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.

/* Test program to compare the compile-time version of SDL with the linked
   version of SDL
*/

#include <stdio.h>
#include <stdlib.h>

#include "SDL.h"

int
main(int argc, char *argv[])
{
    SDL_version compiled;
    SDL_version linked;

#if SDL_VERSION_ATLEAST(1, 3, 0)
    printf("Compiled with SDL 1.3 or newer\n");
#else
    printf("Compiled with SDL older than 1.3\n");
#endif
    SDL_VERSION(&compiled);
    printf("Compiled version: %d.%d.%d (%s)\n",
           compiled.major, compiled.minor, compiled.patch, SDL_REVISION);
    SDL_GetVersion(&linked);
    printf("Linked version: %d.%d.%d (%s)\n",
           linked.major, linked.minor, linked.patch, SDL_GetRevision());
    SDL_Quit();
    return (0);
}