rnd-20030902-1-src
[rocksndiamonds.git] / src / game.c
index 7968b389573e613f29b98c94da0921db3427d02c..91c8841ab9657c815e9cdb87359febc4adf9b0d7 100644 (file)
@@ -171,7 +171,6 @@ static void TestIfElementTouchesCustomElement(int, int);
 
 static boolean CheckTriggeredElementChange(int, int, int, int);
 static boolean CheckElementChange(int, int, int, int);
-static void ChangeElementNow(int, int, int);
 
 static void PlaySoundLevel(int, int, int);
 static void PlaySoundLevelNearest(int, int, int);
@@ -216,7 +215,7 @@ struct ChangingElementInfo
   void (*post_change_function)(int x, int y);
 };
 
-static struct ChangingElementInfo changing_element_list[] =
+static struct ChangingElementInfo change_delay_list[] =
 {
   {
     EL_NUT_BREAKING,
@@ -415,19 +414,21 @@ collect_count_list[] =
   { EL_UNDEFINED,              0 },
 };
 
-static boolean changing_element[MAX_NUM_ELEMENTS];
 static unsigned long trigger_events[MAX_NUM_ELEMENTS];
 
-#define IS_AUTO_CHANGING(e)    (changing_element[e])
+#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 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;
@@ -438,7 +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();
@@ -742,7 +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 :
@@ -773,78 +774,82 @@ static void InitGameEngine()
   /* ---------- initialize changing elements ------------------------------- */
 
   /* initialize changing elements information */
-  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+  for (i=0; i < MAX_NUM_ELEMENTS; i++)
   {
-#if 1
-    element_info[i].change.pre_change_function = NULL;
-    element_info[i].change.change_function = NULL;
-    element_info[i].change.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))
     {
-      element_info[i].change.target_element = EL_EMPTY_SPACE;
-      element_info[i].change.delay_fixed = 0;
-      element_info[i].change.delay_random = 0;
-      element_info[i].change.delay_frames = 1;
+      ei->change->target_element = EL_EMPTY_SPACE;
+      ei->change->delay_fixed = 0;
+      ei->change->delay_random = 0;
+      ei->change->delay_frames = 1;
     }
 
-    changing_element[i] = FALSE;
-#else
-    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;
-#endif
+    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 */
-  for (i=0; changing_element_list[i].element != EL_UNDEFINED; i++)
+  for (i=0; change_delay_list[i].element != EL_UNDEFINED; i++)
   {
-    int element = changing_element_list[i].element;
-    struct ChangingElementInfo *ce = &changing_element_list[i];
-    struct ElementChangeInfo *change = &element_info[element].change;
+    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
-    change->target_element       = ce->target_element;
-    change->delay_fixed          = ce->change_delay;
-    change->pre_change_function  = ce->pre_change_function;
-    change->change_function      = ce->change_function;
-    change->post_change_function = ce->post_change_function;
+  /* add change events from custom element configuration */
+  for (i=0; i < NUM_CUSTOM_ELEMENTS; i++)
+  {
+    struct ElementInfo *ei = &element_info[EL_CUSTOM_START + i];
 
-    changing_element[element] = TRUE;
-#else
-    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;
-#endif
+    for (j=0; j < ei->num_change_pages; j++)
+    {
+      if (!ei->change_page[j].can_change)
+       continue;
+
+      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;
-#if 0
-    struct ElementChangeInfo *change = &element_info[element].change;
-#endif
 
     /* only add custom elements that change after fixed/random frame delay */
-    if (!CAN_CHANGE(element) || !HAS_CHANGE_EVENT(element, CE_DELAY))
-      continue;
-
-#if 1
-    changing_element[element] = TRUE;
-#else
-    changing_element[element].base_element = element;
-    changing_element[element].next_element = change->target_element;
-    changing_element[element].change_delay = (change->delay_fixed *
-                                             change->delay_frames);
-#endif
+    if (CAN_CHANGE(element) && HAS_CHANGE_EVENT(element, CE_DELAY))
+      element_info[element].change_events |= CH_EVENT_BIT(CE_DELAY);
   }
+#endif
 
