view test/testtimer.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 c121d94672cb
children
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line source


/* Test program to check the resolution of the SDL timer on the current
   platform
*/

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

#include "SDL.h"

#define DEFAULT_RESOLUTION	1

static int ticks = 0;

static Uint32 SDLCALL
ticktock(Uint32 interval)
{
    ++ticks;
    return (interval);
}

static Uint32 SDLCALL
callback(Uint32 interval, void *param)
{
    printf("Timer %d : param = %d\n", interval, (int) (uintptr_t) param);
    return interval;
}

int
main(int argc, char *argv[])
{
    int desired;
    SDL_TimerID t1, t2, t3;

    if (SDL_Init(SDL_INIT_TIMER) < 0) {
        fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError());
        return (1);
    }

    /* Start the timer */
    desired = 0;
    if (argv[1]) {
        desired = atoi(argv[1]);
    }
    if (desired == 0) {
        desired = DEFAULT_RESOLUTION;
    }
    SDL_SetTimer(desired, ticktock);

    /* Wait 10 seconds */
    printf("Waiting 10 seconds\n");
    SDL_Delay(10 * 1000);

    /* Stop the timer */
    SDL_SetTimer(0, NULL);

    /* Print the results */
    if (ticks) {
        fprintf(stderr,
                "Timer resolution: desired = %d ms, actual = %f ms\n",
                desired, (double) (10 * 1000) / ticks);
    }

    /* Test multiple timers */
    printf("Testing multiple timers...\n");
    t1 = SDL_AddTimer(100, callback, (void *) 1);
    if (!t1)
        fprintf(stderr, "Could not create timer 1: %s\n", SDL_GetError());
    t2 = SDL_AddTimer(50, callback, (void *) 2);
    if (!t2)
        fprintf(stderr, "Could not create timer 2: %s\n", SDL_GetError());
    t3 = SDL_AddTimer(233, callback, (void *) 3);
    if (!t3)
        fprintf(stderr, "Could not create timer 3: %s\n", SDL_GetError());

    /* Wait 10 seconds */
    printf("Waiting 10 seconds\n");
    SDL_Delay(10 * 1000);

    printf("Removing timer 1 and waiting 5 more seconds\n");
    SDL_RemoveTimer(t1);

    SDL_Delay(5 * 1000);

    SDL_RemoveTimer(t2);
    SDL_RemoveTimer(t3);

    SDL_Quit();
    return (0);
}