rnd-20040314-1-src
[rocksndiamonds.git] / src / game.c
index cd919a2b3406687e2110a8c10123d032718c662f..0e84aa846bfd0dcc5fb94defd73f147919012f1b 100644 (file)
 #define GET_MAX_MOVE_DELAY(e)  (   (element_info[e].move_delay_fixed) + \
                                    (element_info[e].move_delay_random))
 
-#define ELEMENT_CAN_ENTER_FIELD_BASE(e, x, y, condition)               \
+#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)))
 
-#if 0
-#define ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, 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_PLAYER(x, y) &&             \
                                         !PLAYER_ENEMY_PROTECTED(x, y))))
-#else
+
+#if 0
 #define ELEMENT_CAN_ENTER_FIELD_GENERIC(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_PLAYER(x, y) &&             \
                                         !PLAYER_ENEMY_PROTECTED(x, y))))
 #endif
 
-#define ELEMENT_CAN_ENTER_FIELD_GENERIC_2(x, y, condition)             \
-               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (condition)))
-
 #define ELEMENT_CAN_ENTER_FIELD(e, x, y)                               \
-       ELEMENT_CAN_ENTER_FIELD_GENERIC(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))
+       ELEMENT_CAN_ENTER_FIELD_BASE_4(e, x, y, 0)
 
-#define ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(x, y)                                \
-       ELEMENT_CAN_ENTER_FIELD_GENERIC_2(x, y, (Feld[x][y] == EL_ACID))
+#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))
-#else
-#define ENEMY_CAN_ENTER_FIELD(e, x, y) ELEMENT_CAN_ENTER_FIELD_BASE(e, x, y, 0)
 #endif
 
-#define YAMYAM_CAN_ENTER_FIELD(x, y)                                   \
+#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 MOLE_CAN_ENTER_FIELD(e, x, y, condition)                       \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, (condition))
+
+#define SPRING_CAN_ENTER_FIELD(e, x, y)                                        \
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
+
+#else
+
+#define YAMYAM_CAN_ENTER_FIELD(e, x, y)                                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
-                                       (CAN_MOVE_INTO_ACID(EL_YAMYAM) && \
+                                       (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(EL_DARK_YAMYAM) &&\
+                                       (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(EL_PACMAN) && \
+                                       (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(EL_PIG) &&  \
+                                       (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(EL_PENGUIN) && \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
                                         Feld[x][y] == EL_ACID) ||      \
                                        IS_FOOD_PENGUIN(Feld[x][y]) ||  \
                                        Feld[x][y] == EL_EXIT_OPEN))
 
-#define DRAGON_CAN_ENTER_FIELD(x, y)                                   \
+#define DRAGON_CAN_ENTER_FIELD(e, x, y)                                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(EL_DRAGON) && \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
                                         Feld[x][y] == EL_ACID)))
 
-#define MOLE_CAN_ENTER_FIELD(x, y, condition)                          \
+#define MOLE_CAN_ENTER_FIELD(e, x, y, condition)                       \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(EL_MOLE) && \
+                                       (CAN_MOVE_INTO_ACID(e) &&       \
                                         Feld[x][y] == EL_ACID) ||      \
                                        (condition)))
 
-#define SPRING_CAN_ENTER_FIELD(x, y)                                   \
+#define SPRING_CAN_ENTER_FIELD(e, x, y)                                        \
                (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
-                                       (CAN_MOVE_INTO_ACID(EL_SPRING) && \
+                                       (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, nr)     (element_info[e].in_group[nr] == TRUE)
 #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))
+       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))
@@ -241,18 +280,38 @@ 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 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, -1, 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, -1, s, -1)
+#define CheckTriggeredElementChangePage(x, y, e, ev, p)                        \
+       CheckTriggeredElementChangeExt(x, y, e, ev, -1, CH_SIDE_ANY, p)
+
+static boolean CheckElementChangeExt(int, int, int, int, int, int, int);
+#define CheckElementChange(x, y, e, ev)                                        \
+       CheckElementChangeExt(x, y, e, ev, -1, CH_SIDE_ANY, -1)
+#define CheckElementChangePlayer(x, y, e, ev, p, s)                    \
+       CheckElementChangeExt(x, y, e, ev, p, s, -1)
+#define CheckElementChangeSide(x, y, e, ev, s)                         \
+       CheckElementChangeExt(x, y, e, ev, -1, s, -1)
+#define CheckElementChangePage(x, y, e, ev, p)                         \
+       CheckElementChangeExt(x, y, e, ev, -1, CH_SIDE_ANY, p)
 
