added smooth game element movements for native BD engine

[rocksndiamonds.git] / src / game_bd / bd_graphics.c

diff --git a/src/game_bd/bd_graphics.c b/src/game_bd/bd_graphics.c
index 2c0e1335ad05573c81313f83b919d223762abb08..34b34b39631d1ed37a0f0b8f7f2cef06d197a891 100644 (file)
--- a/src/game_bd/bd_graphics.c
+++ b/src/game_bd/bd_graphics.c
@@ -301,6 +301,10 @@ int gd_drawcave(Bitmap *dest, GdGame *game, boolean force_redraw)
   int scroll_y_aligned = scroll_y;
   int x, y, xd, yd;
 
+  /* force redraw if maximum number of cycles has changed (to redraw moving elements) */
+  if (game->itermax != game->itermax_last)
+    redraw_all = TRUE;
+
   if (!game->cave->gate_open_flash)
   {
     show_flash_count = 0;
@@ -327,8 +331,15 @@ int gd_drawcave(Bitmap *dest, GdGame *game, boolean force_redraw)
   {
     for (x = game->cave->x1, xd = 0; x <= game->cave->x2; x++, xd++)
     {
-      if (redraw_all || game->gfx_buffer[y][x] & GD_REDRAW)
+      /* potential movement direction of game element */
+      int dir = game->dir_buffer[y][x];
+
+      if (redraw_all || game->gfx_buffer[y][x] & GD_REDRAW || dir != GD_MV_STILL)
       {
+       /* skip redrawing already drawn element with movement */
+       if (game->element_buffer[y][x] & SKIPPED)
+         continue;
+
        /* if it needs to be redrawn */
        SDL_Rect offset;
 
@@ -345,6 +356,57 @@ int gd_drawcave(Bitmap *dest, GdGame *game, boolean force_redraw)
        struct GraphicInfo_BD *g = &graphic_info_bd_object[tile][frame];
        int width  = g->width  * TILESIZE_VAR / TILESIZE;
        int height = g->height * TILESIZE_VAR / TILESIZE;
+       boolean use_smooth_movements = TRUE;
+
+       /* if game element is just moving, draw movement animation between two tiles */
+       if (use_smooth_movements && dir != GD_MV_STILL)
+       {
+         if (!(game->last_element_buffer[y][x] & SKIPPED))
+         {
+           /* redraw previous game element on the cave field the new element is moving to */
+           int tile_old = game->last_element_buffer[y][x] & ~SKIPPED;
+           struct GraphicInfo_BD *g_old = &graphic_info_bd_object[tile_old][frame];
+
+           blit_bitmap(g_old->bitmap, dest, g_old->src_x, g_old->src_y, width, height,
+                       offset.x, offset.y);
+         }
+
+         /* 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 = game->cave->getx(game->cave, x + dx, y + dy);
+         int old_y = game->cave->gety(game->cave, x + dx, y + dy);
+
+         if (old_x >= game->cave->x1 &&
+             old_x <= game->cave->x2 &&
+             old_y >= game->cave->y1 &&
+             old_y <= game->cave->y2)
+         {
+           if (game->dir_buffer[old_y][old_x] == GD_MV_STILL)
+           {
+             /* redraw game element on the cave field the element is moving from */
+             int tile_from = game->element_buffer[old_y][old_x];
+             struct GraphicInfo_BD *g_from = &graphic_info_bd_object[tile_from][0];
+
+             blit_bitmap(g_from->bitmap, dest, g_from->src_x, g_from->src_y, width, height,
+                         offset.x + dx * cell_size, offset.y + dy * cell_size);
+
+             game->element_buffer[old_y][old_x] |= SKIPPED;
+           }
+           else
+           {
+             /* if old tile also moving (like pushing player), do not redraw it again */
+             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;
+
+         offset.x += dx * shift;
+         offset.y += dy * shift;
+       }
 
        blit_bitmap(g->bitmap, dest, g->src_x, g->src_y, width, height, offset.x, offset.y);