added basic support for additional empty space elements in game engine
[rocksndiamonds.git] / src / game.c
index 05de29db43be435e1cfbedca18e76af34bbc95ee..8ac2616131b19c07bf66ea9e47abaec49a95bb8a 100644 (file)
@@ -1058,7 +1058,10 @@ static void CheckGravityMovementWhenNotMoving(struct PlayerInfo *);
 static void KillPlayerUnlessEnemyProtected(int, int);
 static void KillPlayerUnlessExplosionProtected(int, int);
 
+static void CheckNextToConditions(int, int);
+static void TestIfPlayerNextToCustomElement(int, int);
 static void TestIfPlayerTouchesCustomElement(int, int);
+static void TestIfElementNextToCustomElement(int, int);
 static void TestIfElementTouchesCustomElement(int, int);
 static void TestIfElementHitsCustomElement(int, int, int);
 
@@ -1106,7 +1109,7 @@ void ContinueMoving(int, int);
 void Bang(int, int);
 void InitMovDir(int, int);
 void InitAmoebaNr(int, int);
-int NewHiScore(int);
+void NewHighScore(int, boolean);
 
 void TestIfGoodThingHitsBadThing(int, int, int);
 void TestIfBadThingHitsGoodThing(int, int, int);
@@ -2025,6 +2028,11 @@ static void InitField(int x, int y, boolean init_game)
 
        InitField(x, y, init_game);
       }
+      else if (IS_EMPTY_ELEMENT(element))
+      {
+       GfxElementEmpty[x][y] = element;
+       Tile[x][y] = EL_EMPTY;
+      }
 
       break;
   }
@@ -3542,7 +3550,6 @@ void InitGame(void)
   int fade_mask = REDRAW_FIELD;
 
   boolean emulate_bd = TRUE;   // unless non-BOULDERDASH elements found
-  boolean emulate_sb = TRUE;   // unless non-SOKOBAN     elements found
   boolean emulate_sp = TRUE;   // unless non-SUPAPLEX    elements found
   int initial_move_dir = MV_DOWN;
   int i, j, x, y;
@@ -3876,7 +3883,9 @@ void InitGame(void)
 
     GfxFrame[x][y] = 0;
     GfxRandom[x][y] = INIT_GFX_RANDOM();
+    GfxRandomStatic[x][y] = INIT_GFX_RANDOM();
     GfxElement[x][y] = EL_UNDEFINED;
+    GfxElementEmpty[x][y] = EL_EMPTY;
     GfxAction[x][y] = ACTION_DEFAULT;
     GfxDir[x][y] = MV_NONE;
     GfxRedraw[x][y] = GFX_REDRAW_NONE;
@@ -3886,8 +3895,6 @@ void InitGame(void)
   {
     if (emulate_bd && !IS_BD_ELEMENT(Tile[x][y]))
       emulate_bd = FALSE;
-    if (emulate_sb && !IS_SB_ELEMENT(Tile[x][y]))
-      emulate_sb = FALSE;
     if (emulate_sp && !IS_SP_ELEMENT(Tile[x][y]))
       emulate_sp = FALSE;
 
@@ -3912,7 +3919,6 @@ void InitGame(void)
   }
 
   game.emulation = (emulate_bd ? EMU_BOULDERDASH :
-                   emulate_sb ? EMU_SOKOBAN :
                    emulate_sp ? EMU_SUPAPLEX : EMU_NONE);
 
   // initialize type of slippery elements
@@ -4310,7 +4316,7 @@ void InitGame(void)
        {
          // check for player created from custom element as single target
          content = element_info[element].change_page[i].target_element;
-         is_player = ELEM_IS_PLAYER(content);
+         is_player = IS_PLAYER_ELEMENT(content);
 
          if (is_player && (found_rating < 3 ||
                            (found_rating == 3 && element < found_element)))
@@ -4328,7 +4334,7 @@ void InitGame(void)
       {
        // check for player created from custom element as explosion content
        content = element_info[element].content.e[xx][yy];
-       is_player = ELEM_IS_PLAYER(content);
+       is_player = IS_PLAYER_ELEMENT(content);
 
        if (is_player && (found_rating < 2 ||
                          (found_rating == 2 && element < found_element)))
@@ -4349,7 +4355,7 @@ void InitGame(void)
          content =
            element_info[element].change_page[i].target_content.e[xx][yy];
 
