rnd-20030902-1-src
[rocksndiamonds.git] / src / game.c
index c4764283bb635d6a25c086410d69e80695cd4c53..91c8841ab9657c815e9cdb87359febc4adf9b0d7 100644 (file)
@@ -89,6 +89,9 @@
 #define DOUBLE_PLAYER_SPEED(p) (HALVE_MOVE_DELAY((p)->move_delay_value))
 #define HALVE_PLAYER_SPEED(p)  (DOUBLE_MOVE_DELAY((p)->move_delay_value))
 
+/* values for other actions */
+#define MOVE_STEPSIZE_NORMAL   (TILEX / MOVE_DELAY_NORMAL_SPEED)
+
 #define        INIT_GFX_RANDOM()       (SimpleRND(1000000))
 
 #define GET_NEW_PUSH_DELAY(e)  (   (element_info[e].push_delay_fixed) + \
 #define GET_NEW_MOVE_DELAY(e)  (   (element_info[e].move_delay_fixed) + \
                                 RND(element_info[e].move_delay_random))
 
+#define ELEMENT_CAN_ENTER_FIELD_GENERIC(e, x, y, condition)            \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       (condition) ||                  \
+                                       (DONT_COLLIDE_WITH(e) &&        \
+                                        IS_FREE_OR_PLAYER(x, y))))
+
+#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))
+
+#define ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(x, y)                                \
+       ELEMENT_CAN_ENTER_FIELD_GENERIC_2(x, y, (Feld[x][y] == EL_ACID))
+
+#define ENEMY_CAN_ENTER_FIELD(x, y) (IN_LEV_FIELD(x, y) && IS_FREE(x, y))
+
+#define YAMYAM_CAN_ENTER_FIELD(x, y)                                   \
+               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       Feld[x][y] == EL_DIAMOND))
+
+#define DARK_YAMYAM_CAN_ENTER_FIELD(x, y)                              \
+               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       IS_FOOD_DARK_YAMYAM(Feld[x][y])))
+
+#define PACMAN_CAN_ENTER_FIELD(x, y)                                   \
+               (IN_LEV_FIELD(x, y) && (IS_FREE_OR_PLAYER(x, y) ||      \
+                                       IS_AMOEBOID(Feld[x][y])))
+
+#define PIG_CAN_ENTER_FIELD(x, y)                                      \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       IS_FOOD_PIG(Feld[x][y])))
+
+#define PENGUIN_CAN_ENTER_FIELD(x, y)                                  \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) ||                \
+                                       IS_FOOD_PENGUIN(Feld[x][y]) ||  \
+                                       Feld[x][y] == EL_EXIT_OPEN ||   \
+                                       Feld[x][y] == EL_ACID))
+
+#define MOLE_CAN_ENTER_FIELD(x, y, condition)                          \
+               (IN_LEV_FIELD(x, y) && (IS_FREE(x, y) || (condition)))
+
+#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))
+
 /* game button identifiers */
 #define GAME_CTRL_ID_STOP              0
 #define GAME_CTRL_ID_PAUSE             1
@@ -114,6 +166,12 @@ static void CloseAllOpenTimegates(void);
 static void CheckGravityMovement(struct PlayerInfo *);
 static void KillHeroUnlessProtected(int, int);
 
+static void TestIfPlayerTouchesCustomElement(int, int);
+static void TestIfElementTouchesCustomElement(int, int);
+
+static boolean CheckTriggeredElementChange(int, int, int, int);
+static boolean CheckElementChange(int, int, int, int);
+
 static void PlaySoundLevel(int, int, int);
 static void PlaySoundLevelNearest(int, int, int);
 static void PlaySoundLevelAction(int, int, int);
@@ -149,15 +207,15 @@ static void RunTimegateWheel(int x, int y);
 
 struct ChangingElementInfo
 {
-  int base_element;
-  int next_element;
+  int element;
+  int target_element;
   int change_delay;
   void (*pre_change_function)(int x, int y);
   void (*change_function)(int x, int y);
   void (*post_change_function)(int x, int y);
 };
 
-static struct ChangingElementInfo changing_element_list[] =
+static struct ChangingElementInfo change_delay_list[] =
 {
   {
     EL_NUT_BREAKING,
@@ -299,15 +357,78 @@ static struct ChangingElementInfo changing_element_list[] =
   }
 };
 
-static struct ChangingElementInfo changing_element[MAX_NUM_ELEMENTS];
+struct
+{
+  int element;
+  int push_delay_fixed, push_delay_random;
+}
+push_delay_list[] =
+{
+  { EL_SPRING,                 0, 0 },
+  { EL_BALLOON,                        0, 0 },
+
+  { EL_SOKOBAN_OBJECT,         2, 0 },
+  { EL_SOKOBAN_FIELD_FULL,     2, 0 },
+  { EL_SATELLITE,              2, 0 },
+  { EL_SP_DISK_YELLOW,         2, 0 },
+
+  { EL_UNDEFINED,              0, 0 },
+};
+
+struct
+{
+  int element;
+  int move_stepsize;
+}
+move_stepsize_list[] =
+{
+  { EL_AMOEBA_DROP,            2 },
+  { EL_AMOEBA_DROPPING,                2 },
+  { EL_QUICKSAND_FILLING,      1 },
+  { EL_QUICKSAND_EMPTYING,     1 },
+  { EL_MAGIC_WALL_FILLING,     2 },
+  { EL_BD_MAGIC_WALL_FILLING,  2 },
+  { EL_MAGIC_WALL_EMPTYING,    2 },
+  { EL_BD_MAGIC_WALL_EMPTYING, 2 },
+
+  { EL_UNDEFINED,              0 },
+};
+
+struct
+{
+  int element;
+  int count;
+}
+collect_count_list[] =
+{
+  { EL_EMERALD,                        1 },
+  { EL_BD_DIAMOND,             1 },
+  { EL_EMERALD_YELLOW,         1 },
+  { EL_EMERALD_RED,            1 },
+  { EL_EMERALD_PURPLE,         1 },
+  { EL_DIAMOND,                        3 },
+  { EL_SP_INFOTRON,            1 },
+  { EL_PEARL,                  5 },
+  { EL_CRYSTAL,                        8 },
+
+  { EL_UNDEFINED,              0 },
+};
+
+static unsigned long trigger_events[MAX_NUM_ELEMENTS];
+
+#define IS_AUTO_CHANGING(e)    (element_info[e].change_events & \
+                                CH_EVENT_BIT(CE_DELAY))
+#define IS_JUST_CHANGING(x, y) (ChangeDelay[x][y] != 0)
+#define IS_CHANGING(x, y)      (IS_AUTO_CHANGING(Feld[x][y]) || \
+                                IS_JUST_CHANGING(x, y))
 
-#define IS_AUTO_CHANGING(e)  (changing_element[e].base_element != EL_UNDEFINED)
+#define CE_PAGE(e, ce)         (element_info[e].event_page[ce])
 
 
 void GetPlayerConfig()
 {
   if (!audio.sound_available)
-    setup.sound = FALSE;
+    setup.sound_simple = FALSE;
 
   if (!audio.loops_available)
     setup.sound_loops = FALSE;
@@ -318,7 +439,7 @@ void GetPlayerConfig()
   if (!video.fullscreen_available)
     setup.fullscreen = FALSE;
 
-  setup.sound_simple = setup.sound;
+  setup.sound = (setup.sound_simple || setup.sound_loops || setup.sound_music);
 
   SetAudioMode(setup.sound);
   InitJoysticks();
@@ -375,62 +496,71 @@ static int getBeltDirFromBeltSwitchElement(int element)
   return belt_move_dir[belt_dir_nr];
 }
 
-static void InitField(int x, int y, boolean init_game)
+static void InitPlayerField(int x, int y, int element, boolean init_game)
 {
-  int element = Feld[x][y];
-
-  switch (element)
+  if (element == EL_SP_MURPHY)
   {
-    case EL_SP_MURPHY:
-      if (init_game)
+    if (init_game)
+    {
+      if (stored_player[0].present)
       {
-       if (stored_player[0].present)
-       {
-         Feld[x][y] = EL_SP_MURPHY_CLONE;
-         break;
-       }
-       else
-       {
-         stored_player[0].use_murphy_graphic = TRUE;
-       }
+       Feld[x][y] = EL_SP_MURPHY_CLONE;
 
-       Feld[x][y] = EL_PLAYER_1;
+       return;
       }
-      /* no break! */
-    case EL_PLAYER_1:
-    case EL_PLAYER_2:
-    case EL_PLAYER_3:
-    case EL_PLAYER_4:
-      if (init_game)
+      else
       {
-       struct PlayerInfo *player = &stored_player[Feld[x][y] - EL_PLAYER_1];
-       int jx = player->jx, jy = player->jy;
+       stored_player[0].use_murphy_graphic = TRUE;
+      }
 
-       player->present = TRUE;
+      Feld[x][y] = EL_PLAYER_1;
+    }
+  }
 
-       if (!options.network || player->connected)
-       {
-         player->active = TRUE;
+  if (init_game)
+  {
+    struct PlayerInfo *player = &stored_player[Feld[x][y] - EL_PLAYER_1];
+    int jx = player->jx, jy = player->jy;
 
-         /* remove potentially duplicate players */
-         if (StorePlayer[jx][jy] == Feld[x][y])
-           StorePlayer[jx][jy] = 0;
+    player->present = TRUE;
 
-         StorePlayer[x][y] = Feld[x][y];
+    if (!options.network || player->connected)
+    {
+      player->active = TRUE;
 
-         if (options.debug)
-         {
-           printf("Player %d activated.\n", player->element_nr);
-           printf("[Local player is %d and currently %s.]\n",
-                  local_player->element_nr,
-                  local_player->active ? "active" : "not active");
-         }
-       }
+      /* remove potentially duplicate players */
+      if (StorePlayer[jx][jy] == Feld[x][y])
+       StorePlayer[jx][jy] = 0;
 
-       Feld[x][y] = EL_EMPTY;
-       player->jx = player->last_jx = x;
-       player->jy = player->last_jy = y;
+      StorePlayer[x][y] = Feld[x][y];
+
+      if (options.debug)
+      {
+       printf("Player %d activated.\n", player->element_nr);
+       printf("[Local player is %d and currently %s.]\n",
+              local_player->element_nr,
+              local_player->active ? "active" : "not active");
       }
+    }
+
+    Feld[x][y] = EL_EMPTY;
+    player->jx = player->last_jx = x;
+    player->jy = player->last_jy = y;
+  }
+}
+
+static void InitField(int x, int y, boolean init_game)
+{
+  int element = Feld[x][y];
+
+  switch (element)
+  {
+    case EL_SP_MURPHY:
+    case EL_PLAYER_1:
+    case EL_PLAYER_2:
+    case EL_PLAYER_3:
+    case EL_PLAYER_4:
+      InitPlayerField(x, y, element, init_game);
       break;
 
     case EL_STONEBLOCK:
@@ -595,7 +725,7 @@ void DrawGameDoorValues()
   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->dynamite, 3), FONT_TEXT_2);
+          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,
@@ -613,7 +743,7 @@ void DrawGameDoorValues()
 
 static void InitGameEngine()
 {
-  int i;
+  int i, j, k;
 
   /* set game engine from tape file when re-playing, else from level file */
   game.engine_version = (tape.playing ? tape.engine_version :
@@ -630,6 +760,8 @@ static void InitGameEngine()
     printf("       => game.engine_version == %06d\n", game.engine_version);
 #endif
 
+  /* ---------- initialize player's initial move delay --------------------- */
+
   /* dynamically adjust player properties according to game engine version */
   game.initial_move_delay =
     (game.engine_version <= VERSION_IDENT(2,0,1) ? INITIAL_MOVE_DELAY_ON :
@@ -639,49 +771,166 @@ static void InitGameEngine()
   game.initial_move_delay_value =
     (level.double_speed ? MOVE_DELAY_HIGH_SPEED : MOVE_DELAY_NORMAL_SPEED);
 
+  /* ---------- initialize changing elements ------------------------------- */
+
   /* initialize changing elements information */
-  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+  for (i=0; i < MAX_NUM_ELEMENTS; i++)
   {
-    changing_element[i].base_element = EL_UNDEFINED;
-    changing_element[i].next_element = EL_UNDEFINED;
-    changing_element[i].change_delay = -1;
-    changing_element[i].pre_change_function = NULL;
-    changing_element[i].change_function = NULL;
-    changing_element[i].post_change_function = NULL;
+    struct ElementInfo *ei = &element_info[i];
+
+    /* this pointer might have been changed in the level editor */
+    ei->change = &ei->change_page[0];
+
+    if (!IS_CUSTOM_ELEMENT(i))
+    {
+      ei->change->target_element = EL_EMPTY_SPACE;
+      ei->change->delay_fixed = 0;
+      ei->change->delay_random = 0;
+      ei->change->delay_frames = 1;
+    }
+
+    ei->change_events = CE_BITMASK_DEFAULT;
+    for (j=0; j < NUM_CHANGE_EVENTS; j++)
+    {
+      ei->event_page_num[j] = 0;
+      ei->event_page[j] = &ei->change_page[0];
+    }
   }
 
   /* add changing elements from pre-defined list */
-  i = 0;
-  while (changing_element_list[i].base_element != EL_UNDEFINED)
+  for (i=0; change_delay_list[i].element != EL_UNDEFINED; i++)
+  {
+    struct ChangingElementInfo *ch_delay = &change_delay_list[i];
+    struct ElementInfo *ei = &element_info[ch_delay->element];
+
+    ei->change->target_element       = ch_delay->target_element;
+    ei->change->delay_fixed          = ch_delay->change_delay;
+
+    ei->change->pre_change_function  = ch_delay->pre_change_function;
+    ei->change->change_function      = ch_delay->change_function;
+    ei->change->post_change_function = ch_delay->post_change_function;
+
+    ei->change_events |= CH_EVENT_BIT(CE_DELAY);
+  }
+
+#if 1
+  /* add change events from custom element configuration */
+  for (i=0; i < NUM_CUSTOM_ELEMENTS; i++)
   {
-    struct ChangingElementInfo *ce = &changing_element_list[i];
-    int element = ce->base_element;
+    struct ElementInfo *ei = &element_info[EL_CUSTOM_START + i];
 
-    changing_element[element].base_element         = ce->base_element;
-    changing_element[element].next_element         = ce->next_element;
-    changing_element[element].change_delay         = ce->change_delay;
-    changing_element[element].pre_change_function  = ce->pre_change_function;
-    changing_element[element].change_function      = ce->change_function;
-    changing_element[element].post_change_function = ce->post_change_function;
+    for (j=0; j < ei->num_change_pages; j++)
+    {
+      if (!ei->change_page[j].can_change)
+       continue;
 
-    i++;
+      for (k=0; k < NUM_CHANGE_EVENTS; k++)
+      {
+       /* only add event page for the first page found with this event */
+       if (ei->change_page[j].events & CH_EVENT_BIT(k) &&
+           !(ei->change_events & CH_EVENT_BIT(k)))
+       {
+         ei->change_events |= CH_EVENT_BIT(k);
+         ei->event_page_num[k] = j;
+         ei->event_page[k] = &ei->change_page[j];
+       }
+      }
+    }
   }
 
-  /* add changing elements from custom element configuration */
+#else
+
+  /* add change events from custom element configuration */
   for (i=0; i < NUM_CUSTOM_ELEMENTS; i++)
   {
     int element = EL_CUSTOM_START + i;
-    struct ElementChangeInfo *change = &element_info[element].change;
 
     /* only add custom elements that change after fixed/random frame delay */
-    if (!CAN_CHANGE(element) || !HAS_CHANGE_EVENT(element, CE_DELAY))
-      continue;
+    if (CAN_CHANGE(element) && HAS_CHANGE_EVENT(element, CE_DELAY))
+      element_info[element].change_events |= CH_EVENT_BIT(CE_DELAY);
+  }
+#endif
+
+  /* ---------- initialize trigger events ---------------------------------- */
+
+  /* initialize trigger events information */
+  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+    trigger_events[i] = EP_BITMASK_DEFAULT;
+
+#if 1
+  /* add trigger events from element change event properties */
+  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+  {
+    struct ElementInfo *ei = &element_info[i];
+
+    for (j=0; j < ei->num_change_pages; j++)
+    {
+      if (!ei->change_page->can_change)
+       continue;
+
+      if (ei->change_page[j].events & CH_EVENT_BIT(CE_BY_OTHER))
+      {
+       int trigger_element = ei->change_page[j].trigger_element;
+
+       trigger_events[trigger_element] |= ei->change_page[j].events;
+      }
+    }
+  }
+#else
+  /* add trigger events from element change event properties */
+  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+    if (HAS_CHANGE_EVENT(i, CE_BY_OTHER))
+      trigger_events[element_info[i].change->trigger_element] |=
+       element_info[i].change->events;
+#endif
+
+  /* ---------- initialize push delay -------------------------------------- */
+
+  /* initialize push delay values to default */
+  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+  {
+    if (!IS_CUSTOM_ELEMENT(i))
+    {
+      element_info[i].push_delay_fixed = 2;
+      element_info[i].push_delay_random = 8;
+    }
+  }
+
+  /* set push delay value for certain elements from pre-defined list */
+  for (i=0; push_delay_list[i].element != EL_UNDEFINED; i++)
+  {
+    int e = push_delay_list[i].element;
+
+    element_info[e].push_delay_fixed  = push_delay_list[i].push_delay_fixed;
+    element_info[e].push_delay_random = push_delay_list[i].push_delay_random;
+  }
+
+  /* ---------- initialize move stepsize ----------------------------------- */
+
+  /* initialize move stepsize values to default */
+  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+    if (!IS_CUSTOM_ELEMENT(i))
+      element_info[i].move_stepsize = MOVE_STEPSIZE_NORMAL;
 
-    changing_element[element].base_element = element;
-    changing_element[element].next_element = change->successor;
-    changing_element[element].change_delay = (change->delay_fixed *
-                                             change->delay_frames);
+  /* set move stepsize value for certain elements from pre-defined list */
+  for (i=0; move_stepsize_list[i].element != EL_UNDEFINED; i++)
+  {
+    int e = move_stepsize_list[i].element;
+
+    element_info[e].move_stepsize = move_stepsize_list[i].move_stepsize;
   }
+
+  /* ---------- initialize gem count --------------------------------------- */
+
+  /* initialize gem count values for each element */
+  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+    if (!IS_CUSTOM_ELEMENT(i))
+      element_info[i].collect_count = 0;
+
+  /* add gem count values for all elements from pre-defined list */
+  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;
 }
 
 
@@ -738,7 +987,6 @@ void InitGame()
     for (j=0; j<4; j++)
       player->key[j] = FALSE;
 
-    player->dynamite = 0;
     player->dynabomb_count = 0;
     player->dynabomb_size = 1;
     player->dynabombs_left = 0;
@@ -760,7 +1008,6 @@ void InitGame()
     player->actual_frame_counter = 0;
 
     player->last_move_dir = MV_NO_MOVING;
-    player->is_moving = FALSE;
 
     player->is_moving = FALSE;
     player->is_waiting = FALSE;
@@ -781,6 +1028,8 @@ void InitGame()
     player->shield_normal_time_left = 0;
     player->shield_deadly_time_left = 0;
 
+    player->inventory_size = 0;
+
     DigField(player, 0, 0, 0, 0, DF_NO_PUSH);
     SnapField(player, 0, 0);
 
@@ -833,12 +1082,15 @@ void InitGame()
   {
     for (y=0; y<lev_fieldy; y++)
     {
-      Feld[x][y] = Ur[x][y];
+      Feld[x][y] = level.field[x][y];
       MovPos[x][y] = MovDir[x][y] = MovDelay[x][y] = 0;
+      ChangeDelay[x][y] = 0;
       Store[x][y] = Store2[x][y] = StorePlayer[x][y] = Back[x][y] = 0;
       AmoebaNr[x][y] = 0;
       JustStopped[x][y] = 0;
       Stop[x][y] = FALSE;
+      Pushed[x][y] = FALSE;
+      Changing[x][y] = FALSE;
       ExplodePhase[x][y] = 0;
       ExplodeField[x][y] = EX_NO_EXPLOSION;
 