 static void PlayLevelSound(int, int, int);
 static void PlayLevelSoundNearest(int, int, int);
@@ -890,7 +949,7 @@ 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(3,0,9,0) &&
+  if (game.engine_version < VERSION_IDENT(3,1,0,0) &&
       CAN_MOVE(Feld[x][y]))
     InitMovDir(x, y);
 }
@@ -902,7 +961,7 @@ static inline void InitField_WithBug2(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(3,0,9,0) &&
+  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);
@@ -1240,14 +1299,14 @@ static void InitGameEngine()
   }
 
   /* set push delay value for Supaplex elements for newer engine versions */
-  if (game.engine_version >= VERSION_IDENT(3,0,9,0))
+  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;
-       element_info[i].push_delay_random = 0;
+       element_info[i].push_delay_fixed  = 6;  /* just enough to escape ... */
+       element_info[i].push_delay_random = 0;  /* ... from falling zonk     */
       }
     }
   }
@@ -1336,6 +1395,7 @@ 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;
@@ -1370,6 +1430,7 @@ 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;
 
@@ -1454,6 +1515,7 @@ 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, 0, 0, DF_NO_PUSH);
@@ -1477,6 +1539,7 @@ void InitGame()
   TimeFrames = 0;
   TimePlayed = 0;
   TimeLeft = level.time;
+  TapeTime = 0;
 
   ScreenMovDir = MV_NO_MOVING;
   ScreenMovPos = 0;
@@ -1566,23 +1629,32 @@ void InitGame()
   {
     if (!IS_CUSTOM_ELEMENT(i))
     {
-      int num_phase = 9;
-      int delay = (game.emulation == EMU_SUPAPLEX ? 3 : 2);
-      int last_phase = num_phase * delay;
+      int num_phase = 8;
+      int delay = ((IS_SP_ELEMENT(i) &&
+                   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;
+      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 (element_info[i].explosion_delay < 2)   /* !!! check again !!! */
-      element_info[i].explosion_delay = 2;
+#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 */
@@ -1611,6 +1683,10 @@ void InitGame()
          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;
          player->jy = player->last_jy = jy;
@@ -2518,6 +2594,9 @@ void RelocatePlayer(int x, int y, int element_raw)
   boolean no_delay = (tape.index_search);
   int frame_delay_value = (ffwd_delay ? FfwdFrameDelay : GameFrameDelay);
   int wait_delay_value = (no_delay ? 0 : frame_delay_value);
+#if 1
+  int old_jx, old_jy;
+#endif
 
   if (player->GameOver)                /* do not reanimate dead player */
     return;
@@ -2547,9 +2626,49 @@ void RelocatePlayer(int x, int y, int element_raw)
     player->is_moving = FALSE;
   }
 
+#if 1
+  old_jx = player->jx;
+  old_jy = player->jy;
+#endif
+
   Feld[x][y] = element;
   InitPlayerField(x, y, element, TRUE);
 
+#if 0
+  if (player == local_player)
+  {
+#if 1
+
+    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);
+
+#else
+    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);
+#endif
+
+    RedrawPlayfield(TRUE, 0,0,0,0);
+#if 0
+    DrawAllPlayers();
+    BackToFront();
+#endif
+  }
+
+#else
+
   if (player == local_player)
   {
     int scroll_xx = -999, scroll_yy = -999;
@@ -2589,6 +2708,7 @@ void RelocatePlayer(int x, int y, int element_raw)
       Delay(wait_delay_value);
     }
   }
+#endif
 }
 
 void Explode(int ex, int ey, int phase, int mode)
@@ -2620,6 +2740,10 @@ 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 */
@@ -2644,9 +2768,18 @@ void Explode(int ex, int ey, int phase, int mode)
     }
 
 #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;
@@ -2750,8 +2883,13 @@ void Explode(int ex, int ey, int phase, int mode)
            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;
@@ -2825,6 +2963,15 @@ void Explode(int ex, int ey, int phase, int mode)
 #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;
     }
 