-         is_player = ELEM_IS_PLAYER(content);
+         is_player = IS_PLAYER_ELEMENT(content);
 
          if (is_player && (found_rating < 1 ||
                            (found_rating == 1 && element < found_element)))
@@ -4480,6 +4486,8 @@ void InitGame(void)
     if (setup.sound_music)
       PlayLevelMusic();
   }
+
+  SetPlayfieldMouseCursorEnabled(!game.use_mouse_actions);
 }
 
 void UpdateEngineValues(int actual_scroll_x, int actual_scroll_y,
@@ -4700,6 +4708,40 @@ void InitAmoebaNr(int x, int y)
   AmoebaCnt2[group_nr]++;
 }
 
+static void LevelSolved_SetFinalGameValues(void)
+{
+  game.time_final = (game.no_time_limit ? TimePlayed : TimeLeft);
+  game.score_time_final = (level.use_step_counter ? TimePlayed :
+                          TimePlayed * FRAMES_PER_SECOND + TimeFrames);
+
+  game.score_final = (level.game_engine_type == GAME_ENGINE_TYPE_EM ?
+                     game_em.lev->score :
+                     level.game_engine_type == GAME_ENGINE_TYPE_MM ?
+                     game_mm.score :
+                     game.score);
+
+  game.health_final = (level.game_engine_type == GAME_ENGINE_TYPE_MM ?
+                      MM_HEALTH(game_mm.laser_overload_value) :
+                      game.health);
+
+  game.LevelSolved_CountingTime = game.time_final;
+  game.LevelSolved_CountingScore = game.score_final;
+  game.LevelSolved_CountingHealth = game.health_final;
+}
+
+static void LevelSolved_DisplayFinalGameValues(int time, int score, int health)
+{
+  game.LevelSolved_CountingTime = time;
+  game.LevelSolved_CountingScore = score;
+  game.LevelSolved_CountingHealth = health;
+
+  game_panel_controls[GAME_PANEL_TIME].value = time;
+  game_panel_controls[GAME_PANEL_SCORE].value = score;
+  game_panel_controls[GAME_PANEL_HEALTH].value = health;
+
+  DisplayGameControlValues();
+}
+
 static void LevelSolved(void)
 {
   if (level.game_engine_type == GAME_ENGINE_TYPE_RND &&
@@ -4708,6 +4750,9 @@ static void LevelSolved(void)
 
   game.LevelSolved = TRUE;
   game.GameOver = TRUE;
+
+  // needed here to display correct panel values while player walks into exit
+  LevelSolved_SetFinalGameValues();
 }
 
 void GameWon(void)
@@ -4730,23 +4775,8 @@ void GameWon(void)
     if (local_player->active && local_player->MovPos)
       return;
 
-    game.time_final = (game.no_time_limit ? TimePlayed : TimeLeft);
-    game.score_time_final = (level.use_step_counter ? TimePlayed :
-                            TimePlayed * FRAMES_PER_SECOND + TimeFrames);
-
-    game.score_final = (level.game_engine_type == GAME_ENGINE_TYPE_EM ?
-                       game_em.lev->score :
-                       level.game_engine_type == GAME_ENGINE_TYPE_MM ?
-                       game_mm.score :
-                       game.score);
-
-    game.health_final = (level.game_engine_type == GAME_ENGINE_TYPE_MM ?
-                        MM_HEALTH(game_mm.laser_overload_value) :
-                        game.health);
-
-    game.LevelSolved_CountingTime = game.time_final;
-    game.LevelSolved_CountingScore = game.score_final;
-    game.LevelSolved_CountingHealth = game.health_final;
+    // calculate final game values after player finished walking into exit
+    LevelSolved_SetFinalGameValues();
 
     game.LevelSolved_GameWon = TRUE;
     game.LevelSolved_SaveTape = tape.recording;
@@ -4772,6 +4802,10 @@ void GameWon(void)
     score = score_final = game.score_final;
     health = health_final = game.health_final;
 
+    // update game panel values before (delayed) counting of score (if any)
+    LevelSolved_DisplayFinalGameValues(time, score, health);
+
+    // if level has time score defined, calculate new final game values
     if (time_score > 0)
     {
       int time_final_max = 999;
@@ -4805,18 +4839,13 @@ void GameWon(void)
       game.health_final = health_final;
     }
 
+    // if not counting score after game, immediately update game panel values
     if (level_editor_test_game || !setup.count_score_after_game)
     {
       time = time_final;
       score = score_final;
 
-      game.LevelSolved_CountingTime = time;
-      game.LevelSolved_CountingScore = score;
-
-      game_panel_controls[GAME_PANEL_TIME].value = time;
-      game_panel_controls[GAME_PANEL_SCORE].value = score;
-
-      DisplayGameControlValues();
+      LevelSolved_DisplayFinalGameValues(time, score, health);
     }
 
     if (level.game_engine_type == GAME_ENGINE_TYPE_RND)
@@ -4893,13 +4922,7 @@ void GameWon(void)
       if (time == time_final)
        score = score_final;
 
