From 556fd6c80969ab9a474f2c66ae1aceec3866f16a Mon Sep 17 00:00:00 2001
From: jsancho <devnull@localhost>
Date: Tue, 16 Aug 2011 19:20:58 +0000
Subject: [PATCH]

---
 src/gacela.scm      | 3 ++-
 src/gacela_GL.c     | 1 +
 src/gacela_SDL.c    | 7 +++++++
 src/gacela_draw.scm | 5 +++--
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/gacela.scm b/src/gacela.scm
index 6a0b501..dba48e6 100644
--- a/src/gacela.scm
+++ b/src/gacela.scm
@@ -114,8 +114,9 @@
   (glClearColor 0 0 0 0)
 ;  (glClearDepth 1)
 ;  (glDepthFunc GL_LEQUAL)
-;  (glEnable GL_BLEND)
+  (glEnable GL_BLEND)
 ;  (glBlendFunc GL_SRC_ALPHA GL_ONE)
+  (glBlendFunc GL_SRC_ALPHA GL_ONE_MINUS_SRC_ALPHA)
   (glHint GL_PERSPECTIVE_CORRECTION_HINT GL_NICEST)
   #t)
 
diff --git a/src/gacela_GL.c b/src/gacela_GL.c
index da64a2e..541e4ab 100644
--- a/src/gacela_GL.c
+++ b/src/gacela_GL.c
@@ -417,6 +417,7 @@ GL_register_functions (void* data)
   // Blending
   scm_c_define ("GL_BLEND", scm_from_int (GL_BLEND));
   scm_c_define ("GL_ONE", scm_from_int (GL_ONE));
+  scm_c_define ("GL_ONE_MINUS_SRC_ALPHA", scm_from_int (GL_ONE_MINUS_SRC_ALPHA));
   scm_c_define ("GL_SRC_ALPHA", scm_from_int (GL_SRC_ALPHA));
 
   // Fog
diff --git a/src/gacela_SDL.c b/src/gacela_SDL.c
index 7977444..f7f4151 100644
--- a/src/gacela_SDL.c
+++ b/src/gacela_SDL.c
@@ -214,6 +214,12 @@ gacela_SDL_SetColorKey (SCM surface, SCM flag, SCM key)
   return scm_from_int (SDL_SetColorKey (get_surface_address (surface), scm_to_int (flag), scm_to_int (key)));
 }
 
+SCM
+gacela_SDL_SetAlpha (SCM surface, SCM flag, SCM alpha)
+{
+  return scm_from_int (SDL_SetAlpha (get_surface_address (surface), scm_to_int (flag), scm_to_int (alpha)));
+}
+
 SCM
 gacela_SDL_LoadBMP (SCM file)
 {
@@ -479,6 +485,7 @@ SDL_register_functions (void* data)
   scm_c_define_gsubr ("SDL_DisplayFormat", 1, 0, 0, gacela_SDL_DisplayFormat);
   scm_c_define_gsubr ("SDL_MapRGB", 4, 0, 0, gacela_SDL_MapRGB);
   scm_c_define_gsubr ("SDL_SetColorKey", 3, 0, 0, gacela_SDL_SetColorKey);
+  scm_c_define_gsubr ("SDL_SetAlpha", 3, 0, 0, gacela_SDL_SetAlpha);
   scm_c_define_gsubr ("SDL_LoadBMP", 1, 0, 0, gacela_SDL_LoadBMP);
   scm_c_define_gsubr ("IMG_Load", 1, 0, 0, gacela_IMG_Load);
   scm_c_define_gsubr ("SDL_GetVideoInfo", 0, 0, 0, gacela_SDL_GetVideoInfo);
diff --git a/src/gacela_draw.scm b/src/gacela_draw.scm
index 184eba2..5fbc92e 100644
--- a/src/gacela_draw.scm
+++ b/src/gacela_draw.scm
@@ -63,6 +63,7 @@
   (init-sdl)
   (let ((image (IMG_Load filename)))
     (cond (image
+	   (SDL_SetAlpha image 0 0)
 	   (let* ((width (surface-w image)) (height (surface-h image))
 		  (power-2 (nearest-power-of-two (min width height)))
 		  (resized-image #f))
@@ -85,8 +86,8 @@
     (cond (image
 	   (let ((width (surface-w image)) (height (surface-h image))
 		 (byteorder (if (= SDL_BYTEORDER SDL_LIL_ENDIAN)
-				(if (= (surface-format-BytesPerPixel image) 3) GL_BGR GL_BGRA)
-				(if (= (surface-format-BytesPerPixel image) 3) GL_RGB GL_RGBA)))
+				(if (= (surface-format-BytesPerPixel image) 3) GL_RGB GL_RGBA)
+				(if (= (surface-format-BytesPerPixel image) 3) GL_BGR GL_BGRA)))
 		 (texture (car (glGenTextures 1))))
 
 	     (glBindTexture GL_TEXTURE_2D texture)
-- 
2.39.2