added support for alpha channel transparency for global animation images

[rocksndiamonds.git] / src / libgame / sdl.c

diff --git a/src/libgame/sdl.c b/src/libgame/sdl.c
index d431aacf29c96c34d73b2a4db489d075608a5640..d11636646c90b0e9ac913b494a993a9464e535ec 100644 (file)
--- a/src/libgame/sdl.c
+++ b/src/libgame/sdl.c
@@ -53,7 +53,7 @@ void SDLLimitScreenUpdates(boolean enable)
 static void UpdateScreen(SDL_Rect *rect)
 {
   static unsigned int update_screen_delay = 0;
-  unsigned int update_screen_delay_value = 20;         /* (milliseconds) */
+  unsigned int update_screen_delay_value = 50;         /* (milliseconds) */
   SDL_Surface *screen = backbuffer->surface;
 
   if (limit_screen_updates &&
@@ -89,9 +89,17 @@ static void UpdateScreen(SDL_Rect *rect)
     BlitBitmap(backbuffer, gfx.final_screen_bitmap, 0, 0,
               gfx.win_xsize, gfx.win_ysize, 0, 0);
 
-    // copy global animations to render target buffer, if defined
+    // copy global animations to render target buffer, if defined (below border)
     if (gfx.draw_global_anim_function != NULL)
-      gfx.draw_global_anim_function();
+      gfx.draw_global_anim_function(DRAW_GLOBAL_ANIM_STAGE_1);
+
+    // copy global masked border to render target buffer, if defined
+    if (gfx.draw_global_border_function != NULL)
+      gfx.draw_global_border_function(REDRAW_ALL);
+
+    // copy global animations to render target buffer, if defined (above border)
+    if (gfx.draw_global_anim_function != NULL)
+      gfx.draw_global_anim_function(DRAW_GLOBAL_ANIM_STAGE_2);
 
     screen = gfx.final_screen_bitmap->surface;
 
@@ -126,9 +134,17 @@ static void UpdateScreen(SDL_Rect *rect)
   SDL_RenderCopy(sdl_renderer, sdl_texture, NULL, NULL);
 
 #if !USE_FINAL_SCREEN_BITMAP
-  // copy global animations to render target buffer, if defined
+  // copy global animations to render target buffer, if defined (below border)
   if (gfx.draw_global_anim_function != NULL)
-    gfx.draw_global_anim_function();
+    gfx.draw_global_anim_function(DRAW_GLOBAL_ANIM_STAGE_1);
+
+  // copy global masked border to render target buffer, if defined
+  if (gfx.draw_global_border_function != NULL)
+    gfx.draw_global_border_function(REDRAW_ALL);
+
+  // copy global animations to render target buffer, if defined (above border)
+  if (gfx.draw_global_anim_function != NULL)
+    gfx.draw_global_anim_function(DRAW_GLOBAL_ANIM_STAGE_2);
 #endif
 
   // show render target buffer on screen
@@ -262,15 +278,23 @@ boolean SDLSetNativeSurface(SDL_Surface **surface)
 
 SDL_Surface *SDLGetNativeSurface(SDL_Surface *surface)
 {
+  SDL_PixelFormat format;
   SDL_Surface *new_surface;
 
   if (surface == NULL)
     return NULL;
 
   if (backbuffer && backbuffer->surface)
-    new_surface = SDL_ConvertSurface(surface, backbuffer->surface->format, 0);
+  {
+    format = *backbuffer->surface->format;
+    format.Amask = surface->format->Amask;     // keep alpha channel
+  }
   else
-    new_surface = SDL_ConvertSurface(surface, surface->format, 0);
+  {
+    format = *surface->format;
+  }
+
+  new_surface = SDL_ConvertSurface(surface, &format, 0);
 
   if (new_surface == NULL)
     Error(ERR_EXIT, "SDL_ConvertSurface() failed: %s", SDL_GetError());
@@ -1098,6 +1122,13 @@ void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
   int dst_x = x, dst_y = y;
   unsigned int time_last, time_current;
 
+  // store function for drawing global masked border
+  void (*draw_global_border_function)(int) = gfx.draw_global_border_function;
+
+  // deactivate drawing of global border while fading, if needed
+  if (draw_border_function == NULL)
+    gfx.draw_global_border_function = NULL;
+
   /* check if screen size has changed */
   if (surface_source != NULL && (video.width  != surface_source->w ||
                                 video.height != surface_source->h))
@@ -1430,6 +1461,9 @@ void SDLFadeRectangle(Bitmap *bitmap_cross, int x, int y, int width, int height,
       time_current = SDL_GetTicks();
     }
   }
+
+  // restore function for drawing global masked border
+  gfx.draw_global_border_function = draw_global_border_function;
 }
 
 void SDLDrawSimpleLine(Bitmap *dst_bitmap, int from_x, int from_y,
@@ -2436,8 +2470,9 @@ Bitmap *SDLLoadImage(char *filename)
   UPDATE_BUSY_STATE();
 
   /* create native transparent surface for current image */
-  SDL_SetColorKey(sdl_image_tmp, SET_TRANSPARENT_PIXEL,
-                 SDL_MapRGB(sdl_image_tmp->format, 0x00, 0x00, 0x00));
+  if (sdl_image_tmp->format->Amask == 0)
+    SDL_SetColorKey(sdl_image_tmp, SET_TRANSPARENT_PIXEL,
+                   SDL_MapRGB(sdl_image_tmp->format, 0x00, 0x00, 0x00));
 
   if ((new_bitmap->surface_masked = SDLGetNativeSurface(sdl_image_tmp)) == NULL)
   {