, y)                                        \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
+                                        Feld[x][y] == EL_ACID)))
+
 #endif
 
+#define GROUP_NR(e)            ((e) - EL_GROUP_START)
 #define MOVE_ENTER_EL(e)       (element_info[e].move_enter_element)
-#define IS_IN_GROUP(e, g)      (element_info[e].in_group[g] == TRUE)
+#define IS_IN_GROUP(e, nr)     (element_info[e].in_group[nr] == TRUE)
 #define IS_IN_GROUP_EL(e, ge)  (IS_IN_GROUP(e, (ge) - EL_GROUP_START))
 
+#define IS_EQUAL_OR_IN_GROUP(e, ge)                                    \
+       (IS_GROUP_ELEMENT(ge) ? IS_IN_GROUP(e, GROUP_NR(ge)) : (e) == (ge))
+
+#if 0
 #define CE_ENTER_FIELD_COND(e, x, y)                                   \
                (!IS_PLAYER(x, y) &&                                    \
                 (Feld[x][y] == EL_ACID ||                              \
-                 Feld[x][y] == MOVE_ENTER_EL(e) ||                     \
-                 (IS_GROUP_ELEMENT(MOVE_ENTER_EL(e)) &&                \
-                  IS_IN_GROUP_EL(Feld[x][y], MOVE_ENTER_EL(e)))))
+                 IS_EQUAL_OR_IN_GROUP(Feld[x][y], MOVE_ENTER_EL(e))))
+#else
+#define CE_ENTER_FIELD_COND(e, x, y)                                   \
+               (!IS_PLAYER(x, y) &&                                    \
+                IS_EQUAL_OR_IN_GROUP(Feld[x][y], MOVE_ENTER_EL(e)))
+#endif
 
 #define CUSTOM_ELEMENT_CAN_ENTER_FIELD(e, x, y)                                \
-       ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, CE_ENTER_FIELD_COND(e, x, y))
-
-#define MOLE_CAN_ENTER_FIELD(x, y, condition)                          \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) || (condition)))
+       ELEMENT_CAN_ENTER_FIELD_BASE_4(e, x, y, CE_ENTER_FIELD_COND(e, x, y))
 
 #define IN_LEV_FIELD_AND_IS_FREE(x, y)  (IN_LEV_FIELD(x, y) &&  IS_FREE(x, y))
 #define IN_LEV_FIELD_AND_NOT_FREE(x, y) (IN_LEV_FIELD(x, y) && !IS_FREE(x, y))
@@ -193,20 +283,45 @@ static boolean MovePlayer(struct PlayerInfo *, int, int);
 static void ScrollPlayer(struct PlayerInfo *, int);
 static void ScrollScreen(struct PlayerInfo *, int);
 
+int DigField(struct PlayerInfo *, int, int, int, int, int, int, int);
+
 static void InitBeltMovement(void);
 static void CloseAllOpenTimegates(void);
 static void CheckGravityMovement(struct PlayerInfo *);
-static void KillHeroUnlessProtected(int, int);
+static void CheckGravityMovementWhenNotMoving(struct PlayerInfo *);
+static void KillHeroUnlessEnemyProtected(int, int);
+static void KillHeroUnlessExplosionProtected(int, int);
 
 static void TestIfPlayerTouchesCustomElement(int, int);
 static void TestIfElementTouchesCustomElement(int, int);
 static void TestIfElementHitsCustomElement(int, int, int);
+#if 0
+static void TestIfElementSmashesCustomElement(int, int, int);
+#endif
 
 static void ChangeElement(int, int, int);
-static boolean CheckTriggeredElementSideChange(int, int, int, int, int);
-static boolean CheckTriggeredElementChange(int, int, int, int);
-static boolean CheckElementSideChange(int, int, int, int, int, int);
-static boolean CheckElementChange(int, int, int, int);
+
+static boolean CheckTriggeredElementChangeExt(int, int, int, int, int,int,int);
+#define CheckTriggeredElementChange(x, y, e, ev)                       \
+       CheckTriggeredElementChangeExt(x, y, e, ev, CH_PLAYER_ANY,      \
+                                      CH_SIDE_ANY, -1)
+#define CheckTriggeredElementChangePlayer(x, y, e, ev, p, s)           \
+       CheckTriggeredElementChangeExt(x, y, e, ev, p, s, -1)
+#define CheckTriggeredElementChangeSide(x, y, e, ev, s)                        \
+       CheckTriggeredElementChangeExt(x, y, e, ev, CH_PLAYER_ANY, s, -1)
+#define CheckTriggeredElementChangePage(x, y, e, ev, p)                        \
+       CheckTriggeredElementChangeExt(x, y, e, ev, CH_PLAYER_ANY,      \
+                                      CH_SIDE_ANY, p)
+
+static boolean CheckElementChangeExt(int, int, int, int, int, int, int, int);
+#define CheckElementChange(x, y, e, te, ev)                            \
+       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, CH_SIDE_ANY, -1)
+#define CheckElementChangePlayer(x, y, e, ev, p, s)                    \
+       CheckElementChangeExt(x, y, e, EL_EMPTY, ev, p, s, CH_PAGE_ANY)
+#define CheckElementChangeSide(x, y, e, te, ev, s)                     \
+       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, s, CH_PAGE_ANY)
+#define CheckElementChangePage(x, y, e, te, ev, p)                     \
+       CheckElementChangeExt(x, y, e, te, ev, CH_PLAYER_ANY, CH_SIDE_ANY, p)
 
 static void PlayLevelSound(int, int, int);
 static void PlayLevelSoundNearest(int, int, int);
@@ -476,6 +591,28 @@ collect_count_list[] =
   { EL_UNDEFINED,              0 },
 };
 
+struct
+{
+  int element;
+  int direction;
+}
+tube_access[] =
+{
+  { EL_TUBE_ANY,               MV_LEFT | MV_RIGHT | MV_UP | MV_DOWN },
+  { EL_TUBE_VERTICAL,                               MV_UP | MV_DOWN },
+  { EL_TUBE_HORIZONTAL,                MV_LEFT | MV_RIGHT                   },
+  { EL_TUBE_VERTICAL_LEFT,     MV_LEFT |            MV_UP | MV_DOWN },
+  { EL_TUBE_VERTICAL_RIGHT,              MV_RIGHT | MV_UP | MV_DOWN },
+  { EL_TUBE_HORIZONTAL_UP,     MV_LEFT | MV_RIGHT | MV_UP           },
+  { EL_TUBE_HORIZONTAL_DOWN,   MV_LEFT | MV_RIGHT |         MV_DOWN },
+  { EL_TUBE_LEFT_UP,           MV_LEFT |            MV_UP           },
+  { EL_TUBE_LEFT_DOWN,         MV_LEFT |                    MV_DOWN },
+  { EL_TUBE_RIGHT_UP,                    MV_RIGHT | MV_UP           },
+  { EL_TUBE_RIGHT_DOWN,                          MV_RIGHT |         MV_DOWN },
+
+  { EL_UNDEFINED,              0                                    }
+};
+
 static unsigned long trigger_events[MAX_NUM_ELEMENTS];
 
 #define IS_AUTO_CHANGING(e)    (element_info[e].change_events & \
@@ -586,6 +723,10 @@ static void InitPlayerField(int x, int y, int element, boolean init_game)
 
     player->present = TRUE;
 
+    player->block_last_field = (element == EL_SP_MURPHY ?
+                               level.sp_block_last_field :
+                               level.block_last_field);
+
     if (!options.network || player->connected)
     {
       player->active = TRUE;
@@ -625,6 +766,18 @@ static void InitField(int x, int y, boolean init_game)
       InitPlayerField(x, y, element, init_game);
       break;
 
+    case EL_SOKOBAN_FIELD_PLAYER:
+      element = Feld[x][y] = EL_PLAYER_1;
+      InitField(x, y, init_game);
+
+      element = Feld[x][y] = EL_SOKOBAN_FIELD_EMPTY;
+      InitField(x, y, init_game);
+      break;
+
+    case EL_SOKOBAN_FIELD_EMPTY:
+      local_player->sokobanfields_still_needed++;
+      break;
+
     case EL_STONEBLOCK:
       if (x < lev_fieldx-1 && Feld[x+1][y] == EL_ACID)
        Feld[x][y] = EL_ACID_POOL_TOPLEFT;
@@ -702,10 +855,6 @@ static void InitField(int x, int y, boolean init_game)
       local_player->lights_still_needed++;
       break;
 
-    case EL_SOKOBAN_FIELD_EMPTY:
-      local_player->sokobanfields_still_needed++;
-      break;
-
     case EL_PENGUIN:
       local_player->friends_still_needed++;
       break;
@@ -782,9 +931,22 @@ static void InitField(int x, int y, boolean init_game)
       else if (IS_GROUP_ELEMENT(element))
       {
        struct ElementGroupInfo *group = element_info[element].group;
-       int random_pos = RND(group->num_elements_resolved);
+       int last_anim_random_frame = gfx.anim_random_frame;
+       int element_pos;
 
-       Feld[x][y] = group->element_resolved[random_pos];
+       if (group->choice_mode == ANIM_RANDOM)
+         gfx.anim_random_frame = RND(group->num_elements_resolved);
+
+       element_pos = getAnimationFrame(group->num_elements_resolved, 1,
+                                       group->choice_mode, 0,
+                                       group->choice_pos);
+
+       if (group->choice_mode == ANIM_RANDOM)
+         gfx.anim_random_frame = last_anim_random_frame;
+
+       group->choice_pos++;
+
+       Feld[x][y] = group->element_resolved[element_pos];
 
        InitField(x, y, init_game);
       }
@@ -792,24 +954,106 @@ static void InitField(int x, int y, boolean init_game)
   }
 }
 
+static inline void InitField_WithBug1(int x, int y, boolean init_game)
+{
+  InitField(x, y, init_game);
+
+  /* not needed to call InitMovDir() -- already done by InitField()! */
+  if (game.engine_version < VERSION_IDENT(3,1,0,0) &&
+      CAN_MOVE(Feld[x][y]))
+    InitMovDir(x, y);
+}
+
+static inline void InitField_WithBug2(int x, int y, boolean init_game)
+{
+  int old_element = Feld[x][y];
+
+  InitField(x, y, init_game);
+
+  /* not needed to call InitMovDir() -- already done by InitField()! */
+  if (game.engine_version < VERSION_IDENT(3,1,0,0) &&
+      CAN_MOVE(old_element) &&
+      (old_element < EL_MOLE_LEFT || old_element > EL_MOLE_DOWN))
+    InitMovDir(x, y);
+
+  /* this case is in fact a combination of not less than three bugs:
+     first, it calls InitMovDir() for elements that can move, although this is
+     already done by InitField(); then, it checks the element that was at this
+     field _before_ the call to InitField() (which can change it)
+
+ */
+}
+
+inline void DrawGameValue_Emeralds(int value)
+{
+  DrawText(DX_EMERALDS, DY_EMERALDS, int2str(value, 3), FONT_TEXT_2);
+}
+
+inline void DrawGameValue_Dynamite(int value)
+{
+  DrawText(DX_DYNAMITE, DY_DYNAMITE, int2str(value, 3), FONT_TEXT_2);
+}
+
+inline void DrawGameValue_Keys(struct PlayerInfo *player)
+{
+  int i;
+
+  for (i = 0; i < MAX_KEYS; i++)
+    if (player->key[i])
+      DrawMiniGraphicExt(drawto, DX_KEYS + i * MINI_TILEX, DY_KEYS,
+                        el2edimg(EL_KEY_1 + i));
+}
+
+inline void DrawGameValue_Score(int value)
+{
+  DrawText(DX_SCORE, DY_SCORE, int2str(value, 5), FONT_TEXT_2);
+}
+
+inline void DrawGameValue_Time(int value)
+{
+  if (value < 1000)
+    DrawText(DX_TIME1, DY_TIME, int2str(value, 3), FONT_TEXT_2);
+  else
+    DrawText(DX_TIME2, DY_TIME, int2str(value, 4), FONT_LEVEL_NUMBER);
+}
+
+inline void DrawGameValue_Level(int value)
+{
+  if (level_nr < 100)
+    DrawText(DX_LEVEL, DY_LEVEL, int2str(value, 2), FONT_TEXT_2);
+  else
+  {
+    /* misuse area for displaying emeralds to draw bigger level number */
+    DrawTextExt(drawto, DX_EMERALDS, DY_EMERALDS,
+               int2str(value, 3), FONT_LEVEL_NUMBER, BLIT_OPAQUE);
+
+    /* now copy it to the area for displaying level number */
+    BlitBitmap(drawto, drawto,
+              DX_EMERALDS, DY_EMERALDS + 1,
+              getFontWidth(FONT_LEVEL_NUMBER) * 3,
+              getFontHeight(FONT_LEVEL_NUMBER) - 1,
+              DX_LEVEL - 1, DY_LEVEL + 1);
+
+    /* restore the area for displaying emeralds */
+    DrawGameValue_Emeralds(local_player->gems_still_needed);
+
+    /* yes, this is all really ugly :-) */
+  }
+}
+
 void DrawGameDoorValues()
 {
-  int i, j;
+  int i;
+
+  DrawGameValue_Level(level_nr);
 
   for (i = 0; i < MAX_PLAYERS; i++)
-    for (j = 0; j < 4; j++)
-      if (stored_player[i].key[j])
-       DrawMiniGraphicExt(drawto, DX_KEYS + j * MINI_TILEX, DY_KEYS,
-                          el2edimg(EL_KEY_1 + j));
+    DrawGameValue_Keys(&stored_player[i]);
 
-  DrawText(DX + XX_EMERALDS, DY + YY_EMERALDS,
-          int2str(local_player->gems_still_needed, 3), FONT_TEXT_2);
-  DrawText(DX + XX_DYNAMITE, DY + YY_DYNAMITE,
-          int2str(local_player->inventory_size, 3), FONT_TEXT_2);
-  DrawText(DX + XX_SCORE, DY + YY_SCORE,
-          int2str(local_player->score, 5), FONT_TEXT_2);
-  DrawText(DX + XX_TIME, DY + YY_TIME,
-          int2str(TimeLeft, 3), FONT_TEXT_2);
+  DrawGameValue_Emeralds(local_player->gems_still_needed);
+  DrawGameValue_Dynamite(local_player->inventory_size);
+  DrawGameValue_Score(local_player->score);
+  DrawGameValue_Time(TimeLeft);
 }
 
 static void resolve_group_element(int group_element, int recursion_depth)
@@ -825,7 +1069,7 @@ static void resolve_group_element(int group_element, int recursion_depth)
          group_element - EL_GROUP_START + 1);
 
     /* replace element which caused too deep recursion by question mark */
-    group->element_resolved[group->num_elements_resolved++] = EL_CHAR_QUESTION;
+    group->element_resolved[group->num_elements_resolved++] = EL_UNKNOWN;
 
     return;
   }
@@ -833,8 +1077,10 @@ static void resolve_group_element(int group_element, int recursion_depth)
   if (recursion_depth == 0)                    /* initialization */
   {
     group = element_info[group_element].group;
-    group->num_elements_resolved = 0;
     group_nr = group_element - EL_GROUP_START;
+
+    group->num_elements_resolved = 0;
+    group->choice_pos = 0;
   }
 
   for (i = 0; i < actual_group->num_elements; i++)
@@ -959,6 +1205,10 @@ static void InitGameEngine()
     ei->change->post_change_function = ch_delay->post_change_function;
 
     ei->change_events |= CH_EVENT_BIT(CE_DELAY);
+
+#if 1
+    SET_PROPERTY(ch_delay->element, EP_CAN_CHANGE, TRUE);
+#endif
   }
 
 #if 1
@@ -999,6 +1249,19 @@ static void InitGameEngine()
   }
 #endif
 
+  /* ---------- initialize run-time trigger player and element ------------- */
+
+  for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
+  {
+    struct ElementInfo *ei = &element_info[EL_CUSTOM_START + i];
+
+    for (j = 0; j < ei->num_change_pages; j++)
+    {
+      ei->change_page[j].actual_trigger_element = EL_EMPTY;
+      ei->change_page[j].actual_trigger_player = EL_PLAYER_1;
+    }
+  }
+
   /* ---------- initialize trigger events ---------------------------------- */
 
   /* initialize trigger events information */
@@ -1020,7 +1283,16 @@ static void InitGameEngine()
       {
        int trigger_element = ei->change_page[j].trigger_element;
 
-       trigger_events[trigger_element] |= ei->change_page[j].events;
+       if (IS_GROUP_ELEMENT(trigger_element))
+       {
+         struct ElementGroupInfo *group = element_info[trigger_element].group;
+
+         for (k = 0; k < group->num_elements_resolved; k++)
+           trigger_events[group->element_resolved[k]]
+             |= ei->change_page[j].events;
+       }
+       else
+         trigger_events[trigger_element] |= ei->change_page[j].events;
       }
     }
   }
@@ -1053,6 +1325,19 @@ static void InitGameEngine()
     element_info[e].push_delay_random = push_delay_list[i].push_delay_random;
   }
 
+  /* set push delay value for Supaplex elements for newer engine versions */
+  if (game.engine_version >= VERSION_IDENT(3,1,0,0))
+  {
+    for (i = 0; i < MAX_NUM_ELEMENTS; i++)
+    {
+      if (IS_SP_ELEMENT(i))
+      {
+       element_info[i].push_delay_fixed  = 6;  /* just enough to escape ... */
+       element_info[i].push_delay_random = 0;  /* ... from falling zonk     */
+      }
+    }
+  }
+
   /* ---------- initialize move stepsize ----------------------------------- */
 
   /* initialize move stepsize values to default */
@@ -1068,6 +1353,16 @@ static void InitGameEngine()
     element_info[e].move_stepsize = move_stepsize_list[i].move_stepsize;
   }
 
+#if 0
+  /* ---------- initialize move dig/leave ---------------------------------- */
+
+  for (i = 0; i < MAX_NUM_ELEMENTS; i++)
+  {
+    element_info[i].can_leave_element = FALSE;
+    element_info[i].can_leave_element_last = FALSE;
+  }
+#endif
+
   /* ---------- initialize gem count --------------------------------------- */
 
   /* initialize gem count values for each element */
@@ -1079,6 +1374,18 @@ static void InitGameEngine()
   for (i = 0; collect_count_list[i].element != EL_UNDEFINED; i++)
     element_info[collect_count_list[i].element].collect_count =
       collect_count_list[i].count;
+
+  /* ---------- initialize access direction -------------------------------- */
+
+  /* initialize access direction values to default */
+  for (i = 0; i < MAX_NUM_ELEMENTS; i++)
+    if (!IS_CUSTOM_ELEMENT(i))
+      element_info[i].access_direction = MV_ALL_DIRECTIONS;
+
+  /* set access direction value for certain elements from pre-defined list */
+  for (i = 0; tube_access[i].element != EL_UNDEFINED; i++)
+    element_info[tube_access[i].element].access_direction =
+      tube_access[i].direction;
 }
 
 
@@ -1117,6 +1424,7 @@ void InitGame()
     struct PlayerInfo *player = &stored_player[i];
 
     player->index_nr = i;
+    player->index_bit = (1 << i);
     player->element_nr = EL_PLAYER_1 + i;
 
     player->present = FALSE;
@@ -1132,7 +1440,7 @@ void InitGame()
     player->lights_still_needed = 0;
     player->friends_still_needed = 0;
 
-    for (j = 0; j < 4; j++)
+    for (j = 0; j < MAX_KEYS; j++)
       player->key[j] = FALSE;
 
     player->dynabomb_count = 0;
@@ -1150,6 +1458,9 @@ void InitGame()
 
     player->use_murphy_graphic = FALSE;
 
+    player->block_last_field = FALSE;
+    player->can_fall_into_acid = CAN_MOVE_INTO_ACID(player->element_nr);
+
     player->actual_frame_counter = 0;
 
     player->step_counter = 0;
@@ -1233,9 +1544,10 @@ void InitGame()
     player->shield_normal_time_left = 0;
     player->shield_deadly_time_left = 0;
 
+    player->inventory_infinite_element = EL_UNDEFINED;
     player->inventory_size = 0;
 
-    DigField(player, 0, 0, 0, 0, DF_NO_PUSH);
+    DigField(player, 0, 0, 0, 0, 0, 0, DF_NO_PUSH);
     SnapField(player, 0, 0);
 
     player->LevelSolved = FALSE;
@@ -1256,6 +1568,7 @@ void InitGame()
   TimeFrames = 0;
   TimePlayed = 0;
   TimeLeft = level.time;
+  TapeTime = 0;
 
   ScreenMovDir = MV_NO_MOVING;
   ScreenMovPos = 0;
@@ -1277,7 +1590,7 @@ void InitGame()
 
   game.envelope_active = FALSE;
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_BELTS; i++)
   {
     game.belt_dir[i] = MV_NO_MOVING;
     game.belt_dir_nr[i] = 3;           /* not moving, next moving left */
@@ -1305,7 +1618,8 @@ void InitGame()
       ChangeEvent[x][y] = CE_BITMASK_DEFAULT;
 
       ExplodePhase[x][y] = 0;
-      ExplodeField[x][y] = EX_NO_EXPLOSION;
+      ExplodeDelay[x][y] = 0;
+      ExplodeField[x][y] = EX_TYPE_NONE;
 
       RunnerVisit[x][y] = 0;
       PlayerVisit[x][y] = 0;
@@ -1339,8 +1653,41 @@ void InitGame()
                    emulate_sb ? EMU_SOKOBAN :
                    emulate_sp ? EMU_SUPAPLEX : EMU_NONE);
 