   /* ---------- initialize trigger events ---------------------------------- */
 
@@ -852,11 +857,32 @@ static void InitGameEngine()
   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;
+      trigger_events[element_info[i].change->trigger_element] |=
+       element_info[i].change->events;
+#endif
 
   /* ---------- initialize push delay -------------------------------------- */
 
@@ -1222,46 +1248,65 @@ void InitGame()
   {
     int start_x = 0, start_y = 0;
     int found_rating = 0;
+    int found_element = EL_UNDEFINED;
 
-    for(y=0; y < lev_fieldy; y++)
+    for(y=0; y < lev_fieldy; y++) for(x=0; x < lev_fieldx; x++)
     {
-      for(x=0; x < lev_fieldx; x++)
-      {
-       int element = Feld[x][y];
+      int element = Feld[x][y];
+      int content;
+      int xx, yy;
+      boolean is_player;
 
-       if (IS_CUSTOM_ELEMENT(element))
+      if (!IS_CUSTOM_ELEMENT(element))
+       continue;
+
+      if (CAN_CHANGE(element))
+      {
+       for (i=0; i < element_info[element].num_change_pages; i++)
        {
-         int xx, yy;
+         content = element_info[element].change_page[i].target_element;
+         is_player = ELEM_IS_PLAYER(content);
 
-         for(yy=0; yy < 3; yy++)
+         if (is_player && (found_rating < 3 || element < found_element))
          {
-           for(xx=0; xx < 3; xx++)
-           {
-             int content;
-             boolean is_player;
+           start_x = x;
+           start_y = y;
 
-             content = element_info[element].content[xx][yy];
-             is_player = (ELEM_IS_PLAYER(content) || content == EL_SP_MURPHY);
+           found_rating = 3;
+           found_element = element;
+         }
+       }
+      }
 
-             if (is_player && found_rating < 2)
-             {
-               start_x = x + xx - 1;
-               start_y = y + yy - 1;
+      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);
 
-               found_rating = 2;
-             }
+       if (is_player && (found_rating < 2 || element < found_element))
+       {
+         start_x = x + xx - 1;
+         start_y = y + yy - 1;
 
-             content = element_info[element].change.content[xx][yy];
-             is_player = (ELEM_IS_PLAYER(content) || content == EL_SP_MURPHY);
+         found_rating = 2;
+         found_element = element;
+       }
 
-             if (is_player && found_rating < 1)
-             {
-               start_x = x + xx - 1;
-               start_y = y + yy - 1;
+       if (!CAN_CHANGE(element))
+         continue;
 
-               found_rating = 1;
-             }
-           }
+       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;
          }
        }
       }
@@ -1944,6 +1989,75 @@ void CheckDynamite(int x, int y)
   Bang(x, y);
 }
 
+void ShowEnvelope()
+{
+  int i, x, y;
+
+  /* open envelope window horizontally */
+  for (i=2; i <= level.envelope_xsize + 2; i += 2)
+  {
+    int startx = (SXSIZE / MINI_TILEX - i) / 2;
+    int starty = (SYSIZE / MINI_TILEY) / 2 - 1;
+
+    SetDrawtoField(DRAW_BUFFERED);
+
+    BlitBitmap(fieldbuffer, backbuffer, FX, FY, SXSIZE, SYSIZE, SX, SY);
+
+    SetDrawtoField(DRAW_BACKBUFFER);
+
+    for (y=0; y < 2; y++) for (x=0; x < i; x++)
+    {
+      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);
+    }
+
+    redraw_mask |= REDRAW_FIELD | REDRAW_FROM_BACKBUFFER;
+    BackToFront();
+
+    Delay(GAME_FRAME_DELAY);
+  }
+
+  /* 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;
+
+    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];
@@ -2852,24 +2966,12 @@ void Impact(int x, int y)
     PlaySoundLevel(x, y, SND_PEARL_BREAKING);
     return;
   }
-#if 1
   else if (impact && CheckElementChange(x, y, element, CE_IMPACT))
   {
     PlaySoundLevelElementAction(x, y, element, ACTION_IMPACT);
 
     return;
   }
-#else
-  else if (impact && CAN_CHANGE(element) &&
-          HAS_CHANGE_EVENT(element, CE_IMPACT))
-  {
-    PlaySoundLevelElementAction(x, y, element, ACTION_IMPACT);
-
-    ChangeElementNow(x, y, element);
-
-    return;
-  }
-#endif
 
