rnd-20070121-2-src
[rocksndiamonds.git] / src / game.c
index 3f3e6317d9629e25c395e863fc4ea8babdfe51bd..be311d801f790c1e62d5091c7e4acd9ca63b020a 100644 (file)
        ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, IS_FOOD_PIG(Feld[x][y]))
 
 #define PENGUIN_CAN_ENTER_FIELD(e, x, y)                               \
-       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, (Feld[x][y] == EL_EXIT_OPEN ||\
+       ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, (Feld[x][y] == EL_EXIT_OPEN || \
+                                                Feld[x][y] == EL_EM_EXIT_OPEN || \
+                                                Feld[x][y] == EL_STEEL_EXIT_OPEN || \
+                                                Feld[x][y] == EL_EM_STEEL_EXIT_OPEN || \
                                                 IS_FOOD_PENGUIN(Feld[x][y])))
 #define DRAGON_CAN_ENTER_FIELD(e, x, y)                                        \
        ELEMENT_CAN_ENTER_FIELD_BASE_2(e, x, y, 0)
@@ -379,6 +382,33 @@ static int getInvisibleFromInvisibleActiveElement(int);
 
 static struct GadgetInfo *game_gadget[NUM_GAME_BUTTONS];
 
+/* for detection of endless loops, caused by custom element programming */
+/* (using maximal playfield width x 10 is just a rough approximation) */
+#define MAX_ELEMENT_CHANGE_RECURSION_DEPTH     (MAX_PLAYFIELD_WIDTH * 10)
+
+#define RECURSION_LOOP_DETECTION_START(e, rc)                          \
+{                                                                      \
+  if (recursion_loop_detected)                                         \
+    return (rc);                                                       \
+                                                                       \
+  if (recursion_loop_depth > MAX_ELEMENT_CHANGE_RECURSION_DEPTH)       \
+  {                                                                    \
+    recursion_loop_detected = TRUE;                                    \
+    recursion_loop_element = (e);                                      \
+  }                                                                    \
+                                                                       \
+  recursion_loop_depth++;                                              \
+}
+
+#define RECURSION_LOOP_DETECTION_END()                                 \
+{                                                                      \
+  recursion_loop_depth--;                                              \
+}
+
+static int recursion_loop_depth;
+static boolean recursion_loop_detected;
+static boolean recursion_loop_element;
+
 
 /* ------------------------------------------------------------------------- */
 /* definition of elements that automatically change to other elements after  */
@@ -447,6 +477,62 @@ static struct ChangingElementInfo change_delay_list[] =
     NULL,
     NULL
   },
+  {
+    EL_STEEL_EXIT_OPENING,
+    EL_STEEL_EXIT_OPEN,
+    29,
+    NULL,
+    NULL,
+    NULL
+  },
+  {
+    EL_STEEL_EXIT_CLOSING,
+    EL_STEEL_EXIT_CLOSED,
+    29,
+    NULL,
+    NULL,
+    NULL
+  },
+  {
+    EL_EM_EXIT_OPENING,
+    EL_EM_EXIT_OPEN,
+    29,
+    NULL,
+    NULL,
+    NULL
+  },
+  {
+    EL_EM_EXIT_CLOSING,
+#if 1
+    EL_EMPTY,
+#else
+    EL_EM_EXIT_CLOSED,
+#endif
+    29,
+    NULL,
+    NULL,
+    NULL
+  },
+  {
+    EL_EM_STEEL_EXIT_OPENING,
+    EL_EM_STEEL_EXIT_OPEN,
+    29,
+    NULL,
+    NULL,
+    NULL
+  },
+  {
+    EL_EM_STEEL_EXIT_CLOSING,
+#if 1
+    EL_STEELWALL,
+#else
+    EL_EM_STEEL_EXIT_CLOSED,
+#endif
+    29,
+    NULL,
+    NULL,
+    NULL
+  },
   {
     EL_SP_EXIT_OPENING,
     EL_SP_EXIT_OPEN,
@@ -568,6 +654,14 @@ static struct ChangingElementInfo change_delay_list[] =
     RunTimegateWheel,
     NULL
   },
+  {
+    EL_DC_TIMEGATE_SWITCH_ACTIVE,
+    EL_DC_TIMEGATE_SWITCH,
+    0,
+    InitTimegateWheel,
+    RunTimegateWheel,
+    NULL
+  },
   {
     EL_EMC_MAGIC_BALL_ACTIVE,
     EL_EMC_MAGIC_BALL_ACTIVE,
@@ -640,10 +734,14 @@ move_stepsize_list[] =
   { EL_AMOEBA_DROPPING,                2 },
   { EL_QUICKSAND_FILLING,      1 },
   { EL_QUICKSAND_EMPTYING,     1 },
+  { EL_QUICKSAND_FAST_FILLING, 2 },
+  { EL_QUICKSAND_FAST_EMPTYING,        2 },
   { EL_MAGIC_WALL_FILLING,     2 },
-  { EL_BD_MAGIC_WALL_FILLING,  2 },
   { EL_MAGIC_WALL_EMPTYING,    2 },
+  { EL_BD_MAGIC_WALL_FILLING,  2 },
   { EL_BD_MAGIC_WALL_EMPTYING, 2 },
+  { EL_DC_MAGIC_WALL_FILLING,  2 },
+  { EL_DC_MAGIC_WALL_EMPTYING, 2 },
 
   { EL_UNDEFINED,              0 },
 };
@@ -1133,6 +1231,11 @@ static void InitField(int x, int y, boolean init_game)
       if (init_game)
        Feld[x][y] = EL_SWITCHGATE_SWITCH_UP;
       break;
+
+    case EL_DC_SWITCHGATE_SWITCH_DOWN: /* always start with same switch pos */
+      if (init_game)
+       Feld[x][y] = EL_DC_SWITCHGATE_SWITCH_UP;
+      break;
 #endif
 
     case EL_LIGHT_SWITCH_ACTIVE:
@@ -1786,6 +1889,11 @@ static void InitGameEngine()
         EL_EMPTY);
     }
   }
+
+  /* ---------- initialize recursion detection ------------------------------ */
+  recursion_loop_depth = 0;
+  recursion_loop_detected = FALSE;
+  recursion_loop_element = EL_UNDEFINED;
 }
 
 int get_num_special_action(int element, int action_first, int action_last)
@@ -1862,6 +1970,8 @@ void InitGame()
     for (j = 0; j < MAX_NUM_KEYS; j++)
       player->key[j] = FALSE;
 