-      game.LevelSolved_CountingTime = time;
-      game.LevelSolved_CountingScore = score;
-
-      game_panel_controls[GAME_PANEL_TIME].value = time;
-      game_panel_controls[GAME_PANEL_SCORE].value = score;
-
-      DisplayGameControlValues();
+      LevelSolved_DisplayFinalGameValues(time, score, health);
 
       if (time == time_final)
        StopSound(SND_GAME_LEVELTIME_BONUS);
@@ -4925,13 +4948,7 @@ void GameWon(void)
       health += health_count_dir;
       score  += time_score;
 
-      game.LevelSolved_CountingHealth = health;
-      game.LevelSolved_CountingScore = score;
-
-      game_panel_controls[GAME_PANEL_HEALTH].value = health;
-      game_panel_controls[GAME_PANEL_SCORE].value = score;
-
-      DisplayGameControlValues();
+      LevelSolved_DisplayFinalGameValues(time, score, health);
 
       if (health == health_final)
        StopSound(SND_GAME_LEVELTIME_BONUS);
@@ -4960,7 +4977,7 @@ void GameEnd(void)
 {
   // used instead of "level_nr" (needed for network games)
   int last_level_nr = levelset.level_nr;
-  int highlight_position;
+  boolean tape_saved = FALSE;
 
   game.LevelSolved_GameEnd = TRUE;
 
@@ -4970,7 +4987,8 @@ void GameEnd(void)
     if (!global.use_envelope_request)
       CloseDoor(DOOR_CLOSE_1);
 
-    SaveTapeChecked_LevelSolved(tape.level_nr);                // ask to save tape
+    // ask to save tape
+    tape_saved = SaveTapeChecked_LevelSolved(tape.level_nr);
 
     // set unique basename for score tape (also saved in high score table)
     strcpy(tape.score_tape_basename, getScoreTapeBasename(setup.player_name));
@@ -5004,6 +5022,9 @@ void GameEnd(void)
     SaveLevelSetup_SeriesInfo();
   }
 
+  // save score and score tape before potentially erasing tape below
+  NewHighScore(last_level_nr, tape_saved);
+
   if (setup.increment_levels &&
       level_nr < leveldir_current->last_level &&
       !network_playing)
@@ -5019,13 +5040,11 @@ void GameEnd(void)
     }
   }
 
-  highlight_position = NewHiScore(last_level_nr);
-
-  if (highlight_position >= 0 && setup.show_scores_after_game)
+  if (scores.last_added >= 0 && setup.show_scores_after_game)
   {
     SetGameStatus(GAME_MODE_SCORES);
 
-    DrawHallOfFame(last_level_nr, highlight_position);
+    DrawHallOfFame(last_level_nr);
   }
   else if (setup.auto_play_next_level && setup.increment_levels &&
           last_level_nr < leveldir_current->last_level &&
@@ -5041,25 +5060,21 @@ void GameEnd(void)
   }
 }
 
-int NewHiScore(int level_nr)
+static int addScoreEntry(struct ScoreInfo *list, struct ScoreEntry *new_entry,
+                        boolean one_score_entry_per_name)
 {
-  int i, l;
-  int position = -1;
-  boolean one_score_entry_per_name = !program.many_scores_per_name;
-
-  LoadScore(level_nr);
+  int i;
 
-  if (strEqual(setup.player_name, EMPTY_PLAYER_NAME) ||
-      game.score_final < scores.entry[MAX_SCORE_ENTRIES - 1].score)
+  if (strEqual(new_entry->name, EMPTY_PLAYER_NAME))
     return -1;
 
   for (i = 0; i < MAX_SCORE_ENTRIES; i++)
   {
-    struct ScoreEntry *entry = &scores.entry[i];
-    boolean score_is_better = (game.score_final      >  entry->score);
-    boolean score_is_equal  = (game.score_final      == entry->score);
-    boolean time_is_better  = (game.score_time_final <  entry->time);
-    boolean time_is_equal   = (game.score_time_final == entry->time);
+    struct ScoreEntry *entry = &list->entry[i];
+    boolean score_is_better = (new_entry->score >  entry->score);
+    boolean score_is_equal  = (new_entry->score == entry->score);
+    boolean time_is_better  = (new_entry->time  <  entry->time);
+    boolean time_is_equal   = (new_entry->time  == entry->time);
     boolean better_by_score = (score_is_better ||
                               (score_is_equal && time_is_better));
     boolean better_by_time  = (time_is_better ||
@@ -5069,6 +5084,12 @@ int NewHiScore(int level_nr)
     boolean entry_is_empty = (entry->score == 0 &&
                              entry->time == 0);
 