   if (impact && element == EL_AMOEBA_DROP)
   {
@@ -3001,17 +3103,10 @@ void Impact(int x, int y)
        {
          ToggleLightSwitch(x, y + 1);
        }
-#if 1
        else
        {
          CheckElementChange(x, y + 1, smashed, CE_SMASHED);
        }
-#else
-       else if (CAN_CHANGE(smashed) && HAS_CHANGE_EVENT(smashed, CE_SMASHED))
-       {
-         ChangeElementNow(x, y + 1, smashed);
-       }
-#endif
       }
       else
       {
@@ -3607,7 +3702,8 @@ void StartMoving(int x, int y)
 
   if (CAN_FALL(element) && y < lev_fieldy - 1)
   {
-    if ((x>0 && IS_PLAYER(x-1, y)) || (x<lev_fieldx-1 && IS_PLAYER(x+1, y)))
+    if ((x > 0 && IS_PLAYER(x - 1, y)) ||
+       (x < lev_fieldx-1 && IS_PLAYER(x + 1, y)))
       if (JustBeingPushed(x, y))
        return;
 
@@ -4008,7 +4104,8 @@ void StartMoving(int x, int y)
 
     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
@@ -5297,13 +5394,14 @@ static void ChangeActiveTrap(int x, int y)
 
 static void ChangeElementNowExt(int x, int y, int target_element)
 {
-#if 0  /* !!! let the player exacpe from a suddenly unaccessible element */
-  if (IS_PLAYER(x, y) && !IS_ACCESSIBLE(target_element))
+  /* 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;
   }
-#endif
 
   RemoveField(x, y);
   Feld[x][y] = target_element;
@@ -5328,17 +5426,12 @@ static void ChangeElementNowExt(int x, int y, int target_element)
     RelocatePlayer(x, y, target_element);
 }
 
-static void ChangeElementNow(int x, int y, int element)
+static void ChangeElementNow(int x, int y, int element, int page)
 {
-  struct ElementChangeInfo *change = &element_info[element].change;
-
-  /* prevent CheckTriggeredElementChange() from looping */
-  Changing[x][y] = TRUE;
+  struct ElementChangeInfo *change = &element_info[element].change_page[page];
 
   CheckTriggeredElementChange(x, y, Feld[x][y], CE_OTHER_IS_CHANGING);
 
-  Changing[x][y] = FALSE;
-
   if (change->explode)
   {
     Bang(x, y);
@@ -5435,42 +5528,21 @@ static void ChangeElementNow(int x, int y, int element)
   }
 }
 
-static void ChangeElement(int x, int y)
+static void ChangeElement(int x, int y, int page)
 {
-#if 1
   int element = MovingOrBlocked2Element(x, y);
-#else
-  int element = Feld[x][y];
-#endif
-  struct ElementChangeInfo *change = &element_info[element].change;
+  struct ElementChangeInfo *change = &element_info[element].change_page[page];
 
   if (ChangeDelay[x][y] == 0)          /* initialize element change */
   {
-#if 1
     ChangeDelay[x][y] = (    change->delay_fixed  * change->delay_frames +
                         RND(change->delay_random * change->delay_frames)) + 1;
-#else
-    ChangeDelay[x][y] = changing_element[element].change_delay + 1;
-
-    if (IS_CUSTOM_ELEMENT(element) && HAS_CHANGE_EVENT(element, CE_DELAY))
-    {
-      int max_random_delay = element_info[element].change.delay_random;
-      int delay_frames = element_info[element].change.delay_frames;
-
-      ChangeDelay[x][y] += RND(max_random_delay * delay_frames);
-    }
-#endif
 
     ResetGfxAnimation(x, y);
     ResetRandomAnimationValue(x, y);
 
-#if 1
     if (change->pre_change_function)
       change->pre_change_function(x, y);
-#else
-    if (changing_element[element].pre_change_function)
-      changing_element[element].pre_change_function(x, y);
-#endif
   }
 
   ChangeDelay[x][y]--;
@@ -5482,20 +5554,11 @@ static void ChangeElement(int x, int y)
     if (IS_ANIMATED(graphic))
       DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
 
