Mercurial > sdl-ios-xcode
view test/testaudioinfo.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 | 5ea5e4e6103f |
children |
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#include <stdio.h> #include "SDL.h" static void print_devices(int iscapture) { const char *typestr = ((iscapture) ? "capture" : "output"); int n = SDL_GetNumAudioDevices(iscapture); printf("%s devices:\n", typestr); if (n == -1) printf(" Driver can't detect specific devices.\n\n", typestr); else if (n == 0) printf(" No %s devices found.\n\n", typestr); else { int i; for (i = 0; i < n; i++) { printf(" %s\n", SDL_GetAudioDeviceName(i, iscapture)); } printf("\n"); } } int main(int argc, char **argv) { /* Load the SDL library */ if (SDL_Init(SDL_INIT_AUDIO) < 0) { fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); return (1); } /* Print available audio drivers */ int n = SDL_GetNumAudioDrivers(); if (n == 0) { printf("No built-in audio drivers\n\n"); } else { int i; printf("Built-in audio drivers:\n"); for (i = 0; i < n; ++i) { printf(" %s\n", SDL_GetAudioDriver(i)); } printf("\n"); } printf("Using audio driver: %s\n\n", SDL_GetCurrentAudioDriver()); print_devices(0); print_devices(1); SDL_Quit(); return 0; }