+    // prevent adding server score entries if also existing in local score file
+    // (special case: historic score entries have an empty tape basename entry)
+    if (strEqual(new_entry->tape_basename, entry->tape_basename) &&
+       !strEqual(new_entry->tape_basename, UNDEFINED_FILENAME))
+      return -1;
+
     if (is_better || entry_is_empty)
     {
       // player has made it to the hall of fame
@@ -5076,11 +5097,12 @@ int NewHiScore(int level_nr)
       if (i < MAX_SCORE_ENTRIES - 1)
       {
        int m = MAX_SCORE_ENTRIES - 1;
+       int l;
 
        if (one_score_entry_per_name)
        {
          for (l = i; l < MAX_SCORE_ENTRIES; l++)
-           if (strEqual(setup.player_name, scores.entry[l].name))
+           if (strEqual(list->entry[l].name, new_entry->name))
              m = l;
 
          if (m == i)   // player's new highscore overwrites his old one
@@ -5088,36 +5110,99 @@ int NewHiScore(int level_nr)
        }
 
        for (l = m; l > i; l--)
-       {
-         strcpy(scores.entry[l].name, scores.entry[l - 1].name);
-         scores.entry[l].score = scores.entry[l - 1].score;
-         scores.entry[l].time  = scores.entry[l - 1].time;
-       }
+         list->entry[l] = list->entry[l - 1];
       }
 
       put_into_list:
 
-      strcpy(entry->tape_basename, tape.score_tape_basename);
-      strncpy(entry->name, setup.player_name, MAX_PLAYER_NAME_LEN);
-      entry->name[MAX_PLAYER_NAME_LEN] = '\0';
-      entry->score = game.score_final;
-      entry->time = game.score_time_final;
-      position = i;
+      *entry = *new_entry;
 
-      break;
+      return i;
     }
     else if (one_score_entry_per_name &&
-            !strncmp(setup.player_name, entry->name, MAX_PLAYER_NAME_LEN))
-      break;   // player already there with a higher score
+            strEqual(entry->name, new_entry->name))
+    {
+      // player already in high score list with better score or time
+
+      return -1;
+    }
   }
 
-  if (position >= 0)
+  return -1;
+}
+
+void NewHighScore(int level_nr, boolean tape_saved)
+{
+  struct ScoreEntry new_entry = {{ 0 }}; // (prevent warning from GCC bug 53119)
+  boolean one_per_name = FALSE;
+
+  strncpy(new_entry.tape_basename, tape.score_tape_basename, MAX_FILENAME_LEN);
+  strncpy(new_entry.name, setup.player_name, MAX_PLAYER_NAME_LEN);
+
+  new_entry.score = game.score_final;
+  new_entry.time = game.score_time_final;
+
+  LoadScore(level_nr);
+
+  scores.last_added = addScoreEntry(&scores, &new_entry, one_per_name);
+
+  if (scores.last_added < 0)
+    return;
+
+  SaveScore(level_nr);
+
+  // store last added local score entry (before merging server scores)
+  scores.last_added_local = scores.last_added;
+
+  if (!game.LevelSolved_SaveTape)
+    return;
+
+  SaveScoreTape(level_nr);
+
+  if (setup.ask_for_using_api_server)
   {
-    SaveScoreTape(level_nr);
-    SaveScore(level_nr);
+    setup.use_api_server =
+      Request("Upload your score and tape to the high score server?", REQ_ASK);
+
+    if (!setup.use_api_server)
+      Request("Not using high score server! Use setup menu to enable again!",
+             REQ_CONFIRM);
+
+    runtime.use_api_server = setup.use_api_server;
+
+    // after asking for using API server once, do not ask again
+    setup.ask_for_using_api_server = FALSE;
+
+    SaveSetup_ServerSetup();
   }
 
-  return position;
+  SaveServerScore(level_nr, tape_saved);
+}
+
+void MergeServerScore(void)
+{
+  struct ScoreEntry last_added_entry;
+  boolean one_per_name = FALSE;
+  int i;
+
+  if (scores.last_added >= 0)
+    last_added_entry = scores.entry[scores.last_added];
+
+  for (i = 0; i < server_scores.num_entries; i++)
+  {
+    int pos = addScoreEntry(&scores, &server_scores.entry[i], one_per_name);
+
+    if (pos >= 0 && pos <= scores.last_added)
+      scores.last_added++;
+  }
+
+  if (scores.last_added >= MAX_SCORE_ENTRIES)
+  {
+    scores.last_added = MAX_SCORE_ENTRIES - 1;
+    scores.force_last_added = TRUE;
+
+    scores.entry[scores.last_added] = last_added_entry;
+  }
 }
 
 static int getElementMoveStepsizeExt(int x, int y, int direction)
@@ -5397,7 +5482,7 @@ void DrawDynamite(int x, int y)
   else if (game.use_masked_elements)
     DrawLevelElement(x, y, EL_EMPTY);
 