+    player->num_white_keys = 0;
+
     player->dynabomb_count = 0;
     player->dynabomb_size = 1;
     player->dynabombs_left = 0;
@@ -2740,16 +2850,33 @@ void GameWon()
       if (ExitX >= 0 && ExitY >= 0)    /* local player has left the level */
       {
        /* close exit door after last player */
-       if (AllPlayersGone &&
-           (Feld[ExitX][ExitY] == EL_EXIT_OPEN ||
-            Feld[ExitX][ExitY] == EL_SP_EXIT_OPEN))
+       if ((AllPlayersGone &&
+            (Feld[ExitX][ExitY] == EL_EXIT_OPEN ||
+             Feld[ExitX][ExitY] == EL_SP_EXIT_OPEN ||
+             Feld[ExitX][ExitY] == EL_STEEL_EXIT_OPEN)) ||
+           Feld[ExitX][ExitY] == EL_EM_EXIT_OPEN ||
+           Feld[ExitX][ExitY] == EL_EM_STEEL_EXIT_OPEN)
        {
          int element = Feld[ExitX][ExitY];
 
-         Feld[ExitX][ExitY] = (element == EL_EXIT_OPEN ? EL_EXIT_CLOSING :
-                               EL_SP_EXIT_CLOSING);
-
-         PlayLevelSoundElementAction(ExitX, ExitY, element, ACTION_CLOSING);
+#if 0
+         if (element == EL_EM_EXIT_OPEN ||
+             element == EL_EM_STEEL_EXIT_OPEN)
+         {
+           Bang(ExitX, ExitY);
+         }
+         else
+#endif
+         {
+           Feld[ExitX][ExitY] =
+             (element == EL_EXIT_OPEN          ? EL_EXIT_CLOSING :
+              element == EL_EM_EXIT_OPEN       ? EL_EM_EXIT_CLOSING :
+              element == EL_SP_EXIT_OPEN       ? EL_SP_EXIT_CLOSING:
+              element == EL_STEEL_EXIT_OPEN    ? EL_STEEL_EXIT_CLOSING:
+              EL_EM_STEEL_EXIT_CLOSING);
+
+           PlayLevelSoundElementAction(ExitX, ExitY, element, ACTION_CLOSING);
+         }
        }
 
        /* player disappears */
@@ -3216,8 +3343,10 @@ void RemoveMovingField(int x, int y)
 
   if (element == EL_BLOCKED &&
       (Feld[oldx][oldy] == EL_QUICKSAND_EMPTYING ||
+       Feld[oldx][oldy] == EL_QUICKSAND_FAST_EMPTYING ||
        Feld[oldx][oldy] == EL_MAGIC_WALL_EMPTYING ||
        Feld[oldx][oldy] == EL_BD_MAGIC_WALL_EMPTYING ||
+       Feld[oldx][oldy] == EL_DC_MAGIC_WALL_EMPTYING ||
        Feld[oldx][oldy] == EL_AMOEBA_DROPPING))
     next_element = get_next_element(Feld[oldx][oldy]);
 
@@ -3979,6 +4108,14 @@ void Bang(int x, int y)
       explosion_type = EX_TYPE_DYNA;
       break;
 
+    case EL_DC_LANDMINE:
+#if 0
+    case EL_EM_EXIT_OPEN:
+    case EL_EM_STEEL_EXIT_OPEN:
+#endif
+      explosion_type = EX_TYPE_CENTER;
+      break;
+
     case EL_PENGUIN:
     case EL_LAMP:
     case EL_LAMP_ACTIVE:
@@ -4192,6 +4329,12 @@ static void ToggleSwitchgateSwitch(int x, int y)
       Feld[xx][yy] = EL_SWITCHGATE_SWITCH_UP + game.switchgate_pos;
       DrawLevelField(xx, yy);
     }
+    else if (element == EL_DC_SWITCHGATE_SWITCH_UP ||
+            element == EL_DC_SWITCHGATE_SWITCH_DOWN)
+    {
+      Feld[xx][yy] = EL_DC_SWITCHGATE_SWITCH_UP + game.switchgate_pos;
+      DrawLevelField(xx, yy);
+    }
 #else
     if (element == EL_SWITCHGATE_SWITCH_UP)
     {
@@ -4203,6 +4346,16 @@ static void ToggleSwitchgateSwitch(int x, int y)
       Feld[xx][yy] = EL_SWITCHGATE_SWITCH_UP;
       DrawLevelField(xx, yy);
     }
+    else if (element == EL_DC_SWITCHGATE_SWITCH_UP)
+    {
+      Feld[xx][yy] = EL_DC_SWITCHGATE_SWITCH_DOWN;
+      DrawLevelField(xx, yy);
+    }
+    else if (element == EL_DC_SWITCHGATE_SWITCH_DOWN)
+    {
+      Feld[xx][yy] = EL_DC_SWITCHGATE_SWITCH_UP;
+      DrawLevelField(xx, yy);
+    }
 #endif
     else if (element == EL_SWITCHGATE_OPEN ||
             element == EL_SWITCHGATE_OPENING)
@@ -4419,7 +4572,7 @@ static void ActivateTimegateSwitch(int x, int y)
        element == EL_TIMEGATE_CLOSING)
     {
       Feld[xx][yy] = EL_TIMEGATE_OPENING;
-      PlayLevelSound(xx, yy, SND_TIMEGATE_OPENING);
+      PlayLevelSound(xx, yy, SND_CLASS_TIMEGATE_OPENING);
     }
 