@@ -2841,6 +2988,15 @@ 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
@@ -2871,6 +3027,10 @@ void Explode(int ex, int ey, int phase, int mode)
   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)
   {
@@ -2960,6 +3120,10 @@ void Explode(int ex, int ey, int phase, int mode)
   {
     int element;
 
+#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;
@@ -2991,7 +3155,7 @@ void Explode(int ex, int ey, int phase, int mode)
 #if 1
     /* !!! not needed !!! */
 #if 1
-    if (game.engine_version < VERSION_IDENT(3,0,9,0) &&
+    if (game.engine_version < VERSION_IDENT(3,1,0,0) &&
        CAN_MOVE(Feld[x][y]) && Feld[x][y] != EL_MOLE)
       InitMovDir(x, y);
 #else
@@ -3027,7 +3191,20 @@ 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],
@@ -3169,11 +3346,9 @@ 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);
       else
@@ -3770,12 +3945,15 @@ void Impact(int x, int y)
        }
        else
        {
+#if 0
+         TestIfElementSmashesCustomElement(x, y, MV_DOWN);
+#endif
+
          CheckElementChange(x, y + 1, smashed, 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, CE_SWITCHED, CH_SIDE_TOP);
        }
       }
       else
@@ -3867,6 +4045,7 @@ 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)
   {
@@ -3885,10 +4064,38 @@ 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);
@@ -3903,8 +4110,10 @@ 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);
@@ -3919,8 +4128,8 @@ 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);
@@ -3935,9 +4144,9 @@ 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);
@@ -3998,9 +4207,9 @@ inline static void TurnRoundExt(int x, int y)
   }
   else if (element == EL_DRAGON)
   {
-    boolean can_turn_left  = DRAGON_CAN_ENTER_FIELD(left_x, left_y);
-    boolean can_turn_right = DRAGON_CAN_ENTER_FIELD(right_x, right_y);
-    boolean can_move_on    = DRAGON_CAN_ENTER_FIELD(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);
 
@@ -4048,17 +4257,17 @@ 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)
@@ -4081,12 +4290,12 @@ inline static void TurnRoundExt(int x, int y)
   {
 #if 0
     if (MovDir[x][y] & MV_HORIZONTAL &&
-       !SPRING_CAN_ENTER_FIELD(move_x, move_y))
+       !SPRING_CAN_ENTER_FIELD(element, move_x, move_y))
       MovDir[x][y] = MV_NO_MOVING;
 #else
     if (MovDir[x][y] & MV_HORIZONTAL &&
-       (!SPRING_CAN_ENTER_FIELD(move_x, move_y) ||
-        SPRING_CAN_ENTER_FIELD(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
 
@@ -4193,14 +4402,14 @@ 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;
@@ -4222,14 +4431,14 @@ 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;
@@ -4835,7 +5044,7 @@ 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)))
     {
@@ -5066,7 +5275,7 @@ void StartMoving(int x, int y)
     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(3,0,8,0)))
+             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)
@@ -5632,8 +5841,8 @@ 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))
@@ -5650,8 +5859,8 @@ 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))
@@ -5663,11 +5872,11 @@ 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,
+                                    CE_OTHER_IS_HITTING, i);
              break;
            }
          }
@@ -5683,11 +5892,11 @@ 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,
+                                    CE_OTHER_GETS_HIT, i);
              break;
            }
          }
@@ -6659,7 +6868,7 @@ 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)
   {
@@ -6833,10 +7042,12 @@ 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;
 
@@ -6858,16 +7069,11 @@ 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 &&
-#if 1
-         IS_EQUAL_OR_IN_GROUP(trigger_element, change->trigger_element)
-#else
-         change->trigger_element == trigger_element
-#endif
-         )
+         change->trigger_side & trigger_side &&
+         change->trigger_player & trigger_player &&
+         change->trigger_page & (1 << trigger_page) &&
+         IS_EQUAL_OR_IN_GROUP(trigger_element, change->trigger_element))
       {
 #if 0
        if (!(change->events & CH_EVENT_BIT(trigger_event)))
@@ -6904,15 +7110,12 @@ 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_event,
+                                    int trigger_player,
+                                    int trigger_side,
+                                    int trigger_page)
 {
   if (!CAN_CHANGE(element) || !HAS_ANY_CHANGE_EVENT(element, trigger_event))
     return FALSE;
@@ -6924,7 +7127,7 @@ static boolean CheckElementSideChange(int x, int y, int element, int side,
   }
 