@@ -990,16 +1242,107 @@ void InitGame()
   if (lev_fieldy + (SBY_Upper == -1 ? 2 : 0) <= SCR_FIELDY)
     SBY_Upper = SBY_Lower = -1 * (SCR_FIELDY - lev_fieldy) / 2;
 
-  scroll_x = SBX_Left;
-  scroll_y = SBY_Upper;
-  if (local_player->jx >= SBX_Left + MIDPOSX)
-    scroll_x = (local_player->jx <= SBX_Right + MIDPOSX ?
-               local_player->jx - MIDPOSX :
-               SBX_Right);
-  if (local_player->jy >= SBY_Upper + MIDPOSY)
-    scroll_y = (local_player->jy <= SBY_Lower + MIDPOSY ?
-               local_player->jy - MIDPOSY :
-               SBY_Lower);
+  /* if local player not found, look for custom element that might create
+     the player (make some assumptions about the right custom element) */
+  if (!local_player->present)
+  {
+    int start_x = 0, start_y = 0;
+    int found_rating = 0;
+    int found_element = EL_UNDEFINED;
+
+    for(y=0; y < lev_fieldy; y++) for(x=0; x < lev_fieldx; x++)
+    {
+      int element = Feld[x][y];
+      int content;
+      int xx, yy;
+      boolean is_player;
+
+      if (!IS_CUSTOM_ELEMENT(element))
+       continue;
+
+      if (CAN_CHANGE(element))
+      {
+       for (i=0; i < element_info[element].num_change_pages; i++)
+       {
+         content = element_info[element].change_page[i].target_element;
+         is_player = ELEM_IS_PLAYER(content);
+
+         if (is_player && (found_rating < 3 || element < found_element))
+         {
+           start_x = x;
+           start_y = y;
+
+           found_rating = 3;
+           found_element = element;
+         }
+       }
+      }
+
+      for(yy=0; yy < 3; yy++) for(xx=0; xx < 3; xx++)
+      {
+       content = element_info[element].content[xx][yy];
+       is_player = ELEM_IS_PLAYER(content);
+
+       if (is_player && (found_rating < 2 || element < found_element))
+       {
+         start_x = x + xx - 1;
+         start_y = y + yy - 1;
+
+         found_rating = 2;
+         found_element = element;
+       }
+
+       if (!CAN_CHANGE(element))
+         continue;
+
+       for (i=0; i < element_info[element].num_change_pages; i++)
+       {
+         content = element_info[element].change_page[i].content[xx][yy];
+         is_player = ELEM_IS_PLAYER(content);
+
+         if (is_player && (found_rating < 1 || element < found_element))
+         {
+           start_x = x + xx - 1;
+           start_y = y + yy - 1;
+
+           found_rating = 1;
+           found_element = element;
+         }
+       }
+      }
+    }
+
+    scroll_x = (start_x < SBX_Left  + MIDPOSX ? SBX_Left :
+               start_x > SBX_Right + MIDPOSX ? SBX_Right :
+               start_x - MIDPOSX);
+
+    scroll_y = (start_y < SBY_Upper + MIDPOSY ? SBY_Upper :
+               start_y > SBY_Lower + MIDPOSY ? SBY_Lower :
+               start_y - MIDPOSY);
+  }
+  else
+  {
+#if 1
+    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
+    scroll_x = SBX_Left;
+    scroll_y = SBY_Upper;
+    if (local_player->jx >= SBX_Left + MIDPOSX)
+      scroll_x = (local_player->jx <= SBX_Right + MIDPOSX ?
+                 local_player->jx - MIDPOSX :
+                 SBX_Right);
+    if (local_player->jy >= SBY_Upper + MIDPOSY)
+      scroll_y = (local_player->jy <= SBY_Lower + MIDPOSY ?
+                 local_player->jy - MIDPOSY :
+                 SBY_Lower);
+#endif
+  }
 
   CloseDoor(DOOR_CLOSE_1);
 
@@ -1143,7 +1486,9 @@ void InitMovDir(int x, int y)
       {
        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)
+       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)
          MovDir[x][y] = 1 << RND(4);
        else if (element_info[element].move_pattern == MV_HORIZONTAL)
          MovDir[x][y] = (RND(2) ? MV_LEFT : MV_RIGHT);
@@ -1436,8 +1781,10 @@ static void ResetGfxAnimation(int x, int y)
 void InitMovingField(int x, int y, int direction)
 {
   int element = Feld[x][y];
-  int newx = x + (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
-  int newy = y + (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
+  int dx = (direction == MV_LEFT ? -1 : direction == MV_RIGHT ? +1 : 0);
+  int dy = (direction == MV_UP   ? -1 : direction == MV_DOWN  ? +1 : 0);
+  int newx = x + dx;
+  int newy = y + dy;
 
   if (!JustStopped[x][y] || direction != MovDir[x][y])
     ResetGfxAnimation(x, y);
@@ -1526,17 +1873,26 @@ static int MovingOrBlocked2ElementIfNotLeaving(int x, int y)
 static void RemoveField(int x, int y)
 {
   Feld[x][y] = EL_EMPTY;
-  GfxElement[x][y] = EL_UNDEFINED;
+
   MovPos[x][y] = 0;
   MovDir[x][y] = 0;
   MovDelay[x][y] = 0;
+
+  AmoebaNr[x][y] = 0;
+  ChangeDelay[x][y] = 0;
+  Pushed[x][y] = FALSE;
+
+  GfxElement[x][y] = EL_UNDEFINED;
+  GfxAction[x][y] = ACTION_DEFAULT;
 }
 
 void RemoveMovingField(int x, int y)
 {
   int oldx = x, oldy = y, newx = x, newy = y;
+  int element = Feld[x][y];
+  int next_element = EL_UNDEFINED;
 
-  if (Feld[x][y] != EL_BLOCKED && !IS_MOVING(x, y))
+  if (element != EL_BLOCKED && !IS_MOVING(x, y))
     return;
 
   if (IS_MOVING(x, y))
@@ -1545,28 +1901,27 @@ void RemoveMovingField(int x, int y)
     if (Feld[newx][newy] != EL_BLOCKED)
       return;
   }
-  else if (Feld[x][y] == EL_BLOCKED)
+  else if (element == EL_BLOCKED)
   {
     Blocked2Moving(x, y, &oldx, &oldy);
     if (!IS_MOVING(oldx, oldy))
       return;
   }
 
-  if (Feld[x][y] == EL_BLOCKED &&
+  if (element == EL_BLOCKED &&
       (Feld[oldx][oldy] == EL_QUICKSAND_EMPTYING ||
        Feld[oldx][oldy] == EL_MAGIC_WALL_EMPTYING ||
        Feld[oldx][oldy] == EL_BD_MAGIC_WALL_EMPTYING ||
        Feld[oldx][oldy] == EL_AMOEBA_DROPPING))
-    Feld[oldx][oldy] = get_next_element(Feld[oldx][oldy]);
-  else
-    Feld[oldx][oldy] = EL_EMPTY;
+    next_element = get_next_element(Feld[oldx][oldy]);
+
+  RemoveField(oldx, oldy);
+  RemoveField(newx, newy);
 
   Store[oldx][oldy] = Store2[oldx][oldy] = 0;
 
-  Feld[newx][newy] = EL_EMPTY;
-  MovPos[oldx][oldy] = MovDir[oldx][oldy] = MovDelay[oldx][oldy] = 0;
-  MovPos[newx][newy] = MovDir[newx][newy] = MovDelay[newx][newy] = 0;
-  GfxAction[oldx][oldy] = GfxAction[newx][newy] = ACTION_DEFAULT;
+  if (next_element != EL_UNDEFINED)
+    Feld[oldx][oldy] = next_element;
 
   DrawLevelField(oldx, oldy);
   DrawLevelField(newx, newy);
@@ -1634,57 +1989,212 @@ void CheckDynamite(int x, int y)
   Bang(x, y);
 }
 
-void Explode(int ex, int ey, int phase, int mode)
+void ShowEnvelope()
 {
-  int x, y;
-  int num_phase = 9;
-  int delay = (game.emulation == EMU_SUPAPLEX ? 3 : 2);
-  int last_phase = num_phase * delay;
-  int half_phase = (num_phase / 2) * delay;
-  int first_phase_after_start = EX_PHASE_START + 1;
+  int i, x, y;
 
-  if (game.explosions_delayed)
+  /* open envelope window horizontally */
+  for (i=2; i <= level.envelope_xsize + 2; i += 2)
   {
-    ExplodeField[ex][ey] = mode;
-    return;
-  }
+    int startx = (SXSIZE / MINI_TILEX - i) / 2;
+    int starty = (SYSIZE / MINI_TILEY) / 2 - 1;
 
-  if (phase == EX_PHASE_START)         /* initialize 'Store[][]' field */
-  {
-    int center_element = Feld[ex][ey];
+    SetDrawtoField(DRAW_BUFFERED);
 
-    /* remove things displayed in background while burning dynamite */
-    if (!IS_INDESTRUCTIBLE(Back[ex][ey]))
-      Back[ex][ey] = 0;
+    BlitBitmap(fieldbuffer, backbuffer, FX, FY, SXSIZE, SYSIZE, SX, SY);
 
-    if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
+    SetDrawtoField(DRAW_BACKBUFFER);
+
+    for (y=0; y < 2; y++) for (x=0; x < i; x++)
     {
-      /* put moving element to center field (and let it explode there) */
-      center_element = MovingOrBlocked2Element(ex, ey);
-      RemoveMovingField(ex, ey);
-      Feld[ex][ey] = center_element;
+      int ex = (x == 0 ? -1 : x == i - 1 ? +1 : 0);
+      int ey = (y == 0 ? -1 : y == 1     ? +1 : 0);
+
+      DrawEnvelopeBorder(startx + x, starty + y, ex, ey);
     }
 
-    for (y = ey - 1; y <= ey + 1; y++) for(x = ex - 1; x <= ex + 1; x++)
-    {
-      int element;
+    redraw_mask |= REDRAW_FIELD | REDRAW_FROM_BACKBUFFER;
+    BackToFront();
 
-      if (!IN_LEV_FIELD(x, y) ||
-         ((mode != EX_NORMAL || center_element == EL_AMOEBA_TO_DIAMOND) &&
-          (x != ex || y != ey)))
-       continue;
+    Delay(GAME_FRAME_DELAY);
+  }
 
-      element = Feld[x][y];
+  /* open envelope window vertically */
+  for (i=2; i <= level.envelope_ysize + 2; i += 2)
+  {
+    int xsize = level.envelope_xsize + 2;
+    int startx = (SXSIZE / MINI_TILEX - (xsize - 1)) / 2;
+    int starty = (SYSIZE / MINI_TILEY - i) / 2;
 
-      if (IS_MOVING(x, y) || IS_BLOCKED(x, y))
+    SetDrawtoField(DRAW_BUFFERED);
+
+    BlitBitmap(fieldbuffer, backbuffer, FX, FY, SXSIZE, SYSIZE, SX, SY);
+
+    SetDrawtoField(DRAW_BACKBUFFER);
+
+    for (y=0; y < i; y++) for (x=0; x < xsize; x++)
+    {
+      int ex = (x == 0 ? -1 : x == xsize - 1 ? +1 : 0);
+      int ey = (y == 0 ? -1 : y == i - 1     ? +1 : 0);
+
+      DrawEnvelopeBorder(startx + x, starty + y, ex, ey);
+    }
+
+    DrawTextToTextArea(SX + (startx + 1) * MINI_TILEX,
+                      SY + (starty + 1) * MINI_TILEY, level.envelope,
+                      FONT_TEXT_1, level.envelope_xsize, i - 2);
+
+    redraw_mask |= REDRAW_FIELD | REDRAW_FROM_BACKBUFFER;
+    BackToFront();
+
+    Delay(GAME_FRAME_DELAY);
+  }
+
+  Delay(3000);
+
+  SetDrawtoField(DRAW_BUFFERED);
+
+  redraw_mask |= REDRAW_FIELD;
+  BackToFront();
+}
+
+void RelocatePlayer(int x, int y, int element)
+{
+  struct PlayerInfo *player = &stored_player[element - EL_PLAYER_1];
+
+  if (player->present)
+  {
+    while (player->MovPos)
+    {
+      ScrollFigure(player, SCROLL_GO_ON);
+      ScrollScreen(NULL, SCROLL_GO_ON);
+      FrameCounter++;
+      DrawAllPlayers();
+      BackToFront();
+    }
+
+    RemoveField(player->jx, player->jy);
+    DrawLevelField(player->jx, player->jy);
+  }
+
+  InitPlayerField(x, y, element, TRUE);
+
+  if (player == local_player)
+  {
+    int scroll_xx = -999, scroll_yy = -999;
+
+    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);
+
+      scroll_x -= dx;
+      scroll_y -= dy;
+
+      fx += dx * TILEX / 2;
+      fy += dy * TILEY / 2;
+
+      ScrollLevel(dx, dy);
+      DrawAllPlayers();
+
+      /* scroll in to steps of half tile size to make things smoother */
+      BlitBitmap(drawto_field, window, fx, fy, SXSIZE, SYSIZE, SX, SY);
+      FlushDisplay();
+      Delay(GAME_FRAME_DELAY);
+
+      /* scroll second step to align at full tile size */
+      BackToFront();
+      Delay(GAME_FRAME_DELAY);
+    }
+  }
+}
+
+void Explode(int ex, int ey, int phase, int mode)
+{
+  int x, y;
+  int num_phase = 9;
+  int delay = (game.emulation == EMU_SUPAPLEX ? 3 : 2);
+  int last_phase = num_phase * delay;
+  int half_phase = (num_phase / 2) * delay;
+  int first_phase_after_start = EX_PHASE_START + 1;
+
+  if (game.explosions_delayed)
+  {
+    ExplodeField[ex][ey] = mode;
+    return;
+  }
+
+  if (phase == EX_PHASE_START)         /* initialize 'Store[][]' field */
+  {
+    int center_element = Feld[ex][ey];
+
+#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 >= RELEASE_IDENT(2,2,0,7) &&
+       center_element == EL_EMPTY && (mode == EX_NORMAL || mode == EX_CENTER))
+      return;
+#endif
+
+    if (mode == EX_NORMAL || mode == EX_CENTER)
+      PlaySoundLevelAction(ex, ey, ACTION_EXPLODING);
+
+    /* remove things displayed in background while burning dynamite */
+    if (Back[ex][ey] != EL_EMPTY && !IS_INDESTRUCTIBLE(Back[ex][ey]))
+      Back[ex][ey] = 0;
+
+    if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
+    {
+      /* put moving element to center field (and let it explode there) */
+      center_element = MovingOrBlocked2Element(ex, ey);
+      RemoveMovingField(ex, ey);
+      Feld[ex][ey] = center_element;
+    }
+
+    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 (!IN_LEV_FIELD(x, y) ||
+         ((mode != EX_NORMAL || center_element == EL_AMOEBA_TO_DIAMOND) &&
+          (x != ex || y != ey)))
+       continue;
+
+      element = Feld[x][y];
+
+      if (IS_MOVING(x, y) || IS_BLOCKED(x, y))
       {
        element = MovingOrBlocked2Element(x, y);
-       RemoveMovingField(x, y);
+
+       if (!IS_EXPLOSION_PROOF(element))
+         RemoveMovingField(x, y);
       }
 
 #if 1
+
+#if 0
       if (IS_EXPLOSION_PROOF(element))
        continue;
+#else
+      /* indestructible elements can only explode in center (but not flames) */
+      if ((IS_EXPLOSION_PROOF(element) && (x != ex || y != ey)) ||
+         element == EL_FLAMES)
+       continue;
+#endif
+
 #else
       if ((IS_INDESTRUCTIBLE(element) &&
           (game.engine_version < VERSION_IDENT(2,2,0) ||
@@ -1706,13 +2216,31 @@ void Explode(int ex, int ey, int phase, int mode)
       }
 
       /* save walkable background elements while explosion on same tile */
+#if 0
       if (IS_INDESTRUCTIBLE(element))
        Back[x][y] = element;
+#else
+      if (IS_WALKABLE(element) && IS_INDESTRUCTIBLE(element))
+       Back[x][y] = element;
+#endif
 
       /* ignite explodable elements reached by other explosion */
       if (element == EL_EXPLOSION)
        element = Store2[x][y];
 
+#if 1
+      if (AmoebaNr[x][y] &&
+         (element == EL_AMOEBA_FULL ||
+          element == EL_BD_AMOEBA ||
+          element == EL_AMOEBA_GROWING))
+      {
+       AmoebaCnt[AmoebaNr[x][y]]--;
+       AmoebaCnt2[AmoebaNr[x][y]]--;
+      }
+
+      RemoveField(x, y);
+#endif
+
       if (IS_PLAYER(ex, ey) && !PLAYER_PROTECTED(ex, ey))
       {
        switch(StorePlayer[ex][ey])
@@ -1748,11 +2276,10 @@ void Explode(int ex, int ey, int phase, int mode)
       else if (center_element == EL_AMOEBA_TO_DIAMOND)
        Store[x][y] = level.amoeba_content;
       else if (center_element == EL_YAMYAM)
-       Store[x][y] =
-         level.yamyam_content[game.yamyam_content_nr][x - ex + 1][y - ey + 1];
-      else if (IS_CUSTOM_ELEMENT(center_element))
-       Store[x][y] =
-         element_info[center_element].content[x - ex + 1][y - ey + 1];
+       Store[x][y] = level.yamyam_content[game.yamyam_content_nr][xx][yy];
+      else if (IS_CUSTOM_ELEMENT(center_element) &&
+              element_info[center_element].content[xx][yy] != EL_EMPTY)
+       Store[x][y] = element_info[center_element].content[xx][yy];
       else if (element == EL_WALL_EMERALD)
        Store[x][y] = EL_EMERALD;
       else if (element == EL_WALL_DIAMOND)
@@ -1769,6 +2296,8 @@ void Explode(int ex, int ey, int phase, int mode)
        Store[x][y] = EL_PEARL;
       else if (element == EL_WALL_CRYSTAL)
        Store[x][y] = EL_CRYSTAL;
+      else if (IS_CUSTOM_ELEMENT(element) && !CAN_EXPLODE(element))
+       Store[x][y] = element_info[element].content[1][1];
       else
        Store[x][y] = EL_EMPTY;
 
@@ -1776,6 +2305,7 @@ void Explode(int ex, int ey, int phase, int mode)
          center_element == EL_AMOEBA_TO_DIAMOND || mode == EX_BORDER)
        Store2[x][y] = element;
 
+#if 0
       if (AmoebaNr[x][y] &&
          (element == EL_AMOEBA_FULL ||
           element == EL_BD_AMOEBA ||
@@ -1785,10 +2315,21 @@ void Explode(int ex, int ey, int phase, int mode)
        AmoebaCnt2[AmoebaNr[x][y]]--;
       }
 
-      Feld[x][y] = EL_EXPLOSION;
-      GfxElement[x][y] = EL_UNDEFINED;
+#if 1
+      RemoveField(x, y);
+#else
       MovDir[x][y] = MovPos[x][y] = 0;
       AmoebaNr[x][y] = 0;
+#endif
+#endif
+
+      Feld[x][y] = EL_EXPLOSION;
+#if 1
+      GfxElement[x][y] = center_element;
+#else
+      GfxElement[x][y] = EL_UNDEFINED;
+#endif
+
       ExplodePhase[x][y] = 1;
       Stop[x][y] = TRUE;
     }
@@ -1841,26 +2382,37 @@ void Explode(int ex, int ey, int phase, int mode)
 
     element = Feld[x][y] = Store[x][y];
     Store[x][y] = Store2[x][y] = 0;
+    GfxElement[x][y] = EL_UNDEFINED;
 
     if (Back[x][y] && IS_INDESTRUCTIBLE(Back[x][y]))
       element = Feld[x][y] = Back[x][y];
     Back[x][y] = 0;
 