     /*
@@ -4432,7 +4585,12 @@ static void ActivateTimegateSwitch(int x, int y)
 
   }
 
+#if 1
+  Feld[x][y] = (Feld[x][y] == EL_TIMEGATE_SWITCH ? EL_TIMEGATE_SWITCH_ACTIVE :
+               EL_DC_TIMEGATE_SWITCH_ACTIVE);
+#else
   Feld[x][y] = EL_TIMEGATE_SWITCH_ACTIVE;
+#endif
 }
 
 void Impact(int x, int y)
@@ -4467,6 +4625,16 @@ void Impact(int x, int y)
 
       object_hit = TRUE;
     }
+
+    if (Feld[x][y + 1] == EL_QUICKSAND_FAST_EMPTYING && object_hit == FALSE)
+    {
+      RemoveMovingField(x, y + 1);
+      Feld[x][y + 1] = EL_QUICKSAND_FAST_EMPTY;
+      Feld[x][y + 2] = EL_ROCK;
+      DrawLevelField(x, y + 2);
+
+      object_hit = TRUE;
+    }
 #endif
 
     if (object_hit)
@@ -4495,7 +4663,8 @@ void Impact(int x, int y)
     Bang(x, y);
     return;
   }
-  else if (impact && element == EL_PEARL)
+  else if (impact && element == EL_PEARL &&
+          smashed != EL_DC_MAGIC_WALL && smashed != EL_DC_MAGIC_WALL_ACTIVE)
   {
     ResetGfxAnimation(x, y);
 
@@ -4528,26 +4697,33 @@ void Impact(int x, int y)
 
   if (object_hit)              /* check which object was hit */
   {
-    if (CAN_PASS_MAGIC_WALL(element) && 
-       (smashed == EL_MAGIC_WALL ||
-        smashed == EL_BD_MAGIC_WALL))
+    if ((CAN_PASS_MAGIC_WALL(element) && 
+        (smashed == EL_MAGIC_WALL ||
+         smashed == EL_BD_MAGIC_WALL)) ||
+       (CAN_PASS_DC_MAGIC_WALL(element) &&
+        smashed == EL_DC_MAGIC_WALL))
     {
       int xx, yy;
       int activated_magic_wall =
        (smashed == EL_MAGIC_WALL ? EL_MAGIC_WALL_ACTIVE :
-        EL_BD_MAGIC_WALL_ACTIVE);
+        smashed == EL_BD_MAGIC_WALL ? EL_BD_MAGIC_WALL_ACTIVE :
+        EL_DC_MAGIC_WALL_ACTIVE);
 
       /* activate magic wall / mill */
       SCAN_PLAYFIELD(xx, yy)
+      {
        if (Feld[xx][yy] == smashed)
          Feld[xx][yy] = activated_magic_wall;
+      }
 
       game.magic_wall_time_left = level.time_magic_wall * FRAMES_PER_SECOND;
       game.magic_wall_active = TRUE;
 
       PlayLevelSound(x, y, (smashed == EL_MAGIC_WALL ?
                            SND_MAGIC_WALL_ACTIVATING :
-                           SND_BD_MAGIC_WALL_ACTIVATING));
+                           smashed == EL_BD_MAGIC_WALL ?
+                           SND_BD_MAGIC_WALL_ACTIVATING :
+                           SND_DC_MAGIC_WALL_ACTIVATING));
     }
 
     if (IS_PLAYER(x, y + 1))
@@ -4627,7 +4803,9 @@ void Impact(int x, int y)
          ToggleBeltSwitch(x, y + 1);
        }
        else if (smashed == EL_SWITCHGATE_SWITCH_UP ||
-                smashed == EL_SWITCHGATE_SWITCH_DOWN)
+                smashed == EL_SWITCHGATE_SWITCH_DOWN ||
+                smashed == EL_DC_SWITCHGATE_SWITCH_UP ||
+                smashed == EL_DC_SWITCHGATE_SWITCH_DOWN)
        {
          ToggleSwitchgateSwitch(x, y + 1);
        }
@@ -4660,12 +4838,15 @@ void Impact(int x, int y)
   /* play sound of magic wall / mill */
   if (!last_line &&
       (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE ||
-       Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE))
+       Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE ||
+       Feld[x][y + 1] == EL_DC_MAGIC_WALL_ACTIVE))
   {
     if (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE)
       PlayLevelSound(x, y, SND_MAGIC_WALL_FILLING);
     else if (Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE)
       PlayLevelSound(x, y, SND_BD_MAGIC_WALL_FILLING);
+    else if (Feld[x][y + 1] == EL_DC_MAGIC_WALL_ACTIVE)
+      PlayLevelSound(x, y, SND_DC_MAGIC_WALL_FILLING);
 
     return;
   }
@@ -5022,7 +5203,10 @@ inline static void TurnRoundExt(int x, int y)
        int ex = x + xy[i][0];
        int ey = y + xy[i][1];
 
