added support for setting alpha value for global animations

To set alpha value for global animation graphics, just use the new
attribute ".alpha" for the global animation's graphics definition,
where the value "0" means transparent and "255" means "opaque".

diff --git a/src/anim.c b/src/anim.c
index 222369e1abb3b0c364e6198dfae4f23bae4256b8..5967bb735525e288e93621c3379ff248c2af75d1 100644 (file)
--- a/src/anim.c
+++ b/src/anim.c
@@ -781,6 +781,8 @@ static void BlitGlobalAnimation(struct GlobalAnimPartControlInfo *part,
       dst_x += part->viewport_x;
       dst_y += part->viewport_y;
 
+      SetBitmapAlphaNextBlit(src_bitmap, g->alpha);
+
       if (drawing_target == DRAW_TO_SCREEN)
        blit_screen(src_bitmap, src_x, src_y, width, height,
                    dst_x, dst_y);

diff --git a/src/conf_gfx.c b/src/conf_gfx.c
index 73eb60dbcd3f70232e43956a874275bf086e9139..31b17a70836e48ddd1f190bd6a21ba986e02a5fb 100644 (file)
--- a/src/conf_gfx.c
+++ b/src/conf_gfx.c
@@ -82,6 +82,7 @@ struct ConfigTypeInfo image_config_suffix[] =
   { ".sort_priority",                  ARG_UNDEFINED,  TYPE_INTEGER    },
   { ".class",                          ARG_UNDEFINED,  TYPE_STRING     },
   { ".style",                          ARG_UNDEFINED,  TYPE_STRING     },
+  { ".alpha",                          ARG_UNDEFINED,  TYPE_INTEGER    },
   { ".active_xoffset",                 "0",            TYPE_INTEGER    },
   { ".active_yoffset",                 "0",            TYPE_INTEGER    },
   { ".pressed_xoffset",                        "0",            TYPE_INTEGER    },

diff --git a/src/init.c b/src/init.c
index e96344eb51caf8da240895cc395e18bc1b096e16..33c47f98e9c423f7c056b7d74a53ded8173e8826 100644 (file)
--- a/src/init.c
+++ b/src/init.c
@@ -1412,6 +1412,7 @@ static void set_graphic_parameters_ext(int graphic, int *parameter,
   g->sort_priority = 0;                        // default for title screens
   g->class = 0;
   g->style = STYLE_DEFAULT;
+  g->alpha = -1;
 
   g->bitmaps = src_bitmaps;
   g->bitmap = src_bitmap;
@@ -1686,6 +1687,8 @@ static void set_graphic_parameters_ext(int graphic, int *parameter,
     g->class = parameter[GFX_ARG_CLASS];
   if (parameter[GFX_ARG_STYLE] != ARG_UNDEFINED_VALUE)
     g->style = parameter[GFX_ARG_STYLE];
+  if (parameter[GFX_ARG_ALPHA] != ARG_UNDEFINED_VALUE)
+    g->alpha = parameter[GFX_ARG_ALPHA];
 
   // this is only used for drawing menu buttons and text
   g->active_xoffset = parameter[GFX_ARG_ACTIVE_XOFFSET];

diff --git a/src/libgame/sdl.c b/src/libgame/sdl.c
index 59fe7c3df988d35d5a7269041c2c83e2c0745e30..64d28bdbb6fb5c17243947b6d81899324a2c32d2 100644 (file)
--- a/src/libgame/sdl.c
+++ b/src/libgame/sdl.c
@@ -351,7 +351,7 @@ static boolean SDLHasAlpha(SDL_Surface *surface)
   return (blend_mode == SDL_BLENDMODE_BLEND);
 }
 
-void SDLSetAlpha(SDL_Surface *surface, boolean set, int alpha)
+static void SDLSetSurfaceAlpha(SDL_Surface *surface, boolean set, int alpha)
 {
   SDL_BlendMode blend_mode = (set ? SDL_BLENDMODE_BLEND : SDL_BLENDMODE_NONE);
 
@@ -359,6 +359,49 @@ void SDLSetAlpha(SDL_Surface *surface, boolean set, int alpha)
   SDL_SetSurfaceAlphaMod(surface, alpha);
 }
 
+static void SDLSetTextureAlpha(SDL_Texture *texture, boolean set, int alpha)
+{
+  SDL_BlendMode blend_mode = (set ? SDL_BLENDMODE_BLEND : SDL_BLENDMODE_NONE);
+
+  SDL_SetTextureBlendMode(texture, blend_mode);
+  SDL_SetTextureAlphaMod(texture, alpha);
+}
+
+static void SDLSetBitmapAlpha(Bitmap *bitmap, boolean is_texture,
+                             boolean is_masked)
+{
+  int alpha_next_blit = bitmap->alpha_next_blit;
+
+  // alpha value must be requested every time before blitting, if needed
+  bitmap->alpha_next_blit = -1;
+
+  // nothing to do if requested alpha value is already set
+  if (bitmap->alpha[is_texture][is_masked] == alpha_next_blit)
+    return;
+
+  // store requested alpha value for masked/unmasked surface/texture
+  bitmap->alpha[is_texture][is_masked] = alpha_next_blit;
+
+  // set blend mode if bitmap is masked or if alpha value is defined
+  boolean set_blend_mode = (is_masked || alpha_next_blit != -1);
+
+  // if alpha value is undefined, use default (opaque) alpha value
+  if (alpha_next_blit == -1)
+    alpha_next_blit = SDL_ALPHA_OPAQUE;
+
+  if (is_texture)
+    SDLSetTextureAlpha(is_masked ? bitmap->texture_masked : bitmap->texture,
+                      set_blend_mode, alpha_next_blit);
+  else
+    SDLSetSurfaceAlpha(is_masked ? bitmap->surface_masked : bitmap->surface,
+                      set_blend_mode, alpha_next_blit);
+}
+
+void SDLSetAlpha(SDL_Surface *surface, boolean set, int alpha)
+{
+  SDLSetSurfaceAlpha(surface, set, alpha);
+}
+
 const char *SDLGetRendererName(void)
 {
   static SDL_RendererInfo renderer_info;
@@ -986,6 +1029,8 @@ void SDLCopyArea(Bitmap *src_bitmap, Bitmap *dst_bitmap,
   dst_rect.w = width;
   dst_rect.h = height;
 