+  /* initialize explosion and ignition delay */
+  for (i = 0; i < MAX_NUM_ELEMENTS; i++)
+  {
+    if (!IS_CUSTOM_ELEMENT(i))
+    {
+      int num_phase = 8;
+      int delay = (((IS_SP_ELEMENT(i) && i != EL_EMPTY_SPACE) &&
+                   game.engine_version >= VERSION_IDENT(3,1,0,0)) ||
+                  game.emulation == EMU_SUPAPLEX ? 3 : 2);
+      int last_phase = (num_phase + 1) * delay;
+      int half_phase = (num_phase / 2) * delay;
+
+      element_info[i].explosion_delay = last_phase - 1;
+      element_info[i].ignition_delay = half_phase;
+
+#if 0
+      if (i == EL_BLACK_ORB)
+       element_info[i].ignition_delay = 0;
+#else
+      if (i == EL_BLACK_ORB)
+       element_info[i].ignition_delay = 1;
+#endif
+    }
+
+#if 0
+    if (element_info[i].explosion_delay < 1)   /* !!! check again !!! */
+      element_info[i].explosion_delay = 1;
+
+    if (element_info[i].ignition_delay < 1)    /* !!! check again !!! */
+      element_info[i].ignition_delay = 1;
+#endif
+  }
+
   /* correct non-moving belts to start moving left */
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_BELTS; i++)
     if (game.belt_dir[i] == MV_NO_MOVING)
       game.belt_dir_nr[i] = 3;         /* not moving, next moving left */
 
@@ -1361,7 +1708,13 @@ void InitGame()
        {
          player->present = TRUE;
          player->active = TRUE;
+
          some_player->present = FALSE;
+         some_player->active = FALSE;
+
+#if 0
+         player->element_nr = some_player->element_nr;
+#endif
 
          StorePlayer[jx][jy] = player->element_nr;
          player->jx = player->last_jx = jx;
@@ -1375,7 +1728,7 @@ void InitGame()
 
   if (tape.playing)
   {
-    /* when playing a tape, eliminate all players who do not participate */
+    /* when playing a tape, eliminate all players which do not participate */
 
     for (i = 0; i < MAX_PLAYERS; i++)
     {
@@ -1406,6 +1759,8 @@ void InitGame()
            int jx = player->jx, jy = player->jy;
 
            player->active = FALSE;
+           player->present = FALSE;
+
            StorePlayer[jx][jy] = 0;
            Feld[jx][jy] = EL_EMPTY;
          }
@@ -1514,7 +1869,7 @@ void InitGame()
 
        for (i = 0; i < element_info[element].num_change_pages; i++)
        {
-         content = element_info[element].change_page[i].content[xx][yy];
+         content= element_info[element].change_page[i].target_content[xx][yy];
          is_player = ELEM_IS_PLAYER(content);
 
          if (is_player && (found_rating < 1 || element < found_element))
@@ -1580,19 +1935,6 @@ void InitGame()
   BlitBitmap(graphic_info[IMG_GLOBAL_DOOR].bitmap, drawto,
             DOOR_GFX_PAGEX5, DOOR_GFX_PAGEY1, DXSIZE, DYSIZE, DX, DY);
 
-  if (level_nr < 100)
-    DrawText(DX + XX_LEVEL, DY + YY_LEVEL, int2str(level_nr, 2), FONT_TEXT_2);
-  else
-  {
-    DrawTextExt(drawto, DX + XX_EMERALDS, DY + YY_EMERALDS,
-               int2str(level_nr, 3), FONT_LEVEL_NUMBER, BLIT_OPAQUE);
-    BlitBitmap(drawto, drawto,
-              DX + XX_EMERALDS, DY + YY_EMERALDS + 1,
-              getFontWidth(FONT_LEVEL_NUMBER) * 3,
-              getFontHeight(FONT_LEVEL_NUMBER) - 1,
-              DX + XX_LEVEL - 1, DY + YY_LEVEL + 1);
-  }
-
   DrawGameDoorValues();
 
   UnmapGameButtons();
@@ -1618,7 +1960,7 @@ void InitGame()
 
   if (options.debug)
   {
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < MAX_PLAYERS; i++)
       printf("Player %d %sactive.\n",
             i + 1, (stored_player[i].active ? "" : "not "));
   }
@@ -1706,38 +2048,57 @@ void InitMovDir(int x, int y)
     default:
       if (IS_CUSTOM_ELEMENT(element))
       {
-       if (element_info[element].move_direction_initial != MV_NO_MOVING)
-         MovDir[x][y] = element_info[element].move_direction_initial;
-       else if (element_info[element].move_pattern == MV_ALL_DIRECTIONS ||
-                element_info[element].move_pattern == MV_TURNING_LEFT ||
-                element_info[element].move_pattern == MV_TURNING_RIGHT ||
-                element_info[element].move_pattern == MV_TURNING_LEFT_RIGHT ||
-                element_info[element].move_pattern == MV_TURNING_RIGHT_LEFT ||
-                element_info[element].move_pattern == MV_TURNING_RANDOM)
+       struct ElementInfo *ei = &element_info[element];
+       int move_direction_initial = ei->move_direction_initial;
+       int move_pattern = ei->move_pattern;
+
+       if (move_direction_initial == MV_START_PREVIOUS)
+       {
+         if (MovDir[x][y] != MV_NO_MOVING)
+           return;
+
+         move_direction_initial = MV_START_AUTOMATIC;
+       }
+
+       if (move_direction_initial == MV_START_RANDOM)
+         MovDir[x][y] = 1 << RND(4);
+       else if (move_direction_initial & MV_ANY_DIRECTION)
+         MovDir[x][y] = move_direction_initial;
+       else if (move_pattern == MV_ALL_DIRECTIONS ||
+                move_pattern == MV_TURNING_LEFT ||
+                move_pattern == MV_TURNING_RIGHT ||
+                move_pattern == MV_TURNING_LEFT_RIGHT ||
+                move_pattern == MV_TURNING_RIGHT_LEFT ||
+                move_pattern == MV_TURNING_RANDOM)
          MovDir[x][y] = 1 << RND(4);
-       else if (element_info[element].move_pattern == MV_HORIZONTAL)
+       else if (move_pattern == MV_HORIZONTAL)
          MovDir[x][y] = (RND(2) ? MV_LEFT : MV_RIGHT);
-       else if (element_info[element].move_pattern == MV_VERTICAL)
+       else if (move_pattern == MV_VERTICAL)
          MovDir[x][y] = (RND(2) ? MV_UP : MV_DOWN);
-       else if (element_info[element].move_pattern & MV_ANY_DIRECTION)
+       else if (move_pattern & MV_ANY_DIRECTION)
          MovDir[x][y] = element_info[element].move_pattern;
-       else if (element_info[element].move_pattern == MV_ALONG_LEFT_SIDE ||
-                element_info[element].move_pattern == MV_ALONG_RIGHT_SIDE)
+       else if (move_pattern == MV_ALONG_LEFT_SIDE ||
+                move_pattern == MV_ALONG_RIGHT_SIDE)
        {
-         for (i = 0; i < 4; i++)
+         for (i = 0; i < NUM_DIRECTIONS; i++)
          {
            int x1 = x + xy[i][0];
            int y1 = y + xy[i][1];
 
            if (!IN_LEV_FIELD(x1, y1) || !IS_FREE(x1, y1))
            {
-             if (element_info[element].move_pattern == MV_ALONG_RIGHT_SIDE)
+             if (move_pattern == MV_ALONG_RIGHT_SIDE)
                MovDir[x][y] = direction[0][i];
              else
                MovDir[x][y] = direction[1][i];
 
              break;
            }
+
+#if 1
+           if (MovDir[x][y] == MV_NO_MOVING)   /* no start direction found */
+             MovDir[x][y] = 1 << RND(4);       /* => use random direction */
+#endif
          }
        }                
       }
@@ -1751,7 +2112,7 @@ void InitMovDir(int x, int y)
            element != EL_BD_FIREFLY)
          break;
 
-       for (i = 0; i < 4; i++)
+       for (i = 0; i < NUM_DIRECTIONS; i++)
        {
          int x1 = x + xy[i][0];
          int y1 = y + xy[i][1];
@@ -1836,7 +2197,9 @@ void GameWon()
        TimeLeft -= 10;
       else
        TimeLeft--;
-      DrawText(DX_TIME, DY_TIME, int2str(TimeLeft, 3), FONT_TEXT_2);
+
+      DrawGameValue_Time(TimeLeft);
+
       BackToFront();
 
       if (!tape.playing)
@@ -1862,7 +2225,9 @@ void GameWon()
        TimePlayed += 10;
       else
        TimePlayed++;
-      DrawText(DX_TIME, DY_TIME, int2str(TimePlayed, 3), FONT_TEXT_2);
+
+      DrawGameValue_Time(TimePlayed);
+
       BackToFront();
 
       if (!tape.playing)
@@ -2147,8 +2512,25 @@ void RemoveMovingField(int x, int y)
   if (IS_MOVING(x, y))
   {
     Moving2Blocked(x, y, &newx, &newy);
+#if 0
+    if (Feld[newx][newy] != EL_BLOCKED)
+      return;
+#else
     if (Feld[newx][newy] != EL_BLOCKED)
+    {
+      /* element is moving, but target field is not free (blocked), but
+        already occupied by something different (example: acid pool);
+        in this case, only remove the moving field, but not the target */
+
+      RemoveField(oldx, oldy);
+
+      Store[oldx][oldy] = Store2[oldx][oldy] = 0;
+
+      DrawLevelField(oldx, oldy);
+
       return;
+    }
+#endif
   }
   else if (element == EL_BLOCKED)
   {
@@ -2238,17 +2620,21 @@ void CheckDynamite(int x, int y)
   Bang(x, y);
 }
 
-void RelocatePlayer(int x, int y, int element)
+void RelocatePlayer(int x, int y, int element_raw)
 {
+  int element = (element_raw == EL_SP_MURPHY ? EL_PLAYER_1 : element_raw);
   struct PlayerInfo *player = &stored_player[element - EL_PLAYER_1];
+  boolean ffwd_delay = (tape.playing && tape.fast_forward);
+  boolean no_delay = (tape.warp_forward);
+  int frame_delay_value = (ffwd_delay ? FfwdFrameDelay : GameFrameDelay);
+  int wait_delay_value = (no_delay ? 0 : frame_delay_value);
+  int old_jx, old_jy;
 
   if (player->GameOver)                /* do not reanimate dead player */
     return;
 
-#if 1
   RemoveField(x, y);           /* temporarily remove newly placed player */
   DrawLevelField(x, y);
-#endif
 
   if (player->present)
   {
@@ -2261,7 +2647,7 @@ void RelocatePlayer(int x, int y, int element)
       DrawPlayer(player);
 
       BackToFront();
-      Delay(GAME_FRAME_DELAY);
+      Delay(wait_delay_value);
     }
 
     DrawPlayer(player);                /* needed here only to cleanup last field */
@@ -2270,13 +2656,77 @@ void RelocatePlayer(int x, int y, int element)
     player->is_moving = FALSE;
   }
 
+  old_jx = player->jx;
+  old_jy = player->jy;
+
   Feld[x][y] = element;
   InitPlayerField(x, y, element, TRUE);
 
-  if (player == local_player)
+  if (player != local_player)  /* do not visually relocate other players */
+    return;
+
+  if (level.instant_relocation)
+  {
+#if 1
+    int offset = (setup.scroll_delay ? 3 : 0);
+    int jx = local_player->jx;
+    int jy = local_player->jy;
+
+    if (!IN_VIS_FIELD(SCREENX(jx), SCREENY(jy)))
+    {
+      scroll_x = (local_player->jx < SBX_Left  + MIDPOSX ? SBX_Left :
+                 local_player->jx > SBX_Right + MIDPOSX ? SBX_Right :
+                 local_player->jx - MIDPOSX);
+
+      scroll_y = (local_player->jy < SBY_Upper + MIDPOSY ? SBY_Upper :
+                 local_player->jy > SBY_Lower + MIDPOSY ? SBY_Lower :
+                 local_player->jy - MIDPOSY);
+    }
+    else
+    {
+      if ((player->MovDir == MV_LEFT  && scroll_x > jx - MIDPOSX + offset) ||
+         (player->MovDir == MV_RIGHT && scroll_x < jx - MIDPOSX - offset))
+       scroll_x = jx - MIDPOSX + (scroll_x < jx-MIDPOSX ? -offset : +offset);
+
+      if ((player->MovDir == MV_UP  && scroll_y > jy - MIDPOSY + offset) ||
+         (player->MovDir == MV_DOWN && scroll_y < jy - MIDPOSY - offset))
+       scroll_y = jy - MIDPOSY + (scroll_y < jy-MIDPOSY ? -offset : +offset);
+
+      /* don't scroll over playfield boundaries */
+      if (scroll_x < SBX_Left || scroll_x > SBX_Right)
+       scroll_x = (scroll_x < SBX_Left ? SBX_Left : SBX_Right);
+
+      /* don't scroll over playfield boundaries */
+      if (scroll_y < SBY_Upper || scroll_y > SBY_Lower)
+       scroll_y = (scroll_y < SBY_Upper ? SBY_Upper : SBY_Lower);
+    }
+#else
+    scroll_x += (local_player->jx - old_jx);
+    scroll_y += (local_player->jy - old_jy);
+
+    /* don't scroll over playfield boundaries */
+    if (scroll_x < SBX_Left || scroll_x > SBX_Right)
+      scroll_x = (scroll_x < SBX_Left ? SBX_Left : SBX_Right);
+
+    /* don't scroll over playfield boundaries */
+    if (scroll_y < SBY_Upper || scroll_y > SBY_Lower)
+      scroll_y = (scroll_y < SBY_Upper ? SBY_Upper : SBY_Lower);
+#endif
+
+    RedrawPlayfield(TRUE, 0,0,0,0);
+  }
+  else
   {
+#if 1
+#if 0
+    int offset = (setup.scroll_delay ? 3 : 0);
+    int jx = local_player->jx;
+    int jy = local_player->jy;
+#endif
     int scroll_xx = -999, scroll_yy = -999;
 
+    ScrollScreen(NULL, SCROLL_GO_ON);  /* scroll last frame to full tile */
+
     while (scroll_xx != scroll_x || scroll_yy != scroll_y)
     {
       int dx = 0, dy = 0;
@@ -2293,11 +2743,66 @@ void RelocatePlayer(int x, int y, int element)
       dx = (scroll_xx < scroll_x ? +1 : scroll_xx > scroll_x ? -1 : 0);
       dy = (scroll_yy < scroll_y ? +1 : scroll_yy > scroll_y ? -1 : 0);
 
-      scroll_x -= dx;
-      scroll_y -= dy;
-
-      fx += dx * TILEX / 2;
-      fy += dy * TILEY / 2;
+#if 1
+      if (dx == 0 && dy == 0)          /* no scrolling needed at all */
+       break;
+#else
+      if (scroll_xx == scroll_x && scroll_yy == scroll_y)
+       break;
+#endif
+
+      scroll_x -= dx;
+      scroll_y -= dy;
+
+      fx += dx * TILEX / 2;
+      fy += dy * TILEY / 2;
+
+      ScrollLevel(dx, dy);
+      DrawAllPlayers();
+
+      /* scroll in two steps of half tile size to make things smoother */
+      BlitBitmap(drawto_field, window, fx, fy, SXSIZE, SYSIZE, SX, SY);
+      FlushDisplay();
+      Delay(wait_delay_value);
+
+      /* scroll second step to align at full tile size */
+      BackToFront();
+      Delay(wait_delay_value);
+    }
+#else
+    int scroll_xx = -999, scroll_yy = -999;
+
+    ScrollScreen(NULL, SCROLL_GO_ON);  /* scroll last frame to full tile */
+
+    while (scroll_xx != scroll_x || scroll_yy != scroll_y)
+    {
+      int dx = 0, dy = 0;
+      int fx = FX, fy = FY;
+
+      scroll_xx = (local_player->jx < SBX_Left  + MIDPOSX ? SBX_Left :
+                  local_player->jx > SBX_Right + MIDPOSX ? SBX_Right :
+                  local_player->jx - MIDPOSX);
+
+      scroll_yy = (local_player->jy < SBY_Upper + MIDPOSY ? SBY_Upper :
+                  local_player->jy > SBY_Lower + MIDPOSY ? SBY_Lower :
+                  local_player->jy - MIDPOSY);
+
+      dx = (scroll_xx < scroll_x ? +1 : scroll_xx > scroll_x ? -1 : 0);
+      dy = (scroll_yy < scroll_y ? +1 : scroll_yy > scroll_y ? -1 : 0);
+
+#if 1
+      if (dx == 0 && dy == 0)          /* no scrolling needed at all */
+       break;
+#else
+      if (scroll_xx == scroll_x && scroll_yy == scroll_y)
+       break;
+#endif
+
+      scroll_x -= dx;
+      scroll_y -= dy;
+
+      fx += dx * TILEX / 2;
+      fy += dy * TILEY / 2;
 
       ScrollLevel(dx, dy);
       DrawAllPlayers();
@@ -2305,23 +2810,34 @@ void RelocatePlayer(int x, int y, int element)
       /* scroll in two steps of half tile size to make things smoother */
       BlitBitmap(drawto_field, window, fx, fy, SXSIZE, SYSIZE, SX, SY);
       FlushDisplay();
-      Delay(GAME_FRAME_DELAY);
+      Delay(wait_delay_value);
 
       /* scroll second step to align at full tile size */
       BackToFront();
-      Delay(GAME_FRAME_DELAY);
+      Delay(wait_delay_value);
     }
+#endif
   }
 }
 
 void Explode(int ex, int ey, int phase, int mode)
 {
   int x, y;
+#if 0
   int num_phase = 9;
+#endif
+
+  /* !!! eliminate this variable !!! */
   int delay = (game.emulation == EMU_SUPAPLEX ? 3 : 2);
+
+#if 1
+  int last_phase;
+#else
   int last_phase = num_phase * delay;
   int half_phase = (num_phase / 2) * delay;
   int first_phase_after_start = EX_PHASE_START + 1;
+#endif
+  int border_element;
 
   if (game.explosions_delayed)
   {
@@ -2333,15 +2849,20 @@ void Explode(int ex, int ey, int phase, int mode)
   {
     int center_element = Feld[ex][ey];
 
+#if 0
+    printf("::: start explosion %d,%d [%d]\n", ex, ey, FrameCounter);
+#endif
+
 #if 0
     /* --- This is only really needed (and now handled) in "Impact()". --- */
     /* do not explode moving elements that left the explode field in time */
     if (game.engine_version >= VERSION_IDENT(2,2,0,7) &&
-       center_element == EL_EMPTY && (mode == EX_NORMAL || mode == EX_CENTER))
+       center_element == EL_EMPTY &&
+       (mode == EX_TYPE_NORMAL || mode == EX_TYPE_CENTER))
       return;
 #endif
 
-    if (mode == EX_NORMAL || mode == EX_CENTER)
+    if (mode == EX_TYPE_NORMAL || mode == EX_TYPE_CENTER)
       PlayLevelSoundAction(ex, ey, ACTION_EXPLODING);
 
     /* remove things displayed in background while burning dynamite */
@@ -2356,16 +2877,43 @@ void Explode(int ex, int ey, int phase, int mode)
       Feld[ex][ey] = center_element;
     }
 
+#if 1
+
+#if 1
+    last_phase = element_info[center_element].explosion_delay + 1;
+#else
+    last_phase = element_info[center_element].explosion_delay;
+#endif
+
+#if 0
+    printf("::: %d -> %d\n", center_element, last_phase);
+#endif
+#endif
+
     for (y = ey - 1; y <= ey + 1; y++) for (x = ex - 1; x <= ex + 1; x++)
     {
       int xx = x - ex + 1;
       int yy = y - ey + 1;
       int element;
 
+#if 1
+#if 1
+      if (!IN_LEV_FIELD(x, y) ||
+         (mode & EX_TYPE_SINGLE_TILE && (x != ex || y != ey)) ||
+         (mode == EX_TYPE_CROSS      && (x != ex && y != ey)))
+       continue;
+#else
+      if (!IN_LEV_FIELD(x, y) ||
+         (mode != EX_TYPE_NORMAL && (x != ex || y != ey)))
+       continue;
+#endif
+#else
       if (!IN_LEV_FIELD(x, y) ||
-         ((mode != EX_NORMAL || center_element == EL_AMOEBA_TO_DIAMOND) &&
+         ((mode != EX_TYPE_NORMAL ||
+           center_element == EL_AMOEBA_TO_DIAMOND) &&
           (x != ex || y != ey)))
        continue;
+#endif
 
       element = Feld[x][y];
 
@@ -2435,27 +2983,32 @@ void Explode(int ex, int ey, int phase, int mode)
       RemoveField(x, y);
 #endif
 
-      if (IS_PLAYER(ex, ey) && !PLAYER_PROTECTED(ex, ey))
+      if (IS_PLAYER(ex, ey) && !PLAYER_EXPLOSION_PROTECTED(ex, ey))
       {
        switch(StorePlayer[ex][ey])
        {
          case EL_PLAYER_2:
-           Store[x][y] = EL_EMERALD_RED;
+           Store[x][y] = EL_PLAYER_IS_EXPLODING_2;
            break;
          case EL_PLAYER_3:
-           Store[x][y] = EL_EMERALD;
+           Store[x][y] = EL_PLAYER_IS_EXPLODING_3;
            break;
          case EL_PLAYER_4:
-           Store[x][y] = EL_EMERALD_PURPLE;
+           Store[x][y] = EL_PLAYER_IS_EXPLODING_4;
            break;
          case EL_PLAYER_1:
          default:
-           Store[x][y] = EL_EMERALD_YELLOW;
+           Store[x][y] = EL_PLAYER_IS_EXPLODING_1;
            break;
        }
 
+#if 1
+       if (PLAYERINFO(ex, ey)->use_murphy_graphic)
+         Store[x][y] = EL_EMPTY;
+#else
        if (game.emulation == EMU_SUPAPLEX)
          Store[x][y] = EL_EMPTY;
+#endif
       }
       else if (center_element == EL_MOLE)
        Store[x][y] = EL_EMERALD_RED;
@@ -2496,7 +3049,7 @@ void Explode(int ex, int ey, int phase, int mode)
        Store[x][y] = EL_EMPTY;
 
       if (x != ex || y != ey ||
-         center_element == EL_AMOEBA_TO_DIAMOND || mode == EX_BORDER)
+         center_element == EL_AMOEBA_TO_DIAMOND || mode == EX_TYPE_BORDER)
        Store2[x][y] = element;
 
 #if 0
@@ -2526,6 +3079,18 @@ void Explode(int ex, int ey, int phase, int mode)
 #endif
 