-       if (IN_LEV_FIELD(ex, ey) && Feld[ex][ey] == EL_EXIT_OPEN)
+       if (IN_LEV_FIELD(ex, ey) && (Feld[ex][ey] == EL_EXIT_OPEN ||
+                                    Feld[ex][ey] == EL_EM_EXIT_OPEN ||
+                                    Feld[ex][ey] == EL_STEEL_EXIT_OPEN ||
+                                    Feld[ex][ey] == EL_EM_STEEL_EXIT_OPEN))
        {
          attr_x = ex;
          attr_y = ey;
@@ -5579,6 +5763,43 @@ void StartMoving(int x, int y)
        PlayLevelSoundAction(x, y, ACTION_FILLING);
       }
     }
+    else if (element == EL_QUICKSAND_FAST_FULL)
+    {
+      if (IS_FREE(x, y + 1))
+      {
+       InitMovingField(x, y, MV_DOWN);
+       started_moving = TRUE;
+
+       Feld[x][y] = EL_QUICKSAND_FAST_EMPTYING;
+#if USE_QUICKSAND_BD_ROCK_BUGFIX
+       if (Store[x][y] != EL_ROCK && Store[x][y] != EL_BD_ROCK)
+         Store[x][y] = EL_ROCK;
+#else
+       Store[x][y] = EL_ROCK;
+#endif
+
+       PlayLevelSoundAction(x, y, ACTION_EMPTYING);
+      }
+      else if (Feld[x][y + 1] == EL_QUICKSAND_FAST_EMPTY)
+      {
+       if (!MovDelay[x][y])
+         MovDelay[x][y] = TILEY + 1;
+
+       if (MovDelay[x][y])
+       {
+         MovDelay[x][y]--;
+         if (MovDelay[x][y])
+           return;
+       }
+
+       Feld[x][y] = EL_QUICKSAND_FAST_EMPTY;
+       Feld[x][y + 1] = EL_QUICKSAND_FAST_FULL;
+       Store[x][y + 1] = Store[x][y];
+       Store[x][y] = 0;
+
+       PlayLevelSoundAction(x, y, ACTION_FILLING);
+      }
+    }
     else if ((element == EL_ROCK || element == EL_BD_ROCK) &&
             Feld[x][y + 1] == EL_QUICKSAND_EMPTY)
     {
@@ -5590,6 +5811,17 @@ void StartMoving(int x, int y)
 
       PlayLevelSoundAction(x, y, ACTION_FILLING);
     }
+    else if ((element == EL_ROCK || element == EL_BD_ROCK) &&
+            Feld[x][y + 1] == EL_QUICKSAND_FAST_EMPTY)
+    {
+      InitMovingField(x, y, MV_DOWN);
+      started_moving = TRUE;
+
+      Feld[x][y] = EL_QUICKSAND_FAST_FILLING;
+      Store[x][y] = element;
+
+      PlayLevelSoundAction(x, y, ACTION_FILLING);
+    }
     else if (element == EL_MAGIC_WALL_FULL)
     {
       if (IS_FREE(x, y + 1))
@@ -5626,7 +5858,7 @@ void StartMoving(int x, int y)
        started_moving = TRUE;
 
        Feld[x][y] = EL_BD_MAGIC_WALL_EMPTYING;
-       Store[x][y] = EL_CHANGED2(Store[x][y]);
+       Store[x][y] = EL_CHANGED_BD(Store[x][y]);
       }
       else if (Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE)
       {
@@ -5642,20 +5874,52 @@ 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]);
+       Store[x][y + 1] = EL_CHANGED_BD(Store[x][y]);
+       Store[x][y] = 0;
+      }
+    }
+    else if (element == EL_DC_MAGIC_WALL_FULL)
+    {
+      if (IS_FREE(x, y + 1))
+      {
+       InitMovingField(x, y, MV_DOWN);
+       started_moving = TRUE;
+
+       Feld[x][y] = EL_DC_MAGIC_WALL_EMPTYING;
+       Store[x][y] = EL_CHANGED_DC(Store[x][y]);
+      }
+      else if (Feld[x][y + 1] == EL_DC_MAGIC_WALL_ACTIVE)
+      {
+       if (!MovDelay[x][y])
+         MovDelay[x][y] = TILEY/4 + 1;
+
+       if (MovDelay[x][y])
+       {
+         MovDelay[x][y]--;
+         if (MovDelay[x][y])
+           return;
+       }
+
+       Feld[x][y] = EL_DC_MAGIC_WALL_ACTIVE;
+       Feld[x][y + 1] = EL_DC_MAGIC_WALL_FULL;
+       Store[x][y + 1] = EL_CHANGED_DC(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))
+    else if ((CAN_PASS_MAGIC_WALL(element) &&
+             (Feld[x][y + 1] == EL_MAGIC_WALL_ACTIVE ||
+              Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE)) ||
+            (CAN_PASS_DC_MAGIC_WALL(element) &&
+             (Feld[x][y + 1] == EL_DC_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 :
-        EL_BD_MAGIC_WALL_FILLING);
+        Feld[x][y + 1] == EL_BD_MAGIC_WALL_ACTIVE ? EL_BD_MAGIC_WALL_FILLING :
+        EL_DC_MAGIC_WALL_FILLING);
       Store[x][y] = element;
     }
     else if (CAN_FALL(element) && Feld[x][y + 1] == EL_ACID)
@@ -6019,7 +6283,10 @@ void StartMoving(int x, int y)
     }
     else if (element == EL_PENGUIN && IN_LEV_FIELD(newx, newy))
     {
-      if (Feld[newx][newy] == EL_EXIT_OPEN)
+      if (Feld[newx][newy] == EL_EXIT_OPEN ||
+         Feld[newx][newy] == EL_EM_EXIT_OPEN ||
+         Feld[newx][newy] == EL_STEEL_EXIT_OPEN ||
+         Feld[newx][newy] == EL_EM_STEEL_EXIT_OPEN)
       {
        RemoveField(x, y);
        DrawLevelField(x, y);
@@ -6468,6 +6735,16 @@ void ContinueMoving(int x, int y)
     Feld[x][y] = get_next_element(element);
     element = Feld[newx][newy] = Store[x][y];
   }
+  else if (element == EL_QUICKSAND_FAST_FILLING)
+  {
+    element = Feld[newx][newy] = get_next_element(element);
+    Store[newx][newy] = Store[x][y];
+  }
+  else if (element == EL_QUICKSAND_FAST_EMPTYING)
+  {
+    Feld[x][y] = get_next_element(element);
+    element = Feld[newx][newy] = Store[x][y];
+  }
   else if (element == EL_MAGIC_WALL_FILLING)
   {
     element = Feld[newx][newy] = get_next_element(element);
@@ -6500,6 +6777,24 @@ void ContinueMoving(int x, int y)
       Feld[x][y] = EL_BD_MAGIC_WALL_DEAD;
     element = Feld[newx][newy] = Store[x][y];
 
