Mercurial > sdl-ios-xcode
view test/torturethread.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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/* Simple test of the SDL threading code */ #include <stdio.h> #include <stdlib.h> #include <signal.h> #include <string.h> #include "SDL.h" #include "SDL_thread.h" #define NUMTHREADS 10 static char volatile time_for_threads_to_die[NUMTHREADS]; /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */ static void quit(int rc) { SDL_Quit(); exit(rc); } int SDLCALL SubThreadFunc(void *data) { while (!*(int volatile *) data) { ; /*SDL_Delay(10); *//* do nothing */ } return 0; } int SDLCALL ThreadFunc(void *data) { SDL_Thread *sub_threads[NUMTHREADS]; int flags[NUMTHREADS]; int i; int tid = (int) (uintptr_t) data; fprintf(stderr, "Creating Thread %d\n", tid); for (i = 0; i < NUMTHREADS; i++) { flags[i] = 0; sub_threads[i] = SDL_CreateThread(SubThreadFunc, &flags[i]); } printf("Thread '%d' waiting for signal\n", tid); while (time_for_threads_to_die[tid] != 1) { ; /* do nothing */ } printf("Thread '%d' sending signals to subthreads\n", tid); for (i = 0; i < NUMTHREADS; i++) { flags[i] = 1; SDL_WaitThread(sub_threads[i], NULL); } printf("Thread '%d' exiting!\n", tid); return 0; } int main(int argc, char *argv[]) { SDL_Thread *threads[NUMTHREADS]; int i; /* Load the SDL library */ if (SDL_Init(0) < 0) { fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); return (1); } signal(SIGSEGV, SIG_DFL); for (i = 0; i < NUMTHREADS; i++) { time_for_threads_to_die[i] = 0; threads[i] = SDL_CreateThread(ThreadFunc, (void *) (uintptr_t) i); if (threads[i] == NULL) { fprintf(stderr, "Couldn't create thread: %s\n", SDL_GetError()); quit(1); } } for (i = 0; i < NUMTHREADS; i++) { time_for_threads_to_die[i] = 1; } for (i = 0; i < NUMTHREADS; i++) { SDL_WaitThread(threads[i], NULL); } SDL_Quit(); return (0); }