Mercurial > sdl-ios-xcode
view src/audio/SDL_wave.h @ 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 | f7b03b6838cb |
children | b530ef003506 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2010 Sam Lantinga This library is SDL_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 */ #include "SDL_config.h" /* WAVE files are little-endian */ /*******************************************/ /* Define values for Microsoft WAVE format */ /*******************************************/ #define RIFF 0x46464952 /* "RIFF" */ #define WAVE 0x45564157 /* "WAVE" */ #define FACT 0x74636166 /* "fact" */ #define LIST 0x5453494c /* "LIST" */ #define FMT 0x20746D66 /* "fmt " */ #define DATA 0x61746164 /* "data" */ #define PCM_CODE 0x0001 #define MS_ADPCM_CODE 0x0002 #define IEEE_FLOAT_CODE 0x0003 #define IMA_ADPCM_CODE 0x0011 #define MP3_CODE 0x0055 #define WAVE_MONO 1 #define WAVE_STEREO 2 /* Normally, these three chunks come consecutively in a WAVE file */ typedef struct WaveFMT { /* Not saved in the chunk we read: Uint32 FMTchunk; Uint32 fmtlen; */ Uint16 encoding; Uint16 channels; /* 1 = mono, 2 = stereo */ Uint32 frequency; /* One of 11025, 22050, or 44100 Hz */ Uint32 byterate; /* Average bytes per second */ Uint16 blockalign; /* Bytes per sample block */ Uint16 bitspersample; /* One of 8, 12, 16, or 4 for ADPCM */ } WaveFMT; /* The general chunk found in the WAVE file */ typedef struct Chunk { Uint32 magic; Uint32 length; Uint8 *data; } Chunk; /* vi: set ts=4 sw=4 expandtab: */