Add GLX_X_VISUAL_TYPE_EXT so created window will use DirectColor if a…

…vailable (instead of TrueColor). Our new X11 window was being created with the TrueColor attribute, and trying to set the gamma on that would fail. This change checks for the visual_info extension, and uses that to ask for DirectColor if available.
libsdl-org · Oct 11, 2012 · 6e12a12 · 6e12a12
1 parent fe51dbe
commit 6e12a12
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Showing 2 changed files with 24 additions and 1 deletion.
diff --git a/src/video/x11/SDL_x11opengl.c b/src/video/x11/SDL_x11opengl.c
@@ -60,6 +60,12 @@
 #define GLX_NON_CONFORMANT_VISUAL_EXT      0x800D
 #endif
 
+#ifndef GLX_EXT_visual_info
+#define GLX_EXT_visual_info
+#define GLX_X_VISUAL_TYPE_EXT              0x22
+#define GLX_DIRECT_COLOR_EXT               0x8003
+#endif
+
 #ifndef GLX_ARB_create_context
 #define GLX_ARB_create_context
 #define GLX_CONTEXT_MAJOR_VERSION_ARB      0x2091
@@ -353,6 +359,11 @@ X11_GL_InitExtensions(_THIS)
         _this->gl_data->HAS_GLX_EXT_visual_rating = SDL_TRUE;
     }
 
+    /* Check for GLX_EXT_visual_info */
+    if (HasExtension("GLX_EXT_visual_info", extensions)) {
+        _this->gl_data->HAS_GLX_EXT_visual_info = SDL_TRUE;
+    }
+
     if (context) {
         _this->gl_data->glXMakeCurrent(display, None, NULL);
         _this->gl_data->glXDestroyContext(display, context);
@@ -368,9 +379,10 @@ int
 X11_GL_GetAttributes(_THIS, Display * display, int screen, int * attribs, int size, Bool for_FBConfig)
 {
     int i = 0;
+	const int MAX_ATTRIBUTES = 64;
 
     /* assert buffer is large enough to hold all SDL attributes. */ 
-    SDL_assert(size >= 32);
+    SDL_assert(size >= MAX_ATTRIBUTES);
 
     /* Setup our GLX attributes according to the gl_config. */
     if( for_FBConfig ) {
@@ -448,7 +460,17 @@ X11_GL_GetAttributes(_THIS, Display * display, int screen, int * attribs, int si
                                                       GLX_SLOW_VISUAL_EXT;
     }
 
+    // If we're supposed to use DirectColor visuals, and we've got the EXT_visual_info
+    //  extension, then add GLX_X_VISUAL_TYPE_EXT.
+    if (X11_UseDirectColorVisuals() &&
+        _this->gl_data->HAS_GLX_EXT_visual_info) {
+        attribs[i++] = GLX_X_VISUAL_TYPE_EXT;
+        attribs[i++] = GLX_DIRECT_COLOR_EXT;
+    }
+
     attribs[i++] = None;
+
+    SDL_assert(i <= MAX_ATTRIBUTES);
 
     return i;
 }

diff --git a/src/video/x11/SDL_x11opengl.h b/src/video/x11/SDL_x11opengl.h
@@ -30,6 +30,7 @@
 struct SDL_GLDriverData
 {
     SDL_bool HAS_GLX_EXT_visual_rating;
+    SDL_bool HAS_GLX_EXT_visual_info;
     SDL_bool HAS_GLX_EXT_swap_control_tear;
 
     void *(*glXGetProcAddress) (const GLubyte*);