Fixed bug #1026 Vittorio Giovara 2010-07-16 19:09:28 PDT i was reading SDL_renderer_gles and i noticed that every time we there is some gl call the gl state is modified with a couple of glEnableClientState()/glDisableClientState. While this is completely fine for desktops systems, this is a major performace kill on mobile devices, right where opengles is implemented. Normal practice in this case is to update the glstate once, keep it always the same and disable/enable other states only in very special occasions. On the web there's plenty of documentation (on the top of my head http://developer.apple.com/iphone/library/documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/Performance/Performance.html#//apple_ref/doc/uid/TP40008793-CH105-SW5 ) and i personally tried this. I modified my code and got a 10 fps boost, then modified SDL_render_gles and shifted from 40 fps to 50 fps alone -- considering that i started from ~30fps i got an 80% performance increase with this technique. I have attached a dif of my changes, hope that it will be included in mainstream.

/* Definitions for platform dependent windowing functions to test SDL
   integration with native windows
*/

#include "SDL.h"

/* This header includes all the necessary system headers for native windows */
#include "SDL_syswm.h"

typedef struct
{
    const char *tag;
    void *(*CreateNativeWindow) (int w, int h);
    void (*DestroyNativeWindow) (void *window);
} NativeWindowFactory;

#ifdef SDL_VIDEO_DRIVER_WIN32
#define TEST_NATIVE_WIN32
extern NativeWindowFactory Win32WindowFactory;
#endif

#ifdef SDL_VIDEO_DRIVER_X11
#define TEST_NATIVE_X11
extern NativeWindowFactory X11WindowFactory;
#endif

#ifdef SDL_VIDEO_DRIVER_COCOA
/* Actually, we don't really do this, since it involves adding Objective C
   support to the build system, which is a little tricky.  You can uncomment
   it manually though and link testnativecocoa.m into the test application.
*/
#if 1
#define TEST_NATIVE_COCOA
extern NativeWindowFactory CocoaWindowFactory;
#endif
#endif