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First shot at new audio data types (int32 and float32). Notable changes: - Converters between types are autogenerated. Instead of making multiple passes over the data with seperate filters for endianess, size, signedness, etc, converting between data types is always one specialized filter. This simplifies SDL_BuildAudioCVT(), which otherwise had a million edge cases with the new types, and makes the actually conversions more CPU cache friendly. Left a stub for adding specific optimized versions of these routines (SSE/MMX/Altivec, assembler, etc) - Autogenerated converters are built by SDL/src/audio/sdlgenaudiocvt.pl. This does not need to be run unless tweaking the code, and thus doesn't need integration into the build system. - Went through all the drivers and tried to weed out all the "Uint16" references that are better specified with the new SDL_AudioFormat typedef. - Cleaned out a bunch of hardcoded bitwise magic numbers and replaced them with new SDL_AUDIO_* macros. - Added initial float32 and int32 support code. Theoretically, existing drivers will push these through converters to get the data they want to feed to the hardware. Still TODO: - Optimize and debug new converters. - Update the CoreAudio backend to accept float32 data directly. - Other backends, too? - SDL_LoadWAV() needs to be updated to support int32 and float32 .wav files (both of which exist and can be generated by 'sox' for testing purposes). - Update the mixer to handle new datatypes. - Optionally update SDL_sound and SDL_mixer, etc.
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 24 Aug 2006 12:10:46 +0000
parents 355632dca928
children
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<HTML
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>Chapter 5. General</H1
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><DT
><A
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>SDL_Init</A
>&nbsp;--&nbsp;Initializes SDL</DT
><DT
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>SDL_InitSubSystem</A
>&nbsp;--&nbsp;Initialize subsystems</DT
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>SDL_QuitSubSystem</A
>&nbsp;--&nbsp;Shut down a subsystem</DT
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>SDL_Quit</A
>&nbsp;--&nbsp;Shut down SDL</DT
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>SDL_WasInit</A
>&nbsp;--&nbsp;Check which subsystems are initialized</DT
><DT
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>SDL_GetError</A
>&nbsp;--&nbsp;Get SDL error string</DT
><DT
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>SDL_envvars</A
>&nbsp;--&nbsp;SDL environment variables</DT
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><P
>Before SDL can be used in a program it must be initialized with <A
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><TT
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>. <TT
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>SDL_Init</TT
> initializes all the subsystems that the user requests (video, audio, joystick, timers and/or cdrom). Once SDL is initialized with <TT
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>SDL_Init</TT
> subsystems can be shut down and initialized as needed using <A
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> and <A
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>.</P
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>SDL must also be shut down before the program exits to make sure it cleans up correctly. Calling <A
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