Mercurial > sdl-ios-xcode
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: */