-  frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
+  frame = getGraphicAnimationFrameXY(graphic, x, y);
 
   if (Back[x][y] || Store[x][y] || game.use_masked_elements)
     DrawGraphicThruMask(sx, sy, graphic, frame);
@@ -5640,7 +5725,7 @@ static void RelocatePlayer(int jx, int jy, int el_player_raw)
      possible that the relocation target field did not contain a player element,
      but a walkable element, to which the new player was relocated -- in this
      case, restore that (already initialized!) element on the player field */
-  if (!ELEM_IS_PLAYER(element))        // player may be set on walkable element
+  if (!IS_PLAYER_ELEMENT(element))     // player may be set on walkable element
   {
     Tile[jx][jy] = element;    // restore previously existing element
   }
@@ -5810,7 +5895,7 @@ static void Explode(int ex, int ey, int phase, int mode)
 
       // !!! check this case -- currently needed for rnd_rado_negundo_v,
       // !!! levels 015 018 019 020 021 022 023 026 027 028 !!!
-      else if (ELEM_IS_PLAYER(center_element))
+      else if (IS_PLAYER_ELEMENT(center_element))
        Store[x][y] = EL_EMPTY;
       else if (center_element == EL_YAMYAM)
        Store[x][y] = level.yamyam_content[game.yamyam_content_nr].e[xx][yy];
@@ -5950,13 +6035,13 @@ static void Explode(int ex, int ey, int phase, int mode)
     if (IS_PLAYER(x, y) && !PLAYERINFO(x, y)->present)
       StorePlayer[x][y] = 0;
 
-    if (ELEM_IS_PLAYER(element))
+    if (IS_PLAYER_ELEMENT(element))
       RelocatePlayer(x, y, element);
   }
   else if (IN_SCR_FIELD(SCREENX(x), SCREENY(y)))
   {
     int graphic = el_act2img(GfxElement[x][y], ACTION_EXPLODING);
-    int frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
+    int frame = getGraphicAnimationFrameXY(graphic, x, y);
 
     if (phase == delay)
       TEST_DrawLevelFieldCrumbled(x, y);
@@ -8145,7 +8230,7 @@ static void StartMoving(int x, int y)
                       dir == MV_RIGHT  ? IMG_FLAMES_1_RIGHT :
                       dir == MV_UP     ? IMG_FLAMES_1_UP :
                       dir == MV_DOWN   ? IMG_FLAMES_1_DOWN : IMG_EMPTY);
-       int frame = getGraphicAnimationFrame(graphic, GfxFrame[x][y]);
+       int frame = getGraphicAnimationFrameXY(graphic, x, y);
 
        GfxAction[x][y] = ACTION_ATTACKING;
 
@@ -8736,7 +8821,7 @@ void ContinueMoving(int x, int y)
     if (GFX_CRUMBLED(Tile[x][y]))
       TEST_DrawLevelFieldCrumbledNeighbours(x, y);
 
-    if (ELEM_IS_PLAYER(move_leave_element))
+    if (IS_PLAYER_ELEMENT(move_leave_element))
       RelocatePlayer(x, y, move_leave_element);
   }
 
@@ -10546,7 +10631,7 @@ static void CreateFieldExt(int x, int y, int element, boolean is_change)
   int previous_move_direction = MovDir[x][y];
   int last_ce_value = CustomValue[x][y];
   boolean player_explosion_protected = PLAYER_EXPLOSION_PROTECTED(x, y);
-  boolean new_element_is_player = ELEM_IS_PLAYER(new_element);
+  boolean new_element_is_player = IS_PLAYER_ELEMENT(new_element);
   boolean add_player_onto_element = (new_element_is_player &&
                                     new_element != EL_SOKOBAN_FIELD_PLAYER &&
                                     IS_WALKABLE(old_element));
@@ -10722,7 +10807,7 @@ static boolean ChangeElement(int x, int y, int element, int page)
          (change->replace_when == CP_WHEN_COLLECTIBLE  && is_collectible) ||
          (change->replace_when == CP_WHEN_REMOVABLE    && is_removable) ||
          (change->replace_when == CP_WHEN_DESTRUCTIBLE && is_destructible)) &&
-        !(IS_PLAYER(ex, ey) && ELEM_IS_PLAYER(content_element)));
+        !(IS_PLAYER(ex, ey) && IS_PLAYER_ELEMENT(content_element)));
 
       if (!can_replace[xx][yy])
        complete_replace = FALSE;
@@ -10784,6 +10869,10 @@ static boolean ChangeElement(int x, int y, int element, int page)
       Store[x][y] = EL_EMPTY;
     }
 
