Mercurial > sdl-ios-xcode
view src/audio/dummy/SDL_dummyaudio.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 | 4160ba33b597 |
children | b530ef003506 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2010 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org This file written by Ryan C. Gordon (icculus@icculus.org) */ #include "SDL_config.h" /* Output audio to nowhere... */ #include "SDL_audio.h" #include "../SDL_audio_c.h" #include "SDL_dummyaudio.h" static int DUMMYAUD_OpenDevice(_THIS, const char *devname, int iscapture) { return 1; /* always succeeds. */ } static int DUMMYAUD_Init(SDL_AudioDriverImpl * impl) { /* Set the function pointers */ impl->OpenDevice = DUMMYAUD_OpenDevice; impl->OnlyHasDefaultOutputDevice = 1; return 1; /* this audio target is available. */ } AudioBootStrap DUMMYAUD_bootstrap = { "dummy", "SDL dummy audio driver", DUMMYAUD_Init, 1 }; /* vi: set ts=4 sw=4 expandtab: */