+#if USE_NEW_CUSTOM_VALUE
+    InitField(newx, newy, FALSE);
+#endif
+  }
+  else if (element == EL_DC_MAGIC_WALL_FILLING)
+  {
+    element = Feld[newx][newy] = get_next_element(element);
+    if (!game.magic_wall_active)
+      element = Feld[newx][newy] = EL_DC_MAGIC_WALL_DEAD;
+    Store[newx][newy] = Store[x][y];
+  }
+  else if (element == EL_DC_MAGIC_WALL_EMPTYING)
+  {
+    Feld[x][y] = get_next_element(element);
+    if (!game.magic_wall_active)
+      Feld[x][y] = EL_DC_MAGIC_WALL_DEAD;
+    element = Feld[newx][newy] = Store[x][y];
+
 #if USE_NEW_CUSTOM_VALUE
     InitField(newx, newy, FALSE);
 #endif
@@ -7003,7 +7298,8 @@ void AmoebeAbleger(int ax, int ay)
 
     if (IS_FREE(x, y) ||
        CAN_GROW_INTO(Feld[x][y]) ||
-       Feld[x][y] == EL_QUICKSAND_EMPTY)
+       Feld[x][y] == EL_QUICKSAND_EMPTY ||
+       Feld[x][y] == EL_QUICKSAND_FAST_EMPTY)
     {
       newax = x;
       neway = y;
@@ -7028,7 +7324,8 @@ void AmoebeAbleger(int ax, int ay)
 
       if (IS_FREE(x, y) ||
          CAN_GROW_INTO(Feld[x][y]) ||
-         Feld[x][y] == EL_QUICKSAND_EMPTY)
+         Feld[x][y] == EL_QUICKSAND_EMPTY ||
+         Feld[x][y] == EL_QUICKSAND_FAST_EMPTY)
       {
        newax = x;
        neway = y;
@@ -7213,7 +7510,7 @@ static void InitTimegateWheel(int x, int y)
 
 static void RunTimegateWheel(int x, int y)
 {
-  PlayLevelSound(x, y, SND_TIMEGATE_SWITCH_ACTIVE);
+  PlayLevelSound(x, y, SND_CLASS_TIMEGATE_SWITCH_ACTIVE);
 }
 
 static void InitMagicBallDelay(int x, int y)
@@ -7280,6 +7577,75 @@ void CheckExit(int x, int y)
   PlayLevelSoundNearest(x, y, SND_CLASS_EXIT_OPENING);
 }
 
+void CheckExitEM(int x, int y)
+{
+  if (local_player->gems_still_needed > 0 ||
+      local_player->sokobanfields_still_needed > 0 ||
+      local_player->lights_still_needed > 0)
+  {
+    int element = Feld[x][y];
+    int graphic = el2img(element);
+
+    if (IS_ANIMATED(graphic))
+      DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
+
+    return;
+  }
+
+  if (AllPlayersGone)  /* do not re-open exit door closed after last player */
+    return;
+
+  Feld[x][y] = EL_EM_EXIT_OPENING;
+
+  PlayLevelSoundNearest(x, y, SND_CLASS_EM_EXIT_OPENING);
+}
+
+void CheckExitSteel(int x, int y)
+{
+  if (local_player->gems_still_needed > 0 ||
+      local_player->sokobanfields_still_needed > 0 ||
+      local_player->lights_still_needed > 0)
+  {
+    int element = Feld[x][y];
+    int graphic = el2img(element);
+
+    if (IS_ANIMATED(graphic))
+      DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
+
+    return;
+  }
+
+  if (AllPlayersGone)  /* do not re-open exit door closed after last player */
+    return;
+
+  Feld[x][y] = EL_STEEL_EXIT_OPENING;
+
+  PlayLevelSoundNearest(x, y, SND_CLASS_STEEL_EXIT_OPENING);
+}
+
+void CheckExitSteelEM(int x, int y)
+{
+  if (local_player->gems_still_needed > 0 ||
+      local_player->sokobanfields_still_needed > 0 ||
+      local_player->lights_still_needed > 0)
+  {
+    int element = Feld[x][y];
+    int graphic = el2img(element);
+
+    if (IS_ANIMATED(graphic))
+      DrawLevelGraphicAnimationIfNeeded(x, y, graphic);
+
+    return;
+  }
+
+  if (AllPlayersGone)  /* do not re-open exit door closed after last player */
+    return;
+
+  Feld[x][y] = EL_EM_STEEL_EXIT_OPENING;
+
+  PlayLevelSoundNearest(x, y, SND_CLASS_EM_STEEL_EXIT_OPENING);
+}
+
 void CheckExitSP(int x, int y)
 {
   if (local_player->gems_still_needed > 0)
@@ -7518,6 +7884,108 @@ void MauerAbleger(int ax, int ay)
     PlayLevelSoundAction(ax, ay, ACTION_GROWING);
 }
 