-    MovDir[x][y] = MovPos[x][y] = MovDelay[x][y] = 0;
+    MovDir[x][y] = MovPos[x][y] = MovDelay[x][y] = ChangeDelay[x][y] = 0;
     InitField(x, y, FALSE);
     if (CAN_MOVE(element))
       InitMovDir(x, y);
     DrawLevelField(x, y);
 
+    if (CAN_BE_CRUMBLED(element))
+      DrawLevelFieldCrumbledSandNeighbours(x, y);
+
     if (IS_PLAYER(x, y) && !PLAYERINFO(x,y)->present)
       StorePlayer[x][y] = 0;
+
+    if (ELEM_IS_PLAYER(element))
+      RelocatePlayer(x, y, element);
   }
   else if (phase >= delay && IN_SCR_FIELD(SCREENX(x), SCREENY(y)))
   {
+#if 1
+    int graphic = el_act2img(GfxElement[x][y], ACTION_EXPLODING);
+#else
     int stored = Store[x][y];
     int graphic = (game.emulation != EMU_SUPAPLEX ? IMG_EXPLOSION :
                   stored == EL_SP_INFOTRON ? IMG_SP_EXPLOSION_INFOTRON :
                   IMG_SP_EXPLOSION);
+#endif
     int frame = getGraphicAnimationFrame(graphic, phase - delay);
 
     if (phase == delay)
@@ -1924,6 +2476,7 @@ void DynaExplode(int ex, int ey)
 
       Explode(x, y, EX_PHASE_START, EX_BORDER);
 
+      /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
       if (element != EL_EMPTY &&
          element != EL_SAND &&
          element != EL_EXPLOSION &&
@@ -1935,12 +2488,30 @@ void DynaExplode(int ex, int ey)
 
 void Bang(int x, int y)
 {
+#if 1
+  int element = MovingOrBlocked2Element(x, y);
+#else
   int element = Feld[x][y];
+#endif
+
+  if (IS_PLAYER(x, y))
+  {
+    struct PlayerInfo *player = PLAYERINFO(x, y);
+
+    element = Feld[x][y] = (player->use_murphy_graphic ? EL_SP_MURPHY :
+                           player->element_nr);
+  }
 
+#if 0
+#if 1
+  PlaySoundLevelAction(x, y, ACTION_EXPLODING);
+#else
   if (game.emulation == EMU_SUPAPLEX)
     PlaySoundLevel(x, y, SND_SP_ELEMENT_EXPLODING);
   else
     PlaySoundLevel(x, y, SND_ELEMENT_EXPLODING);
+#endif
+#endif
 
 #if 0
   if (IS_PLAYER(x, y)) /* remove objects that might cause smaller explosion */
@@ -1979,9 +2550,14 @@ void Bang(int x, int y)
        Explode(x, y, EX_PHASE_START, EX_CENTER);
       break;
     default:
-      Explode(x, y, EX_PHASE_START, EX_NORMAL);
+      if (CAN_EXPLODE_1X1(element))
+       Explode(x, y, EX_PHASE_START, EX_CENTER);
+      else
+       Explode(x, y, EX_PHASE_START, EX_NORMAL);
       break;
   }
+
+  CheckTriggeredElementChange(x, y, element, CE_OTHER_IS_EXPLODING);
 }
 
 void SplashAcid(int x, int y)
@@ -2214,14 +2790,16 @@ static int getInvisibleActiveFromInvisibleElement(int element)
 {
   return (element == EL_INVISIBLE_STEELWALL ? EL_INVISIBLE_STEELWALL_ACTIVE :
          element == EL_INVISIBLE_WALL      ? EL_INVISIBLE_WALL_ACTIVE :
-         EL_INVISIBLE_SAND_ACTIVE);
+         element == EL_INVISIBLE_SAND      ? EL_INVISIBLE_SAND_ACTIVE :
+         element);
 }
 
 static int getInvisibleFromInvisibleActiveElement(int element)
 {
   return (element == EL_INVISIBLE_STEELWALL_ACTIVE ? EL_INVISIBLE_STEELWALL :
          element == EL_INVISIBLE_WALL_ACTIVE      ? EL_INVISIBLE_WALL :
-         EL_INVISIBLE_SAND);
+         element == EL_INVISIBLE_SAND_ACTIVE      ? EL_INVISIBLE_SAND :
+         element);
 }
 
 static void RedrawAllLightSwitchesAndInvisibleElements()
@@ -2312,6 +2890,29 @@ static void ActivateTimegateSwitch(int x, int y)
   Feld[x][y] = EL_TIMEGATE_SWITCH_ACTIVE;
 }
 
+inline static int getElementMoveStepsize(int x, int y)
+{
+  int element = Feld[x][y];
+  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);
+  int horiz_move = (dx != 0);
+  int sign = (horiz_move ? dx : dy);
+  int step = sign * element_info[element].move_stepsize;
+
+  /* special values for move stepsize for spring and things on conveyor belt */
+  if (horiz_move)
+  {
+    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;
+  }
+
+  return step;
+}
+
 void Impact(int x, int y)
 {
   boolean lastline = (y == lev_fieldy-1);
@@ -2322,14 +2923,22 @@ void Impact(int x, int y)
 
   if (!lastline)       /* check if element below was hit */
   {
-    if (Feld[x][y+1] == EL_PLAYER_IS_LEAVING)
+    if (Feld[x][y + 1] == EL_PLAYER_IS_LEAVING)
       return;
 
-    object_hit = (!IS_FREE(x, y+1) && (!IS_MOVING(x, y+1) ||
-                                     MovDir[x][y+1] != MV_DOWN ||
-                                     MovPos[x][y+1] <= TILEY / 2));
+    object_hit = (!IS_FREE(x, y + 1) && (!IS_MOVING(x, y + 1) ||
+                                        MovDir[x][y + 1] != MV_DOWN ||
+                                        MovPos[x][y + 1] <= TILEY / 2));
+
+    /* do not smash moving elements that left the smashed field in time */
+    if (game.engine_version >= RELEASE_IDENT(2,2,0,7) && IS_MOVING(x, y + 1) &&
+       ABS(MovPos[x][y + 1] + getElementMoveStepsize(x, y + 1)) >= TILEX)
+      object_hit = FALSE;
+
     if (object_hit)
-      smashed = MovingOrBlocked2Element(x, y+1);
+      smashed = MovingOrBlocked2Element(x, y + 1);
+
+    impact = (lastline || object_hit);
   }
 
   if (!lastline && smashed == EL_ACID) /* element falls into acid */
@@ -2338,35 +2947,36 @@ void Impact(int x, int y)
     return;
   }
 
-  if (impact)
+  /* only reset graphic animation if graphic really changes after impact */
+  if (impact &&
+      el_act_dir2img(element, GfxAction[x][y], MV_DOWN) != el2img(element))
   {
     ResetGfxAnimation(x, y);
     DrawLevelField(x, y);
   }
 
-#if 1
   if (impact && CAN_EXPLODE_IMPACT(element))
-#else
-  if ((element == EL_BOMB ||
-       element == EL_SP_DISK_ORANGE ||
-       element == EL_DX_SUPABOMB) &&
-      (lastline || object_hit))                /* element is bomb */
-#endif
   {
     Bang(x, y);
     return;
   }
-  else if (element == EL_PEARL)
+  else if (impact && element == EL_PEARL)
   {
     Feld[x][y] = EL_PEARL_BREAKING;
     PlaySoundLevel(x, y, SND_PEARL_BREAKING);
     return;
   }
+  else if (impact && CheckElementChange(x, y, element, CE_IMPACT))
+  {
+    PlaySoundLevelElementAction(x, y, element, ACTION_IMPACT);
+
+    return;
+  }
 
   if (impact && element == EL_AMOEBA_DROP)
   {
-    if (object_hit && IS_PLAYER(x, y+1))
-      KillHeroUnlessProtected(x, y+1);
+    if (object_hit && IS_PLAYER(x, y + 1))
+      KillHeroUnlessProtected(x, y + 1);
     else if (object_hit && smashed == EL_PENGUIN)
       Bang(x, y + 1);
     else
@@ -2379,7 +2989,7 @@ void Impact(int x, int y)
     return;
   }
 
-  if (!lastline && object_hit)         /* check which object was hit */
+  if (object_hit)              /* check which object was hit */
   {
     if (CAN_PASS_MAGIC_WALL(element) && 
        (smashed == EL_MAGIC_WALL ||
@@ -2406,13 +3016,19 @@ void Impact(int x, int y)
 
     if (IS_PLAYER(x, y + 1))
     {
-      KillHeroUnlessProtected(x, y+1);
-      return;
+      if (CAN_SMASH_PLAYER(element))
+      {
+       KillHeroUnlessProtected(x, y + 1);
+       return;
+      }
     }
     else if (smashed == EL_PENGUIN)
     {
-      Bang(x, y + 1);
-      return;
+      if (CAN_SMASH_PLAYER(element))
+      {
+       Bang(x, y + 1);
+       return;
+      }
     }
     else if (element == EL_BD_DIAMOND)
     {
@@ -2431,23 +3047,22 @@ void Impact(int x, int y)
       Bang(x, y + 1);
       return;
     }
-    else if (element == EL_ROCK ||
-            element == EL_SP_ZONK ||
-            element == EL_BD_ROCK)
+#if 0
+    else if (CAN_SMASH_ENEMIES(element) && IS_CLASSIC_ENEMY(smashed))
+    {
+      Bang(x, y + 1);
+      return;
+    }
+#endif
+    else if (CAN_SMASH_EVERYTHING(element))
     {
       if (IS_CLASSIC_ENEMY(smashed) ||
-         smashed == EL_BOMB ||
-         smashed == EL_SP_DISK_ORANGE ||
-         smashed == EL_DX_SUPABOMB ||
-         smashed == EL_SATELLITE ||
-         smashed == EL_PIG ||
-         smashed == EL_DRAGON ||
-         smashed == EL_MOLE)
+         CAN_EXPLODE_SMASHED(smashed))
       {
        Bang(x, y + 1);
        return;
       }
-      else if (!IS_MOVING(x, y + 1))
+      else if (!IS_MOVING(x, y + 1) && !IS_BLOCKED(x, y + 1))
       {
        if (smashed == EL_LAMP ||
            smashed == EL_LAMP_ACTIVE)
@@ -2457,49 +3072,57 @@ void Impact(int x, int y)
        }
        else if (smashed == EL_NUT)
        {
-         Feld[x][y+1] = EL_NUT_BREAKING;
+         Feld[x][y + 1] = EL_NUT_BREAKING;
          PlaySoundLevel(x, y, SND_NUT_BREAKING);
          RaiseScoreElement(EL_NUT);
          return;
        }
        else if (smashed == EL_PEARL)
        {
-         Feld[x][y+1] = EL_PEARL_BREAKING;
+         Feld[x][y + 1] = EL_PEARL_BREAKING;
          PlaySoundLevel(x, y, SND_PEARL_BREAKING);
          return;
        }
        else if (smashed == EL_DIAMOND)
        {
-         Feld[x][y+1] = EL_EMPTY;
+         Feld[x][y + 1] = EL_DIAMOND_BREAKING;
          PlaySoundLevel(x, y, SND_DIAMOND_BREAKING);
          return;
        }
        else if (IS_BELT_SWITCH(smashed))
        {
-         ToggleBeltSwitch(x, y+1);
+         ToggleBeltSwitch(x, y + 1);
        }
        else if (smashed == EL_SWITCHGATE_SWITCH_UP ||
                 smashed == EL_SWITCHGATE_SWITCH_DOWN)
        {
-         ToggleSwitchgateSwitch(x, y+1);
+         ToggleSwitchgateSwitch(x, y + 1);
        }
        else if (smashed == EL_LIGHT_SWITCH ||
                 smashed == EL_LIGHT_SWITCH_ACTIVE)
        {
-         ToggleLightSwitch(x, y+1);
+         ToggleLightSwitch(x, y + 1);
+       }
+       else
+       {
+         CheckElementChange(x, y + 1, smashed, CE_SMASHED);
        }
       }
+      else
+      {
+       CheckElementChange(x, y + 1, smashed, CE_SMASHED);
+      }
     }
   }
 
   /* play sound of magic wall / mill */
   if (!lastline &&
-      (Feld[x][y+1] == EL_MAGIC_WALL_ACTIVE ||
-       Feld[x][y+1] == EL_BD_MAGIC_WALL_ACTIVE))
+      (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE ||
+       Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE))
   {
-    if (Feld[x][y+1] == EL_MAGIC_WALL_ACTIVE)
+    if (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE)
       PlaySoundLevel(x, y, SND_MAGIC_WALL_FILLING);
-    else if (Feld[x][y+1] == EL_BD_MAGIC_WALL_ACTIVE)
+    else if (Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE)
       PlaySoundLevel(x, y, SND_BD_MAGIC_WALL_FILLING);
 
     return;
@@ -2535,7 +3158,9 @@ void TurnRound(int x, int y)
     { MV_UP,   MV_DOWN,        MV_LEFT  },
     { 0,       0,              0        },
     { MV_LEFT, MV_RIGHT,       MV_DOWN  },
-    { 0,0,0 }, { 0,0,0 },      { 0,0,0  },
+    { 0,       0,              0        },
+    { 0,       0,              0        },
+    { 0,       0,              0        },
     { MV_RIGHT,        MV_LEFT,        MV_UP    }
   };
 
@@ -2554,15 +3179,15 @@ void TurnRound(int x, int y)
   int right_x = x + right_dx, right_y = y + right_dy;
   int move_x  = x + move_dx,  move_y  = y + move_dy;
 
+  int xx, yy;
+
   if (element == EL_BUG || element == EL_BD_BUTTERFLY)
   {
     TestIfBadThingTouchesOtherBadThing(x, y);
 
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       IS_FREE(right_x, right_y))
+    if (ENEMY_CAN_ENTER_FIELD(right_x, right_y))
       MovDir[x][y] = right_dir;
-    else if (!IN_LEV_FIELD(move_x, move_y) ||
-            !IS_FREE(move_x, move_y))
+    else if (!ENEMY_CAN_ENTER_FIELD(move_x, move_y))
       MovDir[x][y] = left_dir;
 
     if (element == EL_BUG && MovDir[x][y] != old_move_dir)
@@ -2575,15 +3200,14 @@ void TurnRound(int x, int y)
   {
     TestIfBadThingTouchesOtherBadThing(x, y);
 
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       IS_FREE(left_x, left_y))
+    if (ENEMY_CAN_ENTER_FIELD(left_x, left_y))
       MovDir[x][y] = left_dir;
-    else if (!IN_LEV_FIELD(move_x, move_y) ||
-            !IS_FREE(move_x, move_y))
+    else if (!ENEMY_CAN_ENTER_FIELD(move_x, move_y))
       MovDir[x][y] = right_dir;
 
     if ((element == EL_SPACESHIP ||
-        element == EL_SP_SNIKSNAK || element == EL_SP_ELECTRON)
+        element == EL_SP_SNIKSNAK ||
+        element == EL_SP_ELECTRON)
        && MovDir[x][y] != old_move_dir)
       MovDelay[x][y] = 9;
     else if (element == EL_BD_FIREFLY)     /* && MovDir[x][y] == right_dir) */
@@ -2591,16 +3215,8 @@ void TurnRound(int x, int y)
   }
   else if (element == EL_YAMYAM)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE;
-
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       (IS_FREE_OR_PLAYER(left_x, left_y) ||
-        Feld[left_x][left_y] == EL_DIAMOND))
-      can_turn_left = TRUE;
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       (IS_FREE_OR_PLAYER(right_x, right_y) ||
-        Feld[right_x][right_y] == EL_DIAMOND))
-      can_turn_right = TRUE;
+    boolean can_turn_left  = YAMYAM_CAN_ENTER_FIELD(left_x, left_y);
+    boolean can_turn_right = YAMYAM_CAN_ENTER_FIELD(right_x, right_y);
 
     if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
@@ -2611,20 +3227,12 @@ void TurnRound(int x, int y)
     else
       MovDir[x][y] = back_dir;
 
-    MovDelay[x][y] = 16+16*RND(3);
+    MovDelay[x][y] = 16 + 16 * RND(3);
   }
   else if (element == EL_DARK_YAMYAM)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE;
-
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       (IS_FREE_OR_PLAYER(left_x, left_y) ||
-        IS_FOOD_DARK_YAMYAM(Feld[left_x][left_y])))
-      can_turn_left = TRUE;
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       (IS_FREE_OR_PLAYER(right_x, right_y) ||
-        IS_FOOD_DARK_YAMYAM(Feld[right_x][right_y])))
-      can_turn_right = TRUE;
+    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);
 
     if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
@@ -2635,20 +3243,12 @@ void TurnRound(int x, int y)
     else
       MovDir[x][y] = back_dir;
 
-    MovDelay[x][y] = 16+16*RND(3);
+    MovDelay[x][y] = 16 + 16 * RND(3);
   }
   else if (element == EL_PACMAN)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE;
-
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       (IS_FREE_OR_PLAYER(left_x, left_y) ||
-        IS_AMOEBOID(Feld[left_x][left_y])))
-      can_turn_left = TRUE;
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       (IS_FREE_OR_PLAYER(right_x, right_y) ||
-        IS_AMOEBOID(Feld[right_x][right_y])))
-      can_turn_right = TRUE;
+    boolean can_turn_left  = PACMAN_CAN_ENTER_FIELD(left_x, left_y);
+    boolean can_turn_right = PACMAN_CAN_ENTER_FIELD(right_x, right_y);
 
     if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
@@ -2659,56 +3259,45 @@ void TurnRound(int x, int y)
     else
       MovDir[x][y] = back_dir;
 
-    MovDelay[x][y] = 6+RND(40);
+    MovDelay[x][y] = 6 + RND(40);
   }
   else if (element == EL_PIG)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE, can_move_on = FALSE;
-    boolean should_turn_left = FALSE, should_turn_right = FALSE;
-    boolean should_move_on = FALSE;
+    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 should_turn_left, should_turn_right, should_move_on;
     int rnd_value = 24;
     int rnd = RND(rnd_value);
 