       ExplodePhase[x][y] = 1;
+#if 1
+      ExplodeDelay[x][y] = last_phase;
+#endif
+
+#if 0
+#if 1
+      GfxFrame[x][y] = 0;      /* animation does not start until next frame */
+#else
+      GfxFrame[x][y] = -1;     /* animation does not start until next frame */
+#endif
+#endif
+
       Stop[x][y] = TRUE;
     }
 
@@ -2542,6 +3107,19 @@ void Explode(int ex, int ey, int phase, int mode)
   x = ex;
   y = ey;
 
+#if 1
+  if (phase == 1)
+    GfxFrame[x][y] = 0;                /* restart explosion animation */
+#endif
+
+#if 0
+  printf(":X: phase == %d [%d]\n", phase, GfxFrame[x][y]);
+#endif
+
+#if 1
+  last_phase = ExplodeDelay[x][y];
+#endif
+
   ExplodePhase[x][y] = (phase < last_phase ? phase + 1 : 0);
 
 #ifdef DEBUG
@@ -2562,6 +3140,73 @@ void Explode(int ex, int ey, int phase, int mode)
   }
 #endif
 
+#if 1
+
+  border_element = Store2[x][y];
+  if (IS_PLAYER(x, y))
+    border_element = StorePlayer[x][y];
+
+#if 0
+  printf("::: phase == %d\n", phase);
+#endif
+
+  if (phase == element_info[border_element].ignition_delay ||
+      phase == last_phase)
+  {
+    boolean border_explosion = FALSE;
+
+#if 1
+    if (IS_PLAYER(x, y) && PLAYERINFO(x, y)->present)
+#else
+    if (IS_PLAYER(x, y))
+#endif
+    {
+      KillHeroUnlessExplosionProtected(x, y);
+      border_explosion = TRUE;
+
+#if 0
+      if (phase == last_phase)
+       printf("::: IS_PLAYER\n");
+#endif
+    }
+    else if (CAN_EXPLODE_BY_EXPLOSION(border_element))
+    {
+      Feld[x][y] = Store2[x][y];
+      Store2[x][y] = 0;
+      Bang(x, y);
+      border_explosion = TRUE;
+
+#if 0
+      if (phase == last_phase)
+       printf("::: CAN_EXPLODE_BY_EXPLOSION\n");
+#endif
+    }
+    else if (border_element == EL_AMOEBA_TO_DIAMOND)
+    {
+      AmoebeUmwandeln(x, y);
+      Store2[x][y] = 0;
+      border_explosion = TRUE;
+
+#if 0
+      if (phase == last_phase)
+       printf("::: EL_AMOEBA_TO_DIAMOND [%d, %d] [%d]\n",
+              element_info[border_element].explosion_delay,
+              element_info[border_element].ignition_delay,
+              phase);
+#endif
+    }
+
+#if 1
+    /* if an element just explodes due to another explosion (chain-reaction),
+       do not immediately end the new explosion when it was the last frame of
+       the explosion (as it would be done in the following "if"-statement!) */
+    if (border_explosion && phase == last_phase)
+      return;
+#endif
+  }
+
+#else
+
   if (phase == first_phase_after_start)
   {
     int element = Store2[x][y];
@@ -2578,8 +3223,8 @@ void Explode(int ex, int ey, int phase, int mode)
     int element = Store2[x][y];
 
     if (IS_PLAYER(x, y))
-      KillHeroUnlessProtected(x, y);
-    else if (CAN_EXPLODE_BY_FIRE(element))
+      KillHeroUnlessExplosionProtected(x, y);
+    else if (CAN_EXPLODE_BY_EXPLOSION(element))
     {
       Feld[x][y] = Store2[x][y];
       Store2[x][y] = 0;
@@ -2588,15 +3233,35 @@ void Explode(int ex, int ey, int phase, int mode)
     else if (element == EL_AMOEBA_TO_DIAMOND)
       AmoebeUmwandeln(x, y);
   }
+#endif
 
   if (phase == last_phase)
   {
     int element;
 
+#if 0
+  printf("::: done: phase == %d\n", phase);
+#endif
+
+#if 0
+    printf("::: explosion %d,%d done [%d]\n", x, y, FrameCounter);
+#endif
+
     element = Feld[x][y] = Store[x][y];
     Store[x][y] = Store2[x][y] = 0;
     GfxElement[x][y] = EL_UNDEFINED;
 
+    /* player can escape from explosions and might therefore be still alive */
+    if (element >= EL_PLAYER_IS_EXPLODING_1 &&
+       element <= EL_PLAYER_IS_EXPLODING_4)
+      Feld[x][y] = (stored_player[element - EL_PLAYER_IS_EXPLODING_1].active ?
+                   EL_EMPTY :
+                   element == EL_PLAYER_IS_EXPLODING_1 ? EL_EMERALD_YELLOW :
+                   element == EL_PLAYER_IS_EXPLODING_2 ? EL_EMERALD_RED :
+                   element == EL_PLAYER_IS_EXPLODING_3 ? EL_EMERALD :
+                   EL_EMERALD_PURPLE);
+
+    /* restore probably existing indestructible background element */
     if (Back[x][y] && IS_INDESTRUCTIBLE(Back[x][y]))
       element = Feld[x][y] = Back[x][y];
     Back[x][y] = 0;
@@ -2606,9 +3271,22 @@ void Explode(int ex, int ey, int phase, int mode)
     ChangeDelay[x][y] = 0;
     ChangePage[x][y] = -1;
 
+#if 1
+    InitField_WithBug2(x, y, FALSE);
+#else
     InitField(x, y, FALSE);
+#if 1
+    /* !!! not needed !!! */
+#if 1
+    if (game.engine_version < VERSION_IDENT(3,1,0,0) &&
+       CAN_MOVE(Feld[x][y]) && Feld[x][y] != EL_MOLE)
+      InitMovDir(x, y);
+#else
     if (CAN_MOVE(element))
       InitMovDir(x, y);
+#endif
+#endif
+#endif
     DrawLevelField(x, y);
 
     TestIfElementTouchesCustomElement(x, y);
@@ -2616,13 +3294,17 @@ void Explode(int ex, int ey, int phase, int mode)
     if (GFX_CRUMBLED(element))
       DrawLevelFieldCrumbledSandNeighbours(x, y);
 
-    if (IS_PLAYER(x, y) && !PLAYERINFO(x,y)->present)
+    if (IS_PLAYER(x, y) && !PLAYERINFO(x, y)->present)
       StorePlayer[x][y] = 0;
 
     if (ELEM_IS_PLAYER(element))
       RelocatePlayer(x, y, element);
   }
+#if 1
+  else if (IN_SCR_FIELD(SCREENX(x), SCREENY(y)))
+#else
   else if (phase >= delay && IN_SCR_FIELD(SCREENX(x), SCREENY(y)))
+#endif
   {
 #if 1
     int graphic = el_act2img(GfxElement[x][y], ACTION_EXPLODING);
@@ -2632,7 +3314,20 @@ void Explode(int ex, int ey, int phase, int mode)
                   stored == EL_SP_INFOTRON ? IMG_SP_EXPLOSION_INFOTRON :
                   IMG_SP_EXPLOSION);
 #endif
+#if 1
+    int frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
+#else
     int frame = getGraphicAnimationFrame(graphic, phase - delay);
+#endif
+
+#if 0
+  printf("::: phase == %d [%d]\n", phase, GfxFrame[x][y]);
+#endif
+
+#if 0
+    printf("::: %d / %d [%d - %d]\n",
+          GfxFrame[x][y], phase - delay, phase, delay);
+#endif
 
 #if 0
     printf("::: %d ['%s'] -> %d\n", GfxElement[x][y],
@@ -2681,14 +3376,14 @@ void DynaExplode(int ex, int ey)
     player->dynabombs_left++;
   }
 
-  Explode(ex, ey, EX_PHASE_START, EX_CENTER);
+  Explode(ex, ey, EX_PHASE_START, EX_TYPE_CENTER);
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     for (j = 1; j <= dynabomb_size; j++)
     {
-      int x = ex + j * xy[i % 4][0];
-      int y = ey + j * xy[i % 4][1];
+      int x = ex + j * xy[i][0];
+      int y = ey + j * xy[i][1];
       int element;
 
       if (!IN_LEV_FIELD(x, y) || IS_INDESTRUCTIBLE(Feld[x][y]))
@@ -2700,7 +3395,7 @@ void DynaExplode(int ex, int ey)
       if (element == EL_EXPLOSION && IS_ACTIVE_BOMB(Store2[x][y]))
        continue;
 
-      Explode(x, y, EX_PHASE_START, EX_BORDER);
+      Explode(x, y, EX_PHASE_START, EX_TYPE_BORDER);
 
       /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
       if (element != EL_EMPTY &&
@@ -2721,7 +3416,7 @@ void Bang(int x, int y)
 #endif
 
 #if 1
-  if (IS_PLAYER(x, y) && !PLAYER_PROTECTED(x, y))
+  if (IS_PLAYER(x, y) && !PLAYER_EXPLOSION_PROTECTED(x, y))
 #else
   if (IS_PLAYER(x, y))
 #endif
@@ -2760,7 +3455,7 @@ void Bang(int x, int y)
     case EL_PACMAN:
     case EL_MOLE:
       RaiseScoreElement(element);
-      Explode(x, y, EX_PHASE_START, EX_NORMAL);
+      Explode(x, y, EX_PHASE_START, EX_TYPE_NORMAL);
       break;
     case EL_DYNABOMB_PLAYER_1_ACTIVE:
     case EL_DYNABOMB_PLAYER_2_ACTIVE:
@@ -2774,18 +3469,25 @@ void Bang(int x, int y)
     case EL_PENGUIN:
     case EL_LAMP:
     case EL_LAMP_ACTIVE:
+#if 1
+    case EL_AMOEBA_TO_DIAMOND:
+#endif
       if (IS_PLAYER(x, y))
-       Explode(x, y, EX_PHASE_START, EX_NORMAL);
+       Explode(x, y, EX_PHASE_START, EX_TYPE_NORMAL);
       else
-       Explode(x, y, EX_PHASE_START, EX_CENTER);
+       Explode(x, y, EX_PHASE_START, EX_TYPE_CENTER);
       break;
     default:
-      if (CAN_EXPLODE_DYNA(element))
+      if (CAN_EXPLODE_CROSS(element))
+#if 1
+       Explode(x, y, EX_PHASE_START, EX_TYPE_CROSS);
+#else
        DynaExplode(x, y);
+#endif
       else if (CAN_EXPLODE_1X1(element))
-       Explode(x, y, EX_PHASE_START, EX_CENTER);
+       Explode(x, y, EX_PHASE_START, EX_TYPE_CENTER);
       else
-       Explode(x, y, EX_PHASE_START, EX_NORMAL);
+       Explode(x, y, EX_PHASE_START, EX_TYPE_NORMAL);
       break;
   }
 
@@ -2794,23 +3496,42 @@ void Bang(int x, int y)
 
 void SplashAcid(int x, int y)
 {
+#if 1
+  if (IN_LEV_FIELD(x - 1, y - 1) && IS_FREE(x - 1, y - 1) &&
+      (!IN_LEV_FIELD(x - 1, y - 2) ||
+       !CAN_FALL(MovingOrBlocked2Element(x - 1, y - 2))))
+    Feld[x - 1][y - 1] = EL_ACID_SPLASH_LEFT;
+
+  if (IN_LEV_FIELD(x + 1, y - 1) && IS_FREE(x + 1, y - 1) &&
+      (!IN_LEV_FIELD(x + 1, y - 2) ||
+       !CAN_FALL(MovingOrBlocked2Element(x + 1, y - 2))))
+    Feld[x + 1][y - 1] = EL_ACID_SPLASH_RIGHT;
+
+  PlayLevelSound(x, y, SND_ACID_SPLASHING);
+#else
+  /* input: position of element entering acid (obsolete) */
+
   int element = Feld[x][y];
 
+  if (!IN_LEV_FIELD(x, y + 1) || Feld[x][y + 1] != EL_ACID)
+    return;
+
   if (element != EL_ACID_SPLASH_LEFT &&
       element != EL_ACID_SPLASH_RIGHT)
   {
     PlayLevelSound(x, y, SND_ACID_SPLASHING);
 
-    if (IN_LEV_FIELD(x-1, y) && IS_FREE(x-1, y) &&
-       (!IN_LEV_FIELD(x-1, y-1) ||
-        !CAN_FALL(MovingOrBlocked2Element(x-1, y-1))))
-      Feld[x-1][y] = EL_ACID_SPLASH_LEFT;
+    if (IN_LEV_FIELD(x - 1, y) && IS_FREE(x - 1, y) &&
+       (!IN_LEV_FIELD(x - 1, y - 1) ||
+        !CAN_FALL(MovingOrBlocked2Element(x - 1, y - 1))))
+      Feld[x - 1][y] = EL_ACID_SPLASH_LEFT;
 
-    if (IN_LEV_FIELD(x+1, y) && IS_FREE(x+1, y) &&
-       (!IN_LEV_FIELD(x+1, y-1) ||
-        !CAN_FALL(MovingOrBlocked2Element(x+1, y-1))))
-      Feld[x+1][y] = EL_ACID_SPLASH_RIGHT;
+    if (IN_LEV_FIELD(x + 1, y) && IS_FREE(x + 1, y) &&
+       (!IN_LEV_FIELD(x + 1, y - 1) ||
+        !CAN_FALL(MovingOrBlocked2Element(x + 1, y - 1))))
+      Feld[x + 1][y] = EL_ACID_SPLASH_RIGHT;
   }
+#endif
 }
 
 static void InitBeltMovement()
@@ -2833,11 +3554,11 @@ static void InitBeltMovement()
   int x, y, i, j;
 
   /* set frame order for belt animation graphic according to belt direction */
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_BELTS; i++)
   {
     int belt_nr = i;
 
-    for (j = 0; j < 3; j++)
+    for (j = 0; j < NUM_BELT_PARTS; j++)
     {
       int element = belt_base_active_element[belt_nr] + j;
       int graphic = el2img(element);
@@ -2855,7 +3576,7 @@ static void InitBeltMovement()
     {
       int element = Feld[x][y];
 
-      for (i = 0; i < 4; i++)
+      for (i = 0; i < NUM_BELTS; i++)
       {
        if (IS_BELT(element) && game.belt_dir[i] != MV_NO_MOVING)
        {
@@ -2921,7 +3642,7 @@ static void ToggleBeltSwitch(int x, int y)
     belt_dir_nr = 1;
 
   /* set frame order for belt animation graphic according to belt direction */
-  for (i = 0; i < 3; i++)
+  for (i = 0; i < NUM_BELT_PARTS; i++)
   {
     int element = belt_base_active_element[belt_nr] + i;
     int graphic = el2img(element);
@@ -3135,11 +3856,19 @@ inline static int getElementMoveStepsize(int x, int y)
   /* special values for move stepsize for spring and things on conveyor belt */
   if (horiz_move)
   {
+#if 0
+    if (element == EL_SPRING)
+      step = sign * MOVE_STEPSIZE_NORMAL * 2;
+    else if (CAN_FALL(element) && !CAN_MOVE(element) &&
+            y < lev_fieldy - 1 && IS_BELT_ACTIVE(Feld[x][y + 1]))
+      step = sign * MOVE_STEPSIZE_NORMAL / 2;
+#else
     if (CAN_FALL(element) &&
        y < lev_fieldy - 1 && IS_BELT_ACTIVE(Feld[x][y + 1]))
       step = sign * MOVE_STEPSIZE_NORMAL / 2;
     else if (element == EL_SPRING)
       step = sign * MOVE_STEPSIZE_NORMAL * 2;
+#endif
   }
 
   return step;
@@ -3151,7 +3880,7 @@ void Impact(int x, int y)
   boolean object_hit = FALSE;
   boolean impact = (lastline || object_hit);
   int element = Feld[x][y];
-  int smashed = EL_UNDEFINED;
+  int smashed = EL_STEELWALL;
 
   if (!lastline)       /* check if element below was hit */
   {
@@ -3179,7 +3908,7 @@ void Impact(int x, int y)
 
   if (!lastline && smashed == EL_ACID) /* element falls into acid */
   {
-    SplashAcid(x, y);
+    SplashAcid(x, y + 1);
     return;
   }
 
@@ -3202,7 +3931,7 @@ void Impact(int x, int y)
     PlayLevelSound(x, y, SND_PEARL_BREAKING);
     return;
   }
-  else if (impact && CheckElementChange(x, y, element, CE_IMPACT))
+  else if (impact && CheckElementChange(x, y, element, smashed, CE_IMPACT))
   {
     PlayLevelSoundElementAction(x, y, element, ACTION_IMPACT);
 
@@ -3212,7 +3941,7 @@ void Impact(int x, int y)
   if (impact && element == EL_AMOEBA_DROP)
   {
     if (object_hit && IS_PLAYER(x, y + 1))
-      KillHeroUnlessProtected(x, y + 1);
+      KillHeroUnlessEnemyProtected(x, y + 1);
     else if (object_hit && smashed == EL_PENGUIN)
       Bang(x, y + 1);
     else
@@ -3254,7 +3983,7 @@ void Impact(int x, int y)
     {
       if (CAN_SMASH_PLAYER(element))
       {
-       KillHeroUnlessProtected(x, y + 1);
+       KillHeroUnlessEnemyProtected(x, y + 1);
        return;
       }
     }
@@ -3274,11 +4003,13 @@ void Impact(int x, int y)
        return;
       }
     }
-    else if ((element == EL_SP_INFOTRON ||
-             element == EL_SP_ZONK) &&
-            (smashed == EL_SP_SNIKSNAK ||
-             smashed == EL_SP_ELECTRON ||
-             smashed == EL_SP_DISK_ORANGE))
+    else if (((element == EL_SP_INFOTRON ||
+              element == EL_SP_ZONK) &&
+             (smashed == EL_SP_SNIKSNAK ||
+              smashed == EL_SP_ELECTRON ||
+              smashed == EL_SP_DISK_ORANGE)) ||
+            (element == EL_SP_INFOTRON &&
+             smashed == EL_SP_DISK_YELLOW))
     {
       Bang(x, y + 1);
       return;
@@ -3341,17 +4072,21 @@ void Impact(int x, int y)
        }
        else
        {
-         CheckElementChange(x, y + 1, smashed, CE_SMASHED);
+#if 0
+         TestIfElementSmashesCustomElement(x, y, MV_DOWN);
+#endif
+
+         CheckElementChange(x, y + 1, smashed, element, CE_SMASHED);
 
-         CheckTriggeredElementSideChange(x, y + 1, smashed, CH_SIDE_TOP,
-                                         CE_OTHER_IS_SWITCHING);
-         CheckElementSideChange(x, y + 1, smashed, CH_SIDE_TOP,
-                                CE_SWITCHED, -1);
+         CheckTriggeredElementChangeSide(x, y + 1, smashed,
+                                         CE_OTHER_IS_SWITCHING, CH_SIDE_TOP);
+         CheckElementChangeSide(x, y + 1, smashed, element,
+                                CE_SWITCHED, CH_SIDE_TOP);
        }
       }
       else
       {
-       CheckElementChange(x, y + 1, smashed, CE_SMASHED);
+       CheckElementChange(x, y + 1, smashed, element, CE_SMASHED);
       }
     }
   }
@@ -3428,9 +4163,9 @@ inline static void TurnRoundExt(int x, int y)
   {
     TestIfBadThingTouchesOtherBadThing(x, y);
 
-    if (ENEMY_CAN_ENTER_FIELD(right_x, right_y))
+    if (ENEMY_CAN_ENTER_FIELD(element, right_x, right_y))
       MovDir[x][y] = right_dir;
-    else if (!ENEMY_CAN_ENTER_FIELD(move_x, move_y))
+    else if (!ENEMY_CAN_ENTER_FIELD(element, move_x, move_y))
       MovDir[x][y] = left_dir;
 
     if (element == EL_BUG && MovDir[x][y] != old_move_dir)
@@ -3438,14 +4173,15 @@ inline static void TurnRoundExt(int x, int y)
     else if (element == EL_BD_BUTTERFLY)     /* && MovDir[x][y] == left_dir) */
       MovDelay[x][y] = 1;
   }
+#if 0
   else if (element == EL_SPACESHIP || element == EL_BD_FIREFLY ||
           element == EL_SP_SNIKSNAK || element == EL_SP_ELECTRON)
   {
     TestIfBadThingTouchesOtherBadThing(x, y);
 