+void MauerAblegerStahl(int ax, int ay)
+{
+  int element = Feld[ax][ay];
+  int graphic = el2img(element);
+  boolean oben_frei = FALSE, unten_frei = FALSE;
+  boolean links_frei = FALSE, rechts_frei = FALSE;
+  boolean oben_massiv = FALSE, unten_massiv = FALSE;
+  boolean links_massiv = FALSE, rechts_massiv = FALSE;
+  boolean new_wall = FALSE;
+
+  if (IS_ANIMATED(graphic))
+    DrawLevelGraphicAnimationIfNeeded(ax, ay, graphic);
+
+  if (!MovDelay[ax][ay])       /* start building new wall */
+    MovDelay[ax][ay] = 6;
+
+  if (MovDelay[ax][ay])                /* wait some time before building new wall */
+  {
+    MovDelay[ax][ay]--;
+    if (MovDelay[ax][ay])
+      return;
+  }
+
+  if (IN_LEV_FIELD(ax, ay-1) && IS_FREE(ax, ay-1))
+    oben_frei = TRUE;
+  if (IN_LEV_FIELD(ax, ay+1) && IS_FREE(ax, ay+1))
+    unten_frei = TRUE;
+  if (IN_LEV_FIELD(ax-1, ay) && IS_FREE(ax-1, ay))
+    links_frei = TRUE;
+  if (IN_LEV_FIELD(ax+1, ay) && IS_FREE(ax+1, ay))
+    rechts_frei = TRUE;
+
+  if (element == EL_EXPANDABLE_STEELWALL_VERTICAL ||
+      element == EL_EXPANDABLE_STEELWALL_ANY)
+  {
+    if (oben_frei)
+    {
+      Feld[ax][ay-1] = EL_EXPANDABLE_STEELWALL_GROWING;
+      Store[ax][ay-1] = element;
+      GfxDir[ax][ay-1] = MovDir[ax][ay-1] = MV_UP;
+      if (IN_SCR_FIELD(SCREENX(ax), SCREENY(ay-1)))
+       DrawGraphic(SCREENX(ax), SCREENY(ay - 1),
+                   IMG_EXPANDABLE_STEELWALL_GROWING_UP, 0);
+      new_wall = TRUE;
+    }
+    if (unten_frei)
+    {
+      Feld[ax][ay+1] = EL_EXPANDABLE_STEELWALL_GROWING;
+      Store[ax][ay+1] = element;
+      GfxDir[ax][ay+1] = MovDir[ax][ay+1] = MV_DOWN;
+      if (IN_SCR_FIELD(SCREENX(ax), SCREENY(ay+1)))
+       DrawGraphic(SCREENX(ax), SCREENY(ay + 1),
+                   IMG_EXPANDABLE_STEELWALL_GROWING_DOWN, 0);
+      new_wall = TRUE;
+    }
+  }
+
+  if (element == EL_EXPANDABLE_STEELWALL_HORIZONTAL ||
+      element == EL_EXPANDABLE_STEELWALL_ANY)
+  {
+    if (links_frei)
+    {
+      Feld[ax-1][ay] = EL_EXPANDABLE_STEELWALL_GROWING;
+      Store[ax-1][ay] = element;
+      GfxDir[ax-1][ay] = MovDir[ax-1][ay] = MV_LEFT;
+      if (IN_SCR_FIELD(SCREENX(ax-1), SCREENY(ay)))
+       DrawGraphic(SCREENX(ax - 1), SCREENY(ay),
+                   IMG_EXPANDABLE_STEELWALL_GROWING_LEFT, 0);
+      new_wall = TRUE;
+    }
+
+    if (rechts_frei)
+    {
+      Feld[ax+1][ay] = EL_EXPANDABLE_STEELWALL_GROWING;
+      Store[ax+1][ay] = element;
+      GfxDir[ax+1][ay] = MovDir[ax+1][ay] = MV_RIGHT;
+      if (IN_SCR_FIELD(SCREENX(ax+1), SCREENY(ay)))
+       DrawGraphic(SCREENX(ax + 1), SCREENY(ay),
+                   IMG_EXPANDABLE_STEELWALL_GROWING_RIGHT, 0);
+      new_wall = TRUE;
+    }
+  }
+
+  if (!IN_LEV_FIELD(ax, ay-1) || IS_WALL(Feld[ax][ay-1]))
+    oben_massiv = TRUE;
+  if (!IN_LEV_FIELD(ax, ay+1) || IS_WALL(Feld[ax][ay+1]))
+    unten_massiv = TRUE;
+  if (!IN_LEV_FIELD(ax-1, ay) || IS_WALL(Feld[ax-1][ay]))
+    links_massiv = TRUE;
+  if (!IN_LEV_FIELD(ax+1, ay) || IS_WALL(Feld[ax+1][ay]))
+    rechts_massiv = TRUE;
+
+  if (((oben_massiv && unten_massiv) ||
+       element == EL_EXPANDABLE_STEELWALL_HORIZONTAL) &&
+      ((links_massiv && rechts_massiv) ||
+       element == EL_EXPANDABLE_STEELWALL_VERTICAL))
+    Feld[ax][ay] = EL_WALL;
+
+  if (new_wall)
+    PlayLevelSoundAction(ax, ay, ACTION_GROWING);
+}
+
 void CheckForDragon(int x, int y)
 {
   int i, j;
@@ -8578,6 +9046,14 @@ static boolean CheckTriggeredElementChangeExt(int trigger_x, int trigger_y,
   if (!(trigger_events[trigger_element][trigger_event]))
     return FALSE;
 
+#if 0
+  printf("::: CheckTriggeredElementChangeExt %d ... [%d, %d, %d, '%s']\n",
+        trigger_event, recursion_loop_depth, recursion_loop_detected,
+        recursion_loop_element, EL_NAME(recursion_loop_element));
+#endif
+
+  RECURSION_LOOP_DETECTION_START(trigger_element, FALSE);
+
   for (i = 0; i < NUM_CUSTOM_ELEMENTS; i++)
   {
     int element = EL_CUSTOM_START + i;
@@ -8646,6 +9122,8 @@ static boolean CheckTriggeredElementChangeExt(int trigger_x, int trigger_y,
     }
   }
 
+  RECURSION_LOOP_DETECTION_END();
+
   return change_done_any;
 }
 
@@ -8684,6 +9162,14 @@ static boolean CheckElementChangeExt(int x, int y,
     return FALSE;
 #endif
 
+#if 0
+  printf("::: CheckElementChangeExt %d ... [%d, %d, %d, '%s']\n",
+        trigger_event, recursion_loop_depth, recursion_loop_detected,
+        recursion_loop_element, EL_NAME(recursion_loop_element));
+#endif
+
+  RECURSION_LOOP_DETECTION_START(trigger_element, FALSE);
+
   for (p = 0; p < element_info[element].num_change_pages; p++)
   {
     struct ElementChangeInfo *change = &element_info[element].change_page[p];
@@ -8763,6 +9249,8 @@ static boolean CheckElementChangeExt(int x, int y,
     }
   }
 