+  SDLSetBitmapAlpha(src_bitmap, FALSE, mask_mode == BLIT_MASKED);
+
   // if (src_bitmap != backbuffer || dst_bitmap != window)
   if (!(src_bitmap == backbuffer && dst_bitmap == window))
     SDL_BlitSurface((mask_mode == BLIT_MASKED ?
@@ -1020,6 +1065,8 @@ void SDLBlitTexture(Bitmap *bitmap,
   dst_rect.w = width;
   dst_rect.h = height;
 
+  SDLSetBitmapAlpha(bitmap, TRUE, mask_mode == BLIT_MASKED);
+
   SDL_RenderCopy(sdl_renderer, texture, &src_rect, &dst_rect);
 }
 

diff --git a/src/libgame/sdl.h b/src/libgame/sdl.h
index f279ebc4121309254fe5149827b1434671c141f6..31de93da084907c5cb7871d98d74433822ee35bf 100644 (file)
--- a/src/libgame/sdl.h
+++ b/src/libgame/sdl.h
@@ -75,6 +75,10 @@ struct SDLSurfaceInfo
   char *source_filename;
 
   int width, height;
+
+  int alpha[2][2];             // [surface|texture][opaque|masked]
+  int alpha_next_blit;
+
   SDL_Surface *surface;
   SDL_Surface *surface_masked;
   SDL_Texture *texture;

diff --git a/src/libgame/system.c b/src/libgame/system.c
index a3eae88217bc14c3ee295acea1f721530c7ecec2..2f21541d8e0419b5c938853082051c8075f550fe 100644 (file)
--- a/src/libgame/system.c
+++ b/src/libgame/system.c
@@ -601,7 +601,15 @@ void FreeBitmap(Bitmap *bitmap)
 
 Bitmap *CreateBitmapStruct(void)
 {
-  return checked_calloc(sizeof(Bitmap));
+  Bitmap *new_bitmap = checked_calloc(sizeof(Bitmap));
+
+  new_bitmap->alpha[0][0] = -1;
+  new_bitmap->alpha[0][1] = -1;
+  new_bitmap->alpha[1][0] = -1;
+  new_bitmap->alpha[1][1] = -1;
+  new_bitmap->alpha_next_blit = -1;
+
+  return new_bitmap;
 }
 
 Bitmap *CreateBitmap(int width, int height, int depth)
@@ -772,6 +780,12 @@ static boolean InClippedRectangle(Bitmap *bitmap, int *x, int *y,
   return TRUE;
 }
 
+void SetBitmapAlphaNextBlit(Bitmap *bitmap, int alpha)
+{
+  // set alpha value for next blitting of bitmap
+  bitmap->alpha_next_blit = alpha;
+}
+
 void BlitBitmap(Bitmap *src_bitmap, Bitmap *dst_bitmap,
                int src_x, int src_y, int width, int height,
                int dst_x, int dst_y)

diff --git a/src/libgame/system.h b/src/libgame/system.h
index b2f95e358d73182a3ff53224b821cdc3f2163d2f..e5938dee7772abfe95220ff60f10e3f37781b76e 100644 (file)
--- a/src/libgame/system.h
+++ b/src/libgame/system.h
@@ -2013,6 +2013,7 @@ Bitmap *CreateBitmapStruct(void);
 Bitmap *CreateBitmap(int, int, int);
 void ReCreateBitmap(Bitmap **, int, int);
 void FreeBitmap(Bitmap *);
+void SetBitmapAlphaNextBlit(Bitmap *, int);
 void BlitBitmap(Bitmap *, Bitmap *, int, int, int, int, int, int);
 void BlitBitmapTiled(Bitmap *, Bitmap *, int, int, int, int, int, int, int, int);
 void FadeRectangle(int, int, int, int, int, int, int,

diff --git a/src/main.h b/src/main.h
index 8cc19c8f2d9b12921c02617f0b57988ab775cb0e..228ca5a63b0d6b92f462b95ba6259921e22ae57f 100644 (file)
--- a/src/main.h
+++ b/src/main.h
@@ -2497,6 +2497,7 @@ enum
   GFX_ARG_SORT_PRIORITY,
   GFX_ARG_CLASS,
   GFX_ARG_STYLE,
+  GFX_ARG_ALPHA,
   GFX_ARG_ACTIVE_XOFFSET,
   GFX_ARG_ACTIVE_YOFFSET,
   GFX_ARG_PRESSED_XOFFSET,
@@ -3743,6 +3744,7 @@ struct GraphicInfo
 
   int class;
   int style;
+  int alpha;
 
   int active_xoffset;
   int active_yoffset;