diff src/video/x11/SDL_x11opengl.c @ 3100:7dc982143c06

Date: Sun, 22 Mar 2009 12:52:29 +0000 From: Luke Benstead Subject: OpenGL 3.0 Context Creation I've attached a patch which implements OpenGL 3.x context creation on the latest SVN. I've added two options to SDL_GL_SetAttribute, these are SDL_GL_CONTEXT_MAJOR_VERSION and SDL_GL_CONTEXT_MINOR_VERSION. These default to 2 and 1 respectively. If the major version is less than 3 then the current context creation method is used, otherwise the appropriate new context creation function is called (depending on the platform). Sample code: if (SDL_Init(SDL_INIT_VIDEO) != 0) { printf("Unable to initialize SDL: %s\n", SDL_GetError()); return 1; } SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3); //Without these 2 lines, SDL will create a GL 2.x context SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0); SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1); SDL_Surface* screen = SDL_SetVideoMode( 640, 480, 16, SDL_OPENGL | SDL_FULLSCREEN ); I've implemented context creation on both Win32 and X and run basic tests on both. This patch doesn't provide access to all the options allowed by the new context creation (e.g. shared contexts, forward compatible contexts) but they can be added pretty easily.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 24 Mar 2009 10:43:53 +0000
parents 089a77aebb7d
children cdeee9f9b14b
line wrap: on
line diff
--- a/src/video/x11/SDL_x11opengl.c	Tue Mar 24 10:33:12 2009 +0000
+++ b/src/video/x11/SDL_x11opengl.c	Tue Mar 24 10:43:53 2009 +0000
@@ -53,6 +53,15 @@
 #define GLX_NON_CONFORMANT_VISUAL_EXT      0x800D
 #endif
 
+#ifndef GLX_ARB_create_context
+#define GLX_ARB_create_context
+#define GLX_CONTEXT_MAJOR_VERSION_ARB      0x2091
+#define GLX_CONTEXT_MINOR_VERSION_ARB      0x2092
+#define GLX_CONTEXT_FLAGS_ARB              0x2094
+#define GLX_CONTEXT_DEBUG_BIT_ARB          0x0001
+#define GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB 0x0002
+#endif
+
 #define OPENGL_REQUIRS_DLOPEN
 #if defined(OPENGL_REQUIRS_DLOPEN) && defined(SDL_LOADSO_DLOPEN)
 #include <dlfcn.h>
@@ -67,6 +76,9 @@
 
 static void X11_GL_InitExtensions(_THIS);
 
+/* Typedef for the GL 3.0 context creation function */
+typedef GLXContext ( * PFNGLXCREATECONTEXTATTRIBSARBPROC) (Display *dpy, GLXFBConfig config, GLXContext share_context, Bool direct, const int *attrib_list);
+
 int
 X11_GL_LoadLibrary(_THIS, const char *path)
 {
@@ -270,10 +282,9 @@
 
     /* 64 seems nice. */
     int attribs[64];
-    int i;
-
+    int i = 0;
+    
     /* Setup our GLX attributes according to the gl_config. */
-    i = 0;
     attribs[i++] = GLX_RGBA;
     attribs[i++] = GLX_RED_SIZE;
     attribs[i++] = _this->gl_config.red_size;
@@ -384,8 +395,43 @@
     v.visualid = XVisualIDFromVisual(xattr.visual);
     vinfo = XGetVisualInfo(display, VisualScreenMask | VisualIDMask, &v, &n);
     if (vinfo) {
-        context =
-            _this->gl_data->glXCreateContext(display, vinfo, NULL, True);
+        if (_this->gl_config.major_version < 3) {        
+            context =
+                _this->gl_data->glXCreateContext(display, vinfo, NULL, True);
+        } else {
+            /* If we want a GL 3.0 context or later we need to get a temporary
+               context to grab the new context creation function */
+            GLXContext temp_context = _this->gl_data->glXCreateContext(display, vinfo, NULL, True);
+            if (!temp_context) {
+                SDL_SetError("Could not create GL context");        
+                return NULL;
+            } else {
+                int attribs[] = {
+                    GLX_CONTEXT_MAJOR_VERSION_ARB, _this->gl_config.major_version,
+                    GLX_CONTEXT_MINOR_VERSION_ARB, _this->gl_config.minor_version,
+                    0 
+                };
+                                
+                /* Get a pointer to the context creation function for GL 3.0 */
+                PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribs = (PFNGLXCREATECONTEXTATTRIBSARBPROC)glXGetProcAddress((GLubyte*)"glXCreateContextAttribsARB");
+                if (!glXCreateContextAttribs) {
+                    SDL_SetError("GL 3.x is not supported");
+                    context = temp_context;
+                } else {
+                    /* Create a GL 3.0 context */
+                    GLXFBConfig *framebuffer_config = NULL;
+                    int fbcount = 0;                
+                    framebuffer_config = glXChooseFBConfig(display, DefaultScreen(display), NULL, &fbcount);
+                    if (!framebuffer_config) {
+                        SDL_SetError("No good framebuffers found. GL 3.0 disabled");
+                        context = temp_context;
+                    } else {                                    
+                        context = glXCreateContextAttribs(display, framebuffer_config[0], NULL, True, attribs);
+                        glXDestroyContext(display, temp_context);
+                    }
+                }
+            }
+        }
         XFree(vinfo);
     }
     XSync(display, False);