-    if (ENEMY_CAN_ENTER_FIELD(left_x, left_y))
+    if (ENEMY_CAN_ENTER_FIELD(element, left_x, left_y))
       MovDir[x][y] = left_dir;
-    else if (!ENEMY_CAN_ENTER_FIELD(move_x, move_y))
+    else if (!ENEMY_CAN_ENTER_FIELD(element, move_x, move_y))
       MovDir[x][y] = right_dir;
 
     if ((element == EL_SPACESHIP ||
@@ -3456,10 +4192,38 @@ inline static void TurnRoundExt(int x, int y)
     else if (element == EL_BD_FIREFLY)     /* && MovDir[x][y] == right_dir) */
       MovDelay[x][y] = 1;
   }
+#else
+  else if (element == EL_SPACESHIP || element == EL_BD_FIREFLY)
+  {
+    TestIfBadThingTouchesOtherBadThing(x, y);
+
+    if (ENEMY_CAN_ENTER_FIELD(element, left_x, left_y))
+      MovDir[x][y] = left_dir;
+    else if (!ENEMY_CAN_ENTER_FIELD(element, move_x, move_y))
+      MovDir[x][y] = right_dir;
+
+    if (element == EL_SPACESHIP        && MovDir[x][y] != old_move_dir)
+      MovDelay[x][y] = 9;
+    else if (element == EL_BD_FIREFLY)     /* && MovDir[x][y] == right_dir) */
+      MovDelay[x][y] = 1;
+  }
+  else if (element == EL_SP_SNIKSNAK || element == EL_SP_ELECTRON)
+  {
+    TestIfBadThingTouchesOtherBadThing(x, y);
+
+    if (ELEMENT_CAN_ENTER_FIELD_BASE_4(element, left_x, left_y, 0))
+      MovDir[x][y] = left_dir;
+    else if (!ELEMENT_CAN_ENTER_FIELD_BASE_4(element, move_x, move_y, 0))
+      MovDir[x][y] = right_dir;
+
+    if (MovDir[x][y] != old_move_dir)
+      MovDelay[x][y] = 9;
+  }
+#endif
   else if (element == EL_YAMYAM)
   {
-    boolean can_turn_left  = YAMYAM_CAN_ENTER_FIELD(left_x, left_y);
-    boolean can_turn_right = YAMYAM_CAN_ENTER_FIELD(right_x, right_y);
+    boolean can_turn_left  = YAMYAM_CAN_ENTER_FIELD(element, left_x, left_y);
+    boolean can_turn_right = YAMYAM_CAN_ENTER_FIELD(element, right_x, right_y);
 
     if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
@@ -3474,8 +4238,10 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_DARK_YAMYAM)
   {
-    boolean can_turn_left  = DARK_YAMYAM_CAN_ENTER_FIELD(left_x, left_y);
-    boolean can_turn_right = DARK_YAMYAM_CAN_ENTER_FIELD(right_x, right_y);
+    boolean can_turn_left  = DARK_YAMYAM_CAN_ENTER_FIELD(element,
+                                                        left_x, left_y);
+    boolean can_turn_right = DARK_YAMYAM_CAN_ENTER_FIELD(element,
+                                                        right_x, right_y);
 
     if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
@@ -3490,8 +4256,8 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_PACMAN)
   {
-    boolean can_turn_left  = PACMAN_CAN_ENTER_FIELD(left_x, left_y);
-    boolean can_turn_right = PACMAN_CAN_ENTER_FIELD(right_x, right_y);
+    boolean can_turn_left  = PACMAN_CAN_ENTER_FIELD(element, left_x, left_y);
+    boolean can_turn_right = PACMAN_CAN_ENTER_FIELD(element, right_x, right_y);
 
     if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
@@ -3506,9 +4272,9 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_PIG)
   {
-    boolean can_turn_left  = PIG_CAN_ENTER_FIELD(left_x, left_y);
-    boolean can_turn_right = PIG_CAN_ENTER_FIELD(right_x, right_y);
-    boolean can_move_on    = PIG_CAN_ENTER_FIELD(move_x, move_y);
+    boolean can_turn_left  = PIG_CAN_ENTER_FIELD(element, left_x, left_y);
+    boolean can_turn_right = PIG_CAN_ENTER_FIELD(element, right_x, right_y);
+    boolean can_move_on    = PIG_CAN_ENTER_FIELD(element, move_x, move_y);
     boolean should_turn_left, should_turn_right, should_move_on;
     int rnd_value = 24;
     int rnd = RND(rnd_value);
@@ -3569,9 +4335,9 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_DRAGON)
   {
-    boolean can_turn_left  = IN_LEV_FIELD_AND_IS_FREE(left_x, left_y);
-    boolean can_turn_right = IN_LEV_FIELD_AND_IS_FREE(right_x, right_y);
-    boolean can_move_on    = IN_LEV_FIELD_AND_IS_FREE(move_x, move_y);
+    boolean can_turn_left  = DRAGON_CAN_ENTER_FIELD(element, left_x, left_y);
+    boolean can_turn_right = DRAGON_CAN_ENTER_FIELD(element, right_x, right_y);
+    boolean can_move_on    = DRAGON_CAN_ENTER_FIELD(element, move_x, move_y);
     int rnd_value = 24;
     int rnd = RND(rnd_value);
 
@@ -3619,17 +4385,17 @@ inline static void TurnRoundExt(int x, int y)
   else if (element == EL_MOLE)
   {
     boolean can_move_on =
-      (MOLE_CAN_ENTER_FIELD(move_x, move_y,
+      (MOLE_CAN_ENTER_FIELD(element, move_x, move_y,
                            IS_AMOEBOID(Feld[move_x][move_y]) ||
                            Feld[move_x][move_y] == EL_AMOEBA_SHRINKING));
     if (!can_move_on)
     {
       boolean can_turn_left =
-       (MOLE_CAN_ENTER_FIELD(left_x, left_y,
+       (MOLE_CAN_ENTER_FIELD(element, left_x, left_y,
                              IS_AMOEBOID(Feld[left_x][left_y])));
 
       boolean can_turn_right =
-       (MOLE_CAN_ENTER_FIELD(right_x, right_y,
+       (MOLE_CAN_ENTER_FIELD(element, right_x, right_y,
                              IS_AMOEBOID(Feld[right_x][right_y])));
 
       if (can_turn_left && can_turn_right)
@@ -3650,10 +4416,16 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_SPRING)
   {
+#if 0
+    if (MovDir[x][y] & MV_HORIZONTAL &&
+       !SPRING_CAN_ENTER_FIELD(element, move_x, move_y))
+      MovDir[x][y] = MV_NO_MOVING;
+#else
     if (MovDir[x][y] & MV_HORIZONTAL &&
-       (!IN_LEV_FIELD_AND_IS_FREE(move_x, move_y) ||
-        IN_LEV_FIELD_AND_IS_FREE(x, y + 1)))
+       (!SPRING_CAN_ENTER_FIELD(element, move_x, move_y) ||
+        SPRING_CAN_ENTER_FIELD(element, x, y + 1)))
       MovDir[x][y] = MV_NO_MOVING;
+#endif
 
     MovDelay[x][y] = 0;
   }
@@ -3706,10 +4478,10 @@ inline static void TurnRoundExt(int x, int y)
        { 0, +1 }
       };
 
-      for (i = 0; i < 4; i++)
+      for (i = 0; i < NUM_DIRECTIONS; i++)
       {
-       int ex = x + xy[i % 4][0];
-       int ey = y + xy[i % 4][1];
+       int ex = x + xy[i][0];
+       int ey = y + xy[i][1];
 
        if (IN_LEV_FIELD(ex, ey) && Feld[ex][ey] == EL_EXIT_OPEN)
        {
@@ -3758,14 +4530,14 @@ inline static void TurnRoundExt(int x, int y)
          new_move_dir & (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
        Moving2Blocked(x, y, &newx, &newy);
 
-       if (PENGUIN_CAN_ENTER_FIELD(newx, newy))
+       if (PENGUIN_CAN_ENTER_FIELD(EL_PENGUIN, newx, newy))
          return;
 
        MovDir[x][y] =
          new_move_dir & (!first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
        Moving2Blocked(x, y, &newx, &newy);
 
-       if (PENGUIN_CAN_ENTER_FIELD(newx, newy))
+       if (PENGUIN_CAN_ENTER_FIELD(EL_PENGUIN, newx, newy))
          return;
 
        MovDir[x][y] = old_move_dir;
@@ -3787,14 +4559,14 @@ inline static void TurnRoundExt(int x, int y)
          new_move_dir & (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
        Moving2Blocked(x, y, &newx, &newy);
 
-       if (ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(newx, newy))
+       if (SATELLITE_CAN_ENTER_FIELD(newx, newy))
          return;
 
        MovDir[x][y] =
          new_move_dir & (!first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
        Moving2Blocked(x, y, &newx, &newy);
 
-       if (ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(newx, newy))
+       if (SATELLITE_CAN_ENTER_FIELD(newx, newy))
          return;
 
        MovDir[x][y] = old_move_dir;
@@ -3944,7 +4716,7 @@ inline static void TurnRoundExt(int x, int y)
   else if (move_pattern == MV_WHEN_PUSHED ||
           move_pattern == MV_WHEN_DROPPED)
   {
-    if (!IN_LEV_FIELD_AND_IS_FREE(move_x, move_y))
+    if (!CUSTOM_ELEMENT_CAN_ENTER_FIELD(element, move_x, move_y))
       MovDir[x][y] = MV_NO_MOVING;
 
     MovDelay[x][y] = 0;
@@ -3977,7 +4749,7 @@ inline static void TurnRoundExt(int x, int y)
     int start_test = RND(4);
     int i;
 
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < NUM_DIRECTIONS; i++)
     {
       int move_dir = test_dir[start_test + i];
       int move_dir_preference;
@@ -4070,7 +4842,9 @@ static boolean JustBeingPushed(int x, int y)
 
 void StartMoving(int x, int y)
 {
+#if 0
   boolean use_spring_bug = (game.engine_version < VERSION_IDENT(2,2,0,0));
+#endif
   boolean started_moving = FALSE;      /* some elements can fall _and_ move */
   int element = Feld[x][y];
 
@@ -4088,8 +4862,8 @@ void StartMoving(int x, int y)
 
   if (CAN_FALL(element) && y < lev_fieldy - 1)
   {
-    if ((x > 0 && IS_PLAYER(x - 1, y)) ||
-       (x < lev_fieldx-1 && IS_PLAYER(x + 1, y)))
+    if ((x > 0              && IS_PLAYER(x - 1, y)) ||
+       (x < lev_fieldx - 1 && IS_PLAYER(x + 1, y)))
       if (JustBeingPushed(x, y))
        return;
 
@@ -4219,7 +4993,7 @@ void StartMoving(int x, int y)
     else if (CAN_FALL(element) && Feld[x][y + 1] == EL_ACID)
 #endif
     {
-      SplashAcid(x, y);
+      SplashAcid(x, y + 1);
 
       InitMovingField(x, y, MV_DOWN);
       started_moving = TRUE;
@@ -4267,7 +5041,7 @@ void StartMoving(int x, int y)
 
       Impact(x, y);
     }
-    else if (IS_FREE(x, y + 1) && element == EL_SPRING && use_spring_bug)
+    else if (IS_FREE(x, y + 1) && element == EL_SPRING && level.use_spring_bug)
     {
       if (MovDir[x][y] == MV_NO_MOVING)
       {
@@ -4343,7 +5117,11 @@ void StartMoving(int x, int y)
        started_moving = TRUE;
       }
     }
+#if 0
+    else if (IS_BELT_ACTIVE(Feld[x][y + 1]) && !CAN_MOVE(element))
+#else
     else if (IS_BELT_ACTIVE(Feld[x][y + 1]))
+#endif
     {
       boolean left_is_free  = (x > 0 && IS_FREE(x - 1, y));
       boolean right_is_free = (x < lev_fieldx - 1 && IS_FREE(x + 1, y));
@@ -4353,11 +5131,24 @@ void StartMoving(int x, int y)
       if ((belt_dir == MV_LEFT  && left_is_free) ||
          (belt_dir == MV_RIGHT && right_is_free))
       {
+#if 1
+       int nextx = (belt_dir == MV_LEFT ? x - 1 : x + 1);
+#endif
+
        InitMovingField(x, y, belt_dir);
        started_moving = TRUE;
 
+#if 1
+       Pushed[x][y] = TRUE;
+       Pushed[nextx][y] = TRUE;
+#endif
+
        GfxAction[x][y] = ACTION_DEFAULT;
       }
+      else
+      {
+       MovDir[x][y] = 0;       /* if element was moving, stop it */
+      }
     }
   }
 
@@ -4381,7 +5172,7 @@ void StartMoving(int x, int y)
 #endif
 
 #if 1
-    if (game.engine_version >= VERSION_IDENT(3,0,9,0) &&
+    if (game.engine_version >= VERSION_IDENT(3,1,0,0) &&
        WasJustMoving[x][y] && IN_LEV_FIELD(newx, newy) &&
        (Feld[newx][newy] == EL_BLOCKED || IS_PLAYER(newx, newy)))
     {
@@ -4551,11 +5342,30 @@ void StartMoving(int x, int y)
          {
            int flamed = MovingOrBlocked2Element(xx, yy);
 
-           if (IS_CLASSIC_ENEMY(flamed) || CAN_EXPLODE_BY_FIRE(flamed))
+           /* !!! */
+#if 0
+           if (IS_CLASSIC_ENEMY(flamed) || CAN_EXPLODE_BY_DRAGONFIRE(flamed))
+             Bang(xx, yy);
+           else if (IS_MOVING(xx, yy) || IS_BLOCKED(xx, yy))
+             RemoveMovingField(xx, yy);
+           else
+             RemoveField(xx, yy);
+#else
+           if (IS_CLASSIC_ENEMY(flamed) || CAN_EXPLODE_BY_DRAGONFIRE(flamed))
              Bang(xx, yy);
            else
              RemoveMovingField(xx, yy);
+#endif
 
+#if 0
+           if (ChangeDelay[xx][yy])
+             printf("::: !!! [%d]\n", (IS_MOVING(xx, yy) ||
+                                       Feld[xx][yy] == EL_BLOCKED));
+#endif
+
+#if 1
+           ChangeDelay[xx][yy] = 0;
+#endif
            Feld[xx][yy] = EL_FLAMES;
            if (IN_SCR_FIELD(sx, sy))
            {
@@ -4593,7 +5403,7 @@ void StartMoving(int x, int y)
 
     if (DONT_COLLIDE_WITH(element) &&
        IN_LEV_FIELD(newx, newy) && IS_PLAYER(newx, newy) &&
-       !PLAYER_PROTECTED(newx, newy))
+       !PLAYER_ENEMY_PROTECTED(newx, newy))
     {
 #if 1
       TestIfBadThingRunsIntoHero(x, y, MovDir[x][y]);
@@ -4607,6 +5417,18 @@ void StartMoving(int x, int y)
 #endif
 
     }
+#if 1
+#if 1
+    else if (CAN_MOVE_INTO_ACID(element) &&
+            IN_LEV_FIELD(newx, newy) && Feld[newx][newy] == EL_ACID &&
+            (MovDir[x][y] == MV_DOWN ||
+             game.engine_version >= VERSION_IDENT(3,1,0,0)))
+#else
+    else if (CAN_MOVE_INTO_ACID(element) && MovDir[x][y] == MV_DOWN &&
+            IN_LEV_FIELD(newx, newy) && Feld[newx][newy] == EL_ACID)
+#endif
+#else
+
     else if ((element == EL_PENGUIN ||
              element == EL_ROBOT ||
              element == EL_SATELLITE ||
@@ -4614,8 +5436,9 @@ void StartMoving(int x, int y)
              IS_CUSTOM_ELEMENT(element)) &&
             IN_LEV_FIELD(newx, newy) &&
             MovDir[x][y] == MV_DOWN && Feld[newx][newy] == EL_ACID)
+#endif
     {
-      SplashAcid(x, y);
+      SplashAcid(newx, newy);
       Store[x][y] = EL_ACID;
     }
     else if (element == EL_PENGUIN && IN_LEV_FIELD(newx, newy))
@@ -4643,7 +5466,7 @@ void StartMoving(int x, int y)
       }
       else if (IS_FOOD_PENGUIN(Feld[newx][newy]))
       {
-       if (DigField(local_player, newx, newy, 0, 0, DF_DIG) == MF_MOVING)
+       if (DigField(local_player, x, y, newx, newy, 0,0, DF_DIG) == MF_MOVING)
          DrawLevelField(newx, newy);
        else
          GfxDir[x][y] = MovDir[x][y] = MV_NO_MOVING;
@@ -4685,44 +5508,78 @@ void StartMoving(int x, int y)
       }
     }
 
+#if 1
+
     /*
     else if (move_pattern & MV_MAZE_RUNNER_STYLE && IN_LEV_FIELD(newx, newy))
     */
 
     else if (IS_CUSTOM_ELEMENT(element) &&
-            CUSTOM_ELEMENT_CAN_ENTER_FIELD(element, newx, newy))
+            CUSTOM_ELEMENT_CAN_ENTER_FIELD(element, newx, newy)
+
+#if 0
+ &&
+            !IS_FREE(newx, newy)
+#endif
+
+)
     {
       int new_element = Feld[newx][newy];
-      int sound;
 
-      /* no element can dig solid indestructible elements */
-      if (IS_INDESTRUCTIBLE(new_element) &&
-         !IS_DIGGABLE(new_element) &&
-         !IS_COLLECTIBLE(new_element))
-       return;
+#if 0
+      printf("::: '%s' digs '%s' [%d]\n",
+            element_info[element].token_name,
+            element_info[Feld[newx][newy]].token_name,
+            StorePlayer[newx][newy]);
+#endif
 
-      if (AmoebaNr[newx][newy] &&
-         (new_element == EL_AMOEBA_FULL ||
-          new_element == EL_BD_AMOEBA ||
-          new_element == EL_AMOEBA_GROWING))
+      if (!IS_FREE(newx, newy))
       {
-       AmoebaCnt[AmoebaNr[newx][newy]]--;
-       AmoebaCnt2[AmoebaNr[newx][newy]]--;
-      }
+       int action = (IS_DIGGABLE(new_element) ? ACTION_DIGGING :
+                     IS_COLLECTIBLE(new_element) ? ACTION_COLLECTING :
+                     ACTION_BREAKING);
 
-      if (IS_MOVING(newx, newy))
-       RemoveMovingField(newx, newy);
-      else
-      {
-       RemoveField(newx, newy);
-       DrawLevelField(newx, newy);
-      }
+       /* no element can dig solid indestructible elements */
+       if (IS_INDESTRUCTIBLE(new_element) &&
+           !IS_DIGGABLE(new_element) &&
+           !IS_COLLECTIBLE(new_element))
+         return;
+
+       if (AmoebaNr[newx][newy] &&
+           (new_element == EL_AMOEBA_FULL ||
+            new_element == EL_BD_AMOEBA ||
+            new_element == EL_AMOEBA_GROWING))
+       {
+         AmoebaCnt[AmoebaNr[newx][newy]]--;
+         AmoebaCnt2[AmoebaNr[newx][newy]]--;
+       }
+
+       if (IS_MOVING(newx, newy))
+         RemoveMovingField(newx, newy);
+       else
+       {
+         RemoveField(newx, newy);
+         DrawLevelField(newx, newy);
+       }
 
-      sound = (IS_DIGGABLE(new_element) ? ACTION_DIGGING :
-              IS_COLLECTIBLE(new_element) ? ACTION_COLLECTING :
-              ACTION_BREAKING);
+       PlayLevelSoundAction(x, y, action);
+      }
 
-      PlayLevelSoundAction(x, y, sound);
+#if 1
+#if 1
+      Store[newx][newy] = EL_EMPTY;
+      if (IS_EQUAL_OR_IN_GROUP(new_element, MOVE_ENTER_EL(element)))
+       Store[newx][newy] = element_info[element].move_leave_element;
+#else
+      Store[newx][newy] = EL_EMPTY;
+      if (IS_EQUAL_OR_IN_GROUP(new_element, MOVE_ENTER_EL(element)) ||
+         element_info[element].move_leave_type == LEAVE_TYPE_UNLIMITED)
+       Store[newx][newy] = element_info[element].move_leave_element;
+#endif
+#else
+      if (IS_EQUAL_OR_IN_GROUP(new_element, MOVE_ENTER_EL(element)))
+       element_info[element].can_leave_element = TRUE;
+#endif
 
       if (move_pattern & MV_MAZE_RUNNER_STYLE)
       {
@@ -4730,6 +5587,9 @@ void StartMoving(int x, int y)
        PlayerVisit[x][y] /= 8;         /* expire player visit path */
       }
     }
+
+#endif
+
     else if (element == EL_DRAGON && IN_LEV_FIELD(newx, newy))
     {
       if (!IS_FREE(newx, newy))
@@ -4772,11 +5632,25 @@ void StartMoving(int x, int y)
 
          MovDelay[x][y] = 50;
 
+         /* !!! */
+#if 0
+         RemoveField(newx, newy);
+#endif
          Feld[newx][newy] = EL_FLAMES;
          if (IN_LEV_FIELD(newx1, newy1) && Feld[newx1][newy1] == EL_EMPTY)
+         {
+#if 0
+           RemoveField(newx1, newy1);
+#endif
            Feld[newx1][newy1] = EL_FLAMES;
+         }
          if (IN_LEV_FIELD(newx2, newy2) && Feld[newx2][newy2] == EL_EMPTY)
+         {
+#if 0
+           RemoveField(newx2, newy2);
+#endif
            Feld[newx2][newy2] = EL_FLAMES;
+         }
 
          return;
        }
@@ -4806,8 +5680,15 @@ void StartMoving(int x, int y)
          AmoebaCnt[AmoebaNr[newx][newy]]--;
       }
 
+#if 0
+      /* !!! test !!! */
+      if (IS_MOVING(newx, newy) || IS_BLOCKED(newx, newy))
+#else
       if (IS_MOVING(newx, newy))
+#endif
+      {
        RemoveMovingField(newx, newy);
+      }
       else
       {
        Feld[newx][newy] = EL_EMPTY;
@@ -4901,6 +5782,7 @@ void StartMoving(int x, int y)
 void ContinueMoving(int x, int y)
 {
   int element = Feld[x][y];
+  struct ElementInfo *ei = &element_info[element];
   int direction = MovDir[x][y];
   int dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
   int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
@@ -4908,12 +5790,25 @@ void ContinueMoving(int x, int y)
 #if 0
   int nextx = newx + dx, nexty = newy + dy;
 #endif
-  boolean pushed = Pushed[x][y];
+#if 1
+  boolean pushed_by_player   = (Pushed[x][y] && IS_PLAYER(x, y));
+  boolean pushed_by_conveyor = (Pushed[x][y] && !IS_PLAYER(x, y));
+#else
+  boolean pushed_by_player = Pushed[x][y];
+#endif
 
   MovPos[x][y] += getElementMoveStepsize(x, y);
 
-  if (pushed)          /* special case: moving object pushed by player */
+#if 0
+  if (pushed_by_player && IS_PLAYER(x, y))
+  {
+    /* special case: moving object pushed by player */
+    MovPos[x][y] = SIGN(MovPos[x][y]) * (TILEX - ABS(PLAYERINFO(x,y)->MovPos));
+  }
+#else
+  if (pushed_by_player)        /* special case: moving object pushed by player */
     MovPos[x][y] = SIGN(MovPos[x][y]) * (TILEX - ABS(PLAYERINFO(x,y)->MovPos));
+#endif
 
   if (ABS(MovPos[x][y]) < TILEX)
   {
@@ -4991,16 +5886,34 @@ void ContinueMoving(int x, int y)
   {
     element = Feld[newx][newy] = EL_ACID;
   }
+#if 1
+  else if (IS_CUSTOM_ELEMENT(element) && !IS_PLAYER(x, y) &&
+          ei->move_leave_element != EL_EMPTY &&
+          (ei->move_leave_type == LEAVE_TYPE_UNLIMITED ||
+           Store[x][y] != EL_EMPTY))
+  {
+    /* some elements can leave other elements behind after moving */
+
+    Feld[x][y] = ei->move_leave_element;
+    InitField(x, y, FALSE);
+
+    if (GFX_CRUMBLED(Feld[x][y]))
+      DrawLevelFieldCrumbledSandNeighbours(x, y);
+  }
+#endif
 