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       (IS_FREE(left_x, left_y) || IS_FOOD_PIG(Feld[left_x][left_y])))
-      can_turn_left = TRUE;
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       (IS_FREE(right_x, right_y) || IS_FOOD_PIG(Feld[right_x][right_y])))
-      can_turn_right = TRUE;
-    if (IN_LEV_FIELD(move_x, move_y) &&
-       (IS_FREE(move_x, move_y) || IS_FOOD_PIG(Feld[move_x][move_y])))
-      can_move_on = TRUE;
-
-    if (can_turn_left &&
-       (!can_move_on ||
-        (IN_LEV_FIELD(x+back_dx+left_dx, y+back_dy+left_dy) &&
-         !IS_FREE(x+back_dx+left_dx, y+back_dy+left_dy))))
-      should_turn_left = TRUE;
-    if (can_turn_right &&
-       (!can_move_on ||
-        (IN_LEV_FIELD(x+back_dx+right_dx, y+back_dy+right_dy) &&
-         !IS_FREE(x+back_dx+right_dx, y+back_dy+right_dy))))
-      should_turn_right = TRUE;
-    if (can_move_on &&
-       (!can_turn_left || !can_turn_right ||
-        (IN_LEV_FIELD(x+move_dx+left_dx, y+move_dy+left_dy) &&
-         !IS_FREE(x+move_dx+left_dx, y+move_dy+left_dy)) ||
-        (IN_LEV_FIELD(x+move_dx+right_dx, y+move_dy+right_dy) &&
-         !IS_FREE(x+move_dx+right_dx, y+move_dy+right_dy))))
-      should_move_on = TRUE;
+    should_turn_left = (can_turn_left &&
+                       (!can_move_on ||
+                        IN_LEV_FIELD_AND_NOT_FREE(x + back_dx + left_dx,
+                                                  y + back_dy + left_dy)));
+    should_turn_right = (can_turn_right &&
+                        (!can_move_on ||
+                         IN_LEV_FIELD_AND_NOT_FREE(x + back_dx + right_dx,
+                                                   y + back_dy + right_dy)));
+    should_move_on = (can_move_on &&
+                     (!can_turn_left ||
+                      !can_turn_right ||
+                      IN_LEV_FIELD_AND_NOT_FREE(x + move_dx + left_dx,
+                                                y + move_dy + left_dy) ||
+                      IN_LEV_FIELD_AND_NOT_FREE(x + move_dx + right_dx,
+                                                y + move_dy + right_dy)));
 
     if (should_turn_left || should_turn_right || should_move_on)
     {
       if (should_turn_left && should_turn_right && should_move_on)
-       MovDir[x][y] = (rnd < rnd_value/3 ? left_dir :
-                       rnd < 2*rnd_value/3 ? right_dir :
+       MovDir[x][y] = (rnd < rnd_value / 3     ? left_dir :
+                       rnd < 2 * rnd_value / 3 ? right_dir :
                        old_move_dir);
       else if (should_turn_left && should_turn_right)
-       MovDir[x][y] = (rnd < rnd_value/2 ? left_dir : right_dir);
+       MovDir[x][y] = (rnd < rnd_value / 2 ? left_dir : right_dir);
       else if (should_turn_left && should_move_on)
-       MovDir[x][y] = (rnd < rnd_value/2 ? left_dir : old_move_dir);
+       MovDir[x][y] = (rnd < rnd_value / 2 ? left_dir : old_move_dir);
       else if (should_turn_right && should_move_on)
-       MovDir[x][y] = (rnd < rnd_value/2 ? right_dir : old_move_dir);
+       MovDir[x][y] = (rnd < rnd_value / 2 ? right_dir : old_move_dir);
       else if (should_turn_left)
        MovDir[x][y] = left_dir;
       else if (should_turn_right)
@@ -2716,69 +3305,67 @@ void TurnRound(int x, int y)
       else if (should_move_on)
        MovDir[x][y] = old_move_dir;
     }
-    else if (can_move_on && rnd > rnd_value/8)
+    else if (can_move_on && rnd > rnd_value / 8)
       MovDir[x][y] = old_move_dir;
     else if (can_turn_left && can_turn_right)
-      MovDir[x][y] = (rnd < rnd_value/2 ? left_dir : right_dir);
-    else if (can_turn_left && rnd > rnd_value/8)
+      MovDir[x][y] = (rnd < rnd_value / 2 ? left_dir : right_dir);
+    else if (can_turn_left && rnd > rnd_value / 8)
       MovDir[x][y] = left_dir;
     else if (can_turn_right && rnd > rnd_value/8)
       MovDir[x][y] = right_dir;
     else
       MovDir[x][y] = back_dir;
 
-    if (!IS_FREE(x+move_xy[MovDir[x][y]].x, y+move_xy[MovDir[x][y]].y) &&
-       !IS_FOOD_PIG(Feld[x+move_xy[MovDir[x][y]].x][y+move_xy[MovDir[x][y]].y]))
+    xx = x + move_xy[MovDir[x][y]].x;
+    yy = y + move_xy[MovDir[x][y]].y;
+
+    if (!IS_FREE(xx, yy) && !IS_FOOD_PIG(Feld[xx][yy]))
       MovDir[x][y] = old_move_dir;
 
     MovDelay[x][y] = 0;
   }
   else if (element == EL_DRAGON)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE, can_move_on = FALSE;
+    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);
     int rnd_value = 24;
     int rnd = RND(rnd_value);
 
-    if (IN_LEV_FIELD(left_x, left_y) && IS_FREE(left_x, left_y))
-      can_turn_left = TRUE;
-    if (IN_LEV_FIELD(right_x, right_y) && IS_FREE(right_x, right_y))
-      can_turn_right = TRUE;
-    if (IN_LEV_FIELD(move_x, move_y) && IS_FREE(move_x, move_y))
-      can_move_on = TRUE;
-
-    if (can_move_on && rnd > rnd_value/8)
+    if (can_move_on && rnd > rnd_value / 8)
       MovDir[x][y] = old_move_dir;
     else if (can_turn_left && can_turn_right)
-      MovDir[x][y] = (rnd < rnd_value/2 ? left_dir : right_dir);
-    else if (can_turn_left && rnd > rnd_value/8)
+      MovDir[x][y] = (rnd < rnd_value / 2 ? left_dir : right_dir);
+    else if (can_turn_left && rnd > rnd_value / 8)
       MovDir[x][y] = left_dir;
-    else if (can_turn_right && rnd > rnd_value/8)
+    else if (can_turn_right && rnd > rnd_value / 8)
       MovDir[x][y] = right_dir;
     else
       MovDir[x][y] = back_dir;
 
-    if (!IS_FREE(x+move_xy[MovDir[x][y]].x, y+move_xy[MovDir[x][y]].y))
+    xx = x + move_xy[MovDir[x][y]].x;
+    yy = y + move_xy[MovDir[x][y]].y;
+
+    if (!IS_FREE(xx, yy))
       MovDir[x][y] = old_move_dir;
 
     MovDelay[x][y] = 0;
   }
   else if (element == EL_MOLE)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE, can_move_on = FALSE;
-
-    if (IN_LEV_FIELD(move_x, move_y) &&
-       (IS_FREE(move_x, move_y) || IS_AMOEBOID(Feld[move_x][move_y]) ||
-        Feld[move_x][move_y] == EL_AMOEBA_SHRINKING))
-      can_move_on = TRUE;
-
+    boolean can_move_on =
+      (MOLE_CAN_ENTER_FIELD(move_x, move_y,
+                           IS_AMOEBOID(Feld[move_x][move_y]) ||
+                           Feld[move_x][move_y] == EL_AMOEBA_SHRINKING));
     if (!can_move_on)
     {
-      if (IN_LEV_FIELD(left_x, left_y) &&
-         (IS_FREE(left_x, left_y) || IS_AMOEBOID(Feld[left_x][left_y])))
-       can_turn_left = TRUE;
-      if (IN_LEV_FIELD(right_x, right_y) &&
-         (IS_FREE(right_x, right_y) || IS_AMOEBOID(Feld[right_x][right_y])))
-       can_turn_right = TRUE;
+      boolean can_turn_left =
+       (MOLE_CAN_ENTER_FIELD(left_x, left_y,
+                             IS_AMOEBOID(Feld[left_x][left_y])));
+
+      boolean can_turn_right =
+       (MOLE_CAN_ENTER_FIELD(right_x, right_y,
+                             IS_AMOEBOID(Feld[right_x][right_y])));
 
       if (can_turn_left && can_turn_right)
        MovDir[x][y] = (RND(2) ? left_dir : right_dir);
@@ -2798,9 +3385,9 @@ void TurnRound(int x, int y)
   }
   else if (element == EL_SPRING)
   {
-    if ((MovDir[x][y] == MV_LEFT || MovDir[x][y] == MV_RIGHT) &&
-       (!IN_LEV_FIELD(move_x, move_y) || !IS_FREE(move_x, move_y) ||
-        (IN_LEV_FIELD(x, y + 1) && IS_FREE(x, y + 1))))
+    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)))
       MovDir[x][y] = MV_NO_MOVING;
 
     MovDelay[x][y] = 0;
@@ -2828,7 +3415,8 @@ void TurnRound(int x, int y)
        if (!player->active)
          continue;
 
-       if (attr_x == -1 || ABS(jx-x)+ABS(jy-y) < ABS(attr_x-x)+ABS(attr_y-y))
+       if (attr_x == -1 ||
+           ABS(jx - x) + ABS(jy - y) < ABS(attr_x - x) + ABS(attr_y - y))
        {
          attr_x = jx;
          attr_y = jy;
@@ -2886,11 +3474,40 @@ void TurnRound(int x, int y)
       Moving2Blocked(x, y, &newx, &newy);
 
       if (IN_LEV_FIELD(newx, newy) && IS_FREE_OR_PLAYER(newx, newy))
-       MovDelay[x][y] = 8+8*!RND(3);
+       MovDelay[x][y] = 8 + 8 * !RND(3);
       else
        MovDelay[x][y] = 16;
     }
-    else
+    else if (element == EL_PENGUIN)
+    {
+      int newx, newy;
+
+      MovDelay[x][y] = 1;
+
+      if (MovDir[x][y] & MV_HORIZONTAL && MovDir[x][y] & MV_VERTICAL)
+      {
+       boolean first_horiz = RND(2);
+       int new_move_dir = MovDir[x][y];
+
+       MovDir[x][y] =
+         new_move_dir & (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
+       Moving2Blocked(x, y, &newx, &newy);
+
+       if (PENGUIN_CAN_ENTER_FIELD(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))
+         return;
+
+       MovDir[x][y] = old_move_dir;
+       return;
+      }
+    }
+    else       /* (element == EL_SATELLITE) */
     {
       int newx, newy;
 
@@ -2905,24 +3522,14 @@ void TurnRound(int x, int y)
          new_move_dir & (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
        Moving2Blocked(x, y, &newx, &newy);
 
-       if (IN_LEV_FIELD(newx, newy) &&
-           (IS_FREE(newx, newy) ||
-            Feld[newx][newy] == EL_ACID ||
-            (element == EL_PENGUIN &&
-             (Feld[newx][newy] == EL_EXIT_OPEN ||
-              IS_FOOD_PENGUIN(Feld[newx][newy])))))
+       if (ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(newx, newy))
          return;
 
        MovDir[x][y] =
          new_move_dir & (!first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
        Moving2Blocked(x, y, &newx, &newy);
 
-       if (IN_LEV_FIELD(newx, newy) &&
-           (IS_FREE(newx, newy) ||
-            Feld[newx][newy] == EL_ACID ||
-            (element == EL_PENGUIN &&
-             (Feld[newx][newy] == EL_EXIT_OPEN ||
-              IS_FOOD_PENGUIN(Feld[newx][newy])))))
+       if (ELEMENT_CAN_ENTER_FIELD_OR_ACID_2(newx, newy))
          return;
 
        MovDir[x][y] = old_move_dir;
@@ -2930,20 +3537,18 @@ void TurnRound(int x, int y)
       }
     }
   }
-  else if (element_info[element].move_pattern == MV_ALL_DIRECTIONS)
+  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)
   {
-    boolean can_turn_left = FALSE, can_turn_right = FALSE;
-
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       (IS_FREE(left_x, left_y) ||
-        (DONT_COLLIDE_WITH(element) && IS_FREE_OR_PLAYER(left_x, left_y))))
-      can_turn_left = TRUE;
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       (IS_FREE(right_x, right_y) ||
-        (DONT_COLLIDE_WITH(element) && IS_FREE_OR_PLAYER(right_x, right_y))))
-      can_turn_right = TRUE;
+    boolean can_turn_left  = ELEMENT_CAN_ENTER_FIELD(element, left_x, left_y);
+    boolean can_turn_right = ELEMENT_CAN_ENTER_FIELD(element, right_x,right_y);
 
-    if (can_turn_left && can_turn_right)
+    if (element_info[element].move_pattern == MV_TURNING_LEFT)
+      MovDir[x][y] = left_dir;
+    else if (element_info[element].move_pattern == MV_TURNING_RIGHT)
+      MovDir[x][y] = right_dir;
+    else if (can_turn_left && can_turn_right)
       MovDir[x][y] = (RND(3) ? (RND(2) ? left_dir : right_dir) : back_dir);
     else if (can_turn_left)
       MovDir[x][y] = (RND(2) ? left_dir : back_dir);
@@ -2973,13 +3578,9 @@ void TurnRound(int x, int y)
   }
   else if (element_info[element].move_pattern == MV_ALONG_LEFT_SIDE)
   {
-    if (IN_LEV_FIELD(left_x, left_y) &&
-       (IS_FREE(left_x, left_y) ||
-        (DONT_COLLIDE_WITH(element) && IS_FREE_OR_PLAYER(left_x, left_y))))
+    if (ELEMENT_CAN_ENTER_FIELD(element, left_x, left_y))
       MovDir[x][y] = left_dir;
-    else if (!IN_LEV_FIELD(move_x, move_y) ||
-            (!IS_FREE(move_x, move_y) &&
-             (!DONT_COLLIDE_WITH(element) || !IS_FREE_OR_PLAYER(move_x, move_y))))
+    else if (!ELEMENT_CAN_ENTER_FIELD(element, move_x, move_y))
       MovDir[x][y] = right_dir;
 
     if (MovDir[x][y] != old_move_dir)
@@ -2987,13 +3588,9 @@ void TurnRound(int x, int y)
   }
   else if (element_info[element].move_pattern == MV_ALONG_RIGHT_SIDE)
   {
-    if (IN_LEV_FIELD(right_x, right_y) &&
-       (IS_FREE(right_x, right_y) ||
-        (DONT_COLLIDE_WITH(element) && IS_FREE_OR_PLAYER(right_x, right_y))))
+    if (ELEMENT_CAN_ENTER_FIELD(element, right_x, right_y))
       MovDir[x][y] = right_dir;
-    else if (!IN_LEV_FIELD(move_x, move_y) ||
-            (!IS_FREE(move_x, move_y) &&
-             (!DONT_COLLIDE_WITH(element) || !IS_FREE_OR_PLAYER(move_x, move_y))))
+    else if (!ELEMENT_CAN_ENTER_FIELD(element, move_x, move_y))
       MovDir[x][y] = left_dir;
 
     if (MovDir[x][y] != old_move_dir)
@@ -3024,7 +3621,8 @@ void TurnRound(int x, int y)
        if (!player->active)
          continue;
 
-       if (attr_x == -1 || ABS(jx-x)+ABS(jy-y) < ABS(attr_x-x)+ABS(attr_y-y))
+       if (attr_x == -1 ||
+           ABS(jx - x) + ABS(jy - y) < ABS(attr_x - x) + ABS(attr_y - y))
        {
          attr_x = jx;
          attr_y = jy;
@@ -3053,20 +3651,14 @@ void TurnRound(int x, int y)
        new_move_dir & (first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
       Moving2Blocked(x, y, &newx, &newy);
 
-      if (IN_LEV_FIELD(newx, newy) && (IS_FREE(newx, newy) ||
-                                      (DONT_COLLIDE_WITH(element) &&
-                                       IS_FREE_OR_PLAYER(newx, newy)) ||
-                                      Feld[newx][newy] == EL_ACID))
+      if (ELEMENT_CAN_ENTER_FIELD_OR_ACID(element, newx, newy))
        return;
 
       MovDir[x][y] =
        new_move_dir & (!first_horiz ? MV_HORIZONTAL : MV_VERTICAL);
       Moving2Blocked(x, y, &newx, &newy);
 
-      if (IN_LEV_FIELD(newx, newy) && (IS_FREE(newx, newy) ||
-                                      (DONT_COLLIDE_WITH(element) &&
-                                       IS_FREE_OR_PLAYER(newx, newy)) ||
-                                      Feld[newx][newy] == EL_ACID))
+      if (ELEMENT_CAN_ENTER_FIELD_OR_ACID(element, newx, newy))
        return;
 
       MovDir[x][y] = old_move_dir;
@@ -3104,17 +3696,20 @@ void StartMoving(int x, int y)
   if (Stop[x][y])
     return;
 
-  GfxAction[x][y] = ACTION_DEFAULT;
+  /* !!! this should be handled more generic (not only for mole) !!! */
+  if (element != EL_MOLE && GfxAction[x][y] != ACTION_DIGGING)
+    GfxAction[x][y] = ACTION_DEFAULT;
 
   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;
 
     if (element == EL_QUICKSAND_FULL)
     {
-      if (IS_FREE(x, y+1))
+      if (IS_FREE(x, y + 1))
       {
        InitMovingField(x, y, MV_DOWN);
        started_moving = TRUE;
@@ -3127,7 +3722,7 @@ void StartMoving(int x, int y)
        PlaySoundLevel(x, y, SND_QUICKSAND_EMPTYING);
 #endif
       }
-      else if (Feld[x][y+1] == EL_QUICKSAND_EMPTY)
+      else if (Feld[x][y + 1] == EL_QUICKSAND_EMPTY)
       {
        if (!MovDelay[x][y])
          MovDelay[x][y] = TILEY + 1;
@@ -3140,8 +3735,8 @@ void StartMoving(int x, int y)
        }
 
        Feld[x][y] = EL_QUICKSAND_EMPTY;
-       Feld[x][y+1] = EL_QUICKSAND_FULL;
-       Store[x][y+1] = Store[x][y];
+       Feld[x][y + 1] = EL_QUICKSAND_FULL;
+       Store[x][y + 1] = Store[x][y];
        Store[x][y] = 0;
 #if 1
        PlaySoundLevelAction(x, y, ACTION_FILLING);
@@ -3151,7 +3746,7 @@ void StartMoving(int x, int y)
       }
     }
     else if ((element == EL_ROCK || element == EL_BD_ROCK) &&
-            Feld[x][y+1] == EL_QUICKSAND_EMPTY)
+            Feld[x][y + 1] == EL_QUICKSAND_EMPTY)
     {
       InitMovingField(x, y, MV_DOWN);
       started_moving = TRUE;
@@ -3166,7 +3761,7 @@ void StartMoving(int x, int y)
     }
     else if (element == EL_MAGIC_WALL_FULL)
     {
-      if (IS_FREE(x, y+1))
+      if (IS_FREE(x, y + 1))
       {
        InitMovingField(x, y, MV_DOWN);
        started_moving = TRUE;
@@ -3174,7 +3769,7 @@ void StartMoving(int x, int y)
        Feld[x][y] = EL_MAGIC_WALL_EMPTYING;
        Store[x][y] = EL_CHANGED(Store[x][y]);
       }
-      else if (Feld[x][y+1] == EL_MAGIC_WALL_ACTIVE)
+      else if (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE)
       {
        if (!MovDelay[x][y])
          MovDelay[x][y] = TILEY/4 + 1;
@@ -3187,14 +3782,14 @@ void StartMoving(int x, int y)
        }
 
        Feld[x][y] = EL_MAGIC_WALL_ACTIVE;
-       Feld[x][y+1] = EL_MAGIC_WALL_FULL;
-       Store[x][y+1] = EL_CHANGED(Store[x][y]);
+       Feld[x][y + 1] = EL_MAGIC_WALL_FULL;
+       Store[x][y + 1] = EL_CHANGED(Store[x][y]);
        Store[x][y] = 0;
       }
     }
     else if (element == EL_BD_MAGIC_WALL_FULL)
     {
-      if (IS_FREE(x, y+1))
+      if (IS_FREE(x, y + 1))
       {
        InitMovingField(x, y, MV_DOWN);
        started_moving = TRUE;
@@ -3202,7 +3797,7 @@ void StartMoving(int x, int y)
        Feld[x][y] = EL_BD_MAGIC_WALL_EMPTYING;
        Store[x][y] = EL_CHANGED2(Store[x][y]);
       }
-      else if (Feld[x][y+1] == EL_BD_MAGIC_WALL_ACTIVE)
+      else if (Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE)
       {
        if (!MovDelay[x][y])
          MovDelay[x][y] = TILEY/4 + 1;
@@ -3215,27 +3810,27 @@ void StartMoving(int x, int y)
        }
 
        Feld[x][y] = EL_BD_MAGIC_WALL_ACTIVE;
-       Feld[x][y+1] = EL_BD_MAGIC_WALL_FULL;
-       Store[x][y+1] = EL_CHANGED2(Store[x][y]);
+       Feld[x][y + 1] = EL_BD_MAGIC_WALL_FULL;
+       Store[x][y + 1] = EL_CHANGED2(Store[x][y]);
        Store[x][y] = 0;
       }
     }
     else if (CAN_PASS_MAGIC_WALL(element) &&
-            (Feld[x][y+1] == EL_MAGIC_WALL_ACTIVE ||
-             Feld[x][y+1] == EL_BD_MAGIC_WALL_ACTIVE))
+            (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE ||
+             Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE))
     {
       InitMovingField(x, y, MV_DOWN);
       started_moving = TRUE;
 
