Mercurial > sdl-ios-xcode
view src/audio/SDL_wave.h @ 1542:a8bf1aa21020
Fixed bug #15
SDL_blit_A.mmx-speed.patch.txt --
Speed improvements and a bugfix for the current GCC inline mmx
asm code:
- Changed some ops and removed some resulting useless ones.
- Added some instruction parallelism (some gain)
The resulting speed on my Xeon improved upto 35% depending on
the function (measured in fps).
- Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was
setting the alpha component on the destination surfaces (to
opaque-alpha) even when the surface had none.
SDL_blit_A.mmx-msvc.patch.txt --
MSVC mmx intrinsics version of the same GCC asm code.
MSVC compiler tries to parallelize the code and to avoid
register stalls, but does not always do a very good job.
Per-surface blending MSVC functions run quite a bit faster
than their pure-asm counterparts (upto 55% faster for 16bit
ones), but the per-pixel blending runs somewhat slower than asm.
- BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all
variants) can now also handle formats other than (A)RGB8888. Formats
like RGBA8888 and some quite exotic ones are allowed -- like
RAGB8888, or actually anything having channels aligned on 8bit
boundary and full 8bit alpha (for per-pixel alpha blending).
The performance cost of this change is virtually 0 for per-surface
alpha blending (no extra ops inside the loop) and a single non-MMX
op inside the loop for per-pixel blending. In testing, the per-pixel
alpha blending takes a ~2% performance hit, but it still runs much
faster than the current code in CVS. If necessary, a separate function
with this functionality can be made.
This code requires Processor Pack for VC6.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 15 Mar 2006 15:39:29 +0000 |
parents | d910939febfa |
children | 14717b52abc0 |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2006 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 IMA_ADPCM_CODE 0x0011 #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;