From d0ab5a10ecda925e8fd5641aef3fdd9e035492f8 Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Mon, 8 Feb 2016 20:15:16 +0100
Subject: [PATCH] added test code for using bitmaps instead of textures for
 global animations

---
 src/libgame/sdl.c    | 26 ++++++++++++++++++++++++--
 src/libgame/sdl.h    |  2 ++
 src/libgame/system.c | 33 +++++++++++++++++++++++++++++++++
 src/libgame/system.h |  6 ++++++
 4 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/src/libgame/sdl.c b/src/libgame/sdl.c
index 0759b549..182126f1 100644
--- a/src/libgame/sdl.c
+++ b/src/libgame/sdl.c
@@ -54,6 +54,7 @@ static void UpdateScreen(SDL_Rect *rect)
 {
   static unsigned int update_screen_delay = 0;
   unsigned int update_screen_delay_value = 20;		/* (milliseconds) */
+  SDL_Surface *screen = backbuffer->surface;
 
   if (limit_screen_updates &&
       !DelayReached(&update_screen_delay, update_screen_delay_value))
@@ -78,10 +79,29 @@ static void UpdateScreen(SDL_Rect *rect)
   }
 #endif
 
+#if USE_FINAL_SCREEN_BITMAP
+  if (gfx.final_screen_bitmap != NULL)	// may not be initialized yet
+  {
+    // !!! TEST !!!
+    // draw global animations using bitmaps instead of using textures
+    // to prevent texture scaling artefacts (this is potentially slower)
+
+    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
+    if (gfx.draw_global_anim_function != NULL)
+      gfx.draw_global_anim_function();
+
+    screen = gfx.final_screen_bitmap->surface;
+
+    // force full window redraw
+    rect = NULL;
+  }
+#endif
+
 #if defined(TARGET_SDL2)
 #if USE_RENDERER
-  SDL_Surface *screen = backbuffer->surface;
-
   if (rect)
   {
     int bytes_x = screen->pitch / video.width;
@@ -105,9 +125,11 @@ static void UpdateScreen(SDL_Rect *rect)
   // copy backbuffer to render target buffer
   SDL_RenderCopy(sdl_renderer, sdl_texture, NULL, NULL);
 
+#if !USE_FINAL_SCREEN_BITMAP
   // copy global animations to render target buffer, if defined
   if (gfx.draw_global_anim_function != NULL)
     gfx.draw_global_anim_function();
+#endif
 
   // show render target buffer on screen
   SDL_RenderPresent(sdl_renderer);
diff --git a/src/libgame/sdl.h b/src/libgame/sdl.h
index ad21926c..7cc3b459 100644
--- a/src/libgame/sdl.h
+++ b/src/libgame/sdl.h
@@ -58,6 +58,8 @@
 #define FULLSCREEN_STATUS	FULLSCREEN_AVAILABLE
 #endif
 
+#define USE_FINAL_SCREEN_BITMAP	FALSE
+
 #define CURSOR_MAX_WIDTH	32
 #define CURSOR_MAX_HEIGHT	32
 
diff --git a/src/libgame/system.c b/src/libgame/system.c
index a1fbad08..d1cb4d35 100644
--- a/src/libgame/system.c
+++ b/src/libgame/system.c
@@ -207,6 +207,9 @@ void InitGfxWindowInfo(int win_xsize, int win_ysize)
   gfx.background_bitmap_mask = REDRAW_NONE;
 
   ReCreateBitmap(&gfx.background_bitmap, win_xsize, win_ysize, DEFAULT_DEPTH);
+#if USE_FINAL_SCREEN_BITMAP
+  ReCreateBitmap(&gfx.final_screen_bitmap, win_xsize, win_ysize, DEFAULT_DEPTH);
+#endif
 }
 
 void InitGfxScrollbufferInfo(int scrollbuffer_width, int scrollbuffer_height)
@@ -742,6 +745,36 @@ void BlitTextureMasked(Bitmap *bitmap,
 		 BLIT_MASKED);
 }
 
+void BlitToScreen(Bitmap *bitmap,
+		  int src_x, int src_y, int width, int height,
+		  int dst_x, int dst_y)
+{
+  if (bitmap == NULL)
+    return;
+
+#if USE_FINAL_SCREEN_BITMAP
+  BlitBitmap(bitmap, gfx.final_screen_bitmap, src_x, src_y,
+	     width, height, dst_x, dst_y);
+#else
+  BlitTexture(bitmap, src_x, src_y, width, height, dst_x, dst_y);
+#endif
+}
+
+void BlitToScreenMasked(Bitmap *bitmap,
+			int src_x, int src_y, int width, int height,
+			int dst_x, int dst_y)
+{
+  if (bitmap == NULL)
+    return;
+
+#if USE_FINAL_SCREEN_BITMAP
+  BlitBitmapMasked(bitmap, gfx.final_screen_bitmap, src_x, src_y,
+		   width, height, dst_x, dst_y);
+#else
+  BlitTextureMasked(bitmap, src_x, src_y, width, height, dst_x, dst_y);
+#endif
+}
+
 void DrawSimpleBlackLine(Bitmap *bitmap, int from_x, int from_y,
 			 int to_x, int to_y)
 {
diff --git a/src/libgame/system.h b/src/libgame/system.h
index a27653da..875a6540 100644
--- a/src/libgame/system.h
+++ b/src/libgame/system.h
@@ -804,6 +804,10 @@ struct GfxInfo
   Bitmap *background_bitmap;
   int background_bitmap_mask;
 
+#if USE_FINAL_SCREEN_BITMAP
+  Bitmap *final_screen_bitmap;
+#endif
+
   boolean clipping_enabled;
   int clip_x, clip_y;
   int clip_width, clip_height;
@@ -1351,6 +1355,8 @@ boolean DrawingAreaChanged();
 void BlitBitmapOnBackground(Bitmap *, Bitmap *, int, int, int, int, int, int);
 void BlitTexture(Bitmap *, int, int, int, int, int, int);
 void BlitTextureMasked(Bitmap *, int, int, int, int, int, int);
+void BlitToScreen(Bitmap *, int, int, int, int, int, int);
+void BlitToScreenMasked(Bitmap *, int, int, int, int, int, int);
 void DrawSimpleBlackLine(Bitmap *, int, int, int, int);
 void DrawSimpleWhiteLine(Bitmap *, int, int, int, int);
 void DrawLines(Bitmap *, struct XY *, int, Pixel);
-- 
2.34.1