       Feld[x][y] =
-       (Feld[x][y+1] == EL_MAGIC_WALL_ACTIVE ? EL_MAGIC_WALL_FILLING :
+       (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE ? EL_MAGIC_WALL_FILLING :
         EL_BD_MAGIC_WALL_FILLING);
       Store[x][y] = element;
     }
 #if 0
-    else if (CAN_SMASH(element) && Feld[x][y+1] == EL_ACID)
+    else if (CAN_SMASH(element) && Feld[x][y + 1] == EL_ACID)
 #else
-    else if (CAN_FALL(element) && Feld[x][y+1] == EL_ACID)
+    else if (CAN_FALL(element) && Feld[x][y + 1] == EL_ACID)
 #endif
     {
       SplashAcid(x, y);
@@ -3246,15 +3841,30 @@ void StartMoving(int x, int y)
       Store[x][y] = EL_ACID;
 #if 0
       /* !!! TEST !!! better use "_FALLING" etc. !!! */
-      GfxAction[x][y+1] = ACTION_ACTIVE;
+      GfxAction[x][y + 1] = ACTION_ACTIVE;
 #endif
     }
-    else if (CAN_SMASH(element) && Feld[x][y+1] == EL_BLOCKED &&
+#if 1
+#if 1
+    else if (game.engine_version < RELEASE_IDENT(2,2,0,7) &&
+            CAN_SMASH(element) && Feld[x][y + 1] == EL_BLOCKED &&
+            JustStopped[x][y] && !Pushed[x][y + 1])
+#else
+    else if (CAN_SMASH(element) && Feld[x][y + 1] == EL_BLOCKED &&
             JustStopped[x][y])
+#endif
     {
+      /* calling "Impact()" here is not only completely unneccessary
+        (because it already gets called from "ContinueMoving()" in
+        all relevant situations), but also completely bullshit, because
+        "JustStopped" also indicates a finished *horizontal* movement;
+        we must keep this trash for backwards compatibility with older
+        tapes */
+
       Impact(x, y);
     }
-    else if (IS_FREE(x, y+1) && element == EL_SPRING && use_spring_bug)
+#endif
+    else if (IS_FREE(x, y + 1) && element == EL_SPRING && use_spring_bug)
     {
       if (MovDir[x][y] == MV_NO_MOVING)
       {
@@ -3262,7 +3872,7 @@ void StartMoving(int x, int y)
        started_moving = TRUE;
       }
     }
-    else if (IS_FREE(x, y+1))
+    else if (IS_FREE(x, y + 1) || Feld[x][y + 1] == EL_DIAMOND_BREAKING)
     {
       if (JustStopped[x][y])   /* prevent animation from being restarted */
        MovDir[x][y] = MV_DOWN;
@@ -3275,45 +3885,66 @@ void StartMoving(int x, int y)
       Feld[x][y] = EL_AMOEBA_GROWING;
       Store[x][y] = EL_AMOEBA_WET;
     }
-    /* Store[x][y+1] must be zero, because:
-       (EL_QUICKSAND_FULL -> EL_ROCK): Store[x][y+1] == EL_QUICKSAND_EMPTY
+    /* Store[x][y + 1] must be zero, because:
+       (EL_QUICKSAND_FULL -> EL_ROCK): Store[x][y + 1] == EL_QUICKSAND_EMPTY
     */
 #if 0
 #if OLD_GAME_BEHAVIOUR
-    else if (IS_SLIPPERY(Feld[x][y+1]) && !Store[x][y+1])
+    else if (IS_SLIPPERY(Feld[x][y + 1]) && !Store[x][y + 1])
 #else
-    else if (IS_SLIPPERY(Feld[x][y+1]) && !Store[x][y+1] &&
-            !IS_FALLING(x, y+1) && !JustStopped[x][y+1] &&
+    else if (IS_SLIPPERY(Feld[x][y + 1]) && !Store[x][y + 1] &&
+            !IS_FALLING(x, y + 1) && !JustStopped[x][y + 1] &&
             element != EL_DX_SUPABOMB)
 #endif
 #else
-    else if ((IS_SLIPPERY(Feld[x][y+1]) ||
-             (IS_EM_SLIPPERY_WALL(Feld[x][y+1]) && IS_GEM(element))) &&
-            !IS_FALLING(x, y+1) && !JustStopped[x][y+1] &&
+    else if (((IS_SLIPPERY(Feld[x][y + 1]) && !IS_PLAYER(x, y + 1)) ||
+             (IS_EM_SLIPPERY_WALL(Feld[x][y + 1]) && IS_GEM(element))) &&
+            !IS_FALLING(x, y + 1) && !JustStopped[x][y + 1] &&
             element != EL_DX_SUPABOMB && element != EL_SP_DISK_ORANGE)
 #endif
     {
-      boolean left  = (x>0 && IS_FREE(x-1, y) &&
-                      (IS_FREE(x-1, y+1) || Feld[x-1][y+1] == EL_ACID));
-      boolean right = (x<lev_fieldx-1 && IS_FREE(x+1, y) &&
-                      (IS_FREE(x+1, y+1) || Feld[x+1][y+1] == EL_ACID));
+      boolean can_fall_left  = (x > 0 && IS_FREE(x - 1, y) &&
+                               (IS_FREE(x - 1, y + 1) ||
+                                Feld[x - 1][y + 1] == EL_ACID));
+      boolean can_fall_right = (x < lev_fieldx - 1 && IS_FREE(x + 1, y) &&
+                               (IS_FREE(x + 1, y + 1) ||
+                                Feld[x + 1][y + 1] == EL_ACID));
+      boolean can_fall_any  = (can_fall_left || can_fall_right);
+      boolean can_fall_both = (can_fall_left && can_fall_right);
+
+      if (can_fall_any && IS_CUSTOM_ELEMENT(Feld[x][y + 1]))
+      {
+       int slippery_type = element_info[Feld[x][y + 1]].slippery_type;
+
+       if (slippery_type == SLIPPERY_ONLY_LEFT)
+         can_fall_right = FALSE;
+       else if (slippery_type == SLIPPERY_ONLY_RIGHT)
+         can_fall_left = FALSE;
+       else if (slippery_type == SLIPPERY_ANY_LEFT_RIGHT && can_fall_both)
+         can_fall_right = FALSE;
+       else if (slippery_type == SLIPPERY_ANY_RIGHT_LEFT && can_fall_both)
+         can_fall_left = FALSE;
+
+       can_fall_any  = (can_fall_left || can_fall_right);
+       can_fall_both = (can_fall_left && can_fall_right);
+      }
 
-      if (left || right)
+      if (can_fall_any)
       {
-       if (left && right &&
+       if (can_fall_both &&
            (game.emulation != EMU_BOULDERDASH &&
             element != EL_BD_ROCK && element != EL_BD_DIAMOND))
-         left = !(right = RND(2));
+         can_fall_left = !(can_fall_right = RND(2));
 
-       InitMovingField(x, y, left ? MV_LEFT : MV_RIGHT);
+       InitMovingField(x, y, can_fall_left ? MV_LEFT : MV_RIGHT);
        started_moving = TRUE;
       }
     }
-    else if (IS_BELT_ACTIVE(Feld[x][y+1]))
+    else if (IS_BELT_ACTIVE(Feld[x][y + 1]))
     {
-      boolean left_is_free  = (x>0 && IS_FREE(x-1, y));
-      boolean right_is_free = (x<lev_fieldx-1 && IS_FREE(x+1, y));
-      int belt_nr = getBeltNrFromBeltActiveElement(Feld[x][y+1]);
+      boolean left_is_free  = (x > 0 && IS_FREE(x - 1, y));
+      boolean right_is_free = (x < lev_fieldx - 1 && IS_FREE(x + 1, y));
+      int belt_nr = getBeltNrFromBeltActiveElement(Feld[x][y + 1]);
       int belt_dir = game.belt_dir[belt_nr];
 
       if ((belt_dir == MV_LEFT  && left_is_free) ||
@@ -3327,7 +3958,7 @@ void StartMoving(int x, int y)
     }
   }
 
-  /* not "else if" because of EL_SPRING */
+  /* not "else if" because of elements that can fall and move (EL_SPRING) */
   if (CAN_MOVE(element) && !started_moving)
   {
     int newx, newy;
@@ -3360,7 +3991,9 @@ void StartMoving(int x, int y)
       if (element != EL_YAMYAM &&
          element != EL_DARK_YAMYAM &&
          element != EL_PACMAN &&
-         !(element_info[element].move_pattern & MV_ANY_DIRECTION))
+         !(element_info[element].move_pattern & MV_ANY_DIRECTION) &&
+         element_info[element].move_pattern != MV_TURNING_LEFT &&
+         element_info[element].move_pattern != MV_TURNING_RIGHT)
       {
        TurnRound(x, y);
 
@@ -3461,14 +4094,18 @@ void StartMoving(int x, int y)
        return;
       }
 
-      GfxAction[x][y] = ACTION_MOVING;
+      /* special case of "moving" animation of waiting elements (FIX THIS !!!);
+        for all other elements GfxAction will be set by InitMovingField() */
+      if (element == EL_BD_BUTTERFLY || element == EL_BD_FIREFLY)
+       GfxAction[x][y] = ACTION_MOVING;
     }
 
     /* now make next step */
 
     Moving2Blocked(x, y, &newx, &newy);        /* get next screen position */
 
-    if (DONT_COLLIDE_WITH(element) && IS_PLAYER(newx, newy) &&
+    if (DONT_COLLIDE_WITH(element) &&
+       IN_LEV_FIELD(newx, newy) && IS_PLAYER(newx, newy) &&
        !PLAYER_PROTECTED(newx, newy))
     {
 #if 1
@@ -3645,6 +4282,11 @@ void StartMoving(int x, int y)
       {
        Feld[newx][newy] = EL_AMOEBA_SHRINKING;
        PlaySoundLevel(x, y, SND_MOLE_DIGGING);
+
+       ResetGfxAnimation(x, y);
+       GfxAction[x][y] = ACTION_DIGGING;
+       DrawLevelField(x, y);
+
        MovDelay[newx][newy] = 0;       /* start amoeba shrinking delay */
        return;                         /* wait for shrinking amoeba */
       }
@@ -3669,7 +4311,8 @@ void StartMoving(int x, int y)
       TurnRound(x, y);
 
 #if 1
-      DrawLevelElementAnimation(x, y, element);
+      if (GFX_ELEMENT(element) != EL_SAND)     /* !!! FIX THIS (crumble) !!! */
+       DrawLevelElementAnimation(x, y, element);
 #else
       if (element == EL_BUG ||
          element == EL_SPACESHIP ||
@@ -3711,67 +4354,28 @@ void ContinueMoving(int x, int y)
   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);
-  int horiz_move = (dx != 0);
   int newx = x + dx, newy = y + dy;
-  int step = (horiz_move ? dx : dy) * TILEX / MOVE_DELAY_NORMAL_SPEED;
-
-  if (element == EL_AMOEBA_DROP || element == EL_AMOEBA_DROPPING)
-    step /= 2;
-  else if (element == EL_QUICKSAND_FILLING ||
-          element == EL_QUICKSAND_EMPTYING)
-    step /= 4;
-  else if (element == EL_MAGIC_WALL_FILLING ||
-          element == EL_BD_MAGIC_WALL_FILLING ||
-          element == EL_MAGIC_WALL_EMPTYING ||
-          element == EL_BD_MAGIC_WALL_EMPTYING)
-    step /= 2;
-  else if (CAN_FALL(element) && horiz_move &&
-          y < lev_fieldy-1 && IS_BELT_ACTIVE(Feld[x][y+1]))
-    step /= 2;
-  else if (element == EL_SPRING && horiz_move)
-    step *= 2;
-  else if (IS_CUSTOM_ELEMENT(element))
-    step = SIGN(step) * element_info[element].move_stepsize;
+  int nextx = newx + dx, nexty = newy + dy;
+  boolean pushed = Pushed[x][y];
 
-#if OLD_GAME_BEHAVIOUR
-  else if (CAN_FALL(element) && horiz_move && !IS_SP_ELEMENT(element))
-    step*=2;
-#endif
+  MovPos[x][y] += getElementMoveStepsize(x, y);
 
-  MovPos[x][y] += step;
+  if (pushed)          /* special case: moving object pushed by player */
+    MovPos[x][y] = SIGN(MovPos[x][y]) * (TILEX - ABS(PLAYERINFO(x,y)->MovPos));
 
   if (ABS(MovPos[x][y]) >= TILEX)      /* object reached its destination */
   {
     Feld[x][y] = EL_EMPTY;
     Feld[newx][newy] = element;
+    MovPos[x][y] = 0;  /* force "not moving" for "crumbled sand" */
 
     if (element == EL_MOLE)
     {
-      int i;
-      static int xy[4][2] =
-      {
-       { 0, -1 },
-       { -1, 0 },
-       { +1, 0 },
-       { 0, +1 }
-      };
-
       Feld[x][y] = EL_SAND;
-      DrawLevelField(x, y);
-
-      for(i=0; i<4; i++)
-      {
-       int xx, yy;
 
-       xx = x + xy[i][0];
-       yy = y + xy[i][1];
-
-       if (IN_LEV_FIELD(xx, yy) && Feld[xx][yy] == EL_SAND)
-         DrawLevelField(xx, yy);       /* for "crumbled sand" */
-      }
+      DrawLevelFieldCrumbledSandNeighbours(x, y);
     }
-
-    if (element == EL_QUICKSAND_FILLING)
+    else if (element == EL_QUICKSAND_FILLING)
     {
       element = Feld[newx][newy] = get_next_element(element);
       Store[newx][newy] = Store[x][y];
@@ -3814,6 +4418,16 @@ void ContinueMoving(int x, int y)
       Feld[x][y] = get_next_element(element);
       element = Feld[newx][newy] = Store[x][y];
     }
+    else if (element == EL_SOKOBAN_OBJECT)
+    {
+      if (Back[x][y])
+       Feld[x][y] = Back[x][y];
+
+      if (Back[newx][newy])
+       Feld[newx][newy] = EL_SOKOBAN_FIELD_FULL;
+
+      Back[x][y] = Back[newx][newy] = 0;
+    }
     else if (Store[x][y] == EL_ACID)
     {
       element = Feld[newx][newy] = EL_ACID;
@@ -3823,25 +4437,37 @@ void ContinueMoving(int x, int y)
     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];
+
     /* copy animation control values to new field */
     GfxFrame[newx][newy]  = GfxFrame[x][y];
     GfxAction[newx][newy] = GfxAction[x][y];   /* keep action one frame */
     GfxRandom[newx][newy] = GfxRandom[x][y];   /* keep same random value */
 
+    Pushed[x][y] = Pushed[newx][newy] = FALSE;
+
     ResetGfxAnimation(x, y);   /* reset animation values for old field */
 
-#if 1
 #if 0
+    /* 2.1.1 (does not work correctly for spring) */
     if (!CAN_MOVE(element))
       MovDir[newx][newy] = 0;
 #else
-    /*
+
+#if 0
+    /* (does not work for falling objects that slide horizontally) */
     if (CAN_FALL(element) && MovDir[newx][newy] == MV_DOWN)
       MovDir[newx][newy] = 0;
+#else
+    /*
+    if (!CAN_MOVE(element) ||
+       (element == EL_SPRING && MovDir[newx][newy] == MV_DOWN))
+      MovDir[newx][newy] = 0;
     */
 
     if (!CAN_MOVE(element) ||
-       (element == EL_SPRING && MovDir[newx][newy] == MV_DOWN))
+       (CAN_FALL(element) && MovDir[newx][newy] == MV_DOWN))
       MovDir[newx][newy] = 0;
 #endif
 #endif
@@ -3849,8 +4475,10 @@ void ContinueMoving(int x, int y)
     DrawLevelField(x, y);
     DrawLevelField(newx, newy);
 
-    Stop[newx][newy] = TRUE;
-    JustStopped[newx][newy] = 3;
+    Stop[newx][newy] = TRUE;   /* ignore this element until the next frame */
+
+    if (!pushed)       /* special case: moving object pushed by player */
+      JustStopped[newx][newy] = 3;
 
     if (DONT_TOUCH(element))   /* object may be nasty to player or others */
     {
@@ -3861,9 +4489,15 @@ void ContinueMoving(int x, int y)
     else if (element == EL_PENGUIN)
       TestIfFriendTouchesBadThing(newx, newy);
 
-    if (CAN_SMASH(element) && direction == MV_DOWN &&
+    if (CAN_FALL(element) && direction == MV_DOWN &&
        (newy == lev_fieldy - 1 || !IS_FREE(x, newy + 1)))
       Impact(x, newy);
+
+    if (!IN_LEV_FIELD(nextx, nexty) || !IS_FREE(nextx, nexty))
+      CheckElementChange(newx, newy, element, CE_COLLISION);
+
+    TestIfPlayerTouchesCustomElement(newx, newy);
+    TestIfElementTouchesCustomElement(newx, newy);
   }
   else                         /* still moving on */
   {
@@ -4172,6 +4806,7 @@ void AmoebeAbleger(int ax, int ay)
     if (!IN_LEV_FIELD(x, y))
       return;
 
+    /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
     if (IS_FREE(x, y) ||
        Feld[x][y] == EL_SAND || Feld[x][y] == EL_QUICKSAND_EMPTY)
     {
@@ -4196,6 +4831,7 @@ void AmoebeAbleger(int ax, int ay)
       if (!IN_LEV_FIELD(x, y))
        continue;
 
+      /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
       if (IS_FREE(x, y) ||
          Feld[x][y] == EL_SAND || Feld[x][y] == EL_QUICKSAND_EMPTY)
       {
@@ -4340,6 +4976,7 @@ void Life(int ax, int ay)
        changed = TRUE;
       }
     }
+    /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
     else if (IS_FREE(xx, yy) || Feld[xx][yy] == EL_SAND)
     {                                  /* free border field */
       if (nachbarn >= life[2] && nachbarn <= life[3])
@@ -4361,7 +4998,7 @@ void Life(int ax, int ay)
 
 static void InitRobotWheel(int x, int y)
 {
-  MovDelay[x][y] = level.time_wheel * FRAMES_PER_SECOND;
+  ChangeDelay[x][y] = level.time_wheel * FRAMES_PER_SECOND;
 }
 
 static void RunRobotWheel(int x, int y)
@@ -4377,7 +5014,7 @@ static void StopRobotWheel(int x, int y)
 
 static void InitTimegateWheel(int x, int y)
 {
-  MovDelay[x][y] = level.time_wheel * FRAMES_PER_SECOND;
+  ChangeDelay[x][y] = level.time_wheel * FRAMES_PER_SECOND;
 }
 
 static void RunTimegateWheel(int x, int y)
@@ -4703,7 +5340,7 @@ static void InitBuggyBase(int x, int y)
   int element = Feld[x][y];
   int activating_delay = FRAMES_PER_SECOND / 4;
 
-  MovDelay[x][y] =
+  ChangeDelay[x][y] =
     (element == EL_SP_BUGGY_BASE ?
      2 * FRAMES_PER_SECOND + RND(5 * FRAMES_PER_SECOND) - activating_delay :
      element == EL_SP_BUGGY_BASE_ACTIVATING ?
@@ -4738,7 +5375,7 @@ static void WarnBuggyBase(int x, int y)
 
 static void InitTrap(int x, int y)
 {
-  MovDelay[x][y] = 2 * FRAMES_PER_SECOND + RND(5 * FRAMES_PER_SECOND);
+  ChangeDelay[x][y] = 2 * FRAMES_PER_SECOND + RND(5 * FRAMES_PER_SECOND);
 }
 
 static void ActivateTrap(int x, int y)
@@ -4755,66 +5392,285 @@ static void ChangeActiveTrap(int x, int y)
     DrawLevelFieldCrumbledSand(x, y);
 }
 
-static void ChangeElement(int x, int y)
+static void ChangeElementNowExt(int x, int y, int target_element)
 {
-  int element = Feld[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) &&
+      IS_ACCESSIBLE(Feld[x][y]) && !IS_ACCESSIBLE(target_element))
+  {
+    Bang(x, y);
+    return;
+  }
+
+  RemoveField(x, y);
+  Feld[x][y] = target_element;
+
+  ResetGfxAnimation(x, y);
+  ResetRandomAnimationValue(x, y);
+
+  InitField(x, y, FALSE);
+  if (CAN_MOVE(Feld[x][y]))
+    InitMovDir(x, y);
+
+  DrawLevelField(x, y);
+
+  if (CAN_BE_CRUMBLED(Feld[x][y]))
+    DrawLevelFieldCrumbledSandNeighbours(x, y);
+
+  TestIfBadThingTouchesHero(x, y);
+  TestIfPlayerTouchesCustomElement(x, y);
+  TestIfElementTouchesCustomElement(x, y);
+
+  if (ELEM_IS_PLAYER(target_element))
+    RelocatePlayer(x, y, target_element);
+}
 