+    // special case: element changes to player (and may be kept if walkable)
+    if (IS_PLAYER_ELEMENT(target_element) && !level.keep_walkable_ce)
+      CreateElementFromChange(x, y, EL_EMPTY);
+
     CreateElementFromChange(x, y, target_element);
 
     PlayLevelSoundElementAction(x, y, element, ACTION_CHANGING);
@@ -11073,7 +11162,8 @@ static boolean CheckElementChangeExt(int x, int y,
        different to element changes that affect other elements to change on the
        whole playfield (which is handeld by CheckTriggeredElementChangeExt()) */
     boolean check_trigger_element =
-      (trigger_event == CE_TOUCHING_X ||
+      (trigger_event == CE_NEXT_TO_X ||
+       trigger_event == CE_TOUCHING_X ||
        trigger_event == CE_HITTING_X ||
        trigger_event == CE_HIT_BY_X ||
        trigger_event == CE_DIGGING_X); // this one was forgotten until 3.2.3
@@ -11654,7 +11744,7 @@ static void GameActionsExt(void)
     Warn("element '%s' caused endless loop in game engine",
         EL_NAME(recursion_loop_element));
 
-    RequestQuitGameExt(FALSE, level_editor_test_game, message);
+    RequestQuitGameExt(program.headless, level_editor_test_game, message);
 
     recursion_loop_detected = FALSE;   // if game should be continued
 
@@ -12125,6 +12215,9 @@ void GameActions_RND(void)
        TEST_DrawLevelField(x, y);
 
        TestFieldAfterSnapping(x, y, element, move_direction, player_index_bit);
+
+       if (IS_ENVELOPE(element))
+         local_player->show_envelope = element;
       }
     }
 
@@ -12236,6 +12329,8 @@ void GameActions_RND(void)
       graphic = el_act_dir2img(element, GfxAction[x][y], GfxDir[x][y]);
     }
 
+    CheckNextToConditions(x, y);
+
     if (!IS_MOVING(x, y) && (CAN_FALL(element) || CAN_MOVE(element)))
     {
       StartMoving(x, y);
@@ -13213,6 +13308,76 @@ void ScrollScreen(struct PlayerInfo *player, int mode)
     ScreenMovDir = MV_NONE;
 }
 
+void CheckNextToConditions(int x, int y)
+{
+  int element = Tile[x][y];
+
+  if (IS_PLAYER(x, y))
+    TestIfPlayerNextToCustomElement(x, y);
+
+  if (CAN_CHANGE_OR_HAS_ACTION(element) &&
+      HAS_ANY_CHANGE_EVENT(element, CE_NEXT_TO_X))
+    TestIfElementNextToCustomElement(x, y);
+}
+
+void TestIfPlayerNextToCustomElement(int x, int y)
+{
+  static int xy[4][2] =
+  {
+    { 0, -1 },
+    { -1, 0 },
+    { +1, 0 },
+    { 0, +1 }
+  };
+  static int trigger_sides[4][2] =
+  {
+    // center side       border side
+    { CH_SIDE_TOP,     CH_SIDE_BOTTOM  },      // check top
+    { CH_SIDE_LEFT,    CH_SIDE_RIGHT   },      // check left
+    { CH_SIDE_RIGHT,   CH_SIDE_LEFT    },      // check right
+    { CH_SIDE_BOTTOM,  CH_SIDE_TOP     }       // check bottom
+  };
+  int i;
+
+  if (!IS_PLAYER(x, y))
+    return;
+
+  struct PlayerInfo *player = PLAYERINFO(x, y);
+
+  if (player->is_moving)
+    return;
+
+  for (i = 0; i < NUM_DIRECTIONS; i++)
+  {
+    int xx = x + xy[i][0];
+    int yy = y + xy[i][1];
+    int border_side = trigger_sides[i][1];
+    int border_element;
+
+    if (!IN_LEV_FIELD(xx, yy))
+      continue;
+
+    if (IS_MOVING(xx, yy) || IS_BLOCKED(xx, yy))
+      continue;                // center and border element not connected
+
+    border_element = Tile[xx][yy];
+
+    CheckElementChangeByPlayer(xx, yy, border_element, CE_NEXT_TO_PLAYER,
+                               player->index_bit, border_side);
+    CheckTriggeredElementChangeByPlayer(xx, yy, border_element,
+                                        CE_PLAYER_NEXT_TO_X,
+                                        player->index_bit, border_side);
+
+    /* use player element that is initially defined in the level playfield,
+       not the player element that corresponds to the runtime player number
+       (example: a level that contains EL_PLAYER_3 as the only player would
+       incorrectly give EL_PLAYER_1 for "player->element_nr") */
+
+    CheckElementChangeBySide(xx, yy, border_element, player->initial_element,
+                             CE_NEXT_TO_X, border_side);
+  }
+}
+
 void TestIfPlayerTouchesCustomElement(int x, int y)
 {
   static int xy[4][2] =
@@ -13313,6 +13478,51 @@ void TestIfPlayerTouchesCustomElement(int x, int y)
   }
 }
 
