view test/testwm2.c @ 5053:b5b42be9333c

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.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 19 Jan 2011 23:56:16 -0800
parents 9de326b3099c
children 58265e606e4e
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#include <stdlib.h>
#include <stdio.h>

#include "common.h"

static CommonState *state;

/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
    CommonQuit(state);
    exit(rc);
}

int
main(int argc, char *argv[])
{
    int i, done;
    SDL_Event event;

    /* Initialize test framework */
    state = CommonCreateState(argv, SDL_INIT_VIDEO);
    if (!state) {
        return 1;
    }
    state->skip_renderer = SDL_TRUE;
    for (i = 1; i < argc;) {
        int consumed;

        consumed = CommonArg(state, i);
        if (consumed == 0) {
            consumed = -1;
        }
        if (consumed < 0) {
            fprintf(stderr, "Usage: %s %s\n", argv[0], CommonUsage(state));
            quit(1);
        }
        i += consumed;
    }
    if (!CommonInit(state)) {
        quit(2);
    }

    /* Main render loop */
    done = 0;
    while (!done) {
        /* Check for events */
        while (SDL_PollEvent(&event)) {
            CommonEvent(state, &event, &done);
        }
    }
    quit(0);
	// keep the compiler happy ...
	return(0);
}

/* vi: set ts=4 sw=4 expandtab: */