-  Store[x][y] = 0;
+  Store[x][y] = EL_EMPTY;
   MovPos[x][y] = MovDir[x][y] = MovDelay[x][y] = 0;
   MovDelay[newx][newy] = 0;
 
-  /* copy element change control values to new field */
-  ChangeDelay[newx][newy] = ChangeDelay[x][y];
-  ChangePage[newx][newy] = ChangePage[x][y];
-  Changed[newx][newy] = Changed[x][y];
-  ChangeEvent[newx][newy] = ChangeEvent[x][y];
+  if (CAN_CHANGE(element))
+  {
+    /* copy element change control values to new field */
+    ChangeDelay[newx][newy] = ChangeDelay[x][y];
+    ChangePage[newx][newy]  = ChangePage[x][y];
+    Changed[newx][newy]     = Changed[x][y];
+    ChangeEvent[newx][newy] = ChangeEvent[x][y];
+  }
 
   ChangeDelay[x][y] = 0;
   ChangePage[x][y] = -1;
@@ -5017,23 +5930,24 @@ void ContinueMoving(int x, int y)
 
   ResetGfxAnimation(x, y);     /* reset animation values for old field */
 
-  if (IS_CUSTOM_ELEMENT(element) && !IS_PLAYER(x, y))
+#if 0
+  /* some elements can leave other elements behind after moving */
+  if (IS_CUSTOM_ELEMENT(element) && !IS_PLAYER(x, y) &&
+      ei->move_leave_element != EL_EMPTY &&
+      (ei->move_leave_type == LEAVE_TYPE_UNLIMITED ||
+       ei->can_leave_element_last))
   {
-    int new_element = element_info[element].move_leave_element;
-
-    Feld[x][y] = new_element;
-
-    if (new_element != EL_EMPTY)
-    {
-      InitField(x, y, FALSE);
-
-      TestIfElementTouchesCustomElement(x, y);
+    Feld[x][y] = ei->move_leave_element;
+    InitField(x, y, FALSE);
 
-      if (GFX_CRUMBLED(new_element))
-       DrawLevelFieldCrumbledSandNeighbours(x, y);
-    }
+    if (GFX_CRUMBLED(Feld[x][y]))
+      DrawLevelFieldCrumbledSandNeighbours(x, y);
   }
 
+  ei->can_leave_element_last = ei->can_leave_element;
+  ei->can_leave_element = FALSE;
+#endif
+
 #if 0
   /* 2.1.1 (does not work correctly for spring) */
   if (!CAN_MOVE(element))
@@ -5064,12 +5978,19 @@ void ContinueMoving(int x, int y)
   Stop[newx][newy] = TRUE;     /* ignore this element until the next frame */
 
   /* prevent pushed element from moving on in pushed direction */
-  if (pushed && CAN_MOVE(element) &&
+  if (pushed_by_player && CAN_MOVE(element) &&
       element_info[element].move_pattern & MV_ANY_DIRECTION &&
       !(element_info[element].move_pattern & direction))
     TurnRound(newx, newy);
 
-  if (!pushed) /* special case: moving object pushed by player */
+#if 1
+  /* prevent elements on conveyor belt from moving on in last direction */
+  if (pushed_by_conveyor && CAN_FALL(element) &&
+      direction & MV_HORIZONTAL)
+    MovDir[newx][newy] = 0;
+#endif
+
+  if (!pushed_by_player)
   {
     WasJustMoving[newx][newy] = 3;
 
@@ -5093,7 +6014,7 @@ void ContinueMoving(int x, int y)
     Impact(x, newy);
 
 #if 1
-  TestIfElementTouchesCustomElement(x, y);             /* for empty space */
+  TestIfElementTouchesCustomElement(x, y);     /* empty or new element */
 #endif
 
 #if 0
@@ -5112,21 +6033,13 @@ void ContinueMoving(int x, int y)
     int hitting_element = Feld[newx][newy];
 
     /* !!! fix side (direction) orientation here and elsewhere !!! */
-    CheckElementSideChange(newx, newy, hitting_element,
-                          direction, CE_HITTING_SOMETHING, -1);
+    CheckElementChangeSide(newx, newy, hitting_element, CE_HITTING_SOMETHING,
+                          direction);
 
 #if 0
     if (IN_LEV_FIELD(nextx, nexty))
     {
-      static int opposite_directions[] =
-      {
-       MV_RIGHT,
-       MV_LEFT,
-       MV_DOWN,
-       MV_UP
-      };
-      int move_dir_bit = MV_DIR_BIT(direction);
-      int opposite_direction = opposite_directions[move_dir_bit];
+      int opposite_direction = MV_DIR_OPPOSITE(direction);
       int hitting_side = direction;
       int touched_side = opposite_direction;
       int touched_element = MovingOrBlocked2Element(nextx, nexty);
@@ -5138,8 +6051,8 @@ void ContinueMoving(int x, int y)
       {
        int i;
 
-       CheckElementSideChange(nextx, nexty, touched_element,
-                              opposite_direction, CE_HIT_BY_SOMETHING, -1);
+       CheckElementChangeSide(nextx, nexty, touched_element,
+                              CE_HIT_BY_SOMETHING, opposite_direction);
 
        if (IS_CUSTOM_ELEMENT(hitting_element) &&
            HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_HITTING))
@@ -5151,11 +6064,11 @@ void ContinueMoving(int x, int y)
 
            if (change->can_change &&
                change->events & CH_EVENT_BIT(CE_OTHER_IS_HITTING) &&
-               change->sides & touched_side &&
+               change->trigger_side & touched_side &&
                change->trigger_element == touched_element)
            {
-             CheckElementSideChange(newx, newy, hitting_element,
-                                    CH_SIDE_ANY, CE_OTHER_IS_HITTING, i);
+             CheckElementChangePage(newx, newy, hitting_element,
+                                    touched_element, CE_OTHER_IS_HITTING, i);
              break;
            }
          }
@@ -5171,11 +6084,11 @@ void ContinueMoving(int x, int y)
 
            if (change->can_change &&
                change->events & CH_EVENT_BIT(CE_OTHER_GETS_HIT) &&
-               change->sides & hitting_side &&
+               change->trigger_side & hitting_side &&
                change->trigger_element == hitting_element)
            {
-             CheckElementSideChange(nextx, nexty, touched_element,
-                                    CH_SIDE_ANY, CE_OTHER_GETS_HIT, i);
+             CheckElementChangePage(nextx, nexty, touched_element,
+                                    hitting_element, CE_OTHER_GETS_HIT, i);
              break;
            }
          }
@@ -5203,7 +6116,7 @@ int AmoebeNachbarNr(int ax, int ay)
     { 0, +1 }
   };
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int x = ax + xy[i][0];
     int y = ay + xy[i][1];
@@ -5233,7 +6146,7 @@ void AmoebenVereinigen(int ax, int ay)
   if (new_group_nr == 0)
     return;
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     x = ax + xy[i][0];
     y = ay + xy[i][1];
@@ -5311,7 +6224,7 @@ void AmoebeUmwandeln(int ax, int ay)
       { 0, +1 }
     };
 
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < NUM_DIRECTIONS; i++)
     {
       x = ax + xy[i][0];
       y = ay + xy[i][1];
@@ -5507,7 +6420,7 @@ void AmoebeAbleger(int ax, int ay)
     int start = RND(4);
     boolean waiting_for_player = FALSE;
 
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < NUM_DIRECTIONS; i++)
     {
       int j = (start + i) % 4;
       int x = ax + xy[j][0];
@@ -5989,11 +6902,11 @@ void CheckForDragon(int x, int y)
     { 0, +1 }
   };
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     for (j = 0; j < 4; j++)
     {
-      int xx = x + j*xy[i][0], yy = y + j*xy[i][1];
+      int xx = x + j * xy[i][0], yy = y + j * xy[i][1];
 
       if (IN_LEV_FIELD(xx, yy) &&
          (Feld[xx][yy] == EL_FLAMES || Feld[xx][yy] == EL_DRAGON))
@@ -6008,11 +6921,11 @@ void CheckForDragon(int x, int y)
 
   if (!dragon_found)
   {
-    for (i = 0; i < 4; i++)
+    for (i = 0; i < NUM_DIRECTIONS; i++)
     {
       for (j = 0; j < 3; j++)
       {
-       int xx = x + j*xy[i][0], yy = y + j*xy[i][1];
+       int xx = x + j * xy[i][0], yy = y + j * xy[i][1];
   
        if (IN_LEV_FIELD(xx, yy) && Feld[xx][yy] == EL_FLAMES)
        {
@@ -6051,7 +6964,7 @@ static void WarnBuggyBase(int x, int y)
     { 0, +1 }
   };
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int xx = x + xy[i][0], yy = y + xy[i][1];
 
@@ -6085,9 +6998,11 @@ static void ChangeActiveTrap(int x, int y)
 
 static void ChangeElementNowExt(int x, int y, int target_element)
 {
+  int previous_move_direction = MovDir[x][y];
+
   /* check if element under player changes from accessible to unaccessible
      (needed for special case of dropping element which then changes) */
-  if (IS_PLAYER(x, y) && !PLAYER_PROTECTED(x, y) &&
+  if (IS_PLAYER(x, y) && !PLAYER_EXPLOSION_PROTECTED(x, y) &&
       IS_ACCESSIBLE(Feld[x][y]) && !IS_ACCESSIBLE(target_element))
   {
     Bang(x, y);
@@ -6102,9 +7017,16 @@ static void ChangeElementNowExt(int x, int y, int target_element)
   ResetGfxAnimation(x, y);
   ResetRandomAnimationValue(x, y);
 
+  if (element_info[Feld[x][y]].move_direction_initial == MV_START_PREVIOUS)
+    MovDir[x][y] = previous_move_direction;
+
+#if 1
+  InitField_WithBug1(x, y, FALSE);
+#else
   InitField(x, y, FALSE);
   if (CAN_MOVE(Feld[x][y]))
     InitMovDir(x, y);
+#endif
 
   DrawLevelField(x, y);
 
@@ -6122,11 +7044,19 @@ static void ChangeElementNowExt(int x, int y, int target_element)
 static boolean ChangeElementNow(int x, int y, int element, int page)
 {
   struct ElementChangeInfo *change = &element_info[element].change_page[page];
+  int target_element;
 
   /* always use default change event to prevent running into a loop */
   if (ChangeEvent[x][y] == CE_BITMASK_DEFAULT)
     ChangeEvent[x][y] = CH_EVENT_BIT(CE_DELAY);
 
+  if (ChangeEvent[x][y] == CH_EVENT_BIT(CE_DELAY))
+  {
+    /* reset actual trigger element and player */
+    change->actual_trigger_element = EL_EMPTY;
+    change->actual_trigger_player = EL_PLAYER_1;
+  }
+
   /* do not change already changed elements with same change event */
 #if 0
   if (Changed[x][y] & ChangeEvent[x][y])
@@ -6138,7 +7068,7 @@ static boolean ChangeElementNow(int x, int y, int element, int page)
 
   Changed[x][y] |= ChangeEvent[x][y];  /* ignore same changes in this frame */
 
-  CheckTriggeredElementChange(x, y, Feld[x][y], CE_OTHER_IS_CHANGING);
+  CheckTriggeredElementChangePage(x,y, Feld[x][y], CE_OTHER_IS_CHANGING, page);
 
   if (change->explode)
   {
@@ -6147,35 +7077,38 @@ static boolean ChangeElementNow(int x, int y, int element, int page)
     return TRUE;
   }
 
-  if (change->use_content)
+  if (change->use_target_content)
   {
-    boolean complete_change = TRUE;
-    boolean can_change[3][3];
+    boolean complete_replace = TRUE;
+    boolean can_replace[3][3];
     int xx, yy;
 
     for (yy = 0; yy < 3; yy++) for (xx = 0; xx < 3 ; xx++)
     {
-      boolean half_destructible;
+      boolean is_empty;
+      boolean is_diggable;
+      boolean is_destructible;
       int ex = x + xx - 1;
       int ey = y + yy - 1;
+      int content_element = change->target_content[xx][yy];
       int e;
 
-      can_change[xx][yy] = TRUE;
+      can_replace[xx][yy] = TRUE;
 
       if (ex == x && ey == y)  /* do not check changing element itself */
        continue;
 
-      if (change->content[xx][yy] == EL_EMPTY_SPACE)
+      if (content_element == EL_EMPTY_SPACE)
       {
-       can_change[xx][yy] = FALSE;     /* do not change empty borders */
+       can_replace[xx][yy] = FALSE;    /* do not replace border with space */
 
        continue;
       }
 
       if (!IN_LEV_FIELD(ex, ey))
       {
-       can_change[xx][yy] = FALSE;
-       complete_change = FALSE;
+       can_replace[xx][yy] = FALSE;
+       complete_replace = FALSE;
 
        continue;
       }
@@ -6185,39 +7118,64 @@ static boolean ChangeElementNow(int x, int y, int element, int page)
       if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
        e = MovingOrBlocked2Element(ex, ey);
 
+#if 1
+      is_empty = (IS_FREE(ex, ey) || (IS_PLAYER(ex, ey) &&
+                                     IS_WALKABLE(content_element)));
+      is_diggable = (is_empty || IS_DIGGABLE(e));
+      is_destructible = (is_empty || !IS_INDESTRUCTIBLE(e));
+
+      can_replace[xx][yy] =
+       ((change->replace_when == CP_WHEN_EMPTY && is_empty) ||
+        (change->replace_when == CP_WHEN_DIGGABLE && is_diggable) ||
+        (change->replace_when == CP_WHEN_DESTRUCTIBLE && is_destructible));
+
+      if (!can_replace[xx][yy])
+       complete_replace = FALSE;
+#else
+      empty_for_element = (IS_FREE(ex, ey) || (IS_FREE_OR_PLAYER(ex, ey) &&
+                                              IS_WALKABLE(content_element)));
+#if 1
+      half_destructible = (empty_for_element || IS_DIGGABLE(e));
+#else
       half_destructible = (IS_FREE(ex, ey) || IS_DIGGABLE(e));
+#endif
 
-      if ((change->power <= CP_NON_DESTRUCTIVE  && !IS_FREE(ex, ey)) ||
-         (change->power <= CP_HALF_DESTRUCTIVE && !half_destructible) ||
-         (change->power <= CP_FULL_DESTRUCTIVE && IS_INDESTRUCTIBLE(e)))
+      if ((change->replace_when <= CP_WHEN_EMPTY  && !empty_for_element) ||
+         (change->replace_when <= CP_WHEN_DIGGABLE && !half_destructible) ||
+         (change->replace_when <= CP_WHEN_DESTRUCTIBLE && IS_INDESTRUCTIBLE(e)))
       {
-       can_change[xx][yy] = FALSE;
-       complete_change = FALSE;
+       can_replace[xx][yy] = FALSE;
+       complete_replace = FALSE;
       }
+#endif
     }
 
-    if (!change->only_complete || complete_change)
+    if (!change->only_if_complete || complete_replace)
     {
       boolean something_has_changed = FALSE;
 
-      if (change->only_complete && change->use_random_change &&
-         RND(100) < change->random)
+      if (change->only_if_complete && change->use_random_replace &&
+         RND(100) < change->random_percentage)
        return FALSE;
 
       for (yy = 0; yy < 3; yy++) for (xx = 0; xx < 3 ; xx++)
       {
        int ex = x + xx - 1;
        int ey = y + yy - 1;
+       int content_element;
 
-       if (can_change[xx][yy] && (!change->use_random_change ||
-                                  RND(100) < change->random))
+       if (can_replace[xx][yy] && (!change->use_random_replace ||
+                                   RND(100) < change->random_percentage))
        {
          if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
            RemoveMovingField(ex, ey);
 
          ChangeEvent[ex][ey] = ChangeEvent[x][y];
 
-         ChangeElementNowExt(ex, ey, change->content[xx][yy]);
+         content_element = change->target_content[xx][yy];
+         target_element = GET_TARGET_ELEMENT(content_element, change);
+
+         ChangeElementNowExt(ex, ey, target_element);
 
          something_has_changed = TRUE;
 
@@ -6233,7 +7191,9 @@ static boolean ChangeElementNow(int x, int y, int element, int page)
   }
   else
   {
-    ChangeElementNowExt(x, y, change->target_element);
+    target_element = GET_TARGET_ELEMENT(change->target_element, change);
+
+    ChangeElementNowExt(x, y, target_element);
 
     PlayLevelSoundElementAction(x, y, element, ACTION_CHANGING);
   }
@@ -6247,9 +7207,8 @@ static void ChangeElement(int x, int y, int page)
   struct ElementInfo *ei = &element_info[element];
   struct ElementChangeInfo *change = &ei->change_page[page];
 
-#if 0
 #ifdef DEBUG
-  if (!CAN_CHANGE(element))
+  if (!CAN_CHANGE(element) && !CAN_CHANGE(Back[x][y]))
   {
     printf("\n\n");
     printf("ChangeElement(): %d,%d: element = %d ('%s')\n",
@@ -6258,8 +7217,18 @@ static void ChangeElement(int x, int y, int page)
     printf("\n\n");
   }
 #endif
+
+  /* this can happen with classic bombs on walkable, changing elements */
+  if (!CAN_CHANGE(element))
+  {
+#if 0
+    if (!CAN_CHANGE(Back[x][y]))       /* prevent permanent repetition */
+      ChangeDelay[x][y] = 0;
 #endif
 
+    return;
+  }
+
   if (ChangeDelay[x][y] == 0)          /* initialize element change */
   {
     ChangeDelay[x][y] = (    change->delay_fixed  * change->delay_frames +
@@ -6290,6 +7259,8 @@ static void ChangeElement(int x, int y, int page)
     {
       page = ChangePage[x][y];
       ChangePage[x][y] = -1;
+
+      change = &ei->change_page[page];
     }
 
 #if 0
@@ -6312,12 +7283,15 @@ static void ChangeElement(int x, int y, int page)
   }
 }
 
-static boolean CheckTriggeredElementSideChange(int lx, int ly,
-                                              int trigger_element,
-                                              int trigger_side,
-                                              int trigger_event)
+static boolean CheckTriggeredElementChangeExt(int lx, int ly,
+                                             int trigger_element,
+                                             int trigger_event,
+                                             int trigger_player,
+                                             int trigger_side,
+                                             int trigger_page)
 {
   int i, j, x, y;
+  int trigger_page_bits = (trigger_page < 0 ? CH_PAGE_ANY : 1 << trigger_page);
 
   if (!(trigger_events[trigger_element] & CH_EVENT_BIT(trigger_event)))
     return FALSE;
@@ -6337,11 +7311,11 @@ static boolean CheckTriggeredElementSideChange(int lx, int ly,
       struct ElementChangeInfo *change = &element_info[element].change_page[j];
 
       if (change->can_change &&
-#if 1
          change->events & CH_EVENT_BIT(trigger_event) &&
-#endif
-         change->sides & trigger_side &&
-         change->trigger_element == trigger_element)
+         change->trigger_side & trigger_side &&
+         change->trigger_player & trigger_player &&
+         change->trigger_page & trigger_page_bits &&
+         IS_EQUAL_OR_IN_GROUP(trigger_element, change->trigger_element))
       {
 #if 0
        if (!(change->events & CH_EVENT_BIT(trigger_event)))
@@ -6352,6 +7326,9 @@ static boolean CheckTriggeredElementSideChange(int lx, int ly,
        change_element = TRUE;
        page = j;
 
+       change->actual_trigger_element = trigger_element;
+       change->actual_trigger_player = EL_PLAYER_1 + log_2(trigger_player);
+
        break;
       }
     }
@@ -6378,15 +7355,13 @@ static boolean CheckTriggeredElementSideChange(int lx, int ly,
   return TRUE;
 }
 
-static boolean CheckTriggeredElementChange(int lx, int ly, int trigger_element,
-                                          int trigger_event)
-{
-  return CheckTriggeredElementSideChange(lx, ly, trigger_element, CH_SIDE_ANY,
-                                        trigger_event);
-}
-
-static boolean CheckElementSideChange(int x, int y, int element, int side,
-                                     int trigger_event, int page)
+static boolean CheckElementChangeExt(int x, int y,
+                                    int element,
+                                    int trigger_element,
+                                    int trigger_event,
+                                    int trigger_player,
+                                    int trigger_side,
+                                    int trigger_page)
 {
   if (!CAN_CHANGE(element) || !HAS_ANY_CHANGE_EVENT(element, trigger_event))
     return FALSE;
@@ -6397,24 +7372,75 @@ static boolean CheckElementSideChange(int x, int y, int element, int side,
     element = Feld[x][y];
   }
 
-  if (page < 0)
-    page = element_info[element].event_page_nr[trigger_event];
+#if 1
+  if (Feld[x][y] != element)   /* check if element has already changed */
+  {
+#if 0
+    printf("::: %d ('%s') != %d ('%s') [%d]\n",
+          Feld[x][y], element_info[Feld[x][y]].token_name,
+          element, element_info[element].token_name,
+          trigger_event);
+#endif
+
+    return FALSE;
+  }
+#endif
+
+#if 1
+  if (trigger_page < 0)
+  {
+    boolean change_element = FALSE;
+    int i;
+
+    for (i = 0; i < element_info[element].num_change_pages; i++)
+    {
+      struct ElementChangeInfo *change = &element_info[element].change_page[i];
+
+      if (change->can_change &&
+         change->events & CH_EVENT_BIT(trigger_event) &&
+         change->trigger_side & trigger_side &&
+         change->trigger_player & trigger_player)
+      {
+       change_element = TRUE;
+       trigger_page = i;
+
+       change->actual_trigger_element = trigger_element;
+       change->actual_trigger_player = EL_PLAYER_1 + log_2(trigger_player);
+
+       break;
+      }
+    }
+
+    if (!change_element)
+      return FALSE;
+  }
+  else
+  {
+    struct ElementInfo *ei = &element_info[element];
+    struct ElementChangeInfo *change = &ei->change_page[trigger_page];
+
+    change->actual_trigger_element = trigger_element;
+    change->actual_trigger_player = EL_PLAYER_1;       /* unused */
+  }
+
+#else
+
+  /* !!! this check misses pages with same event, but different side !!! */
+
+  if (trigger_page < 0)
+    trigger_page = element_info[element].event_page_nr[trigger_event];
 