-#if 1
     if (change->change_function)
       change->change_function(x, y);
-#else
-    if (changing_element[element].change_function)
-      changing_element[element].change_function(x, y);
-#endif
   }
   else                                 /* finish element change */
   {
-#if 0
-    int next_element = changing_element[element].next_element;
-#endif
-
     if (IS_MOVING(x, y))               /* never change a running system ;-) */
     {
       ChangeDelay[x][y] = 1;           /* try change after next move step */
@@ -5503,37 +5566,59 @@ static void ChangeElement(int x, int y)
       return;
     }
 
-#if 1
-    ChangeElementNow(x, y, element);
+    ChangeElementNow(x, y, element, page);
 
     if (change->post_change_function)
       change->post_change_function(x, y);
-#else
-    if (next_element != EL_UNDEFINED)
-      ChangeElementNow(x, y, next_element);
-    else
-      ChangeElementNow(x, y, element_info[element].change.target_element);
-
-    if (changing_element[element].post_change_function)
-      changing_element[element].post_change_function(x, y);
-#endif
   }
 }
 
 static boolean CheckTriggeredElementChange(int lx, int ly, int trigger_element,
                                           int trigger_event)
 {
-  int i, x, y;
+  int i, j, x, y;
 
   if (!(trigger_events[trigger_element] & CH_EVENT_BIT(trigger_event)))
     return FALSE;
 
-  for (i=0; i<MAX_NUM_ELEMENTS; i++)
+  /* 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++)
   {
-    if (!CAN_CHANGE(i) || !HAS_CHANGE_EVENT(i, trigger_event) ||
-       element_info[i].change.trigger_element != trigger_element)
+    int element = EL_CUSTOM_START + i;
+
+#if 1
+    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
+
     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 */
@@ -5542,31 +5627,45 @@ static boolean CheckTriggeredElementChange(int lx, int ly, int trigger_element,
       if (Changing[x][y])      /* do not change just changing elements */
        continue;
 
-      if (Feld[x][y] == i)
+      if (Feld[x][y] == element)
       {
        ChangeDelay[x][y] = 1;
-       ChangeElement(x, y);
+       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 CheckElementChange(int x, int y, int element, int trigger_event)
+static boolean CheckElementChangeExt(int x, int y, int element,
+                                    int trigger_event, int page)
 {
-  if (!CAN_CHANGE(element) || !HAS_CHANGE_EVENT(element, trigger_event))
+  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);
+  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];
@@ -5619,13 +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;
@@ -5836,7 +5929,7 @@ void GameActions()
     /* this may take place after moving, so 'element' may have changed */
     if (IS_CHANGING(x, y))
     {
-      ChangeElement(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]);
     }
@@ -6328,6 +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;
@@ -6497,6 +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
   {
@@ -6573,6 +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 ||
@@ -6667,8 +6768,9 @@ void TestIfElementTouchesCustomElement(int x, int y)
     { 0, +1 }
   };
   boolean change_center_element = FALSE;
+  int center_element_change_page = 0;
   int center_element = Feld[x][y];
-  int i;
+  int i, j;
 
   if (check_changing)  /* prevent this function from running into a loop */
     return;
@@ -6688,17 +6790,47 @@ void TestIfElementTouchesCustomElement(int x, int y)
 
     /* check for change of center element (but change it only once) */
     if (IS_CUSTOM_ELEMENT(center_element) &&
-       border_element == element_info[center_element].change.trigger_element)
-      change_center_element = TRUE;
+       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) &&
-       center_element == element_info[border_element].change.trigger_element)
-      CheckElementChange(xx, yy, border_element, CE_OTHER_IS_TOUCHING);
+       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)
-    CheckElementChange(x, y, center_element, CE_OTHER_IS_TOUCHING);
+    CheckElementChangeExt(x, y, center_element, CE_OTHER_IS_TOUCHING,
+                         center_element_change_page);
 
   check_changing = FALSE;
 }
@@ -7448,6 +7580,10 @@ int DigField(struct PlayerInfo *player,
                             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;
@@ -7615,8 +7751,15 @@ 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;
   }
 
@@ -7625,12 +7768,25 @@ boolean SnapField(struct PlayerInfo *player, int dx, int dy)
 
   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();