 #if 1
-  if (page < 0)
+  if (trigger_page < 0)
   {
     boolean change_element = FALSE;
     int i;
@@ -6935,10 +7138,11 @@ static boolean CheckElementSideChange(int x, int y, int element, int side,
 
       if (change->can_change &&
          change->events & CH_EVENT_BIT(trigger_event) &&
-         change->sides & side)
+         change->trigger_side & trigger_side &&
+         change->trigger_player & trigger_player)
       {
        change_element = TRUE;
-       page = i;
+       trigger_page = i;
 
        break;
       }
@@ -6952,25 +7156,20 @@ static boolean CheckElementSideChange(int x, int y, int element, int side,
 
   /* !!! this check misses pages with same event, but different side !!! */
 
-  if (page < 0)
-    page = element_info[element].event_page_nr[trigger_event];
+  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;
@@ -7173,6 +7372,11 @@ 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
@@ -7210,7 +7414,7 @@ static byte PlayerActions(struct PlayerInfo *player, byte player_action)
 
     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);
@@ -7291,7 +7495,7 @@ static void PlayerActions(struct PlayerInfo *player, byte player_action)
 
     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);
@@ -7371,6 +7575,21 @@ 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;
@@ -7387,25 +7606,91 @@ 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
@@ -7829,39 +8114,44 @@ 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);
 
-      DrawGameValue_Time(TimeLeft);
+       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 */
-      DrawGameValue_Time(TimePlayed);
+
+    if (tape.recording || tape.playing)
+      DrawVideoDisplay(VIDEO_STATE_TIME_ON, TapeTime);
   }
 
   DrawAllPlayers();
@@ -8031,20 +8321,33 @@ static void CheckGravityMovement(struct PlayerInfo *player)
 {
   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_horizontal = player->action & MV_HORIZONTAL;
+    int move_dir_vertical   = player->action & MV_VERTICAL;
     int move_dir =
-      (player->last_move_dir & (MV_LEFT | MV_RIGHT) ?
+      (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));
+    boolean player_is_snapping = player->action & JOY_BUTTON_1;
+#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 ||
        (IS_SP_PORT(Feld[new_jx][new_jy]) &&
@@ -8056,9 +8359,45 @@ static void CheckGravityMovement(struct PlayerInfo *player)
        (IS_WALKABLE(Feld[jx][jy]) &&
        !(element_info[Feld[jx][jy]].access_direction & MV_DOWN)));
 
-    if (field_under_player_is_free &&
+#if 0
+    printf("::: checking gravity NOW [%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));
+#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;
   }
 }
@@ -8074,7 +8413,7 @@ 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  */
@@ -8086,8 +8425,8 @@ 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;
@@ -8160,18 +8499,17 @@ 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
 
@@ -8211,9 +8549,16 @@ 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 */
@@ -8246,7 +8591,7 @@ 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);
@@ -8364,7 +8709,7 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
 
 #if 1
     {
-      static int change_sides[4][2] =
+      static int trigger_sides[4][2] =
       {
        /* enter side           leave side */
        { CH_SIDE_RIGHT,        CH_SIDE_LEFT    },      /* moving left  */
@@ -8373,24 +8718,27 @@ 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
       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);
+       CheckTriggeredElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                         CE_OTHER_GETS_LEFT,
+                                         player->index_bit, leave_side);
+       CheckElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                CE_LEFT_BY_PLAYER,
+                                player->index_bit, leave_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);
+       CheckTriggeredElementChangePlayer(jx, jy, Feld[jx][jy],
+                                         CE_OTHER_GETS_ENTERED,
+                                         player->index_bit, enter_side);
+       CheckElementChangePlayer(jx, jy, Feld[jx][jy], CE_ENTERED_BY_PLAYER,
+                                player->index_bit, enter_side);
       }
 #endif
 
@@ -8401,7 +8749,7 @@ boolean MovePlayer(struct PlayerInfo *player, int dx, int dy)
   }
   else
   {
-    CheckGravityMovement(player);
+    CheckGravityMovementWhenNotMoving(player);
 
     /*
     player->last_move_dir = MV_NO_MOVING;
@@ -8508,6 +8856,47 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
        player->LevelSolved = player->GameOver = TRUE;
     }
 