-  if (!(element_info[element].change_page[page].sides & side))
+  if (!(element_info[element].change_page[trigger_page].trigger_side & trigger_side))
     return FALSE;
+#endif
 
   ChangeDelay[x][y] = 1;
   ChangeEvent[x][y] = CH_EVENT_BIT(trigger_event);
-  ChangeElement(x, y, page);
+  ChangeElement(x, y, trigger_page);
 
   return TRUE;
 }
 
-static boolean CheckElementChange(int x, int y, int element, int trigger_event)
-{
-  return CheckElementSideChange(x, y, element, CH_SIDE_ANY, trigger_event, -1);
-}
-
 static void PlayPlayerSound(struct PlayerInfo *player)
 {
   int jx = player->jx, jy = player->jy;
@@ -6617,6 +7643,11 @@ static byte PlayerActions(struct PlayerInfo *player, byte player_action)
     printf("::: player %d acts [%d]\n", player->index_nr, FrameCounter);
 #endif
 
+#if 0
+    /* !!! TEST !!! */
+    if (player->MovPos == 0)
+      CheckGravityMovement(player);
+#endif
     if (button1)
       snapped = SnapField(player, dx, dy);
     else
@@ -6652,9 +7683,9 @@ static byte PlayerActions(struct PlayerInfo *player, byte player_action)
 
     /* no actions for this player (no input at player's configured device) */
 
-    DigField(player, 0, 0, 0, 0, DF_NO_PUSH);
+    DigField(player, 0, 0, 0, 0, 0, 0, DF_NO_PUSH);
     SnapField(player, 0, 0);
-    CheckGravityMovement(player);
+    CheckGravityMovementWhenNotMoving(player);
 
     if (player->MovPos == 0)
       SetPlayerWaiting(player, TRUE);
@@ -6733,9 +7764,9 @@ static void PlayerActions(struct PlayerInfo *player, byte player_action)
 
     /* no actions for this player (no input at player's configured device) */
 
-    DigField(player, 0, 0, 0, 0, DF_NO_PUSH);
+    DigField(player, 0, 0, 0, 0, 0, 0, DF_NO_PUSH);
     SnapField(player, 0, 0);
-    CheckGravityMovement(player);
+    CheckGravityMovementWhenNotMoving(player);
 
     if (player->MovPos == 0)
       InitPlayerGfxAnimation(player, ACTION_DEFAULT, player->MovDir);
@@ -6772,7 +7803,7 @@ void GameActions()
   action_delay_value =
     (tape.playing && tape.fast_forward ? FfwdFrameDelay : GameFrameDelay);
 
-  if (tape.playing && tape.index_search && !tape.pausing)
+  if (tape.playing && tape.warp_forward && !tape.pausing)
     action_delay_value = 0;
 
   /* ---------- main game synchronization point ---------- */
@@ -6815,6 +7846,21 @@ void GameActions()
 
   recorded_player_action = (tape.playing ? TapePlayAction() : NULL);
 
+#if 1
+  if (recorded_player_action == NULL && tape.pausing)
+    return;
+#endif
+
+#if 0
+  printf("::: %d\n", stored_player[0].action);
+#endif
+
+#if 0
+  if (recorded_player_action != NULL)
+    for (i = 0; i < MAX_PLAYERS; i++)
+      stored_player[i].action = recorded_player_action[i];
+#endif
+
   for (i = 0; i < MAX_PLAYERS; i++)
   {
     summarized_player_action |= stored_player[i].action;
@@ -6831,25 +7877,91 @@ void GameActions()
   if (!options.network && !setup.team_mode)
     local_player->effective_action = summarized_player_action;
 
+#if 1
+  if (recorded_player_action != NULL)
+    for (i = 0; i < MAX_PLAYERS; i++)
+      stored_player[i].effective_action = recorded_player_action[i];
+#endif
+
+#if 1
+  for (i = 0; i < MAX_PLAYERS; i++)
+  {
+    tape_action[i] = stored_player[i].effective_action;
+
+    if (tape.recording && tape_action[i] && !tape.player_participates[i])
+      tape.player_participates[i] = TRUE;    /* player just appeared from CE */
+  }
+
+  /* only save actions from input devices, but not programmed actions */
+  if (tape.recording)
+    TapeRecordAction(tape_action);
+#endif
+
   for (i = 0; i < MAX_PLAYERS; i++)
   {
     int actual_player_action = stored_player[i].effective_action;
 
+#if 1
+    /* !!! THIS BREAKS THE FOLLOWING TAPES: !!!
+       - rnd_equinox_tetrachloride 048
+       - rnd_equinox_tetrachloride_ii 096
+       - rnd_emanuel_schmieg 002
+       - doctor_sloan_ww 001, 020
+    */
+    if (stored_player[i].MovPos == 0)
+      CheckGravityMovement(&stored_player[i]);
+#endif
+
+#if 1
+    /* overwrite programmed action with tape action */
     if (stored_player[i].programmed_action)
       actual_player_action = stored_player[i].programmed_action;
+#endif
+
+#if 0
+    if (stored_player[i].programmed_action)
+      printf("::: %d\n", stored_player[i].programmed_action);
+#endif
 
     if (recorded_player_action)
+    {
+#if 0
+      if (stored_player[i].programmed_action &&
+         stored_player[i].programmed_action != recorded_player_action[i])
+       printf("::: %d: %d <-> %d\n", i,
+              stored_player[i].programmed_action, recorded_player_action[i]);
+#endif
+
+#if 0
       actual_player_action = recorded_player_action[i];
+#endif
+    }
+
+#if 0
+    /* overwrite tape action with programmed action */
+    if (stored_player[i].programmed_action)
+      actual_player_action = stored_player[i].programmed_action;
+#endif
 
+#if 0
+    if (i == 0)
+      printf("::: action: %d: %x [%d]\n",
+            stored_player[i].MovPos, actual_player_action, FrameCounter);
+#endif
+
+#if 1
+    PlayerActions(&stored_player[i], actual_player_action);
+#else
     tape_action[i] = PlayerActions(&stored_player[i], actual_player_action);
 
     if (tape.recording && tape_action[i] && !tape.player_participates[i])
       tape.player_participates[i] = TRUE;    /* player just appeared from CE */
+#endif
 
     ScrollPlayer(&stored_player[i], SCROLL_GO_ON);
   }
 
-#if 1
+#if 0
   if (tape.recording)
     TapeRecordAction(tape_action);
 #endif
@@ -6867,7 +7979,19 @@ void GameActions()
 #endif
 
 #if 1
+  /* for downwards compatibility, the following code emulates a fixed bug that
+     occured when pushing elements (causing elements that just made their last
+     pushing step to already (if possible) make their first falling step in the
+     same game frame, which is bad); this code is also needed to use the famous
+     "spring push bug" which is used in older levels and might be wanted to be
+     used also in newer levels, but in this case the buggy pushing code is only
+     affecting the "spring" element and no other elements */
+
+#if 1
+  if (game.engine_version < VERSION_IDENT(2,2,0,7) || level.use_spring_bug)
+#else
   if (game.engine_version < VERSION_IDENT(2,2,0,7))
+#endif
   {
     for (i = 0; i < MAX_PLAYERS; i++)
     {
@@ -6875,8 +7999,15 @@ void GameActions()
       int x = player->jx;
       int y = player->jy;
 
+#if 1
+      if (player->active && player->is_pushing && player->is_moving &&
+         IS_MOVING(x, y) &&
+         (game.engine_version < VERSION_IDENT(2,2,0,7) ||
+          Feld[x][y] == EL_SPRING))
+#else
       if (player->active && player->is_pushing && player->is_moving &&
          IS_MOVING(x, y))
+#endif
       {
        ContinueMoving(x, y);
 
@@ -7056,7 +8187,7 @@ void GameActions()
       CheckDynamite(x, y);
 #if 0
     else if (element == EL_EXPLOSION && !game.explosions_delayed)
-      Explode(x, y, ExplodePhase[x][y], EX_NORMAL);
+      Explode(x, y, ExplodePhase[x][y], EX_TYPE_NORMAL);
 #endif
     else if (element == EL_AMOEBA_GROWING)
       AmoebeWaechst(x, y);
@@ -7172,9 +8303,9 @@ void GameActions()
       if (ExplodeField[x][y])
        Explode(x, y, EX_PHASE_START, ExplodeField[x][y]);
       else if (element == EL_EXPLOSION)
-       Explode(x, y, ExplodePhase[x][y], EX_NORMAL);
+       Explode(x, y, ExplodePhase[x][y], EX_TYPE_NORMAL);
 
-      ExplodeField[x][y] = EX_NO_EXPLOSION;
+      ExplodeField[x][y] = EX_TYPE_NONE;
     }
 
     game.explosions_delayed = TRUE;
@@ -7254,39 +8385,44 @@ void GameActions()
   if (TimeFrames >= FRAMES_PER_SECOND)
   {
     TimeFrames = 0;
-    TimePlayed++;
+    TapeTime++;
 
-    for (i = 0; i < MAX_PLAYERS; i++)
+    if (!level.use_step_counter)
     {
-      struct PlayerInfo *player = &stored_player[i];
+      TimePlayed++;
 
-      if (SHIELD_ON(player))
+      for (i = 0; i < MAX_PLAYERS; i++)
       {
-       player->shield_normal_time_left--;
+       struct PlayerInfo *player = &stored_player[i];
 
-       if (player->shield_deadly_time_left > 0)
-         player->shield_deadly_time_left--;
-      }
-    }
+       if (SHIELD_ON(player))
+       {
+         player->shield_normal_time_left--;
 
-    if (tape.recording || tape.playing)
-      DrawVideoDisplay(VIDEO_STATE_TIME_ON, TimePlayed);
+         if (player->shield_deadly_time_left > 0)
+           player->shield_deadly_time_left--;
+       }
+      }
 
-    if (TimeLeft > 0)
-    {
-      TimeLeft--;
+      if (TimeLeft > 0)
+      {
+       TimeLeft--;
 
-      if (TimeLeft <= 10 && setup.time_limit)
-       PlaySoundStereo(SND_GAME_RUNNING_OUT_OF_TIME, SOUND_MIDDLE);
+       if (TimeLeft <= 10 && setup.time_limit)
+         PlaySoundStereo(SND_GAME_RUNNING_OUT_OF_TIME, SOUND_MIDDLE);
 
-      DrawText(DX_TIME, DY_TIME, int2str(TimeLeft, 3), FONT_TEXT_2);
+       DrawGameValue_Time(TimeLeft);
 
-      if (!TimeLeft && setup.time_limit)
-       for (i = 0; i < MAX_PLAYERS; i++)
-         KillHero(&stored_player[i]);
+       if (!TimeLeft && setup.time_limit)
+         for (i = 0; i < MAX_PLAYERS; i++)
+           KillHero(&stored_player[i]);
+      }
+      else if (level.time == 0 && !AllPlayersGone) /* level w/o time limit */
+       DrawGameValue_Time(TimePlayed);
     }
-    else if (level.time == 0 && !AllPlayersGone) /* level without time limit */
-      DrawText(DX_TIME, DY_TIME, int2str(TimePlayed, 3), FONT_TEXT_2);
+
+    if (tape.recording || tape.playing)
+      DrawVideoDisplay(VIDEO_STATE_TIME_ON, TapeTime);
   }
 
   DrawAllPlayers();
@@ -7420,31 +8556,130 @@ void ScrollLevel(int dx, int dy)
   redraw_mask |= REDRAW_FIELD;
 }
 
-static void CheckGravityMovement(struct PlayerInfo *player)
+static boolean canEnterSupaplexPort(int x, int y, int dx, int dy)
 {
-  if (game.gravity && !player->programmed_action)
-  {
-    int move_dir_vertical = player->action & (MV_UP | MV_DOWN);
-    int move_dir_horizontal = player->action & (MV_LEFT | MV_RIGHT);
-    int move_dir =
-      (player->last_move_dir & (MV_LEFT | MV_RIGHT) ?
+  int nextx = x + dx, nexty = y + dy;
+  int element = Feld[x][y];
+
+  if ((dx == -1 &&
+       element != EL_SP_PORT_LEFT &&
+       element != EL_SP_GRAVITY_PORT_LEFT &&
+       element != EL_SP_PORT_HORIZONTAL &&
+       element != EL_SP_PORT_ANY) ||
+      (dx == +1 &&
+       element != EL_SP_PORT_RIGHT &&
+       element != EL_SP_GRAVITY_PORT_RIGHT &&
+       element != EL_SP_PORT_HORIZONTAL &&
+       element != EL_SP_PORT_ANY) ||
+      (dy == -1 &&
+       element != EL_SP_PORT_UP &&
+       element != EL_SP_GRAVITY_PORT_UP &&
+       element != EL_SP_PORT_VERTICAL &&
+       element != EL_SP_PORT_ANY) ||
+      (dy == +1 &&
+       element != EL_SP_PORT_DOWN &&
+       element != EL_SP_GRAVITY_PORT_DOWN &&
+       element != EL_SP_PORT_VERTICAL &&
+       element != EL_SP_PORT_ANY) ||
+      !IN_LEV_FIELD(nextx, nexty) ||
+      !IS_FREE(nextx, nexty))
+    return FALSE;
+
+  return TRUE;
+}
+
+static void CheckGravityMovement(struct PlayerInfo *player)
+{
+  if (game.gravity && !player->programmed_action)
+  {
+#if 1
+    int move_dir_horizontal = player->effective_action & MV_HORIZONTAL;
+    int move_dir_vertical   = player->effective_action & MV_VERTICAL;
+#else
+    int move_dir_horizontal = player->action & MV_HORIZONTAL;
+    int move_dir_vertical   = player->action & MV_VERTICAL;
+#endif
+    int move_dir =
+      (player->last_move_dir & MV_HORIZONTAL ?
        (move_dir_vertical ? move_dir_vertical : move_dir_horizontal) :
        (move_dir_horizontal ? move_dir_horizontal : move_dir_vertical));
     int jx = player->jx, jy = player->jy;
     int dx = (move_dir & MV_LEFT ? -1 : move_dir & MV_RIGHT ? +1 : 0);
     int dy = (move_dir & MV_UP ? -1 : move_dir & MV_DOWN ? +1 : 0);
     int new_jx = jx + dx, new_jy = jy + dy;
-    boolean field_under_player_is_free =
-      (IN_LEV_FIELD(jx, jy + 1) && IS_FREE(jx, jy + 1));
+#if 1
+    boolean player_is_snapping = player->effective_action & JOY_BUTTON_1;
+#else
+    boolean player_is_snapping = player->action & JOY_BUTTON_1;
+#endif
+#if 1
+    boolean player_can_fall_down =
+      (IN_LEV_FIELD(jx, jy + 1) &&
+       (IS_FREE(jx, jy + 1) ||
+       (Feld[jx][jy + 1] == EL_ACID && player->can_fall_into_acid)));
+#else
+    boolean player_can_fall_down =
+      (IN_LEV_FIELD(jx, jy + 1) &&
+       (IS_FREE(jx, jy + 1)));
+#endif
     boolean player_is_moving_to_valid_field =
-      (IN_LEV_FIELD(new_jx, new_jy) &&
+      (
+#if 1
+       !player_is_snapping &&
+#endif
+       IN_LEV_FIELD(new_jx, new_jy) &&
        (Feld[new_jx][new_jy] == EL_SP_BASE ||
-       Feld[new_jx][new_jy] == EL_SAND));
+       Feld[new_jx][new_jy] == EL_SAND ||
+       (IS_SP_PORT(Feld[new_jx][new_jy]) &&
+        canEnterSupaplexPort(new_jx, new_jy, dx, dy))));
     /* !!! extend EL_SAND to anything diggable !!! */
 
-    if (field_under_player_is_free &&
-       !player_is_moving_to_valid_field &&
-       !IS_WALKABLE_INSIDE(Feld[jx][jy]))
+    boolean player_is_standing_on_valid_field =
+      (IS_WALKABLE_INSIDE(Feld[jx][jy]) ||
+       (IS_WALKABLE(Feld[jx][jy]) &&
+       !(element_info[Feld[jx][jy]].access_direction & MV_DOWN)));
+
+#if 0
+    printf("::: checking gravity NOW [%d, %d, %d] [%d] [%d / %d] ...\n",
+          player_can_fall_down,
+          player_is_standing_on_valid_field,
+          player_is_moving_to_valid_field,
+          (player_is_moving_to_valid_field ? Feld[new_jx][new_jy] : -1),
+          player->effective_action,
+          player->can_fall_into_acid);
+#endif
+
+    if (player_can_fall_down &&
+       !player_is_standing_on_valid_field &&
+       !player_is_moving_to_valid_field)
+    {
+#if 0
+      printf("::: setting programmed_action to MV_DOWN [%d,%d - %d] ...\n",
+            jx, jy, FrameCounter);
+#endif
+
+      player->programmed_action = MV_DOWN;
+    }
+  }
+}
+
+static void CheckGravityMovementWhenNotMoving(struct PlayerInfo *player)
+{
+#if 1
+  return CheckGravityMovement(player);
+#endif
+
+  if (game.gravity && !player->programmed_action)
+  {
+    int jx = player->jx, jy = player->jy;
+    boolean field_under_player_is_free =
+      (IN_LEV_FIELD(jx, jy + 1) && IS_FREE(jx, jy + 1));
+    boolean player_is_standing_on_valid_field =
+      (IS_WALKABLE_INSIDE(Feld[jx][jy]) ||
+       (IS_WALKABLE(Feld[jx][jy]) &&
+       !(element_info[Feld[jx][jy]].access_direction & MV_DOWN)));
+
+    if (field_under_player_is_free && !player_is_standing_on_valid_field)
       player->programmed_action = MV_DOWN;
   }
 }
@@ -7460,7 +8695,7 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
                          int dx, int dy, int real_dx, int real_dy)
 {
 #if 0
-  static int change_sides[4][2] =
+  static int trigger_sides[4][2] =
   {
     /* enter side        leave side */
     { CH_SIDE_RIGHT,   CH_SIDE_LEFT    },      /* moving left  */
@@ -7472,8 +8707,8 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
                        dx == +1 ? MV_RIGHT :
                        dy == -1 ? MV_UP :
                        dy == +1 ? MV_DOWN : MV_NO_MOVING);
-  int enter_side = change_sides[MV_DIR_BIT(move_direction)][0];
-  int leave_side = change_sides[MV_DIR_BIT(move_direction)][1];
+  int enter_side = trigger_sides[MV_DIR_BIT(move_direction)][0];
+  int leave_side = trigger_sides[MV_DIR_BIT(move_direction)][1];
 #endif
   int jx = player->jx, jy = player->jy;
   int new_jx = jx + dx, new_jy = jy + dy;
@@ -7504,7 +8739,7 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
   {
     if (element == EL_ACID && dx == 0 && dy == 1)
     {
-      SplashAcid(jx, jy);
+      SplashAcid(new_jx, new_jy);
       Feld[jx][jy] = EL_PLAYER_1;
       InitMovingField(jx, jy, MV_DOWN);
       Store[jx][jy] = EL_ACID;
@@ -7517,7 +8752,7 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
     return MF_MOVING;
   }
 
-  can_move = DigField(player, new_jx, new_jy, real_dx, real_dy, DF_DIG);
+  can_move = DigField(player, jx, jy, new_jx, new_jy, real_dx,real_dy, DF_DIG);
   if (can_move != MF_MOVING)
     return can_move;
 
@@ -7537,7 +8772,9 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
 
   player->step_counter++;
 
+#if 0
   player->drop_delay = 0;
+#endif
 
   PlayerVisit[jx][jy] = FrameCounter;
 
@@ -7546,18 +8783,17 @@ boolean MovePlayerOneStep(struct PlayerInfo *player,
 #if 0
   if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
   {
-    CheckTriggeredElementSideChange(jx, jy, Feld[jx][jy], leave_side,
-                                   CE_OTHER_GETS_LEFT);
-    CheckElementSideChange(jx, jy, Feld[jx][jy], leave_side,
-                          CE_LEFT_BY_PLAYER, -1);
+    CheckTriggeredElementChangeSide(jx, jy, Feld[jx][jy], CE_OTHER_GETS_LEFT,
+                                   leave_side);
+    CheckElementChangeSide(jx, jy, Feld[jx][jy], CE_LEFT_BY_PLAYER,leave_side);
   }
 
   if (IS_CUSTOM_ELEMENT(Feld[new_jx][new_jy]))
   {
-    CheckTriggeredElementSideChange(new_jx, new_jy, Feld[new_jx][new_jy],
-                                   enter_side, CE_OTHER_GETS_ENTERED);
-    CheckElementSideChange(new_jx, new_jy, Feld[new_jx][new_jy], enter_side,
-                          CE_ENTERED_BY_PLAYER, -1);
+    CheckTriggeredElementChangeSide(new_jx, new_jy, Feld[new_jx][new_jy],
+                                   CE_OTHER_GETS_ENTERED, enter_side);
+    CheckElementChangeSide(new_jx, new_jy, Feld[new_jx][new_jy],
+                          CE_ENTERED_BY_PLAYER, enter_side);
   }
 #endif
 
@@ -7597,9 +8833,16 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
       !tape.playing)
     return FALSE;
 #else
+
+#if 1
+  if (!FrameReached(&player->move_delay, player->move_delay_value))
+    return FALSE;
+#else
   if (!FrameReached(&player->move_delay, player->move_delay_value) &&
       !(tape.playing && tape.file_version < FILE_VERSION_2_0))
     return FALSE;
+#endif
+
 #endif
 
   /* remove the last programmed player action */
@@ -7632,7 +8875,7 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
     player->move_delay_value = original_move_delay_value;
   }
 
