Fixed bug 3821 - Allow SDL_CreateWindow and SDL_CreateRenderer with OpenGL ES 3.0 (GLES3) for Angle (Windows)

Carlos

Angle supports GLES3 but when using these functions (SDL_CreateWindow and SDL_CreateRenderer), defaults again to GLES2.0.

A current workaround (hack) to retrieve a GLES3.0 context with Angle is:

1) set

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);

after InitSDL AND after calling SDL_CreateWindow  (before SDL_CreateRenderer)

2) Comment lines 2032-2044 in SDL_render_gles2.c, funtion GLES2_CreateRenderer

    window_flags = SDL_GetWindowFlags(window);
    if (!(window_flags & SDL_WINDOW_OPENGL) ||
        profile_mask != SDL_GL_CONTEXT_PROFILE_ES || major != RENDERER_CONTEXT_MAJOR || minor != RENDERER_CONTEXT_MINOR) {

        changed_window = SDL_TRUE;
        SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);
        SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, RENDERER_CONTEXT_MAJOR);
        SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, RENDERER_CONTEXT_MINOR);

        if (SDL_RecreateWindow(window, window_flags | SDL_WINDOW_OPENGL) < 0) {
            goto error;
        }
    }

This retrives a GLES3 context as confirmed using glGetString(GL_VERSION). This should be fixed by modifying a few if's.

src/render/opengles2/SDL_render_gles2.c

@@ -2031,8 +2031,9 @@ GLES2_CreateRenderer(SDL_Window *window, Uint32 flags)
     }
 
     window_flags = SDL_GetWindowFlags(window);
+    /* OpenGL ES 3.0 is a superset of OpenGL ES 2.0 */
     if (!(window_flags & SDL_WINDOW_OPENGL) ||
-        profile_mask != SDL_GL_CONTEXT_PROFILE_ES || major != RENDERER_CONTEXT_MAJOR || minor != RENDERER_CONTEXT_MINOR) {
+        profile_mask != SDL_GL_CONTEXT_PROFILE_ES || major < RENDERER_CONTEXT_MAJOR) {
 
         changed_window = SDL_TRUE;
         SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);