+void TestIfElementNextToCustomElement(int x, int y)
+{
+  static int xy[4][2] =
+  {
+    { 0, -1 },
+    { -1, 0 },
+    { +1, 0 },
+    { 0, +1 }
+  };
+  static int trigger_sides[4][2] =
+  {
+    // center side     border side
+    { CH_SIDE_TOP,     CH_SIDE_BOTTOM  },      // check top
+    { CH_SIDE_LEFT,    CH_SIDE_RIGHT   },      // check left
+    { CH_SIDE_RIGHT,   CH_SIDE_LEFT    },      // check right
+    { CH_SIDE_BOTTOM,  CH_SIDE_TOP     }       // check bottom
+  };
+  int center_element = Tile[x][y];     // should always be non-moving!
+  int i;
+
+  if (IS_MOVING(x, y) || IS_BLOCKED(x, y))
+    return;
+
+  for (i = 0; i < NUM_DIRECTIONS; i++)
+  {
+    int xx = x + xy[i][0];
+    int yy = y + xy[i][1];
+    int border_side = trigger_sides[i][1];
+    int border_element;
+
+    if (!IN_LEV_FIELD(xx, yy))
+      continue;
+
+    if (IS_MOVING(xx, yy) || IS_BLOCKED(xx, yy))
+      continue;                        // center and border element not connected
+
+    border_element = Tile[xx][yy];
+
+    // check for change of center element (but change it only once)
+    if (CheckElementChangeBySide(x, y, center_element, border_element,
+                                 CE_NEXT_TO_X, border_side))
+      break;
+  }
+}
+
 void TestIfElementTouchesCustomElement(int x, int y)
 {
   static int xy[4][2] =
@@ -13908,7 +14118,11 @@ static void TestFieldAfterSnapping(int x, int y, int element, int direction,
   if (level.finish_dig_collect)
   {
     int dig_side = MV_DIR_OPPOSITE(direction);
+    int change_event = (IS_DIGGABLE(element) ? CE_PLAYER_DIGS_X :
+                       CE_PLAYER_COLLECTS_X);
 
+    CheckTriggeredElementChangeByPlayer(x, y, element, change_event,
+                                       player_index_bit, dig_side);
     CheckTriggeredElementChangeByPlayer(x, y, element, CE_PLAYER_SNAPS_X,
                                        player_index_bit, dig_side);
   }
@@ -13991,7 +14205,6 @@ static int DigField(struct PlayerInfo *player,
       return MP_NO_ACTION;
     }
   }
-
   if (IS_TUBE(Back[jx][jy]) && game.engine_version >= VERSION_IDENT(2,2,0,0))
     old_element = Back[jx][jy];
 
@@ -14282,7 +14495,10 @@ static int DigField(struct PlayerInfo *player,
     }
     else if (IS_ENVELOPE(element))
     {
-      player->show_envelope = element;
+      boolean wait_for_snapping = (mode == DF_SNAP && level.block_snap_field);
+
+      if (!wait_for_snapping)
+       player->show_envelope = element;
     }
     else if (element == EL_EMC_LENSES)
     {
@@ -14469,7 +14685,7 @@ static int DigField(struct PlayerInfo *player,
       if (sokoban_task_solved &&
          game.sokoban_fields_still_needed == 0 &&
          game.sokoban_objects_still_needed == 0 &&
-         (game.emulation == EMU_SOKOBAN || level.auto_exit_sokoban))
+         level.auto_exit_sokoban)
       {
        game.players_still_needed = 0;
 
@@ -15758,6 +15974,7 @@ static ListNode *SaveEngineSnapshotBuffers(void)
 