-  if (player->last_move_dir & (MV_LEFT | MV_RIGHT))
+  if (player->last_move_dir & MV_HORIZONTAL)
   {
     if (!(moved |= MovePlayerOneStep(player, 0, dy, dx, dy)))
       moved |= MovePlayerOneStep(player, dx, 0, dx, dy);
@@ -7664,7 +8907,7 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
     {
       if (jx != old_jx)                /* player has moved horizontally */
       {
-       if ((player->MovDir == MV_LEFT && scroll_x > jx - MIDPOSX + offset) ||
+       if ((player->MovDir == MV_LEFT  && scroll_x > jx - MIDPOSX + offset) ||
            (player->MovDir == MV_RIGHT && scroll_x < jx - MIDPOSX - offset))
          scroll_x = jx-MIDPOSX + (scroll_x < jx-MIDPOSX ? -offset : +offset);
 
@@ -7676,13 +8919,13 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
        scroll_x = old_scroll_x + SIGN(scroll_x - old_scroll_x);
 
        /* don't scroll against the player's moving direction */
-       if ((player->MovDir == MV_LEFT && scroll_x > old_scroll_x) ||
+       if ((player->MovDir == MV_LEFT  && scroll_x > old_scroll_x) ||
            (player->MovDir == MV_RIGHT && scroll_x < old_scroll_x))
          scroll_x = old_scroll_x;
       }
       else                     /* player has moved vertically */
       {
-       if ((player->MovDir == MV_UP && scroll_y > jy - MIDPOSY + offset) ||
+       if ((player->MovDir == MV_UP   && scroll_y > jy - MIDPOSY + offset) ||
            (player->MovDir == MV_DOWN && scroll_y < jy - MIDPOSY - offset))
          scroll_y = jy-MIDPOSY + (scroll_y < jy-MIDPOSY ? -offset : +offset);
 
@@ -7694,7 +8937,7 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
        scroll_y = old_scroll_y + SIGN(scroll_y - old_scroll_y);
 
        /* don't scroll against the player's moving direction */
-       if ((player->MovDir == MV_UP && scroll_y > old_scroll_y) ||
+       if ((player->MovDir == MV_UP   && scroll_y > old_scroll_y) ||
            (player->MovDir == MV_DOWN && scroll_y < old_scroll_y))
          scroll_y = old_scroll_y;
       }
@@ -7748,9 +8991,10 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
     player->is_dropping = FALSE;
 
 
-#if 1
+#if 0
+    /* !!! ENABLE THIS FOR OLD VERSIONS !!! */
     {
-      static int change_sides[4][2] =
+      static int trigger_sides[4][2] =
       {
        /* enter side           leave side */
        { CH_SIDE_RIGHT,        CH_SIDE_LEFT    },      /* moving left  */
@@ -7759,25 +9003,26 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
        { CH_SIDE_TOP,          CH_SIDE_BOTTOM  }       /* moving down  */
       };
       int move_direction = player->MovDir;
-      int enter_side = change_sides[MV_DIR_BIT(move_direction)][0];
-      int leave_side = change_sides[MV_DIR_BIT(move_direction)][1];
+      int enter_side = trigger_sides[MV_DIR_BIT(move_direction)][0];
+      int leave_side = trigger_sides[MV_DIR_BIT(move_direction)][1];
 
 #if 1
+      CheckTriggeredElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                       CE_OTHER_GETS_LEFT,
+                                       player->index_bit, leave_side);
+
       if (IS_CUSTOM_ELEMENT(Feld[old_jx][old_jy]))
-      {
-       CheckTriggeredElementSideChange(old_jx, old_jy, Feld[old_jx][old_jy],
-                                       leave_side, CE_OTHER_GETS_LEFT);
-       CheckElementSideChange(old_jx, old_jy, Feld[old_jx][old_jy],
-                              leave_side, CE_LEFT_BY_PLAYER, -1);
-      }
+       CheckElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                CE_LEFT_BY_PLAYER,
+                                player->index_bit, leave_side);
+
+      CheckTriggeredElementChangePlayer(jx, jy, Feld[jx][jy],
+                                       CE_OTHER_GETS_ENTERED,
+                                       player->index_bit, enter_side);
 
       if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
-      {
-       CheckTriggeredElementSideChange(jx, jy, Feld[jx][jy],
-                                       enter_side, CE_OTHER_GETS_ENTERED);
-       CheckElementSideChange(jx, jy, Feld[jx][jy],
-                              enter_side, CE_ENTERED_BY_PLAYER, -1);
-      }
+       CheckElementChangePlayer(jx, jy, Feld[jx][jy], CE_ENTERED_BY_PLAYER,
+                                player->index_bit, enter_side);
 #endif
 
     }
@@ -7787,7 +9032,7 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
   }
   else
   {
-    CheckGravityMovement(player);
+    CheckGravityMovementWhenNotMoving(player);
 
     /*
     player->last_move_dir = MV_NO_MOVING;
@@ -7827,6 +9072,7 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
 #if 0
     DrawPlayer(player);
 #endif
+
     return;
   }
   else if (!FrameReached(&player->actual_frame_counter, 1))
@@ -7835,7 +9081,8 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
   player->MovPos += (player->MovPos > 0 ? -1 : 1) * move_stepsize;
   player->GfxPos = move_stepsize * (player->MovPos / move_stepsize);
 
-  if (Feld[last_jx][last_jy] == EL_PLAYER_IS_LEAVING)
+  if (!player->block_last_field &&
+      Feld[last_jx][last_jy] == EL_PLAYER_IS_LEAVING)
     Feld[last_jx][last_jy] = EL_EMPTY;
 
   /* before DrawPlayer() to draw correct player graphic for this case */
@@ -7873,6 +9120,10 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
     }
 #endif
 
+    if (player->block_last_field &&
+       Feld[last_jx][last_jy] == EL_PLAYER_IS_LEAVING)
+      Feld[last_jx][last_jy] = EL_EMPTY;
+
     player->last_jx = jx;
     player->last_jy = jy;
 
@@ -7888,6 +9139,46 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
        player->LevelSolved = player->GameOver = TRUE;
     }
 
+#if 1
+    /* !!! ENABLE THIS FOR NEW VERSIONS !!! */
+    /* this breaks one level: "machine", level 000 */
+    {
+      static int trigger_sides[4][2] =
+      {
+       /* enter side           leave side */
+       { CH_SIDE_RIGHT,        CH_SIDE_LEFT    },      /* moving left  */
+       { CH_SIDE_LEFT,         CH_SIDE_RIGHT   },      /* moving right */
+       { CH_SIDE_BOTTOM,       CH_SIDE_TOP     },      /* moving up    */
+       { CH_SIDE_TOP,          CH_SIDE_BOTTOM  }       /* moving down  */
+      };
+      int move_direction = player->MovDir;
+      int enter_side = trigger_sides[MV_DIR_BIT(move_direction)][0];
+      int leave_side = trigger_sides[MV_DIR_BIT(move_direction)][1];
+      int old_jx = last_jx;
+      int old_jy = last_jy;
+
+#if 1
+      CheckTriggeredElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                       CE_OTHER_GETS_LEFT,
+                                       player->index_bit, leave_side);
+
+      if (IS_CUSTOM_ELEMENT(Feld[old_jx][old_jy]))
+       CheckElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                CE_LEFT_BY_PLAYER,
+                                player->index_bit, leave_side);
+
+      CheckTriggeredElementChangePlayer(jx, jy, Feld[jx][jy],
+                                       CE_OTHER_GETS_ENTERED,
+                                       player->index_bit, enter_side);
+
+      if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
+       CheckElementChangePlayer(jx, jy, Feld[jx][jy], CE_ENTERED_BY_PLAYER,
+                                player->index_bit, enter_side);
+#endif
+
+    }
+#endif
+
     if (game.engine_version >= VERSION_IDENT(3,0,7,0))
     {
       TestIfHeroTouchesBadThing(jx, jy);
@@ -7900,6 +9191,42 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
        RemoveHero(player);
     }
 
+    if (level.use_step_counter)
+    {
+      int i;
+
+      TimePlayed++;
+
+      for (i = 0; i < MAX_PLAYERS; i++)
+      {
+       struct PlayerInfo *player = &stored_player[i];
+
+       if (SHIELD_ON(player))
+       {
+         player->shield_normal_time_left--;
+
+         if (player->shield_deadly_time_left > 0)
+           player->shield_deadly_time_left--;
+       }
+      }
+
+      if (TimeLeft > 0)
+      {
+       TimeLeft--;
+
+       if (TimeLeft <= 10 && setup.time_limit)
+         PlaySoundStereo(SND_GAME_RUNNING_OUT_OF_TIME, SOUND_MIDDLE);
+
+       DrawGameValue_Time(TimeLeft);
+
+       if (!TimeLeft && setup.time_limit)
+         for (i = 0; i < MAX_PLAYERS; i++)
+           KillHero(&stored_player[i]);
+      }
+      else if (level.time == 0 && !AllPlayersGone) /* level w/o time limit */
+       DrawGameValue_Time(TimePlayed);
+    }
+
     if (tape.single_step && tape.recording && !tape.pausing &&
        !player->programmed_action)
       TapeTogglePause(TAPE_TOGGLE_AUTOMATIC);
@@ -7943,7 +9270,7 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
     { +1, 0 },
     { 0, +1 }
   };
-  static int change_sides[4][2] =
+  static int trigger_sides[4][2] =
   {
     /* center side       border side */
     { CH_SIDE_TOP,     CH_SIDE_BOTTOM  },      /* check top    */
@@ -7961,12 +9288,12 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
   int center_element = Feld[x][y];     /* should always be non-moving! */
   int i;
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int xx = x + xy[i][0];
     int yy = y + xy[i][1];
-    int center_side = change_sides[i][0];
-    int border_side = change_sides[i][1];
+    int center_side = trigger_sides[i][0];
+    int border_side = trigger_sides[i][1];
     int border_element;
 
     if (!IN_LEV_FIELD(xx, yy))
@@ -7974,6 +9301,8 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
 
     if (IS_PLAYER(x, y))
     {
+      struct PlayerInfo *player = PLAYERINFO(x, y);
+
       if (game.engine_version < VERSION_IDENT(3,0,7,0))
        border_element = Feld[xx][yy];          /* may be moving! */
       else if (!IS_MOVING(xx, yy) && !IS_BLOCKED(xx, yy))
@@ -7983,25 +9312,27 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
       else
        continue;               /* center and border element do not touch */
 
-      CheckTriggeredElementSideChange(xx, yy, border_element, border_side,
-                                     CE_OTHER_GETS_TOUCHED);
-      CheckElementSideChange(xx, yy, border_element, border_side,
-                            CE_TOUCHED_BY_PLAYER, -1);
+      CheckTriggeredElementChangePlayer(xx, yy, border_element,
+                                       CE_OTHER_GETS_TOUCHED,
+                                       player->index_bit, border_side);
+      CheckElementChangePlayer(xx, yy, border_element, CE_TOUCHED_BY_PLAYER,
+                              player->index_bit, border_side);
     }
     else if (IS_PLAYER(xx, yy))
     {
+      struct PlayerInfo *player = PLAYERINFO(xx, yy);
+
       if (game.engine_version >= VERSION_IDENT(3,0,7,0))
       {
-       struct PlayerInfo *player = PLAYERINFO(xx, yy);
-
        if (player->MovPos != 0 && !(player->MovDir & touch_dir[i]))
          continue;             /* center and border element do not touch */
       }
 
-      CheckTriggeredElementSideChange(x, y, center_element, center_side,
-                                     CE_OTHER_GETS_TOUCHED);
-      CheckElementSideChange(x, y, center_element, center_side,
-                            CE_TOUCHED_BY_PLAYER, -1);
+      CheckTriggeredElementChangePlayer(x, y, center_element,
+                                       CE_OTHER_GETS_TOUCHED,
+                                       player->index_bit, center_side);
+      CheckElementChangePlayer(x, y, center_element, CE_TOUCHED_BY_PLAYER,
+                              player->index_bit, center_side);
 
       break;
     }
@@ -8017,7 +9348,7 @@ void TestIfElementTouchesCustomElement(int x, int y)
     { +1, 0 },
     { 0, +1 }
   };
-  static int change_sides[4][2] =
+  static int trigger_sides[4][2] =
   {
     /* center side     border side */
     { CH_SIDE_TOP,     CH_SIDE_BOTTOM  },      /* check top    */
@@ -8035,14 +9366,15 @@ void TestIfElementTouchesCustomElement(int x, int y)
   boolean change_center_element = FALSE;
   int center_element_change_page = 0;
   int center_element = Feld[x][y];     /* should always be non-moving! */
+  int border_trigger_element;
   int i, j;
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int xx = x + xy[i][0];
     int yy = y + xy[i][1];
-    int center_side = change_sides[i][0];
-    int border_side = change_sides[i][1];
+    int center_side = trigger_sides[i][0];
+    int border_side = trigger_sides[i][1];
     int border_element;
 
     if (!IN_LEV_FIELD(xx, yy))
@@ -8069,11 +9401,17 @@ void TestIfElementTouchesCustomElement(int x, int y)
 
        if (change->can_change &&
            change->events & CH_EVENT_BIT(CE_OTHER_IS_TOUCHING) &&
-           change->sides & border_side &&
-           change->trigger_element == border_element)
+           change->trigger_side & border_side &&
+#if 1
+           IS_EQUAL_OR_IN_GROUP(border_element, change->trigger_element)
+#else
+           change->trigger_element == border_element
+#endif
+           )
        {
          change_center_element = TRUE;
          center_element_change_page = j;
+         border_trigger_element = border_element;
 
          break;
        }
@@ -8091,10 +9429,19 @@ void TestIfElementTouchesCustomElement(int x, int y)
 
        if (change->can_change &&
            change->events & CH_EVENT_BIT(CE_OTHER_IS_TOUCHING) &&
-           change->sides & center_side &&
-           change->trigger_element == center_element)
+           change->trigger_side & center_side &&
+#if 1
+           IS_EQUAL_OR_IN_GROUP(center_element, change->trigger_element)
+#else
+           change->trigger_element == center_element
+#endif
+           )
        {
-         CheckElementSideChange(xx, yy, border_element, CH_SIDE_ANY,
+#if 0
+         printf("::: border_element %d, %d\n", x, y);
+#endif
+
+         CheckElementChangePage(xx, yy, border_element, center_element,
                                 CE_OTHER_IS_TOUCHING, j);
          break;
        }
@@ -8103,8 +9450,14 @@ void TestIfElementTouchesCustomElement(int x, int y)
   }
 
   if (change_center_element)
-    CheckElementSideChange(x, y, center_element, CH_SIDE_ANY,
+  {
+#if 0
+    printf("::: center_element %d, %d\n", x, y);
+#endif
+
+    CheckElementChangePage(x, y, center_element, border_trigger_element,
                           CE_OTHER_IS_TOUCHING, center_element_change_page);
+  }
 }
 
 void TestIfElementHitsCustomElement(int x, int y, int direction)
@@ -8113,6 +9466,7 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
   int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
   int hitx = x + dx, hity = y + dy;
   int hitting_element = Feld[x][y];
+  int touched_element;
 #if 0
   boolean object_hit = (IN_LEV_FIELD(hitx, hity) &&
                        !IS_FREE(hitx, hity) &&
@@ -8129,23 +9483,20 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
     return;
 #endif
 
-  CheckElementSideChange(x, y, hitting_element,
-                        direction, CE_HITTING_SOMETHING, -1);
+  touched_element = (IN_LEV_FIELD(hitx, hity) ?
+                    MovingOrBlocked2Element(hitx, hity) : EL_STEELWALL);
+
+  CheckElementChangeSide(x, y, hitting_element, touched_element,
+                        CE_HITTING_SOMETHING, direction);
 
   if (IN_LEV_FIELD(hitx, hity))
   {
-    static int opposite_directions[] =
-    {
-      MV_RIGHT,
-      MV_LEFT,
-      MV_DOWN,
-      MV_UP
-    };
-    int move_dir_bit = MV_DIR_BIT(direction);
-    int opposite_direction = opposite_directions[move_dir_bit];
+    int opposite_direction = MV_DIR_OPPOSITE(direction);
     int hitting_side = direction;
     int touched_side = opposite_direction;
+#if 0
     int touched_element = MovingOrBlocked2Element(hitx, hity);
+#endif
 #if 1
     boolean object_hit = (!IS_MOVING(hitx, hity) ||
                          MovDir[hitx][hity] != direction ||
@@ -8158,8 +9509,8 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
     {
       int i;
 
-      CheckElementSideChange(hitx, hity, touched_element,
-                            opposite_direction, CE_HIT_BY_SOMETHING, -1);
+      CheckElementChangeSide(hitx, hity, touched_element, hitting_element,
+                            CE_HIT_BY_SOMETHING, opposite_direction);
 
       if (IS_CUSTOM_ELEMENT(hitting_element) &&
          HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_HITTING))
@@ -8171,11 +9522,17 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
 
          if (change->can_change &&
              change->events & CH_EVENT_BIT(CE_OTHER_IS_HITTING) &&
-             change->sides & touched_side &&
-             change->trigger_element == touched_element)
+             change->trigger_side & touched_side &&
+         
+#if 1
+             IS_EQUAL_OR_IN_GROUP(touched_element, change->trigger_element)
+#else
+             change->trigger_element == touched_element
+#endif
+             )
          {
-           CheckElementSideChange(x, y, hitting_element,
-                                  CH_SIDE_ANY, CE_OTHER_IS_HITTING, i);
+           CheckElementChangePage(x, y, hitting_element, touched_element,
+                                  CE_OTHER_IS_HITTING, i);
            break;
          }
        }
@@ -8191,11 +9548,123 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
 
          if (change->can_change &&
              change->events & CH_EVENT_BIT(CE_OTHER_GETS_HIT) &&
-             change->sides & hitting_side &&
-             change->trigger_element == hitting_element)
+             change->trigger_side & hitting_side &&
+#if 1
+             IS_EQUAL_OR_IN_GROUP(hitting_element, change->trigger_element)
+#else
+             change->trigger_element == hitting_element
+#endif
+             )
+         {
+           CheckElementChangePage(hitx, hity, touched_element,
+                                  hitting_element, CE_OTHER_GETS_HIT, i);
+           break;
+         }
+       }
+      }
+    }
+  }
+}
+
+#if 0
+void TestIfElementSmashesCustomElement(int x, int y, int direction)
+{
+  int dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
+  int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
+  int hitx = x + dx, hity = y + dy;
+  int hitting_element = Feld[x][y];
+  int touched_element;
+#if 0
+  boolean object_hit = (IN_LEV_FIELD(hitx, hity) &&
+                       !IS_FREE(hitx, hity) &&
+                       (!IS_MOVING(hitx, hity) ||
+                        MovDir[hitx][hity] != direction ||
+                        ABS(MovPos[hitx][hity]) <= TILEY / 2));
+#endif
+
+  if (IN_LEV_FIELD(hitx, hity) && IS_FREE(hitx, hity))
+    return;
+
+#if 0
+  if (IN_LEV_FIELD(hitx, hity) && !object_hit)
+    return;
+#endif
+
+  touched_element = (IN_LEV_FIELD(hitx, hity) ?
+                    MovingOrBlocked2Element(hitx, hity) : EL_STEELWALL);
+
+  CheckElementChangeSide(x, y, hitting_element, touched_element,
+                        EP_CAN_SMASH_EVERYTHING, direction);
+
+  if (IN_LEV_FIELD(hitx, hity))
+  {
+    int opposite_direction = MV_DIR_OPPOSITE(direction);
+    int hitting_side = direction;
+    int touched_side = opposite_direction;
+#if 0
+    int touched_element = MovingOrBlocked2Element(hitx, hity);
+#endif
+#if 1
+    boolean object_hit = (!IS_MOVING(hitx, hity) ||
+                         MovDir[hitx][hity] != direction ||
+                         ABS(MovPos[hitx][hity]) <= TILEY / 2);
+
+    object_hit = TRUE;
+#endif
+
+    if (object_hit)
+    {
+      int i;
+
+      CheckElementChangeSide(hitx, hity, touched_element, hitting_element,
+                            CE_SMASHED_BY_SOMETHING, opposite_direction);
+
+      if (IS_CUSTOM_ELEMENT(hitting_element) &&
+         HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_SMASHING))
+      {
+       for (i = 0; i < element_info[hitting_element].num_change_pages; i++)
+       {
+         struct ElementChangeInfo *change =
+           &element_info[hitting_element].change_page[i];
+
+         if (change->can_change &&
+             change->events & CH_EVENT_BIT(CE_OTHER_IS_SMASHING) &&
+             change->trigger_side & touched_side &&
+         
+#if 1
+             IS_EQUAL_OR_IN_GROUP(touched_element, change->trigger_element)
+#else
+             change->trigger_element == touched_element
+#endif
+             )
          {
-           CheckElementSideChange(hitx, hity, touched_element,
-                                  CH_SIDE_ANY, CE_OTHER_GETS_HIT, i);
+           CheckElementChangePage(x, y, hitting_element, touched_element,
+                                  CE_OTHER_IS_SMASHING, i);
+           break;
+         }
+       }
+      }
+
+      if (IS_CUSTOM_ELEMENT(touched_element) &&
+         HAS_ANY_CHANGE_EVENT(touched_element, CE_OTHER_GETS_SMASHED))
+      {
+       for (i = 0; i < element_info[touched_element].num_change_pages; i++)
+       {
+         struct ElementChangeInfo *change =
+           &element_info[touched_element].change_page[i];
+
+         if (change->can_change &&
+             change->events & CH_EVENT_BIT(CE_OTHER_GETS_SMASHED) &&
+             change->trigger_side & hitting_side &&
+#if 1
+             IS_EQUAL_OR_IN_GROUP(hitting_element, change->trigger_element)
+#else
+             change->trigger_element == hitting_element
+#endif
+             )
+         {
+           CheckElementChangePage(hitx, hity, touched_element,
+                                  hitting_element, CE_OTHER_GETS_SMASHED, i);
            break;
          }
        }
@@ -8203,6 +9672,7 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
     }
   }
 }
+#endif
 
 void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
 {
@@ -8222,7 +9692,7 @@ void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
     MV_DOWN
   };
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int test_x, test_y, test_move_dir, test_element;
 