+#if 0
+    /* !!! ENABLE THIS FOR NEW VERSIONS !!! */
+    {
+      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
+      if (IS_CUSTOM_ELEMENT(Feld[old_jx][old_jy]))
+      {
+       CheckTriggeredElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                         CE_OTHER_GETS_LEFT,
+                                         player->index_bit, leave_side);
+       CheckElementChangePlayer(old_jx, old_jy, Feld[old_jx][old_jy],
+                                CE_LEFT_BY_PLAYER,
+                                player->index_bit, leave_side);
+      }
+
+      if (IS_CUSTOM_ELEMENT(Feld[jx][jy]))
+      {
+       CheckTriggeredElementChangePlayer(jx, jy, Feld[jx][jy],
+                                         CE_OTHER_GETS_ENTERED,
+                                         player->index_bit, enter_side);
+       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);
@@ -8520,6 +8909,42 @@ 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);
@@ -8563,7 +8988,7 @@ 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    */
@@ -8585,8 +9010,8 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
   {
     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))
@@ -8594,6 +9019,8 @@ 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))
@@ -8603,25 +9030,27 @@ 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;
     }
@@ -8637,7 +9066,7 @@ 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    */
@@ -8661,8 +9090,8 @@ void TestIfElementTouchesCustomElement(int x, int y)
   {
     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))
@@ -8689,7 +9118,7 @@ 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_side & border_side &&
 #if 1
            IS_EQUAL_OR_IN_GROUP(border_element, change->trigger_element)
 #else
@@ -8716,7 +9145,7 @@ 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_side & center_side &&
 #if 1
            IS_EQUAL_OR_IN_GROUP(center_element, change->trigger_element)
 #else
@@ -8724,8 +9153,8 @@ void TestIfElementTouchesCustomElement(int x, int y)
 #endif
            )
        {
-         CheckElementSideChange(xx, yy, border_element, CH_SIDE_ANY,
-                                CE_OTHER_IS_TOUCHING, j);
+         CheckElementChangePage(xx, yy, border_element, CE_OTHER_IS_TOUCHING,
+                                j);
          break;
        }
       }
@@ -8733,8 +9162,8 @@ void TestIfElementTouchesCustomElement(int x, int y)
   }
 
   if (change_center_element)
-    CheckElementSideChange(x, y, center_element, CH_SIDE_ANY,
-                          CE_OTHER_IS_TOUCHING, center_element_change_page);
+    CheckElementChangePage(x, y, center_element, CE_OTHER_IS_TOUCHING,
+                          center_element_change_page);
 }
 
 void TestIfElementHitsCustomElement(int x, int y, int direction)
@@ -8759,8 +9188,8 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
     return;
 #endif
 
-  CheckElementSideChange(x, y, hitting_element,
-                        direction, CE_HITTING_SOMETHING, -1);
+  CheckElementChangeSide(x, y, hitting_element, CE_HITTING_SOMETHING,
+                        direction);
 
   if (IN_LEV_FIELD(hitx, hity))
   {
@@ -8780,8 +9209,8 @@ 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, CE_HIT_BY_SOMETHING,
+                            opposite_direction);
 
       if (IS_CUSTOM_ELEMENT(hitting_element) &&
          HAS_ANY_CHANGE_EVENT(hitting_element, CE_OTHER_IS_HITTING))
@@ -8793,7 +9222,7 @@ 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_side & touched_side &&
          
 #if 1
              IS_EQUAL_OR_IN_GROUP(touched_element, change->trigger_element)
@@ -8802,8 +9231,8 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
 #endif
              )
          {
-           CheckElementSideChange(x, y, hitting_element,
-                                  CH_SIDE_ANY, CE_OTHER_IS_HITTING, i);
+           CheckElementChangePage(x, y, hitting_element, CE_OTHER_IS_HITTING,
+                                  i);
            break;
          }
        }
@@ -8819,7 +9248,108 @@ 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_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,
+                                  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];
+#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
+
+  CheckElementChangeSide(x, y, hitting_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;
+    int touched_element = MovingOrBlocked2Element(hitx, hity);
+#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,
+                            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
+             )
+         {
+           CheckElementChangePage(x, y, hitting_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
@@ -8827,8 +9357,8 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
 #endif
              )
          {
-           CheckElementSideChange(hitx, hity, touched_element,
-                                  CH_SIDE_ANY, CE_OTHER_GETS_HIT, i);
+           CheckElementChangePage(hitx, hity, touched_element,
+                                  CE_OTHER_GETS_SMASHED, i);
            break;
          }
        }
@@ -8836,6 +9366,7 @@ void TestIfElementHitsCustomElement(int x, int y, int direction)
     }
   }
 }
+#endif
 
