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.

#include "testnative.h"

#ifdef TEST_NATIVE_X11

static void *CreateWindowX11(int w, int h);
static void DestroyWindowX11(void *window);

NativeWindowFactory X11WindowFactory = {
    "x11",
    CreateWindowX11,
    DestroyWindowX11
};

static Display *dpy;

static void *
CreateWindowX11(int w, int h)
{
    Window window = 0;

    dpy = XOpenDisplay(NULL);
    if (dpy) {
        window =
            XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 0, 0, w, h, 0, 0,
                                0);
        XMapRaised(dpy, window);
        XSync(dpy, False);
    }
    return (void *) window;
}

static void
DestroyWindowX11(void *window)
{
    if (dpy) {
        XDestroyWindow(dpy, (Window) window);
        XCloseDisplay(dpy);
    }
}

#endif