+  RECURSION_LOOP_DETECTION_END();
+
   return change_done;
 }
 
@@ -9164,6 +9652,25 @@ void GameActions()
   byte tape_action[MAX_PLAYERS];
   int i;
 
+  /* detect endless loops, caused by custom element programming */
+  if (recursion_loop_detected && recursion_loop_depth == 0)
+  {
+    char *message = getStringCat3("Internal Error ! Element ",
+                                 EL_NAME(recursion_loop_element),
+                                 " caused endless loop ! Quit the game ?");
+
+    Error(ERR_WARN, "element '%s' caused endless loop in game engine",
+         EL_NAME(recursion_loop_element));
+
+    RequestQuitGameExt(FALSE, level_editor_test_game, message);
+
+    recursion_loop_detected = FALSE;   /* if game should be continued */
+
+    free(message);
+
+    return;
+  }
+
   if (game.restart_level)
     StartGameActions(options.network, setup.autorecord, NEW_RANDOMIZE);
 
@@ -9563,7 +10070,10 @@ void GameActions_RND()
     }
     else if ((element == EL_ACID ||
              element == EL_EXIT_OPEN ||
+             element == EL_EM_EXIT_OPEN ||
              element == EL_SP_EXIT_OPEN ||
+             element == EL_STEEL_EXIT_OPEN ||
+             element == EL_EM_STEEL_EXIT_OPEN ||
              element == EL_SP_TERMINAL ||
              element == EL_SP_TERMINAL_ACTIVE ||
              element == EL_EXTRA_TIME ||
@@ -9589,9 +10099,16 @@ void GameActions_RND()
       Life(x, y);
     else if (element == EL_EXIT_CLOSED)
       CheckExit(x, y);
+    else if (element == EL_EM_EXIT_CLOSED)
+      CheckExitEM(x, y);
+    else if (element == EL_STEEL_EXIT_CLOSED)
+      CheckExitSteel(x, y);
+    else if (element == EL_EM_STEEL_EXIT_CLOSED)
+      CheckExitSteelEM(x, y);
     else if (element == EL_SP_EXIT_CLOSED)
       CheckExitSP(x, y);
-    else if (element == EL_EXPANDABLE_WALL_GROWING)
+    else if (element == EL_EXPANDABLE_WALL_GROWING ||
+            element == EL_EXPANDABLE_STEELWALL_GROWING)
       MauerWaechst(x, y);
     else if (element == EL_EXPANDABLE_WALL ||
             element == EL_EXPANDABLE_WALL_HORIZONTAL ||
@@ -9599,6 +10116,10 @@ void GameActions_RND()
             element == EL_EXPANDABLE_WALL_ANY ||
             element == EL_BD_EXPANDABLE_WALL)
       MauerAbleger(x, y);
+    else if (element == EL_EXPANDABLE_STEELWALL_HORIZONTAL ||
+            element == EL_EXPANDABLE_STEELWALL_VERTICAL ||
+            element == EL_EXPANDABLE_STEELWALL_ANY)
+      MauerAblegerStahl(x, y);
     else if (element == EL_FLAMES)
       CheckForDragon(x, y);
     else if (element == EL_EXPLOSION)
@@ -9627,7 +10148,10 @@ void GameActions_RND()
           element == EL_MAGIC_WALL_EMPTYING ||
           element == EL_BD_MAGIC_WALL_FULL ||
           element == EL_BD_MAGIC_WALL_ACTIVE ||
-          element == EL_BD_MAGIC_WALL_EMPTYING) &&
+          element == EL_BD_MAGIC_WALL_EMPTYING ||
+          element == EL_DC_MAGIC_WALL_FULL ||
+          element == EL_DC_MAGIC_WALL_ACTIVE ||
+          element == EL_DC_MAGIC_WALL_EMPTYING) &&
          ABS(x-jx) + ABS(y-jy) < ABS(magic_wall_x-jx) + ABS(magic_wall_y-jy))
       {
        magic_wall_x = x;
@@ -9652,6 +10176,7 @@ void GameActions_RND()
          (element == EL_EMPTY ||
           CAN_GROW_INTO(element) ||
           element == EL_QUICKSAND_EMPTY ||
+          element == EL_QUICKSAND_FAST_EMPTY ||
           element == EL_ACID_SPLASH_LEFT ||
           element == EL_ACID_SPLASH_RIGHT))
       {
@@ -9698,6 +10223,10 @@ void GameActions_RND()
          element == EL_BD_MAGIC_WALL_ACTIVE ||
          element == EL_BD_MAGIC_WALL_EMPTYING)
        PlayLevelSound(magic_wall_x, magic_wall_y, SND_BD_MAGIC_WALL_ACTIVE);
+      else if (element == EL_DC_MAGIC_WALL_FULL ||
+              element == EL_DC_MAGIC_WALL_ACTIVE ||
+              element == EL_DC_MAGIC_WALL_EMPTYING)
+       PlayLevelSound(magic_wall_x, magic_wall_y, SND_DC_MAGIC_WALL_ACTIVE);
       else
        PlayLevelSound(magic_wall_x, magic_wall_y, SND_MAGIC_WALL_ACTIVE);
     }
@@ -9723,6 +10252,12 @@ void GameActions_RND()
            Feld[x][y] = EL_BD_MAGIC_WALL_DEAD;
            DrawLevelField(x, y);
          }
+         else if (element == EL_DC_MAGIC_WALL_ACTIVE ||
+                  element == EL_DC_MAGIC_WALL_FULL)
+         {
+           Feld[x][y] = EL_DC_MAGIC_WALL_DEAD;
+           DrawLevelField(x, y);
+         }
        }
 
        game.magic_wall_active = FALSE;
@@ -10411,6 +10946,9 @@ void ScrollPlayer(struct PlayerInfo *player, int mode)
     player->last_jy = jy;
 
     if (Feld[jx][jy] == EL_EXIT_OPEN ||
+       Feld[jx][jy] == EL_EM_EXIT_OPEN ||
+       Feld[jx][jy] == EL_STEEL_EXIT_OPEN ||
+       Feld[jx][jy] == EL_EM_STEEL_EXIT_OPEN ||
        Feld[jx][jy] == EL_SP_EXIT_OPEN ||
        Feld[jx][jy] == EL_SP_EXIT_OPENING)     /* <-- special case */
     {
@@ -11096,8 +11634,10 @@ void KillPlayer(struct PlayerInfo *player)
      "kill player X when explosion of <player X>"; the solution using a new
      field "player->killed" was chosen for backwards compatibility, although
      clever use of the fields "player->active" etc. would probably also work */
+#if 1
   if (player->killed)
     return;
+#endif
 
   player->killed = TRUE;
 