 void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
 {
@@ -9168,7 +9699,7 @@ int DigField(struct PlayerInfo *player,
             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 */
@@ -9186,7 +9717,7 @@ int DigField(struct PlayerInfo *player,
                        dy == -1 ? MV_UP :
                        dy == +1 ? MV_DOWN : MV_NO_MOVING);
   int opposite_direction = MV_DIR_OPPOSITE(move_direction);
-  int dig_side = change_sides[MV_DIR_BIT(move_direction)];
+  int dig_side = trigger_sides[MV_DIR_BIT(move_direction)];
   int old_element = Feld[jx][jy];
   int element;
 
@@ -9328,6 +9859,10 @@ 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;
 
@@ -9475,7 +10010,8 @@ 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, CH_SIDE_ANY);
 
 #if 1
        if (mode == DF_SNAP)
@@ -9551,9 +10087,12 @@ 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;
 
          DrawGameValue_Dynamite(local_player->inventory_size);
        }
@@ -9570,7 +10109,9 @@ int DigField(struct PlayerInfo *player,
        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, CH_SIDE_ANY);
 
 #if 1
        if (mode == DF_SNAP)
@@ -9726,10 +10267,10 @@ 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;
       }
@@ -9833,15 +10374,17 @@ 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;
@@ -9864,8 +10407,13 @@ 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;
@@ -9930,25 +10478,43 @@ boolean DropElement(struct PlayerInfo *player)
 {
   int jx = player->jx, jy = player->jy;
   int old_element = Feld[jx][jy];
-  int new_element;
+  int new_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);
 
   /* 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 */
@@ -9956,19 +10522,26 @@ 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);
 
-    DrawGameValue_Dynamite(local_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;
+    }
+
+    Feld[jx][jy] = new_element;
 
     if (IN_SCR_FIELD(SCREENX(jx), SCREENY(jy)))
       DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), el2img(Feld[jx][jy]), 0);
@@ -9980,15 +10553,21 @@ boolean DropElement(struct PlayerInfo *player)
     Changed[jx][jy] = 0;               /* allow another change */
 #endif
 
-    CheckTriggeredElementChange(jx, jy, new_element, CE_OTHER_GETS_DROPPED);
-    CheckElementChange(jx, jy, new_element, CE_DROPPED_BY_PLAYER);
+    CheckTriggeredElementChangePlayer(jx, jy, new_element,
+                                     CE_OTHER_GETS_DROPPED,
+                                     player->index_bit, CH_SIDE_ANY);
+    CheckElementChangePlayer(jx, jy, new_element, CE_DROPPED_BY_PLAYER,
+                            player->index_bit, CH_SIDE_ANY);
 
     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;
 
@@ -10046,8 +10625,8 @@ boolean DropElement(struct PlayerInfo *player)
 #if 1
       TestIfElementHitsCustomElement(jx, jy, direction);
 #else
-      CheckElementSideChange(jx, jy, new_element,
-                            direction, CE_HITTING_SOMETHING, -1);
+      CheckElementChangeSide(jx, jy, new_element, CE_HITTING_SOMETHING,
+                            direction);
 #endif
     }
 
@@ -10281,7 +10860,25 @@ void RequestQuitGame(boolean ask_if_really_quit)
   }
   else
   {
+
+#if 1
+    if (tape.playing && tape.index_search)
+    {
+      SetDrawDeactivationMask(REDRAW_NONE);
+      audio.sound_deactivated = FALSE;
+    }
+#endif
+
     OpenDoor(DOOR_OPEN_1 | DOOR_COPY_BACK);
+
+#if 1
+    if (tape.playing && tape.index_search)
+    {
+      SetDrawDeactivationMask(REDRAW_FIELD);
+      audio.sound_deactivated = TRUE;
+    }
+#endif
+
   }
 }