-  if (IS_MOVING(x, y))                 /* never change a running system :-) */
+static void ChangeElementNow(int x, int y, int element, int page)
+{
+  struct ElementChangeInfo *change = &element_info[element].change_page[page];
+
+  CheckTriggeredElementChange(x, y, Feld[x][y], CE_OTHER_IS_CHANGING);
+
+  if (change->explode)
+  {
+    Bang(x, y);
     return;
+  }
 
-  if (MovDelay[x][y] == 0)             /* initialize element change */
+  if (change->use_content)
   {
-    MovDelay[x][y] = changing_element[element].change_delay + 1;
+    boolean complete_change = TRUE;
+    boolean can_change[3][3];
+    int xx, yy;
+
+    for (yy = 0; yy < 3; yy++) for(xx = 0; xx < 3 ; xx++)
+    {
+      boolean half_destructible;
+      int ex = x + xx - 1;
+      int ey = y + yy - 1;
+      int e;
+
+      can_change[xx][yy] = TRUE;
+
+      if (ex == x && ey == y)  /* do not check changing element itself */
+       continue;
+
+      if (change->content[xx][yy] == EL_EMPTY_SPACE)
+      {
+       can_change[xx][yy] = FALSE;     /* do not change empty borders */
+
+       continue;
+      }
 
-    if (IS_CUSTOM_ELEMENT(element) && HAS_CHANGE_EVENT(element, CE_DELAY))
+      if (!IN_LEV_FIELD(ex, ey))
+      {
+       can_change[xx][yy] = FALSE;
+       complete_change = FALSE;
+
+       continue;
+      }
+
+      e = Feld[ex][ey];
+
+      if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
+       e = MovingOrBlocked2Element(ex, ey);
+
+      half_destructible = (IS_FREE(ex, ey) || IS_DIGGABLE(e));
+
+      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)))
+      {
+       can_change[xx][yy] = FALSE;
+       complete_change = FALSE;
+      }
+    }
+
+    if (!change->only_complete || complete_change)
     {
-      int max_random_delay = element_info[element].change.delay_random;
-      int delay_frames = element_info[element].change.delay_frames;
+      boolean something_has_changed = FALSE;
+
+      if (change->only_complete && change->use_random_change &&
+         RND(100) < change->random)
+       return;
+
+      for (yy = 0; yy < 3; yy++) for(xx = 0; xx < 3 ; xx++)
+      {
+       int ex = x + xx - 1;
+       int ey = y + yy - 1;
 
-      MovDelay[x][y] += RND(max_random_delay * delay_frames);
+       if (can_change[xx][yy] && (!change->use_random_change ||
+                                  RND(100) < change->random))
+       {
+         if (IS_MOVING(ex, ey) || IS_BLOCKED(ex, ey))
+           RemoveMovingField(ex, ey);
+
+         ChangeElementNowExt(ex, ey, change->content[xx][yy]);
+
+         something_has_changed = TRUE;
+
+         /* for symmetry reasons, stop newly created border elements */
+         if (ex != x || ey != y)
+           Stop[ex][ey] = TRUE;
+       }
+      }
+
+      if (something_has_changed)
+       PlaySoundLevelElementAction(x, y, element, ACTION_CHANGING);
     }
+  }
+  else
+  {
+    ChangeElementNowExt(x, y, change->target_element);
+
+    PlaySoundLevelElementAction(x, y, element, ACTION_CHANGING);
+  }
+}
+
+static void ChangeElement(int x, int y, int page)
+{
+  int element = MovingOrBlocked2Element(x, y);
+  struct ElementChangeInfo *change = &element_info[element].change_page[page];
+
+  if (ChangeDelay[x][y] == 0)          /* initialize element change */
+  {
+    ChangeDelay[x][y] = (    change->delay_fixed  * change->delay_frames +
+                        RND(change->delay_random * change->delay_frames)) + 1;
 
     ResetGfxAnimation(x, y);
     ResetRandomAnimationValue(x, y);
 
-    if (changing_element[element].pre_change_function)
-      changing_element[element].pre_change_function(x, y);
+    if (change->pre_change_function)
+      change->pre_change_function(x, y);
   }
 
-  MovDelay[x][y]--;
+  ChangeDelay[x][y]--;
 
-  if (MovDelay[x][y] != 0)             /* continue element change */
+  if (ChangeDelay[x][y] != 0)          /* continue element change */
   {
-    if (IS_ANIMATED(el2img(element)))
-      DrawLevelElementAnimationIfNeeded(x, y, element);
+    int graphic = el_act_dir2img(element, GfxAction[x][y], MovDir[x][y]);
+
+    if (IS_ANIMATED(graphic))
+      DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
 
-    if (changing_element[element].change_function)
-      changing_element[element].change_function(x, y);
+    if (change->change_function)
+      change->change_function(x, y);
   }
   else                                 /* finish element change */
   {
-    Feld[x][y] = changing_element[element].next_element;
+    if (IS_MOVING(x, y))               /* never change a running system ;-) */
+    {
+      ChangeDelay[x][y] = 1;           /* try change after next move step */
 
-    ResetGfxAnimation(x, y);
-    ResetRandomAnimationValue(x, y);
+      return;
+    }
+
+    ChangeElementNow(x, y, element, page);
+
+    if (change->post_change_function)
+      change->post_change_function(x, y);
+  }
+}
+
+static boolean CheckTriggeredElementChange(int lx, int ly, int trigger_element,
+                                          int trigger_event)
+{
+  int i, j, x, y;
+
+  if (!(trigger_events[trigger_element] & CH_EVENT_BIT(trigger_event)))
+    return FALSE;
+
+  /* prevent this function from running into a loop */
+  if (trigger_event == CE_OTHER_IS_CHANGING)
+    Changing[lx][ly] = TRUE;
+
+  for (i=0; i < NUM_CUSTOM_ELEMENTS; i++)
+  {
+    int element = EL_CUSTOM_START + i;
 
 #if 1
-    InitField(x, y, FALSE);
-    if (CAN_MOVE(element))
-      InitMovDir(x, y);
+    boolean change_element = FALSE;
+    int page;
+
+    if (!CAN_CHANGE(element) ||
+       !HAS_ANY_CHANGE_EVENT(element, trigger_event))
+      continue;
+
+    for (j=0; j < element_info[element].num_change_pages; j++)
+    {
+      if (element_info[element].change_page[j].trigger_element ==
+         trigger_element)
+      {
+       change_element = TRUE;
+       page = j;
+
+       break;
+      }
+    }
+
+    if (!change_element)
+      continue;
+
+#else
+    if (!CAN_CHANGE(element) ||
+       !HAS_ANY_CHANGE_EVENT(element, trigger_event) ||
+       element_info[element].change->trigger_element != trigger_element)
+      continue;
 #endif
-    DrawLevelField(x, y);
 
-    if (changing_element[element].post_change_function)
-      changing_element[element].post_change_function(x, y);
+    for (y=0; y<lev_fieldy; y++) for (x=0; x<lev_fieldx; x++)
+    {
+      if (x == lx && y == ly)  /* do not change trigger element itself */
+       continue;
+
+      if (Changing[x][y])      /* do not change just changing elements */
+       continue;
+
+      if (Feld[x][y] == element)
+      {
+       ChangeDelay[x][y] = 1;
+       ChangeElement(x, y, page);
+
+       Changing[x][y] = TRUE;  /* do not change just changed elements */
+      }
+    }
   }
+
+  /* reset change prevention array */
+  for (y=0; y<lev_fieldy; y++) for (x=0; x<lev_fieldx; x++)
+    Changing[x][y] = FALSE;
+
+  return TRUE;
+}
+
+static boolean CheckElementChangeExt(int x, int y, int element,
+                                    int trigger_event, int page)
+{
+  if (!CAN_CHANGE(element) || !HAS_ANY_CHANGE_EVENT(element, trigger_event))
+    return FALSE;
+
+  if (Feld[x][y] == EL_BLOCKED)
+    Blocked2Moving(x, y, &x, &y);
+
+  ChangeDelay[x][y] = 1;
+  ChangeElement(x, y, page);
+
+  return TRUE;
+}
+
+static boolean CheckElementChange(int x, int y, int element, int trigger_event)
+{
+  int page = element_info[element].event_page_num[trigger_event];
+
+  return CheckElementChangeExt(x, y, element, trigger_event, page);
 }
 
 static void PlayerActions(struct PlayerInfo *player, byte player_action)
 {
   static byte stored_player_action[MAX_PLAYERS];
   static int num_stored_actions = 0;
-  boolean moved = FALSE, snapped = FALSE, bombed = FALSE;
+  boolean moved = FALSE, snapped = FALSE, dropped = FALSE;
   int left     = player_action & JOY_LEFT;
   int right    = player_action & JOY_RIGHT;
   int up       = player_action & JOY_UP;
@@ -4837,13 +5693,14 @@ static void PlayerActions(struct PlayerInfo *player, byte player_action)
     else
     {
       if (button2)
-       bombed = PlaceBomb(player);
+       dropped = DropElement(player);
+
       moved = MoveFigure(player, dx, dy);
     }
 
     if (tape.single_step && tape.recording && !tape.pausing)
     {
-      if (button1 || (bombed && !moved))
+      if (button1 || (dropped && !moved))
       {
        TapeTogglePause(TAPE_TOGGLE_AUTOMATIC);
        SnapField(player, 0, 0);                /* stop snapping */
@@ -4861,13 +5718,7 @@ static void PlayerActions(struct PlayerInfo *player, byte player_action)
     CheckGravityMovement(player);
 
     if (player->MovPos == 0)
-    {
-#if 0
-      printf("Trying... Player frame reset\n");
-#endif
-
       InitPlayerGfxAnimation(player, ACTION_DEFAULT, player->MovDir);
-    }
 
     if (player->MovPos == 0)   /* needed for tape.playing */
       player->is_moving = FALSE;
@@ -4976,6 +5827,30 @@ void GameActions()
     stored_player[i].Frame++;
 #endif
 
+#if 1
+  if (game.engine_version < RELEASE_IDENT(2,2,0,7))
+  {
+    for (i=0; i<MAX_PLAYERS; i++)
+    {
+      struct PlayerInfo *player = &stored_player[i];
+      int x = player->jx;
+      int y = player->jy;
+
+      if (player->active && player->Pushing && player->is_moving &&
+         IS_MOVING(x, y))
+      {
+       ContinueMoving(x, y);
+
+       /* continue moving after pushing (this is actually a bug) */
+       if (!IS_MOVING(x, y))
+       {
+         Stop[x][y] = FALSE;
+       }
+      }
+    }
+  }
+#endif
+
   for (y=0; y<lev_fieldy; y++) for (x=0; x<lev_fieldx; x++)
   {
     Stop[x][y] = FALSE;
@@ -4984,6 +5859,16 @@ void GameActions()
 
     GfxFrame[x][y]++;
 
+#if 1
+    /* reset finished pushing action (not done in ContinueMoving() to allow
+       continous pushing animation for elements without push delay) */
+    if (GfxAction[x][y] == ACTION_PUSHING && !IS_MOVING(x, y))
+    {
+      ResetGfxAnimation(x, y);
+      DrawLevelField(x, y);
+    }
+#endif
+
 #if DEBUG
     if (IS_BLOCKED(x, y))
     {
@@ -5040,6 +5925,16 @@ void GameActions()
       continue;
     }
 
+#if 1
+    /* this may take place after moving, so 'element' may have changed */
+    if (IS_CHANGING(x, y))
+    {
+      ChangeElement(x, y, element_info[element].event_page_num[CE_DELAY]);
+      element = Feld[x][y];
+      graphic = el_act_dir2img(element, GfxAction[x][y], MovDir[x][y]);
+    }
+#endif
+
     if (!IS_MOVING(x, y) && (CAN_FALL(element) || CAN_MOVE(element)))
     {
       StartMoving(x, y);
@@ -5047,9 +5942,10 @@ void GameActions()
 #if 1
       graphic = el_act_dir2img(element, GfxAction[x][y], MovDir[x][y]);
 #if 0
-      if (element == EL_PACMAN)
-       printf("::: %d, %d, %d\n",
-              IS_ANIMATED(graphic), IS_MOVING(x, y), Stop[x][y]);
+      if (element == EL_MOLE)
+       printf("::: %d, %d, %d [%d]\n",
+              IS_ANIMATED(graphic), IS_MOVING(x, y), Stop[x][y],
+              GfxAction[x][y]);
 #endif
 #if 0
       if (element == EL_YAMYAM)
@@ -5065,7 +5961,7 @@ void GameActions()
        DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
 
 #if 0
-       if (element == EL_YAMYAM)
+       if (element == EL_MOLE)
          printf("::: %d, %d\n", graphic, GfxFrame[x][y]);
 #endif
       }
@@ -5122,11 +6018,11 @@ void GameActions()
 #endif
     else if (element == EL_EXPLOSION)
       ;        /* drawing of correct explosion animation is handled separately */
-    else if (IS_ANIMATED(graphic) && !IS_AUTO_CHANGING(element))
+    else if (IS_ANIMATED(graphic) && !IS_CHANGING(x, y))
       DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
 
-#if 1
-    /* this may take place after moving, therefore element may have changed */
+#if 0
+    /* this may take place after moving, so 'element' may have changed */
     if (IS_AUTO_CHANGING(Feld[x][y]))
       ChangeElement(x, y);
 #endif
@@ -5172,6 +6068,7 @@ void GameActions()
 #endif
       element = Feld[x][y];
 
+      /* !!! extend EL_SAND to anything diggable (but maybe not SP_BASE) !!! */
       if (!IS_PLAYER(x,y) &&
          (element == EL_EMPTY ||
           element == EL_SAND ||
@@ -5415,24 +6312,24 @@ void ScrollLevel(int dx, int dy)
   int x, y;
 
   BlitBitmap(drawto_field, drawto_field,
-            FX + TILEX*(dx == -1) - softscroll_offset,
-            FY + TILEY*(dy == -1) - softscroll_offset,
-            SXSIZE - TILEX*(dx!=0) + 2*softscroll_offset,
-            SYSIZE - TILEY*(dy!=0) + 2*softscroll_offset,
-            FX + TILEX*(dx == 1) - softscroll_offset,
-            FY + TILEY*(dy == 1) - softscroll_offset);
+            FX + TILEX * (dx == -1) - softscroll_offset,
+            FY + TILEY * (dy == -1) - softscroll_offset,
+            SXSIZE - TILEX * (dx!=0) + 2 * softscroll_offset,
+            SYSIZE - TILEY * (dy!=0) + 2 * softscroll_offset,
+            FX + TILEX * (dx == 1) - softscroll_offset,
+            FY + TILEY * (dy == 1) - softscroll_offset);
 
   if (dx)
   {
     x = (dx == 1 ? BX1 : BX2);
-    for (y=BY1; y<=BY2; y++)
+    for (y=BY1; y <= BY2; y++)
       DrawScreenField(x, y);
   }
 
   if (dy)
   {
     y = (dy == 1 ? BY1 : BY2);
-    for (x=BX1; x<=BX2; x++)
+    for (x=BX1; x <= BX2; x++)
       DrawScreenField(x, y);
   }
 
@@ -5459,6 +6356,7 @@ static void CheckGravityMovement(struct PlayerInfo *player)
       (IN_LEV_FIELD(new_jx, new_jy) &&
        (Feld[new_jx][new_jy] == EL_SP_BASE ||
        Feld[new_jx][new_jy] == EL_SAND));
+    /* !!! extend EL_SAND to anything diggable !!! */
 
     if (field_under_player_is_free &&
        !player_is_moving_to_valid_field &&
@@ -5523,6 +6421,10 @@ boolean MoveFigureOneStep(struct PlayerInfo *player,
   if (can_move != MF_MOVING)
     return can_move;
 
+  /* check if DigField() has caused relocation of the player */
+  if (player->jx != jx || player->jy != jy)
+    return MF_NO_ACTION;
+
   StorePlayer[jx][jy] = 0;
   player->last_jx = jx;
   player->last_jy = jy;
@@ -5692,6 +6594,9 @@ boolean MoveFigure(struct PlayerInfo *player, int dx, int dy)
 
     player->last_move_dir = player->MovDir;
     player->is_moving = TRUE;
+#if 1
+    player->snapped = FALSE;
+#endif
   }
   else
   {
@@ -5704,6 +6609,7 @@ boolean MoveFigure(struct PlayerInfo *player, int dx, int dy)
   }
 
   TestIfHeroTouchesBadThing(jx, jy);
+  TestIfPlayerTouchesCustomElement(jx, jy);
 
   if (!player->active)
     RemoveHero(player);
@@ -5728,7 +6634,9 @@ void ScrollFigure(struct PlayerInfo *player, int mode)
     if (Feld[last_jx][last_jy] == EL_EMPTY)
       Feld[last_jx][last_jy] = EL_PLAYER_IS_LEAVING;
 
+#if 0
     DrawPlayer(player);
+#endif
     return;
   }
   else if (!FrameReached(&player->actual_frame_counter, 1))
@@ -5744,7 +6652,9 @@ void ScrollFigure(struct PlayerInfo *player, int mode)
   if (player->MovPos == 0)
     CheckGravityMovement(player);
 
-  DrawPlayer(player);
+#if 0
+  DrawPlayer(player);  /* needed here only to cleanup last field */
+#endif
 
   if (player->MovPos == 0)
   {
@@ -5763,6 +6673,7 @@ void ScrollFigure(struct PlayerInfo *player, int mode)
     if (Feld[jx][jy] == EL_EXIT_OPEN ||
        Feld[jx][jy] == EL_SP_EXIT_OPEN)
     {
+      DrawPlayer(player);      /* needed here only to cleanup last field */
       RemoveHero(player);
 
       if (local_player->friends_still_needed == 0 ||
@@ -5804,38 +6715,158 @@ void ScrollScreen(struct PlayerInfo *player, int mode)
     ScreenMovDir = MV_NO_MOVING;
 }
 
-void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
+void TestIfPlayerTouchesCustomElement(int x, int y)
 {
-  int i, kill_x = -1, kill_y = -1;
-  static int test_xy[4][2] =
+  static boolean check_changing = FALSE;
+  static int xy[4][2] =
   {
     { 0, -1 },
     { -1, 0 },
     { +1, 0 },
     { 0, +1 }
   };
-  static int test_dir[4] =
-  {
-    MV_UP,
-    MV_LEFT,
-    MV_RIGHT,
-    MV_DOWN
-  };
+  int i;
+
+  if (check_changing)  /* prevent this function from running into a loop */
+    return;
+
+  check_changing = TRUE;
 
   for (i=0; i<4; i++)
   {
-    int test_x, test_y, test_move_dir, test_element;
+    int xx = x + xy[i][0];
+    int yy = y + xy[i][1];
 
-    test_x = good_x + test_xy[i][0];
-    test_y = good_y + test_xy[i][1];
-    if (!IN_LEV_FIELD(test_x, test_y))
+    if (!IN_LEV_FIELD(xx, yy))
       continue;
 
-    test_move_dir =
-      (IS_MOVING(test_x, test_y) ? MovDir[test_x][test_y] : MV_NO_MOVING);
+    if (IS_PLAYER(x, y))
+    {
+      CheckTriggeredElementChange(xx, yy, Feld[xx][yy], CE_OTHER_GETS_TOUCHED);
+      CheckElementChange(xx, yy, Feld[xx][yy], CE_TOUCHED_BY_PLAYER);
+    }
+    else if (IS_PLAYER(xx, yy))
+    {
+      CheckTriggeredElementChange(x, y, Feld[x][y], CE_OTHER_GETS_TOUCHED);
+      CheckElementChange(x, y, Feld[x][y], CE_TOUCHED_BY_PLAYER);
 