@@ -11334,6 +11874,9 @@ int DigField(struct PlayerInfo *player,
     CheckTriggeredElementChangeByPlayer(x, y, element, CE_PLAYER_SNAPS_X,
                                        player->index_bit, dig_side);
 
+    if (element == EL_DC_LANDMINE)
+      Bang(x, y);
+
     if (Feld[x][y] != element)         /* field changed by snapping */
       return MP_ACTION;
 
@@ -11374,6 +11917,9 @@ int DigField(struct PlayerInfo *player,
        return MP_NO_ACTION;
     }
     else if (element == EL_EXIT_OPEN ||
+            element == EL_EM_EXIT_OPEN ||
+            element == EL_STEEL_EXIT_OPEN ||
+            element == EL_EM_STEEL_EXIT_OPEN ||
             element == EL_SP_EXIT_OPEN ||
             element == EL_SP_EXIT_OPENING)
     {
@@ -11429,6 +11975,15 @@ int DigField(struct PlayerInfo *player,
       if (!player->key[EMC_GATE_GRAY_ACTIVE_NR(element)])
        return MP_NO_ACTION;
     }
+    else if (element == EL_DC_GATE_WHITE ||
+            element == EL_DC_GATE_WHITE_GRAY ||
+            element == EL_DC_GATE_WHITE_GRAY_ACTIVE)
+    {
+      if (player->num_white_keys == 0)
+       return MP_NO_ACTION;
+
+      player->num_white_keys--;
+    }
     else if (IS_SP_PORT(element))
     {
       if (element == EL_SP_GRAVITY_PORT_LEFT ||
@@ -11555,6 +12110,13 @@ int DigField(struct PlayerInfo *player,
 
       DrawGameDoorValues();
     }
+    else if (element == EL_DC_KEY_WHITE)
+    {
+      player->num_white_keys++;
+
+      /* display white keys? */
+      /* DrawGameDoorValues(); */
+    }
     else if (IS_ENVELOPE(element))
     {
       player->show_envelope = element;
@@ -11790,7 +12352,9 @@ int DigField(struct PlayerInfo *player,
       ToggleBeltSwitch(x, y);
     }
     else if (element == EL_SWITCHGATE_SWITCH_UP ||
-            element == EL_SWITCHGATE_SWITCH_DOWN)
+            element == EL_SWITCHGATE_SWITCH_DOWN ||
+            element == EL_DC_SWITCHGATE_SWITCH_UP ||
+            element == EL_DC_SWITCHGATE_SWITCH_DOWN)
     {
       ToggleSwitchgateSwitch(x, y);
     }
@@ -11799,7 +12363,8 @@ int DigField(struct PlayerInfo *player,
     {
       ToggleLightSwitch(x, y);
     }
-    else if (element == EL_TIMEGATE_SWITCH)
+    else if (element == EL_TIMEGATE_SWITCH ||
+            element == EL_DC_TIMEGATE_SWITCH)
     {
       ActivateTimegateSwitch(x, y);
     }
@@ -12528,6 +13093,7 @@ void RaiseScoreElement(int element)
     case EL_EMC_KEY_6:
     case EL_EMC_KEY_7:
     case EL_EMC_KEY_8:
+    case EL_DC_KEY_WHITE:
       RaiseScore(level.score[SC_KEY]);
       break;
     default:
@@ -12536,13 +13102,9 @@ void RaiseScoreElement(int element)
   }
 }
 
-void RequestQuitGame(boolean ask_if_really_quit)
+void RequestQuitGameExt(boolean skip_request, boolean quick_quit, char *message)
 {
-  if (AllPlayersGone ||
-      !ask_if_really_quit ||
-      level_editor_test_game ||
-      Request("Do you really want to quit the game ?",
-             REQ_ASK | REQ_STAY_CLOSED))
+  if (skip_request || Request(message, REQ_ASK | REQ_STAY_CLOSED))
   {
 #if defined(NETWORK_AVALIABLE)
     if (options.network)
@@ -12550,7 +13112,7 @@ void RequestQuitGame(boolean ask_if_really_quit)
     else
 #endif
     {
-      if (!ask_if_really_quit || level_editor_test_game)
+      if (quick_quit)
       {
        game_status = GAME_MODE_MAIN;
 
@@ -12566,7 +13128,7 @@ void RequestQuitGame(boolean ask_if_really_quit)
       }
     }
   }
-  else
+  else         /* continue playing the game */
   {
     if (tape.playing && tape.deactivate_display)
       TapeDeactivateDisplayOff(TRUE);
@@ -12578,6 +13140,15 @@ void RequestQuitGame(boolean ask_if_really_quit)
   }
 }
 
+void RequestQuitGame(boolean ask_if_really_quit)
+{
+  boolean quick_quit = (!ask_if_really_quit || level_editor_test_game);
+  boolean skip_request = AllPlayersGone || quick_quit;
+
+  RequestQuitGameExt(skip_request, quick_quit,
+                    "Do you really want to quit the game ?");
+}
+
 
 /* ------------------------------------------------------------------------- */
 /* random generator functions                                                */