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view Xcode/TemplatesForXcodeSnowLeopard/SDL Cocoa Application/main.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 | d44a0a913aa2 |
children |
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/* Simple program: Create a blank window, wait for keypress, quit. Please see the SDL documentation for details on using the SDL API: /Developer/Documentation/SDL/docs.html */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <math.h> #include "SDL.h" int main(int argc, char *argv[]) { Uint32 initflags = SDL_INIT_VIDEO; /* See documentation for details */ SDL_Surface *screen; Uint8 video_bpp = 0; Uint32 videoflags = SDL_SWSURFACE; int done; SDL_Event event; /* Initialize the SDL library */ if ( SDL_Init(initflags) < 0 ) { fprintf(stderr, "Couldn't initialize SDL: %s\n", SDL_GetError()); exit(1); } /* Set 640x480 video mode */ screen=SDL_SetVideoMode(640,480, video_bpp, videoflags); if (screen == NULL) { fprintf(stderr, "Couldn't set 640x480x%d video mode: %s\n", video_bpp, SDL_GetError()); SDL_Quit(); exit(2); } done = 0; while ( !done ) { /* Check for events */ while ( SDL_PollEvent(&event) ) { switch (event.type) { case SDL_MOUSEMOTION: break; case SDL_MOUSEBUTTONDOWN: break; case SDL_KEYDOWN: /* Any keypress quits the app... */ case SDL_QUIT: done = 1; break; default: break; } } } /* Clean up the SDL library */ SDL_Quit(); return(0); }