-#if 0
-    test_element = Feld[test_x][test_y];
+      break;
+    }
+  }
+
+  check_changing = FALSE;
+}
+
+void TestIfElementTouchesCustomElement(int x, int y)
+{
+  static boolean check_changing = FALSE;
+  static int xy[4][2] =
+  {
+    { 0, -1 },
+    { -1, 0 },
+    { +1, 0 },
+    { 0, +1 }
+  };
+  boolean change_center_element = FALSE;
+  int center_element_change_page = 0;
+  int center_element = Feld[x][y];
+  int i, j;
+
+  if (check_changing)  /* prevent this function from running into a loop */
+    return;
+
+  check_changing = TRUE;
+
+  for (i=0; i<4; i++)
+  {
+    int xx = x + xy[i][0];
+    int yy = y + xy[i][1];
+    int border_element;
+
+    if (!IN_LEV_FIELD(xx, yy))
+      continue;
+
+    border_element = Feld[xx][yy];
+
+    /* check for change of center element (but change it only once) */
+    if (IS_CUSTOM_ELEMENT(center_element) &&
+       HAS_ANY_CHANGE_EVENT(center_element, CE_OTHER_IS_TOUCHING) &&
+       !change_center_element)
+    {
+      for (j=0; j < element_info[center_element].num_change_pages; j++)
+      {
+       struct ElementChangeInfo *change =
+         &element_info[center_element].change_page[j];
+
+       if (change->events & CH_EVENT_BIT(CE_OTHER_IS_TOUCHING) &&
+           change->trigger_element == border_element)
+       {
+         change_center_element = TRUE;
+         center_element_change_page = j;
+
+         break;
+       }
+      }
+    }
+
+    /* check for change of border element */
+    if (IS_CUSTOM_ELEMENT(border_element) &&
+       HAS_ANY_CHANGE_EVENT(border_element, CE_OTHER_IS_TOUCHING))
+    {
+      for (j=0; j < element_info[border_element].num_change_pages; j++)
+      {
+       struct ElementChangeInfo *change =
+         &element_info[border_element].change_page[j];
+
+       if (change->events & CH_EVENT_BIT(CE_OTHER_IS_TOUCHING) &&
+           change->trigger_element == center_element)
+       {
+         CheckElementChangeExt(xx,yy, border_element,CE_OTHER_IS_TOUCHING, j);
+         break;
+       }
+      }
+    }
+  }
+
+  if (change_center_element)
+    CheckElementChangeExt(x, y, center_element, CE_OTHER_IS_TOUCHING,
+                         center_element_change_page);
+
+  check_changing = FALSE;
+}
+
+void TestIfGoodThingHitsBadThing(int good_x, int good_y, int good_move_dir)
+{
+  int i, kill_x = -1, kill_y = -1;
+  static int test_xy[4][2] =
+  {
+    { 0, -1 },
+    { -1, 0 },
+    { +1, 0 },
+    { 0, +1 }
+  };
+  static int test_dir[4] =
+  {
+    MV_UP,
+    MV_LEFT,
+    MV_RIGHT,
+    MV_DOWN
+  };
+
+  for (i=0; i<4; i++)
+  {
+    int test_x, test_y, test_move_dir, test_element;
+
+    test_x = good_x + test_xy[i][0];
+    test_y = good_y + test_xy[i][1];
+    if (!IN_LEV_FIELD(test_x, test_y))
+      continue;
+
+    test_move_dir =
+      (IS_MOVING(test_x, test_y) ? MovDir[test_x][test_y] : MV_NO_MOVING);
+
+#if 0
+    test_element = Feld[test_x][test_y];
 #else
     test_element = MovingOrBlocked2ElementIfNotLeaving(test_x, test_y);
 #endif
@@ -6060,7 +7091,11 @@ void BuryHero(struct PlayerInfo *player)
   if (!player->active)
     return;
 
+#if 1
+  PlaySoundLevelElementAction(jx, jy, player->element_nr, ACTION_DYING);
+#else
   PlaySoundLevel(jx, jy, SND_CLASS_PLAYER_DYING);
+#endif
   PlaySoundLevel(jx, jy, SND_GAME_LOSING);
 
   player->GameOver = TRUE;
@@ -6090,10 +7125,12 @@ void RemoveHero(struct PlayerInfo *player)
 }
 
 /*
+  =============================================================================
   checkDiagonalPushing()
   -----------------------------------------------------------------------------
   check if diagonal input device direction results in pushing of object
   (by checking if the alternative direction is walkable, diggable, ...)
+  =============================================================================
 */
 
 static boolean checkDiagonalPushing(struct PlayerInfo *player,
@@ -6116,17 +7153,21 @@ static boolean checkDiagonalPushing(struct PlayerInfo *player,
 }
 
 /*
+  =============================================================================
   DigField()
   -----------------------------------------------------------------------------
   x, y:                        field next to player (non-diagonal) to try to dig to
   real_dx, real_dy:    direction as read from input device (can be diagonal)
+  =============================================================================
 */
 
 int DigField(struct PlayerInfo *player,
             int x, int y, int real_dx, int real_dy, int mode)
 {
+  boolean use_spring_bug = (game.engine_version < VERSION_IDENT(2,2,0));
   int jx = player->jx, jy = player->jy;
   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 :
@@ -6191,166 +7232,12 @@ int DigField(struct PlayerInfo *player,
 
   element = Feld[x][y];
 
-#if 1
   if (mode == DF_SNAP && !IS_SNAPPABLE(element) &&
       game.engine_version >= VERSION_IDENT(2,2,0))
     return MF_NO_ACTION;
-#endif
 
   switch (element)
   {
-    case EL_EMPTY:
-    case EL_SAND:
-    case EL_INVISIBLE_SAND:
-    case EL_INVISIBLE_SAND_ACTIVE:
-    case EL_TRAP:
-    case EL_SP_BASE:
-    case EL_SP_BUGGY_BASE:
-    case EL_SP_BUGGY_BASE_ACTIVATING:
-      RemoveField(x, y);
-#if 1
-      if (mode != DF_SNAP && element != EL_EMPTY)
-      {
-       GfxElement[x][y] = (CAN_BE_CRUMBLED(element) ? EL_SAND : element);
-       player->is_digging = TRUE;
-      }
-#endif
-      PlaySoundLevelElementAction(x, y, element, ACTION_DIGGING);
-      break;
-
-    case EL_EMERALD:
-    case EL_BD_DIAMOND:
-    case EL_EMERALD_YELLOW:
-    case EL_EMERALD_RED:
-    case EL_EMERALD_PURPLE:
-    case EL_DIAMOND:
-    case EL_SP_INFOTRON:
-    case EL_PEARL:
-    case EL_CRYSTAL:
-      RemoveField(x, y);
-#if 1
-      if (mode != DF_SNAP)
-      {
-       GfxElement[x][y] = element;
-       player->is_collecting = TRUE;
-      }
-#endif
-      local_player->gems_still_needed -= (element == EL_DIAMOND ? 3 :
-                                         element == EL_PEARL ? 5 :
-                                         element == EL_CRYSTAL ? 8 : 1);
-      if (local_player->gems_still_needed < 0)
-       local_player->gems_still_needed = 0;
-      RaiseScoreElement(element);
-      DrawText(DX_EMERALDS, DY_EMERALDS,
-              int2str(local_player->gems_still_needed, 3), FONT_TEXT_2);
-      PlaySoundLevelElementAction(x, y, element, ACTION_COLLECTING);
-      break;
-
-    case EL_SPEED_PILL:
-      RemoveField(x, y);
-      player->move_delay_value = MOVE_DELAY_HIGH_SPEED;
-      PlaySoundLevel(x, y, SND_SPEED_PILL_COLLECTING);
-      break;
-
-    case EL_ENVELOPE:
-      Feld[x][y] = EL_EMPTY;
-      PlaySoundLevel(x, y, SND_ENVELOPE_COLLECTING);
-      break;
-
-    case EL_EXTRA_TIME:
-      RemoveField(x, y);
-      if (level.time > 0)
-      {
-       TimeLeft += 10;
-       DrawText(DX_TIME, DY_TIME, int2str(TimeLeft, 3), FONT_TEXT_2);
-      }
-      PlaySoundStereo(SND_EXTRA_TIME_COLLECTING, SOUND_MIDDLE);
-      break;
-
-    case EL_SHIELD_NORMAL:
-      RemoveField(x, y);
-      player->shield_normal_time_left += 10;
-      PlaySoundLevel(x, y, SND_SHIELD_NORMAL_COLLECTING);
-      break;
-
-    case EL_SHIELD_DEADLY:
-      RemoveField(x, y);
-      player->shield_normal_time_left += 10;
-      player->shield_deadly_time_left += 10;
-      PlaySoundLevel(x, y, SND_SHIELD_DEADLY_COLLECTING);
-      break;
-
-    case EL_DYNAMITE:
-    case EL_SP_DISK_RED:
-      RemoveField(x, y);
-      player->dynamite++;
-      player->use_disk_red_graphic = (element == EL_SP_DISK_RED);
-      RaiseScoreElement(EL_DYNAMITE);
-      DrawText(DX_DYNAMITE, DY_DYNAMITE, int2str(local_player->dynamite, 3),
-              FONT_TEXT_2);
-      PlaySoundLevelElementAction(x, y, element, ACTION_COLLECTING);
-      break;
-
-    case EL_DYNABOMB_INCREASE_NUMBER:
-      RemoveField(x, y);
-      player->dynabomb_count++;
-      player->dynabombs_left++;
-      RaiseScoreElement(EL_DYNAMITE);
-      PlaySoundLevel(x, y, SND_DYNABOMB_INCREASE_NUMBER_COLLECTING);
-      break;
-
-    case EL_DYNABOMB_INCREASE_SIZE:
-      RemoveField(x, y);
-      player->dynabomb_size++;
-      RaiseScoreElement(EL_DYNAMITE);
-      PlaySoundLevel(x, y, SND_DYNABOMB_INCREASE_SIZE_COLLECTING);
-      break;
-
-    case EL_DYNABOMB_INCREASE_POWER:
-      RemoveField(x, y);
-      player->dynabomb_xl = TRUE;
-      RaiseScoreElement(EL_DYNAMITE);
-      PlaySoundLevel(x, y, SND_DYNABOMB_INCREASE_POWER_COLLECTING);
-      break;
-
-    case EL_KEY_1:
-    case EL_KEY_2:
-    case EL_KEY_3:
-    case EL_KEY_4:
-    {
-      int key_nr = element - EL_KEY_1;
-      int graphic = el2edimg(element);
-
-      RemoveField(x, y);
-      player->key[key_nr] = TRUE;
-      RaiseScoreElement(element);
-      DrawMiniGraphicExt(drawto, DX_KEYS + key_nr * MINI_TILEX, DY_KEYS,
-                        graphic);
-      DrawMiniGraphicExt(window, DX_KEYS + key_nr * MINI_TILEX, DY_KEYS,
-                        graphic);
-      PlaySoundLevel(x, y, SND_CLASS_KEY_COLLECTING);
-      break;
-    }
-
-    case EL_EM_KEY_1:
-    case EL_EM_KEY_2:
-    case EL_EM_KEY_3:
-    case EL_EM_KEY_4:
-    {
-      int key_nr = element - EL_EM_KEY_1;
-      int graphic = el2edimg(EL_KEY_1 + key_nr);
-
-      RemoveField(x, y);
-      player->key[key_nr] = TRUE;
-      RaiseScoreElement(element);
-      DrawMiniGraphicExt(drawto, DX_KEYS + key_nr * MINI_TILEX, DY_KEYS,
-                        graphic);
-      DrawMiniGraphicExt(window, DX_KEYS + key_nr * MINI_TILEX, DY_KEYS,
-                        graphic);
-      PlaySoundLevel(x, y, SND_CLASS_KEY_COLLECTING);
-      break;
-    }
-
     case EL_ROBOT_WHEEL:
       Feld[x][y] = EL_ROBOT_WHEEL_ACTIVE;
       ZX = x;
@@ -6451,140 +7338,6 @@ int DigField(struct PlayerInfo *player,
       return MF_ACTION;
       break;
 
-      /* the following elements cannot be pushed by "snapping" */
-    case EL_ROCK:
-    case EL_BOMB:
-    case EL_DX_SUPABOMB:
-    case EL_NUT:
-    case EL_TIME_ORB_EMPTY:
-    case EL_SP_ZONK:
-    case EL_SP_DISK_ORANGE:
-    case EL_SPRING:
-      if (mode == DF_SNAP)
-       return MF_NO_ACTION;
-
-      /* no "break" -- fall through to next case */
-
-      /* the following elements can be pushed by "snapping" */
-    case EL_BD_ROCK:
-      if (dy)
-       return MF_NO_ACTION;
-
-      player->Pushing = TRUE;
-
-#if 0
-      if (element == EL_ROCK)
-       printf("::: wanna push [%d] [%d]\n",
-              FrameCounter, player->push_delay_value);
-#endif
-
-      if (!IN_LEV_FIELD(x+dx, y+dy) || !IS_FREE(x+dx, y+dy))
-       return MF_NO_ACTION;
-
-      if (!checkDiagonalPushing(player, x, y, real_dx, real_dy))
-       return MF_NO_ACTION;
-
-      if (player->push_delay == 0)
-       player->push_delay = FrameCounter;
-#if 0
-      if (!FrameReached(&player->push_delay, player->push_delay_value) &&
-         !tape.playing &&
-         element != EL_SPRING)
-       return MF_NO_ACTION;
-#else
-      if (!FrameReached(&player->push_delay, player->push_delay_value) &&
-         !(tape.playing && tape.file_version < FILE_VERSION_2_0) &&
-         element != EL_SPRING)
-       return MF_NO_ACTION;
-#endif
-
-      if (mode == DF_SNAP)
-      {
-       InitMovingField(x, y, move_direction);
-       ContinueMoving(x, y);
-      }
-      else
-      {
-       RemoveField(x, y);
-       Feld[x + dx][y + dy] = element;
-      }
-
-      if (element == EL_SPRING)
-      {
-       Feld[x + dx][y + dy] = EL_SPRING;
-       MovDir[x + dx][y + dy] = move_direction;
-      }
-
-      player->push_delay_value = (element == EL_SPRING ? 0 : 2 + RND(8));
-
-      DrawLevelField(x + dx, y + dy);
-      PlaySoundLevelElementAction(x, y, element, ACTION_PUSHING);
-      break;
-
-    case EL_GATE_1:
-    case EL_GATE_2:
-    case EL_GATE_3:
-    case EL_GATE_4:
-      if (!player->key[element - EL_GATE_1])
-       return MF_NO_ACTION;
-      break;
-
-    case EL_GATE_1_GRAY:
-    case EL_GATE_2_GRAY:
-    case EL_GATE_3_GRAY:
-    case EL_GATE_4_GRAY:
-      if (!player->key[element - EL_GATE_1_GRAY])
-       return MF_NO_ACTION;
-      break;
-
-    case EL_EM_GATE_1:
-    case EL_EM_GATE_2:
-    case EL_EM_GATE_3:
-    case EL_EM_GATE_4:
-      if (!player->key[element - EL_EM_GATE_1])
-       return MF_NO_ACTION;
-      if (!IN_LEV_FIELD(x + dx, y + dy) || !IS_FREE(x + dx, y + dy))
-       return MF_NO_ACTION;
-
-      /* automatically move to the next field with double speed */
-      player->programmed_action = move_direction;
-      DOUBLE_PLAYER_SPEED(player);
-
-      PlaySoundLevel(x, y, SND_CLASS_GATE_PASSING);
-      break;
-
-    case EL_EM_GATE_1_GRAY:
-    case EL_EM_GATE_2_GRAY:
-    case EL_EM_GATE_3_GRAY:
-    case EL_EM_GATE_4_GRAY:
-      if (!player->key[element - EL_EM_GATE_1_GRAY])
-       return MF_NO_ACTION;
-      if (!IN_LEV_FIELD(x + dx, y + dy) || !IS_FREE(x + dx, y + dy))
-       return MF_NO_ACTION;
-
-      /* automatically move to the next field with double speed */
-      player->programmed_action = move_direction;
-      DOUBLE_PLAYER_SPEED(player);
-
-#if 1
-      PlaySoundLevelAction(x, y, ACTION_PASSING);
-#else
-      PlaySoundLevel(x, y, SND_GATE_PASSING);
-#endif
-      break;
-
-    case EL_SWITCHGATE_OPEN:
-    case EL_TIMEGATE_OPEN:
-      if (!IN_LEV_FIELD(x + dx, y + dy) || !IS_FREE(x + dx, y + dy))
-       return MF_NO_ACTION;
-
-      /* automatically move to the next field with double speed */
-      player->programmed_action = move_direction;
-      DOUBLE_PLAYER_SPEED(player);
-
-      PlaySoundLevelElementAction(x, y, element, ACTION_PASSING);
-      break;
-
     case EL_SP_PORT_LEFT:
     case EL_SP_PORT_RIGHT:
     case EL_SP_PORT_UP:
@@ -6616,10 +7369,16 @@ int DigField(struct PlayerInfo *player,
           element != EL_SP_GRAVITY_PORT_DOWN &&
           element != EL_SP_PORT_VERTICAL &&
           element != EL_SP_PORT_ANY) ||
-         !IN_LEV_FIELD(x + dx, y + dy) ||
-         !IS_FREE(x + dx, y + dy))
+         !IN_LEV_FIELD(nextx, nexty) ||
+         !IS_FREE(nextx, nexty))
        return MF_NO_ACTION;
 
+      if (element == EL_SP_GRAVITY_PORT_LEFT ||
+         element == EL_SP_GRAVITY_PORT_RIGHT ||
+         element == EL_SP_GRAVITY_PORT_UP ||
+         element == EL_SP_GRAVITY_PORT_DOWN)
+       level.gravity = !level.gravity;
+
       /* automatically move to the next field with double speed */
       player->programmed_action = move_direction;
       DOUBLE_PLAYER_SPEED(player);
@@ -6666,28 +7425,10 @@ int DigField(struct PlayerInfo *player,
        if (!(tube_enter_directions[i][1] & move_direction))
          return MF_NO_ACTION;  /* tube has no opening in this direction */
 
-       PlaySoundLevel(x, y, SND_CLASS_TUBE_PASSING);
+       PlaySoundLevel(x, y, SND_CLASS_TUBE_WALKING);
       }
       break;
 
-    case EL_EXIT_CLOSED:
-    case EL_SP_EXIT_CLOSED:
-    case EL_EXIT_OPENING:
-      return MF_NO_ACTION;
-      break;
-
-    case EL_EXIT_OPEN:
-    case EL_SP_EXIT_OPEN:
-      if (mode == DF_SNAP)
-       return MF_NO_ACTION;
-
-      if (element == EL_EXIT_OPEN)
-       PlaySoundLevel(x, y, SND_CLASS_EXIT_PASSING);
-      else
-       PlaySoundLevel(x, y, SND_CLASS_SP_EXIT_PASSING);
-
-      break;
-
     case EL_LAMP:
       Feld[x][y] = EL_LAMP_ACTIVE;
       local_player->lights_still_needed--;
@@ -6705,129 +7446,78 @@ int DigField(struct PlayerInfo *player,
       return MF_ACTION;
       break;
 
-    case EL_SOKOBAN_FIELD_EMPTY:
-      break;
-
-    case EL_SOKOBAN_OBJECT:
-    case EL_SOKOBAN_FIELD_FULL:
-    case EL_SATELLITE:
-    case EL_SP_DISK_YELLOW:
-    case EL_BALLOON:
-      if (mode == DF_SNAP)
-       return MF_NO_ACTION;
-
-      player->Pushing = TRUE;
-
-      if (!IN_LEV_FIELD(x+dx, y+dy)
-         || (!IS_FREE(x+dx, y+dy)
-             && (Feld[x+dx][y+dy] != EL_SOKOBAN_FIELD_EMPTY
-                 || !IS_SB_ELEMENT(element))))
-       return MF_NO_ACTION;
-
-      if (!checkDiagonalPushing(player, x, y, real_dx, real_dy))
-       return MF_NO_ACTION;
-
-      if (player->push_delay == 0)
-       player->push_delay = FrameCounter;
-#if 0
-      if (!FrameReached(&player->push_delay, player->push_delay_value) &&
-         !tape.playing && element != EL_BALLOON)
-       return MF_NO_ACTION;
-#else
-      if (!FrameReached(&player->push_delay, player->push_delay_value) &&
-         !(tape.playing && tape.file_version < FILE_VERSION_2_0) &&
-         element != EL_BALLOON)
-       return MF_NO_ACTION;
-#endif
+    default:
 