   SaveSnapshotBuffer(&buffers, ARGS_ADDRESS_AND_SIZEOF(GfxFrame));
   SaveSnapshotBuffer(&buffers, ARGS_ADDRESS_AND_SIZEOF(GfxRandom));
+  SaveSnapshotBuffer(&buffers, ARGS_ADDRESS_AND_SIZEOF(GfxRandomStatic));
   SaveSnapshotBuffer(&buffers, ARGS_ADDRESS_AND_SIZEOF(GfxElement));
   SaveSnapshotBuffer(&buffers, ARGS_ADDRESS_AND_SIZEOF(GfxAction));
   SaveSnapshotBuffer(&buffers, ARGS_ADDRESS_AND_SIZEOF(GfxDir));
@@ -16099,12 +16316,18 @@ static void UnmapGameButtonsAtSamePosition(int id)
 
 static void UnmapGameButtonsAtSamePosition_All(void)
 {
-  if (setup.show_snapshot_buttons)
+  if (setup.show_load_save_buttons)
   {
     UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_SAVE);
     UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_PAUSE2);
     UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_LOAD);
   }
+  else if (setup.show_undo_redo_buttons)
+  {
+    UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_UNDO);
+    UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_PAUSE2);
+    UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_REDO);
+  }
   else
   {
     UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_STOP);
@@ -16117,17 +16340,13 @@ static void UnmapGameButtonsAtSamePosition_All(void)
   }
 }
 
-static void MapGameButtonsAtSamePosition(int id)
+void MapLoadSaveButtons(void)
 {
-  int i;
-
-  for (i = 0; i < NUM_GAME_BUTTONS; i++)
-    if (i != id &&
-       gamebutton_info[i].pos->x == gamebutton_info[id].pos->x &&
-       gamebutton_info[i].pos->y == gamebutton_info[id].pos->y)
-      MapGadget(game_gadget[i]);
+  UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_LOAD);
+  UnmapGameButtonsAtSamePosition(GAME_CTRL_ID_SAVE);
 
-  UnmapGameButtonsAtSamePosition_All();
+  MapGadget(game_gadget[GAME_CTRL_ID_LOAD]);
+  MapGadget(game_gadget[GAME_CTRL_ID_SAVE]);
 }
 
 void MapUndoRedoButtons(void)
@@ -16139,15 +16358,6 @@ void MapUndoRedoButtons(void)
   MapGadget(game_gadget[GAME_CTRL_ID_REDO]);
 }
 
-void UnmapUndoRedoButtons(void)
-{
-  UnmapGadget(game_gadget[GAME_CTRL_ID_UNDO]);
-  UnmapGadget(game_gadget[GAME_CTRL_ID_REDO]);
-
-  MapGameButtonsAtSamePosition(GAME_CTRL_ID_UNDO);
-  MapGameButtonsAtSamePosition(GAME_CTRL_ID_REDO);
-}
-
 void ModifyPauseButtons(void)
 {
   static int ids[] =
@@ -16169,9 +16379,7 @@ static void MapGameButtonsExt(boolean on_tape)
   int i;
 
   for (i = 0; i < NUM_GAME_BUTTONS; i++)
-    if ((!on_tape || gamebutton_info[i].allowed_on_tape) &&
-       i != GAME_CTRL_ID_UNDO &&
-       i != GAME_CTRL_ID_REDO)
+    if (!on_tape || gamebutton_info[i].allowed_on_tape)
       MapGadget(game_gadget[i]);
 
   UnmapGameButtonsAtSamePosition_All();
@@ -16263,6 +16471,8 @@ static void GameUndoRedoExt(void)
   DrawVideoDisplay(VIDEO_STATE_FRAME_ON, FrameCounter);
   DrawVideoDisplay(VIDEO_STATE_1STEP(tape.single_step), 0);
 
+  ModifyPauseButtons();
+
   BackToFront();
 }
 
@@ -16271,8 +16481,12 @@ static void GameUndo(int steps)
   if (!CheckEngineSnapshotList())
     return;
 
+  int tape_property_bits = tape.property_bits;
+
   LoadEngineSnapshot_Undo(steps);
 
+  tape.property_bits |= tape_property_bits | TAPE_PROPERTY_SNAPSHOT;
+
   GameUndoRedoExt();
 }
 
@@ -16281,8 +16495,12 @@ static void GameRedo(int steps)
   if (!CheckEngineSnapshotList())
     return;
 
+  int tape_property_bits = tape.property_bits;
+
   LoadEngineSnapshot_Redo(steps);
 
+  tape.property_bits |= tape_property_bits | TAPE_PROPERTY_SNAPSHOT;
+
   GameUndoRedoExt();
 }