+// returns true if the element is a player
+static inline boolean is_player(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_PLAYER) != 0;
+}
+
+// returns true if the element is diggable
+static inline boolean is_diggable(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_DIGGABLE) != 0;
+}
+
+// returns true if the element is collectible
+static inline boolean is_collectible(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_COLLECTIBLE) != 0;
+}
+
+// returns true if the element is pushable
+static inline boolean is_pushable(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_PUSHABLE) != 0;
+}
+
+// returns true if the element can move
+static inline boolean can_move(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_CAN_MOVE) != 0;
+}
+
+// returns true if the element can fall
+static inline boolean can_fall(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_CAN_FALL) != 0;
+}
+
+// returns true if the element is exploding
+static inline boolean is_explosion(const int element)
+{
+ return (gd_elements[element & O_MASK].properties & P_EXPLOSION) != 0;
+}
+
+static void gd_drawcave_tile(Bitmap *dest, GdGame *game, int x, int y, boolean draw_masked)
+{
+ void (*blit_bitmap)(Bitmap *, Bitmap *, int, int, int, int, int, int) =
+ (draw_masked ? BlitBitmapMasked : BlitBitmap);
+ GdCave *cave = game->cave;
+ int sx = x * cell_size - scroll_x;
+ int sy = y * cell_size - scroll_y;
+ int dir = game->dir_buffer[y][x];
+ int tile = game->element_buffer[y][x];
+ int frame = game->animcycle;
+ struct GraphicInfo_BD *g = &graphic_info_bd_object[tile][frame];
+ Bitmap *tile_bitmap = gd_get_tile_bitmap(g->bitmap);
+ boolean is_movable = (can_move(tile) || can_fall(tile) || is_pushable(tile) || is_player(tile));
+ boolean is_movable_or_diggable = (is_movable || is_diggable(game->last_element_buffer[y][x]));
+ boolean is_moving = (is_movable_or_diggable && dir != GD_MV_STILL);
+ boolean use_smooth_movements =
+ ((setup.bd_smooth_movements == TRUE) ||
+ (setup.bd_smooth_movements == AUTO && !use_native_bd_graphics_engine()));
+
+ // do not use smooth movement animation for exploding game elements (like player)
+ if (is_explosion(tile) && dir != GD_MV_STILL)
+ use_smooth_movements = FALSE;
+
+ // do not use smooth movement animation for player entering exit (engine stopped)
+ if (cave->player_state == GD_PL_EXITED)
+ use_smooth_movements = FALSE;
+
+#if DO_GFX_SANITY_CHECK
+ if (use_native_bd_graphics_engine() && !setup.small_game_graphics && !program.headless)
+ {
+ int old_x = (game->gfx_buffer[y][x] % GD_NUM_OF_CELLS) % GD_NUM_OF_CELLS_X;
+ int old_y = (game->gfx_buffer[y][x] % GD_NUM_OF_CELLS) / GD_NUM_OF_CELLS_X;
+ int new_x = g->src_x / g->width;
+ int new_y = g->src_y / g->height;
+
+ if (new_x != old_x || new_y != old_y)
+ {
+ printf("::: BAD ANIMATION FOR TILE %d, FRAME %d [NEW(%d, %d) != OLD(%d, %d)] ['%s']\n",
+ tile, frame,
+ new_x, new_y,
+ old_x, old_y,
+ gd_elements[tile].name);
+ }
+ }
+#endif
+
+ // if game element not moving (or no smooth movements requested), simply draw tile
+ if (!is_moving || !use_smooth_movements)
+ {
+ blit_bitmap(tile_bitmap, dest, g->src_x, g->src_y, cell_size, cell_size, sx, sy);
+
+ return;
+ }
+
+ // draw smooth animation for game element moving between two cave tiles
+
+ if (!(game->last_element_buffer[y][x] & SKIPPED))
+ {
+ // redraw previous game element on the cave field the new element is moving to
+ int tile_last = game->last_element_buffer[y][x];
+
+ // only redraw previous game element if it is not collectible (like dirt etc.)
+ if (is_collectible(tile_last))
+ tile_last = O_SPACE;
+
+ struct GraphicInfo_BD *g_old = &graphic_info_bd_object[tile_last][frame];
+ Bitmap *tile_bitmap_old = gd_get_tile_bitmap(g_old->bitmap);
+
+ blit_bitmap(tile_bitmap_old, dest, g_old->src_x, g_old->src_y, cell_size, cell_size, sx, sy);
+ }
+
+ // get cave field position the game element is moving from
+ int dx = (dir == GD_MV_LEFT ? +1 : dir == GD_MV_RIGHT ? -1 : 0);
+ int dy = (dir == GD_MV_UP ? +1 : dir == GD_MV_DOWN ? -1 : 0);
+ int old_x = cave->getx(cave, x + dx, y + dy);
+ int old_y = cave->gety(cave, x + dx, y + dy);
+ int tile_from = game->element_buffer[old_y][old_x] & ~SKIPPED; // should never be skipped
+ struct GraphicInfo_BD *g_from = &graphic_info_bd_object[tile_from][frame];
+ Bitmap *tile_bitmap_from = gd_get_tile_bitmap(g_from->bitmap);
+ boolean old_is_player = is_player(tile_from);
+ boolean old_is_moving = (game->dir_buffer[old_y][old_x] != GD_MV_STILL);
+ boolean old_is_visible = (old_x >= cave->x1 &&
+ old_x <= cave->x2 &&
+ old_y >= cave->y1 &&
+ old_y <= cave->y2);
+ if (old_is_visible)
+ {
+ if (!old_is_moving && !old_is_player)
+ {
+ // redraw game element on the cave field the element is moving from
+ blit_bitmap(tile_bitmap_from, dest, g_from->src_x, g_from->src_y, cell_size, cell_size,
+ sx + dx * cell_size, sy + dy * cell_size);
+
+ game->element_buffer[old_y][old_x] |= SKIPPED;
+ }
+ else
+ {
+ // if old tile also moving (like pushing player), do not redraw tile background
+ game->last_element_buffer[old_y][old_x] |= SKIPPED;
+ }
+ }
+
+ // get shifted position between cave fields the game element is moving from/to
+ int itercycle = MIN(MAX(0, game->itermax - game->itercycle - 1), game->itermax);
+ int shift = cell_size * itercycle / game->itermax;
+
+ blit_bitmap(tile_bitmap, dest, g->src_x, g->src_y, cell_size, cell_size,
+ sx + dx * shift, sy + dy * shift);
+
+ // special case: redraw player snapping a game element
+ if (old_is_visible && old_is_player && !old_is_moving)
+ {
+ // redraw game element on the cave field the element is moving from
+ blit_bitmap(tile_bitmap_from, dest, g_from->src_x, g_from->src_y, cell_size, cell_size,
+ sx + dx * cell_size, sy + dy * cell_size);
+ }
+}
+