+ int belt_part = Feld[xx][yy] - belt_base_active_element[belt_nr];
+
+ Feld[xx][yy] = belt_base_element[belt_nr] + belt_part;
+ DrawLevelField(xx, yy);
+ }
+ }
+ }
+ }
+}
+
+static void ToggleSwitchgateSwitch(int x, int y)
+{
+ int xx, yy;
+
+ game.switchgate_pos = !game.switchgate_pos;
+
+ for (yy=0; yy<lev_fieldy; yy++)
+ {
+ for (xx=0; xx<lev_fieldx; xx++)
+ {
+ int element = Feld[xx][yy];
+
+ if (element == EL_SWITCHGATE_SWITCH_UP ||
+ element == EL_SWITCHGATE_SWITCH_DOWN)
+ {
+ Feld[xx][yy] = EL_SWITCHGATE_SWITCH_UP + game.switchgate_pos;
+ DrawLevelField(xx, yy);
+ }
+ else if (element == EL_SWITCHGATE_OPEN ||
+ element == EL_SWITCHGATE_OPENING)
+ {
+ Feld[xx][yy] = EL_SWITCHGATE_CLOSING;
+#if 1
+ PlaySoundLevelAction(xx, yy, ACTION_CLOSING);
+#else
+ PlaySoundLevel(xx, yy, SND_SWITCHGATE_CLOSING);
+#endif
+ }
+ else if (element == EL_SWITCHGATE_CLOSED ||
+ element == EL_SWITCHGATE_CLOSING)
+ {
+ Feld[xx][yy] = EL_SWITCHGATE_OPENING;
+#if 1
+ PlaySoundLevelAction(xx, yy, ACTION_OPENING);
+#else
+ PlaySoundLevel(xx, yy, SND_SWITCHGATE_OPENING);
+#endif
+ }
+ }
+ }
+}
+
+static int getInvisibleActiveFromInvisibleElement(int element)
+{
+ return (element == EL_INVISIBLE_STEELWALL ? EL_INVISIBLE_STEELWALL_ACTIVE :
+ element == EL_INVISIBLE_WALL ? EL_INVISIBLE_WALL_ACTIVE :
+ EL_INVISIBLE_SAND_ACTIVE);
+}
+
+static int getInvisibleFromInvisibleActiveElement(int element)
+{
+ return (element == EL_INVISIBLE_STEELWALL_ACTIVE ? EL_INVISIBLE_STEELWALL :
+ element == EL_INVISIBLE_WALL_ACTIVE ? EL_INVISIBLE_WALL :
+ EL_INVISIBLE_SAND);
+}
+
+static void RedrawAllLightSwitchesAndInvisibleElements()
+{
+ int x, y;
+
+ for (y=0; y<lev_fieldy; y++)
+ {
+ for (x=0; x<lev_fieldx; x++)
+ {
+ int element = Feld[x][y];
+
+ if (element == EL_LIGHT_SWITCH &&
+ game.light_time_left > 0)
+ {
+ Feld[x][y] = EL_LIGHT_SWITCH_ACTIVE;
+ DrawLevelField(x, y);
+ }
+ else if (element == EL_LIGHT_SWITCH_ACTIVE &&
+ game.light_time_left == 0)
+ {
+ Feld[x][y] = EL_LIGHT_SWITCH;
+ DrawLevelField(x, y);
+ }
+ else if (element == EL_INVISIBLE_STEELWALL ||
+ element == EL_INVISIBLE_WALL ||
+ element == EL_INVISIBLE_SAND)
+ {
+ if (game.light_time_left > 0)
+ Feld[x][y] = getInvisibleActiveFromInvisibleElement(element);
+
+ DrawLevelField(x, y);
+ }
+ else if (element == EL_INVISIBLE_STEELWALL_ACTIVE ||
+ element == EL_INVISIBLE_WALL_ACTIVE ||
+ element == EL_INVISIBLE_SAND_ACTIVE)
+ {
+ if (game.light_time_left == 0)
+ Feld[x][y] = getInvisibleFromInvisibleActiveElement(element);
+
+ DrawLevelField(x, y);
+ }
+ }
+ }
+}
+
+static void ToggleLightSwitch(int x, int y)
+{
+ int element = Feld[x][y];
+
+ game.light_time_left =
+ (element == EL_LIGHT_SWITCH ?
+ level.time_light * FRAMES_PER_SECOND : 0);
+
+ RedrawAllLightSwitchesAndInvisibleElements();
+}
+
+static void ActivateTimegateSwitch(int x, int y)
+{
+ int xx, yy;
+
+ game.timegate_time_left = level.time_timegate * FRAMES_PER_SECOND;
+
+ for (yy=0; yy<lev_fieldy; yy++)
+ {
+ for (xx=0; xx<lev_fieldx; xx++)
+ {
+ int element = Feld[xx][yy];
+
+ if (element == EL_TIMEGATE_CLOSED ||
+ element == EL_TIMEGATE_CLOSING)
+ {
+ Feld[xx][yy] = EL_TIMEGATE_OPENING;
+ PlaySoundLevel(xx, yy, SND_TIMEGATE_OPENING);
+ }
+
+ /*
+ else if (element == EL_TIMEGATE_SWITCH_ACTIVE)
+ {
+ Feld[xx][yy] = EL_TIMEGATE_SWITCH;
+ DrawLevelField(xx, yy);
+ }
+ */
+
+ }
+ }
+
+ Feld[x][y] = EL_TIMEGATE_SWITCH_ACTIVE;
+}
+
+void Impact(int x, int y)
+{
+ boolean lastline = (y == lev_fieldy-1);
+ boolean object_hit = FALSE;
+ boolean impact = (lastline || object_hit);
+ int element = Feld[x][y];
+ int smashed = EL_UNDEFINED;
+
+ if (!lastline) /* check if element below was hit */
+ {
+ if (Feld[x][y + 1] == EL_PLAYER_IS_LEAVING)
+ return;
+
+ object_hit = (!IS_FREE(x, y + 1) && (!IS_MOVING(x, y + 1) ||
+ MovDir[x][y + 1] != MV_DOWN ||
+ MovPos[x][y + 1] <= TILEY / 2));
+ if (object_hit)
+ smashed = MovingOrBlocked2Element(x, y + 1);
+
+ impact = (lastline || object_hit);
+ }
+
+ if (!lastline && smashed == EL_ACID) /* element falls into acid */
+ {
+ SplashAcid(x, y);
+ return;
+ }
+
+ if (impact)
+ {
+ ResetGfxAnimation(x, y);
+ DrawLevelField(x, y);
+ }
+
+ if (impact && CAN_EXPLODE_IMPACT(element))
+ {
+ Bang(x, y);
+ return;
+ }
+ else if (impact && element == EL_PEARL)
+ {
+ Feld[x][y] = EL_PEARL_BREAKING;
+ PlaySoundLevel(x, y, SND_PEARL_BREAKING);
+ return;
+ }
+#if 1
+ else if (impact && CheckElementChange(x, y, element, ACTION_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)
+ {
+ if (object_hit && IS_PLAYER(x, y + 1))
+ KillHeroUnlessProtected(x, y + 1);
+ else if (object_hit && smashed == EL_PENGUIN)
+ Bang(x, y + 1);
+ else
+ {
+ Feld[x][y] = EL_AMOEBA_GROWING;
+ Store[x][y] = EL_AMOEBA_WET;
+
+ ResetRandomAnimationValue(x, y);
+ }
+ return;
+ }
+
+ if (object_hit) /* check which object was hit */
+ {
+ if (CAN_PASS_MAGIC_WALL(element) &&
+ (smashed == EL_MAGIC_WALL ||
+ smashed == EL_BD_MAGIC_WALL))
+ {
+ int xx, yy;
+ int activated_magic_wall =
+ (smashed == EL_MAGIC_WALL ? EL_MAGIC_WALL_ACTIVE :
+ EL_BD_MAGIC_WALL_ACTIVE);
+
+ /* activate magic wall / mill */
+ for (yy=0; yy<lev_fieldy; yy++)
+ for (xx=0; xx<lev_fieldx; xx++)
+ 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;
+
+ PlaySoundLevel(x, y, (smashed == EL_MAGIC_WALL ?
+ SND_MAGIC_WALL_ACTIVATING :
+ SND_BD_MAGIC_WALL_ACTIVATING));
+ }
+
+ if (IS_PLAYER(x, y + 1))
+ {
+ if (CAN_SMASH_PLAYER(element))
+ {
+ KillHeroUnlessProtected(x, y + 1);
+ return;
+ }
+ }
+ else if (smashed == EL_PENGUIN)
+ {
+ if (CAN_SMASH_PLAYER(element))
+ {
+ Bang(x, y + 1);
+ return;
+ }
+ }
+ else if (element == EL_BD_DIAMOND)
+ {
+ if (IS_CLASSIC_ENEMY(smashed) && IS_BD_ELEMENT(smashed))
+ {
+ Bang(x, y + 1);
+ return;
+ }
+ }
+ else if ((element == EL_SP_INFOTRON ||
+ element == EL_SP_ZONK) &&
+ (smashed == EL_SP_SNIKSNAK ||
+ smashed == EL_SP_ELECTRON ||
+ smashed == EL_SP_DISK_ORANGE))
+ {
+ Bang(x, y + 1);
+ return;
+ }
+ else if (CAN_SMASH_EVERYTHING(element))
+ {
+ if (IS_CLASSIC_ENEMY(smashed) ||
+ CAN_EXPLODE_SMASHED(smashed))
+ {
+ Bang(x, y + 1);
+ return;
+ }
+ else if (!IS_MOVING(x, y + 1) && !IS_BLOCKED(x, y + 1))
+ {
+ if (smashed == EL_LAMP ||
+ smashed == EL_LAMP_ACTIVE)
+ {
+ Bang(x, y + 1);
+ return;
+ }
+ else if (smashed == EL_NUT)
+ {
+ Feld[x][y + 1] = EL_NUT_BREAKING;
+ PlaySoundLevel(x, y, SND_NUT_BREAKING);
+ RaiseScoreElement(EL_NUT);