@@ -8260,7 +9730,7 @@ void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
 
       if (player->shield_deadly_time_left > 0)
        Bang(kill_x, kill_y);
-      else if (!PLAYER_PROTECTED(good_x, good_y))
+      else if (!PLAYER_ENEMY_PROTECTED(good_x, good_y))
        KillHero(player);
     }
     else
@@ -8297,7 +9767,7 @@ void TestIfBadThingHitsGoodThing(int bad_x, int bad_y, int bad_move_dir)
   if (bad_element == EL_EXPLOSION)     /* skip just exploding bad things */
     return;
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int test_x, test_y, test_move_dir, test_element;
 
@@ -8352,7 +9822,7 @@ void TestIfBadThingHitsGoodThing(int bad_x, int bad_y, int bad_move_dir)
 
       if (player->shield_deadly_time_left > 0)
        Bang(bad_x, bad_y);
-      else if (!PLAYER_PROTECTED(kill_x, kill_y))
+      else if (!PLAYER_ENEMY_PROTECTED(kill_x, kill_y))
        KillHero(player);
     }
     else
@@ -8401,7 +9871,7 @@ void TestIfBadThingTouchesOtherBadThing(int bad_x, int bad_y)
     { 0, +1 }
   };
 
-  for (i = 0; i < 4; i++)
+  for (i = 0; i < NUM_DIRECTIONS; i++)
   {
     int x, y, element;
 
@@ -8442,9 +9912,15 @@ void KillHero(struct PlayerInfo *player)
   BuryHero(player);
 }
 
-static void KillHeroUnlessProtected(int x, int y)
+static void KillHeroUnlessEnemyProtected(int x, int y)
+{
+  if (!PLAYER_ENEMY_PROTECTED(x, y))
+    KillHero(PLAYERINFO(x, y));
+}
+
+static void KillHeroUnlessExplosionProtected(int x, int y)
 {
-  if (!PLAYER_PROTECTED(x, y))
+  if (!PLAYER_EXPLOSION_PROTECTED(x, y))
     KillHero(PLAYERINFO(x, y));
 }
 
@@ -8526,24 +10002,29 @@ static boolean checkDiagonalPushing(struct PlayerInfo *player,
 */
 
 int DigField(struct PlayerInfo *player,
-            int x, int y, int real_dx, int real_dy, int mode)
+            int oldx, int oldy, int x, int y,
+            int real_dx, int real_dy, int mode)
 {
-  static int change_sides[4] =
+  static int trigger_sides[4] =
   {
     CH_SIDE_RIGHT,     /* moving left  */
     CH_SIDE_LEFT,      /* moving right */
     CH_SIDE_BOTTOM,    /* moving up    */
     CH_SIDE_TOP,       /* moving down  */
   };
+#if 0
   boolean use_spring_bug = (game.engine_version < VERSION_IDENT(2,2,0,0));
-  int jx = player->jx, jy = player->jy;
+#endif
+  int jx = oldx, jy = oldy;
   int dx = x - jx, dy = y - jy;
   int nextx = x + dx, nexty = y + dy;
   int move_direction = (dx == -1 ? MV_LEFT :
                        dx == +1 ? MV_RIGHT :
                        dy == -1 ? MV_UP :
                        dy == +1 ? MV_DOWN : MV_NO_MOVING);
-  int dig_side = change_sides[MV_DIR_BIT(move_direction)];
+  int opposite_direction = MV_DIR_OPPOSITE(move_direction);
+  int dig_side = trigger_sides[MV_DIR_BIT(move_direction)];
+  int old_element = Feld[jx][jy];
   int element;
 
   if (player->MovPos == 0)
@@ -8566,6 +10047,8 @@ int DigField(struct PlayerInfo *player,
   if (IS_MOVING(x, y) || IS_PLAYER(x, y))
     return MF_NO_ACTION;
 
+#if 0
+
 #if 0
   if (IS_TUBE(Feld[jx][jy]) || IS_TUBE(Back[jx][jy]))
 #else
@@ -8602,6 +10085,17 @@ int DigField(struct PlayerInfo *player,
       return MF_NO_ACTION;     /* tube has no opening in this direction */
   }
 
+#else
+
+  if (IS_TUBE(Back[jx][jy]) && game.engine_version >= VERSION_IDENT(2,2,0,0))
+    old_element = Back[jx][jy];
+
+#endif
+
+  if (IS_WALKABLE(old_element) &&
+      !(element_info[old_element].access_direction & move_direction))
+    return MF_NO_ACTION;       /* field has no opening in this direction */
+
   element = Feld[x][y];
 
   if (mode == DF_SNAP && !IS_SNAPPABLE(element) &&
@@ -8621,6 +10115,10 @@ int DigField(struct PlayerInfo *player,
     case EL_SP_GRAVITY_PORT_RIGHT:
     case EL_SP_GRAVITY_PORT_UP:
     case EL_SP_GRAVITY_PORT_DOWN:
+#if 1
+      if (!canEnterSupaplexPort(x, y, dx, dy))
+       return MF_NO_ACTION;
+#else
       if ((dx == -1 &&
           element != EL_SP_PORT_LEFT &&
           element != EL_SP_GRAVITY_PORT_LEFT &&
@@ -8644,6 +10142,7 @@ int DigField(struct PlayerInfo *player,
          !IN_LEV_FIELD(nextx, nexty) ||
          !IS_FREE(nextx, nexty))
        return MF_NO_ACTION;
+#endif
 
       if (element == EL_SP_GRAVITY_PORT_LEFT ||
          element == EL_SP_GRAVITY_PORT_RIGHT ||
@@ -8666,9 +10165,14 @@ int DigField(struct PlayerInfo *player,
       DOUBLE_PLAYER_SPEED(player);
 #endif
 
+#if 0
+      printf("::: passing port %d,%d [%d]\n", x, y, FrameCounter);
+#endif
+
       PlayLevelSound(x, y, SND_CLASS_SP_PORT_PASSING);
       break;
 
+#if 0
     case EL_TUBE_ANY:
     case EL_TUBE_VERTICAL:
     case EL_TUBE_HORIZONTAL:
@@ -8711,6 +10215,7 @@ int DigField(struct PlayerInfo *player,
        PlayLevelSound(x, y, SND_CLASS_TUBE_WALKING);
       }
       break;
+#endif
 
     default:
 
@@ -8718,6 +10223,9 @@ int DigField(struct PlayerInfo *player,
       {
        int sound_action = ACTION_WALKING;
 
+       if (!(element_info[element].access_direction & opposite_direction))
+         return MF_NO_ACTION;  /* field not accessible from this direction */
+
        if (element >= EL_GATE_1 && element <= EL_GATE_4)
        {
          if (!player->key[element - EL_GATE_1])
@@ -8752,6 +10260,10 @@ int DigField(struct PlayerInfo *player,
        if (!IN_LEV_FIELD(nextx, nexty) || !IS_FREE(nextx, nexty))
          return MF_NO_ACTION;
 
+       if (IS_CUSTOM_ELEMENT(element) &&
+           !(element_info[element].access_direction & opposite_direction))
+         return MF_NO_ACTION;  /* field not accessible from this direction */
+
 #if 1
        if (CAN_MOVE(element))  /* only fixed elements can be passed! */
          return MF_NO_ACTION;
@@ -8804,7 +10316,8 @@ int DigField(struct PlayerInfo *player,
 
        PlayLevelSoundElementAction(x, y, element, ACTION_DIGGING);
 
-       CheckTriggeredElementChange(x, y, element, CE_OTHER_GETS_DIGGED);
+       CheckTriggeredElementChangePlayer(x, y, element, CE_OTHER_GETS_DIGGED,
+                                         player->index_bit, dig_side);
 
 #if 1
        if (mode == DF_SNAP)
@@ -8828,7 +10341,7 @@ int DigField(struct PlayerInfo *player,
        else if (element == EL_EXTRA_TIME && level.time > 0)
        {
          TimeLeft += 10;
-         DrawText(DX_TIME, DY_TIME, int2str(TimeLeft, 3), FONT_TEXT_2);
+         DrawGameValue_Time(TimeLeft);
        }
        else if (element == EL_SHIELD_NORMAL || element == EL_SHIELD_DEADLY)
        {
@@ -8841,8 +10354,7 @@ int DigField(struct PlayerInfo *player,
          if (player->inventory_size < MAX_INVENTORY_SIZE)
            player->inventory_element[player->inventory_size++] = element;
 
-         DrawText(DX_DYNAMITE, DY_DYNAMITE,
-                  int2str(local_player->inventory_size, 3), FONT_TEXT_2);
+         DrawGameValue_Dynamite(local_player->inventory_size);
        }
        else if (element == EL_DYNABOMB_INCREASE_NUMBER)
        {
@@ -8865,8 +10377,8 @@ int DigField(struct PlayerInfo *player,
 
          player->key[key_nr] = TRUE;
 
-         DrawMiniGraphicExt(drawto, DX_KEYS + key_nr * MINI_TILEX, DY_KEYS,
-                            el2edimg(EL_KEY_1 + key_nr));
+         DrawGameValue_Keys(player);
+
          redraw_mask |= REDRAW_DOOR_1;
        }
        else if (IS_ENVELOPE(element))
@@ -8881,12 +10393,14 @@ int DigField(struct PlayerInfo *player,
        {
          int i;
 
-         for (i = 0; i < element_info[element].collect_count; i++)
-           if (player->inventory_size < MAX_INVENTORY_SIZE)
-             player->inventory_element[player->inventory_size++] = element;
+         if (element_info[element].collect_count == 0)
+           player->inventory_infinite_element = element;
+         else
+           for (i = 0; i < element_info[element].collect_count; i++)
+             if (player->inventory_size < MAX_INVENTORY_SIZE)
+               player->inventory_element[player->inventory_size++] = element;
 
-         DrawText(DX_DYNAMITE, DY_DYNAMITE,
-                  int2str(local_player->inventory_size, 3), FONT_TEXT_2);
+         DrawGameValue_Dynamite(local_player->inventory_size);
        }
        else if (element_info[element].collect_count > 0)
        {
@@ -8895,14 +10409,15 @@ int DigField(struct PlayerInfo *player,
          if (local_player->gems_still_needed < 0)
            local_player->gems_still_needed = 0;
 
-         DrawText(DX_EMERALDS, DY_EMERALDS,
-                  int2str(local_player->gems_still_needed, 3), FONT_TEXT_2);
+         DrawGameValue_Emeralds(local_player->gems_still_needed);
        }
 
        RaiseScoreElement(element);
        PlayLevelSoundElementAction(x, y, element, ACTION_COLLECTING);
 
-       CheckTriggeredElementChange(x, y, element, CE_OTHER_GETS_COLLECTED);
+       CheckTriggeredElementChangePlayer(x, y, element,
+                                         CE_OTHER_GETS_COLLECTED,
+                                         player->index_bit, dig_side);
 
 #if 1
        if (mode == DF_SNAP)
@@ -8920,7 +10435,7 @@ int DigField(struct PlayerInfo *player,
          return MF_NO_ACTION;
 
        if (CAN_FALL(element) && IN_LEV_FIELD(x, y + 1) && IS_FREE(x, y + 1) &&
-           !(element == EL_SPRING && use_spring_bug))
+           !(element == EL_SPRING && level.use_spring_bug))
          return MF_NO_ACTION;
 
 #if 1
@@ -9058,10 +10573,10 @@ int DigField(struct PlayerInfo *player,
        else
          player->push_delay_value = -1;        /* get new value later */
 
-       CheckTriggeredElementSideChange(x, y, element, dig_side,
-                                       CE_OTHER_GETS_PUSHED);
-       CheckElementSideChange(x, y, element, dig_side,
-                              CE_PUSHED_BY_PLAYER, -1);
+       CheckTriggeredElementChangePlayer(x, y, element, CE_OTHER_GETS_PUSHED,
+                                         player->index_bit, dig_side);
+       CheckElementChangePlayer(x, y, element, CE_PUSHED_BY_PLAYER,
+                                player->index_bit, dig_side);
 
        break;
       }
@@ -9146,7 +10661,7 @@ int DigField(struct PlayerInfo *player,
        {
          Feld[x][y] = EL_TIME_ORB_EMPTY;
          TimeLeft += 10;
-         DrawText(DX_TIME, DY_TIME, int2str(TimeLeft, 3), FONT_TEXT_2);
+         DrawGameValue_Time(TimeLeft);
 
          DrawLevelField(x, y);
 
@@ -9165,15 +10680,17 @@ int DigField(struct PlayerInfo *player,
          player->switch_x = x;
          player->switch_y = y;
 
-         CheckTriggeredElementSideChange(x, y, element, dig_side,
-                                         CE_OTHER_IS_SWITCHING);
-         CheckElementSideChange(x, y, element, dig_side, CE_SWITCHED, -1);
+         CheckTriggeredElementChangePlayer(x, y, element,
+                                           CE_OTHER_IS_SWITCHING,
+                                           player->index_bit, dig_side);
+         CheckElementChangePlayer(x, y, element, CE_SWITCHED,
+                                  player->index_bit, dig_side);
        }
 
-       CheckTriggeredElementSideChange(x, y, element, dig_side,
-                                       CE_OTHER_GETS_PRESSED);
-       CheckElementSideChange(x, y, element, dig_side,
-                              CE_PRESSED_BY_PLAYER, -1);
+       CheckTriggeredElementChangePlayer(x, y, element, CE_OTHER_GETS_PRESSED,
+                                         player->index_bit, dig_side);
+       CheckElementChangePlayer(x, y, element, CE_PRESSED_BY_PLAYER,
+                                player->index_bit, dig_side);
       }
 
       return MF_NO_ACTION;
@@ -9196,8 +10713,13 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
                        dy == -1 ? MV_UP :
                        dy == +1 ? MV_DOWN : MV_NO_MOVING);
 
+#if 0
+  if (player->MovPos)
+    return FALSE;
+#else
   if (player->MovPos && game.engine_version >= VERSION_IDENT(2,2,0,0))
     return FALSE;
+#endif
 
   if (!player->active || !IN_LEV_FIELD(x, y))
     return FALSE;
@@ -9238,7 +10760,7 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
 
   player->is_dropping = FALSE;
 
-  if (DigField(player, x, y, 0, 0, DF_SNAP) == MF_NO_ACTION)
+  if (DigField(player, jx, jy, x, y, 0, 0, DF_SNAP) == MF_NO_ACTION)
     return FALSE;
 
   player->is_snapping = TRUE;
@@ -9260,27 +10782,55 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
 
 boolean DropElement(struct PlayerInfo *player)
 {
+  static int trigger_sides[4] =
+  {
+    CH_SIDE_LEFT,      /* dropping left  */
+    CH_SIDE_RIGHT,     /* dropping right */
+    CH_SIDE_TOP,       /* dropping up    */
+    CH_SIDE_BOTTOM,    /* dropping down  */
+  };
   int jx = player->jx, jy = player->jy;
+  int drop_direction = player->MovDir;
+  int drop_side = trigger_sides[MV_DIR_BIT(drop_direction)];
   int old_element = Feld[jx][jy];
-  int new_element;
+  int drop_element = (player->inventory_size > 0 ?
+                     player->inventory_element[player->inventory_size - 1] :
+                     player->inventory_infinite_element != EL_UNDEFINED ?
+                     player->inventory_infinite_element :
+                     player->dynabombs_left > 0 ?
+                     EL_DYNABOMB_PLAYER_1_ACTIVE + player->index_nr :
+                     EL_UNDEFINED);
+  int new_element = drop_element;      /* default: element does not change */
 
   /* check if player is active, not moving and ready to drop */
   if (!player->active || player->MovPos || player->drop_delay > 0)
     return FALSE;
 
   /* check if player has anything that can be dropped */
-  if (player->inventory_size == 0 && player->dynabombs_left == 0)
+#if 1
+  if (new_element == EL_UNDEFINED)
+    return FALSE;
+#else
+  if (player->inventory_size == 0 &&
+      player->inventory_infinite_element == EL_UNDEFINED &&
+      player->dynabombs_left == 0)
     return FALSE;
+#endif
 
   /* check if anything can be dropped at the current position */
   if (IS_ACTIVE_BOMB(old_element) || old_element == EL_EXPLOSION)
     return FALSE;
 
   /* collected custom elements can only be dropped on empty fields */
+#if 1
+  if (IS_CUSTOM_ELEMENT(new_element) && old_element != EL_EMPTY)
+    return FALSE;
+#else
   if (player->inventory_size > 0 &&
       IS_CUSTOM_ELEMENT(player->inventory_element[player->inventory_size - 1])
       && old_element != EL_EMPTY)
     return FALSE;
+#endif
 
   if (old_element != EL_EMPTY)
     Back[jx][jy] = old_element;                /* store old element on this field */
@@ -9288,35 +10838,52 @@ boolean DropElement(struct PlayerInfo *player)
   ResetGfxAnimation(jx, jy);
   ResetRandomAnimationValue(jx, jy);
 
-  if (player->inventory_size > 0)
+  if (player->inventory_size > 0 ||
+      player->inventory_infinite_element != EL_UNDEFINED)
   {
-    player->inventory_size--;
-    new_element = player->inventory_element[player->inventory_size];
+    if (player->inventory_size > 0)
+    {
+      player->inventory_size--;
 
-    if (new_element == EL_DYNAMITE)
-      new_element = EL_DYNAMITE_ACTIVE;
-    else if (new_element == EL_SP_DISK_RED)
-      new_element = EL_SP_DISK_RED_ACTIVE;
+#if 0
+      new_element = player->inventory_element[player->inventory_size];
+#endif
 
-    Feld[jx][jy] = new_element;
+      DrawGameValue_Dynamite(local_player->inventory_size);
 
-    DrawText(DX_DYNAMITE, DY_DYNAMITE,
-            int2str(local_player->inventory_size, 3), FONT_TEXT_2);
+      if (new_element == EL_DYNAMITE)
+       new_element = EL_DYNAMITE_ACTIVE;
+      else if (new_element == EL_SP_DISK_RED)
+       new_element = EL_SP_DISK_RED_ACTIVE;
+    }
+
+    Feld[jx][jy] = new_element;
 
     if (IN_SCR_FIELD(SCREENX(jx), SCREENY(jy)))
       DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), el2img(Feld[jx][jy]), 0);
 
     PlayLevelSoundAction(jx, jy, ACTION_DROPPING);
 
-    CheckTriggeredElementChange(jx, jy, new_element, CE_OTHER_GETS_DROPPED);
-    CheckElementChange(jx, jy, new_element, CE_DROPPED_BY_PLAYER);
+#if 1
+    /* needed if previous element just changed to "empty" in the last frame */
+    Changed[jx][jy] = 0;               /* allow another change */
+#endif
+
+    CheckTriggeredElementChangePlayer(jx, jy, new_element,
+                                     CE_OTHER_GETS_DROPPED,
+                                     player->index_bit, drop_side);
+    CheckElementChangePlayer(jx, jy, new_element, CE_DROPPED_BY_PLAYER,
+                            player->index_bit, drop_side);
 
     TestIfElementTouchesCustomElement(jx, jy);
   }
   else         /* player is dropping a dyna bomb */
   {
     player->dynabombs_left--;
+
+#if 0
     new_element = EL_DYNABOMB_PLAYER_1_ACTIVE + player->index_nr;
+#endif
 
     Feld[jx][jy] = new_element;
 
@@ -9332,20 +10899,26 @@ boolean DropElement(struct PlayerInfo *player)
 
   if (Feld[jx][jy] == new_element)     /* uninitialized unless CE change */
   {
+#if 1
+    InitField_WithBug1(jx, jy, FALSE);
+#else
     InitField(jx, jy, FALSE);
     if (CAN_MOVE(Feld[jx][jy]))
       InitMovDir(jx, jy);
+#endif
   }
 
-  new_element = Feld[jx][jy];
+  new_element = Feld[jx][jy];          /* element might have changed */
 
   if (IS_CUSTOM_ELEMENT(new_element) && CAN_MOVE(new_element) &&
       element_info[new_element].move_pattern == MV_WHEN_DROPPED)
   {
+#if 0
     int move_stepsize = element_info[new_element].move_stepsize;
+#endif
     int direction, dx, dy, nextx, nexty;
 
-    if (element_info[new_element].move_direction_initial == MV_NO_MOVING)
+    if (element_info[new_element].move_direction_initial == MV_START_AUTOMATIC)
       MovDir[jx][jy] = player->MovDir;
 
     direction = MovDir[jx][jy];
@@ -9365,23 +10938,29 @@ boolean DropElement(struct PlayerInfo *player)
     }
     else
     {
-      Changed[jx][jy] = 0;            /* allow another change */
+      Changed[jx][jy] = 0;             /* allow another change */
 
 #if 1
       TestIfElementHitsCustomElement(jx, jy, direction);
 #else
-      CheckElementSideChange(jx, jy, new_element,
-                            direction, CE_HITTING_SOMETHING, -1);
+      CheckElementChangeSide(jx, jy, new_element, touched_element,
+                            CE_HITTING_SOMETHING, direction);
 #endif
     }
 
+#if 0
     player->drop_delay = 2 * TILEX / move_stepsize + 1;
+#endif
   }
 
 #if 0
   player->drop_delay = 8 + 8 + 8;
 #endif
 
+#if 1
+  player->drop_delay = GET_NEW_DROP_DELAY(drop_element);
+#endif
+
 #endif
 
   player->is_dropping = TRUE;
@@ -9511,7 +11090,8 @@ static void PlayLevelMusic()
 void RaiseScore(int value)
 {
   local_player->score += value;
-  DrawText(DX_SCORE, DY_SCORE, int2str(local_player->score, 5), FONT_TEXT_2);
+
+  DrawGameValue_Score(local_player->score);
 }
 
 void RaiseScoreElement(int element)
@@ -9604,7 +11184,19 @@ void RequestQuitGame(boolean ask_if_really_quit)
   }
   else
   {
+
+#if 1
+    if (tape.playing && tape.deactivate_display)
+      TapeDeactivateDisplayOff(TRUE);
+#endif
+
     OpenDoor(DOOR_OPEN_1 | DOOR_COPY_BACK);
+
+#if 1
+    if (tape.playing && tape.deactivate_display)
+      TapeDeactivateDisplayOn();
+#endif
+
   }
 }