-      if (IS_SB_ELEMENT(element))
+      if (IS_WALKABLE(element))
       {
-       if (element == EL_SOKOBAN_FIELD_FULL)
+       int sound_action = ACTION_WALKING;
+
+       if (element >= EL_GATE_1 && element <= EL_GATE_4)
        {
-         Feld[x][y] = EL_SOKOBAN_FIELD_EMPTY;
-         local_player->sokobanfields_still_needed++;
+         if (!player->key[element - EL_GATE_1])
+           return MF_NO_ACTION;
        }
-       else
-         RemoveField(x, y);
-
-       if (Feld[x+dx][y+dy] == EL_SOKOBAN_FIELD_EMPTY)
+       else if (element >= EL_GATE_1_GRAY && element <= EL_GATE_4_GRAY)
        {
-         Feld[x+dx][y+dy] = EL_SOKOBAN_FIELD_FULL;
-         local_player->sokobanfields_still_needed--;
-         if (element == EL_SOKOBAN_OBJECT)
-#if 1
-           PlaySoundLevelAction(x+dx, y+dy, ACTION_FILLING);
-#else
-           PlaySoundLevel(x, y, SND_CLASS_SOKOBAN_FIELD_FILLING);
-#endif
-         else
-#if 1
-           PlaySoundLevelAction(x+dx, y+dy, ACTION_PUSHING);
-#else
-           PlaySoundLevel(x, y, SND_SOKOBAN_OBJECT_PUSHING);
-#endif
+         if (!player->key[element - EL_GATE_1_GRAY])
+           return MF_NO_ACTION;
        }
-       else
+       else if (element == EL_EXIT_OPEN || element == EL_SP_EXIT_OPEN)
        {
-         Feld[x+dx][y+dy] = EL_SOKOBAN_OBJECT;
-         if (element == EL_SOKOBAN_FIELD_FULL)
-#if 1
-           PlaySoundLevelAction(x+dx, y+dy, ACTION_EMPTYING);
-#else
-           PlaySoundLevel(x, y, SND_SOKOBAN_FIELD_EMPTYING);
-#endif
-         else
-#if 1
-           PlaySoundLevelAction(x+dx, y+dy, ACTION_PUSHING);
-#else
-           PlaySoundLevel(x, y, SND_SOKOBAN_OBJECT_PUSHING);
-#endif
+         sound_action = ACTION_PASSING;        /* player is passing exit */
+       }
+       else if (element == EL_EMPTY)
+       {
+         sound_action = ACTION_MOVING;         /* nothing to walk on */
        }
-      }
-      else
-      {
-       RemoveField(x, y);
-       Feld[x+dx][y+dy] = element;
-       PlaySoundLevelElementAction(x, y, element, ACTION_PUSHING);
-      }
-
-      player->push_delay_value = (element == EL_BALLOON ? 0 : 2);
 
-      DrawLevelField(x, y);
-      DrawLevelField(x + dx, y + dy);
+       /* play sound from background or player, whatever is available */
+       if (element_info[element].sound[sound_action] != SND_UNDEFINED)
+         PlaySoundLevelElementAction(x, y, element, sound_action);
+       else
+         PlaySoundLevelElementAction(x, y, player->element_nr, sound_action);
 
-      if (IS_SB_ELEMENT(element) &&
-         local_player->sokobanfields_still_needed == 0 &&
-         game.emulation == EMU_SOKOBAN)
-      {
-       player->LevelSolved = player->GameOver = TRUE;
-       PlaySoundLevel(x, y, SND_GAME_SOKOBAN_SOLVING);
+       break;
       }
+      else if (IS_PASSABLE(element))
+      {
+       if (!IN_LEV_FIELD(nextx, nexty) || !IS_FREE(nextx, nexty))
+         return MF_NO_ACTION;
 
-      break;
+       if (element >= EL_EM_GATE_1 && element <= EL_EM_GATE_4)
+       {
+         if (!player->key[element - EL_EM_GATE_1])
+           return MF_NO_ACTION;
+       }
+       else if (element >= EL_EM_GATE_1_GRAY && element <= EL_EM_GATE_4_GRAY)
+       {
+         if (!player->key[element - EL_EM_GATE_1_GRAY])
+           return MF_NO_ACTION;
+       }
 
-    case EL_PENGUIN:
-    case EL_PIG:
-    case EL_DRAGON:
-      break;
+       /* automatically move to the next field with double speed */
+       player->programmed_action = move_direction;
+       DOUBLE_PLAYER_SPEED(player);
 
-    default:
+       PlaySoundLevelAction(x, y, ACTION_PASSING);
 
-      if (IS_WALKABLE(element))
-      {
        break;
       }
       else if (IS_DIGGABLE(element))
       {
        RemoveField(x, y);
-#if 1
+
        if (mode != DF_SNAP)
        {
+#if 1
+         GfxElement[x][y] = GFX_ELEMENT(element);
+#else
          GfxElement[x][y] =
            (CAN_BE_CRUMBLED(element) ? EL_SAND : GFX_ELEMENT(element));
+#endif
          player->is_digging = TRUE;
        }
-#endif
+
        PlaySoundLevelElementAction(x, y, element, ACTION_DIGGING);
 
        break;
@@ -6835,32 +7525,119 @@ int DigField(struct PlayerInfo *player,
       else if (IS_COLLECTIBLE(element))
       {
        RemoveField(x, y);
-#if 1
+
        if (mode != DF_SNAP)
        {
          GfxElement[x][y] = element;
          player->is_collecting = TRUE;
        }
-#endif
+
+       if (element == EL_SPEED_PILL)
+         player->move_delay_value = MOVE_DELAY_HIGH_SPEED;
+       else if (element == EL_EXTRA_TIME && level.time > 0)
+       {
+         TimeLeft += 10;
+         DrawText(DX_TIME, DY_TIME, int2str(TimeLeft, 3), FONT_TEXT_2);
+       }
+       else if (element == EL_SHIELD_NORMAL || element == EL_SHIELD_DEADLY)
+       {
+         player->shield_normal_time_left += 10;
+         if (element == EL_SHIELD_DEADLY)
+           player->shield_deadly_time_left += 10;
+       }
+       else if (element == EL_DYNAMITE || element == EL_SP_DISK_RED)
+       {
+         if (player->inventory_size < MAX_INVENTORY_SIZE)
+           player->inventory_element[player->inventory_size++] = element;
+
+         player->use_disk_red_graphic = (element == EL_SP_DISK_RED);
+
+         DrawText(DX_DYNAMITE, DY_DYNAMITE,
+                  int2str(local_player->inventory_size, 3), FONT_TEXT_2);
+       }
+       else if (element == EL_DYNABOMB_INCREASE_NUMBER)
+       {
+         player->dynabomb_count++;
+         player->dynabombs_left++;
+       }
+       else if (element == EL_DYNABOMB_INCREASE_SIZE)
+       {
+         player->dynabomb_size++;
+       }
+       else if (element == EL_DYNABOMB_INCREASE_POWER)
+       {
+         player->dynabomb_xl = TRUE;
+       }
+       else if ((element >= EL_KEY_1 && element <= EL_KEY_4) ||
+                (element >= EL_EM_KEY_1 && element <= EL_EM_KEY_4))
+       {
+         int key_nr = (element >= EL_KEY_1 && element <= EL_KEY_4 ?
+                       element - EL_KEY_1 : element - EL_EM_KEY_1);
+
+         player->key[key_nr] = TRUE;
+
+         DrawMiniGraphicExt(drawto, DX_KEYS + key_nr * MINI_TILEX, DY_KEYS,
+                            el2edimg(EL_KEY_1 + key_nr));
+         redraw_mask |= REDRAW_DOOR_1;
+       }
+       else if (element == EL_ENVELOPE)
+       {
+         ShowEnvelope();
+       }
+       else if (IS_DROPPABLE(element)) /* can be collected and dropped */
+       {
+         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;
+
+         DrawText(DX_DYNAMITE, DY_DYNAMITE,
+                  int2str(local_player->inventory_size, 3), FONT_TEXT_2);
+       }
+       else if (element_info[element].collect_count > 0)
+       {
+         local_player->gems_still_needed -=
+           element_info[element].collect_count;
+         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);
+       }
+
+       RaiseScoreElement(element);
        PlaySoundLevelElementAction(x, y, element, ACTION_COLLECTING);
 
+       CheckTriggeredElementChange(x, y, element, CE_OTHER_GETS_COLLECTED);
+
        break;
       }
       else if (IS_PUSHABLE(element))
       {
-       if (mode == DF_SNAP)
+       if (mode == DF_SNAP && element != EL_BD_ROCK)
          return MF_NO_ACTION;
 
        if (CAN_FALL(element) && dy)
          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))
+         return MF_NO_ACTION;
+
+       if (element == EL_SPRING && MovDir[x][y] != MV_NO_MOVING)
+         return MF_NO_ACTION;
+
        if (!player->Pushing &&
            game.engine_version >= RELEASE_IDENT(2,2,0,7))
          player->push_delay_value = GET_NEW_PUSH_DELAY(element);
 
        player->Pushing = TRUE;
 
-       if (!IN_LEV_FIELD(x + dx, y + dy) || !IS_FREE(x + dx, y + dy))
+       if (!(IN_LEV_FIELD(nextx, nexty) &&
+             (IS_FREE(nextx, nexty) ||
+              (Feld[nextx][nexty] == EL_SOKOBAN_FIELD_EMPTY &&
+               IS_SB_ELEMENT(element)))))
          return MF_NO_ACTION;
 
        if (!checkDiagonalPushing(player, x, y, real_dx, real_dy))
@@ -6870,24 +7647,69 @@ int DigField(struct PlayerInfo *player,
          player->push_delay = FrameCounter;
 
        if (!FrameReached(&player->push_delay, player->push_delay_value) &&
-           !(tape.playing && tape.file_version < FILE_VERSION_2_0))
+           !(tape.playing && tape.file_version < FILE_VERSION_2_0) &&
+           element != EL_SPRING && element != EL_BALLOON)
          return MF_NO_ACTION;
 
-       RemoveField(x, y);
-       Feld[x + dx][y + dy] = element;
+       if (IS_SB_ELEMENT(element))
+       {
+         if (element == EL_SOKOBAN_FIELD_FULL)
+         {
+           Back[x][y] = EL_SOKOBAN_FIELD_EMPTY;
+           local_player->sokobanfields_still_needed++;
+         }
+
+         if (Feld[nextx][nexty] == EL_SOKOBAN_FIELD_EMPTY)
+         {
+           Back[nextx][nexty] = EL_SOKOBAN_FIELD_EMPTY;
+           local_player->sokobanfields_still_needed--;
+         }
+
+         Feld[x][y] = EL_SOKOBAN_OBJECT;
+
+         if (Back[x][y] == Back[nextx][nexty])
+           PlaySoundLevelAction(x, y, ACTION_PUSHING);
+         else if (Back[x][y] != 0)
+           PlaySoundLevelElementAction(x, y, EL_SOKOBAN_FIELD_FULL,
+                                       ACTION_EMPTYING);
+         else
+           PlaySoundLevelElementAction(nextx, nexty, EL_SOKOBAN_FIELD_EMPTY,
+                                       ACTION_FILLING);
+
+         if (local_player->sokobanfields_still_needed == 0 &&
+             game.emulation == EMU_SOKOBAN)
+         {
+           player->LevelSolved = player->GameOver = TRUE;
+           PlaySoundLevel(x, y, SND_GAME_SOKOBAN_SOLVING);
+         }
+       }
+       else
+         PlaySoundLevelElementAction(x, y, element, ACTION_PUSHING);
+
+       InitMovingField(x, y, move_direction);
+       GfxAction[x][y] = ACTION_PUSHING;
+
+       if (mode == DF_SNAP)
+         ContinueMoving(x, y);
+       else
+         MovPos[x][y] = (dx != 0 ? dx : dy);
+
+       Pushed[x][y] = TRUE;
+       Pushed[nextx][nexty] = TRUE;
 
-#if 1
        if (game.engine_version < RELEASE_IDENT(2,2,0,7))
          player->push_delay_value = GET_NEW_PUSH_DELAY(element);
-#else
-       player->push_delay_value = 2 + RND(8);
-#endif
 
-       DrawLevelField(x + dx, y + dy);
-       PlaySoundLevelElementAction(x, y, element, ACTION_PUSHING);
+       CheckTriggeredElementChange(x, y, element, CE_OTHER_GETS_PUSHED);
+       CheckElementChange(x, y, element, CE_PUSHED_BY_PLAYER);
 
        break;
       }
+      else
+      {
+       CheckTriggeredElementChange(x, y, element, CE_OTHER_GETS_PRESSED);
+       CheckElementChange(x, y, element, CE_PRESSED_BY_PLAYER);
+      }
 
       return MF_NO_ACTION;
   }
@@ -6904,6 +7726,10 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
 {
   int jx = player->jx, jy = player->jy;
   int x = jx + dx, y = jy + dy;
+  int snap_direction = (dx == -1 ? MV_LEFT :
+                       dx == +1 ? MV_RIGHT :
+                       dy == -1 ? MV_UP :
+                       dy == +1 ? MV_DOWN : MV_NO_MOVING);
 
   if (player->MovPos && game.engine_version >= VERSION_IDENT(2,2,0))
     return FALSE;
@@ -6925,25 +7751,42 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
     {
       player->is_digging = FALSE;
       player->is_collecting = FALSE;
+#if 1
+      player->is_moving = FALSE;
+#endif
     }
 
+#if 0
+    printf("::: trying to snap...\n");
+#endif
+
     return FALSE;
   }
 
   if (player->snapped)
     return FALSE;
 
-  player->MovDir = (dx < 0 ? MV_LEFT :
-                   dx > 0 ? MV_RIGHT :
-                   dy < 0 ? MV_UP :
-                   dy > 0 ? MV_DOWN :  MV_NO_MOVING);
+  player->MovDir = snap_direction;
+
+#if 1
+  player->is_digging = FALSE;
+  player->is_collecting = FALSE;
+#if 1
+  player->is_moving = FALSE;
+#endif
+#endif
 
   if (DigField(player, x, y, 0, 0, DF_SNAP) == MF_NO_ACTION)
     return FALSE;
 
   player->snapped = TRUE;
+#if 1
   player->is_digging = FALSE;
   player->is_collecting = FALSE;
+#if 1
+  player->is_moving = FALSE;
+#endif
+#endif
 
   DrawLevelField(x, y);
   BackToFront();
@@ -6951,66 +7794,68 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
   return TRUE;
 }
 
-boolean PlaceBomb(struct PlayerInfo *player)
+boolean DropElement(struct PlayerInfo *player)
 {
   int jx = player->jx, jy = player->jy;
-  int element;
+  int old_element;
 
   if (!player->active || player->MovPos)
     return FALSE;
 
-  element = Feld[jx][jy];
+  old_element = Feld[jx][jy];
 
-  if ((player->dynamite == 0 && player->dynabombs_left == 0) ||
-      IS_ACTIVE_BOMB(element) || element == EL_EXPLOSION)
+  /* check if player has anything that can be dropped */
+  if (player->inventory_size == 0 && player->dynabombs_left == 0)
     return FALSE;
 
-#if 0
-  if (element != EL_EMPTY)
+  /* check if anything can be dropped at the current position */
+  if (IS_ACTIVE_BOMB(old_element) || old_element == EL_EXPLOSION)
     return FALSE;
-#endif
 
-  if (element != EL_EMPTY)
-  {
-#if 0
-    Store[jx][jy] = element;
-#else
-    Back[jx][jy] = element;
-#endif
-  }
+  /* collected custom elements can only be dropped on empty fields */
+  if (player->inventory_size > 0 &&
+      IS_CUSTOM_ELEMENT(player->inventory_element[player->inventory_size - 1])
+      && old_element != EL_EMPTY)
+    return FALSE;
+
+  if (old_element != EL_EMPTY)
+    Back[jx][jy] = old_element;                /* store old element on this field */
 
   MovDelay[jx][jy] = 96;
 
   ResetGfxAnimation(jx, jy);
   ResetRandomAnimationValue(jx, jy);
 
-  if (player->dynamite)
+  if (player->inventory_size > 0)
   {
+    int new_element = player->inventory_element[--player->inventory_size];
+
+#if 1
+    Feld[jx][jy] = (new_element == EL_DYNAMITE ? EL_DYNAMITE_ACTIVE :
+                   new_element == EL_SP_DISK_RED ? EL_SP_DISK_RED_ACTIVE :
+                   new_element);
+#else
     Feld[jx][jy] = (player->use_disk_red_graphic ? EL_SP_DISK_RED_ACTIVE :
                    EL_DYNAMITE_ACTIVE);
-    player->dynamite--;
+#endif
+
+    DrawText(DX_DYNAMITE, DY_DYNAMITE,
+            int2str(local_player->inventory_size, 3), FONT_TEXT_2);
 
-    DrawText(DX_DYNAMITE, DY_DYNAMITE, int2str(local_player->dynamite, 3),
-            FONT_TEXT_2);
     if (IN_SCR_FIELD(SCREENX(jx), SCREENY(jy)))
-    {
-#if 1
       DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), el2img(Feld[jx][jy]), 0);
-#else
-      if (game.emulation == EMU_SUPAPLEX)
-       DrawGraphic(SCREENX(jx), SCREENY(jy), IMG_SP_DISK_RED, 0);
-      else
-       DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), IMG_DYNAMITE_ACTIVE, 0);
-#endif
-    }
 
     PlaySoundLevelAction(jx, jy, ACTION_DROPPING);
+
+    CheckTriggeredElementChange(jx, jy, new_element, CE_OTHER_GETS_DROPPED);
+    CheckElementChange(jx, jy, new_element, CE_DROPPED_BY_PLAYER);
   }
-  else
+  else         /* player is dropping a dyna bomb */
   {
+    player->dynabombs_left--;
+
     Feld[jx][jy] =
       EL_DYNABOMB_PLAYER_1_ACTIVE + (player->element_nr - EL_PLAYER_1);
-    player->dynabombs_left--;
 
     if (IN_SCR_FIELD(SCREENX(jx), SCREENY(jy)))
       DrawGraphicThruMask(SCREENX(jx), SCREENY(jy), el2img(Feld[jx][jy]), 0);
@@ -7176,6 +8021,7 @@ void RaiseScoreElement(int element)
       RaiseScore(level.score[SC_NUT]);
       break;
     case EL_DYNAMITE:
+    case EL_SP_DISK_RED:
     case EL_DYNABOMB_INCREASE_NUMBER:
     case EL_DYNABOMB_INCREASE_SIZE:
     case EL_DYNABOMB_INCREASE_POWER:
@@ -7195,6 +8041,7 @@ void RaiseScoreElement(int element)
       RaiseScore(level.score[SC_KEY]);
       break;
     default:
+      RaiseScore(element_info[element].collect_score);
       break;
   }
 }
@@ -7421,6 +8268,8 @@ static void HandleGameButtons(struct GadgetInfo *gi)
       else if (audio.music_available)
       { 
        setup.sound = setup.sound_music = TRUE;
+
+       SetAudioMode(setup.sound);
        PlayMusic(level_nr);
       }
       break;
@@ -7429,14 +8278,20 @@ static void HandleGameButtons(struct GadgetInfo *gi)
       if (setup.sound_loops)
        setup.sound_loops = FALSE;
       else if (audio.loops_available)
+      {
        setup.sound = setup.sound_loops = TRUE;
+       SetAudioMode(setup.sound);
+      }
       break;
 
     case SOUND_CTRL_ID_SIMPLE:
       if (setup.sound_simple)
        setup.sound_simple = FALSE;
       else if (audio.sound_available)
+      {
        setup.sound = setup.sound_simple = TRUE;
+       SetAudioMode(setup.sound);
+      }
       break;
 
     default: