| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| #include "../../SDL_internal.h" |
| |
| #if SDL_AUDIO_DRIVER_EMSCRIPTEN |
| |
| #include "SDL_audio.h" |
| #include "SDL_log.h" |
| #include "../SDL_audio_c.h" |
| #include "SDL_emscriptenaudio.h" |
| |
| #include <emscripten/emscripten.h> |
| |
| static int |
| copyData(_THIS) |
| { |
| int byte_len; |
| |
| if (this->hidden->write_off + this->convert.len_cvt > this->hidden->mixlen) { |
| if (this->hidden->write_off > this->hidden->read_off) { |
| SDL_memmove(this->hidden->mixbuf, |
| this->hidden->mixbuf + this->hidden->read_off, |
| this->hidden->mixlen - this->hidden->read_off); |
| this->hidden->write_off = this->hidden->write_off - this->hidden->read_off; |
| } else { |
| this->hidden->write_off = 0; |
| } |
| this->hidden->read_off = 0; |
| } |
| |
| SDL_memcpy(this->hidden->mixbuf + this->hidden->write_off, |
| this->convert.buf, |
| this->convert.len_cvt); |
| this->hidden->write_off += this->convert.len_cvt; |
| byte_len = this->hidden->write_off - this->hidden->read_off; |
| |
| return byte_len; |
| } |
| |
| static void |
| HandleAudioProcess(_THIS) |
| { |
| Uint8 *buf = NULL; |
| int byte_len = 0; |
| int bytes = SDL_AUDIO_BITSIZE(this->spec.format) / 8; |
| int bytes_in = SDL_AUDIO_BITSIZE(this->convert.src_format) / 8; |
| |
| /* Only do soemthing if audio is enabled */ |
| if (!this->enabled) |
| return; |
| |
| if (this->paused) |
| return; |
| |
| if (this->convert.needed) { |
| if (this->hidden->conv_in_len != 0) { |
| this->convert.len = this->hidden->conv_in_len * bytes_in * this->spec.channels; |
| } |
| |
| (*this->spec.callback) (this->spec.userdata, |
| this->convert.buf, |
| this->convert.len); |
| SDL_ConvertAudio(&this->convert); |
| buf = this->convert.buf; |
| byte_len = this->convert.len_cvt; |
| |
| /* size mismatch*/ |
| if (byte_len != this->spec.size) { |
| if (!this->hidden->mixbuf) { |
| this->hidden->mixlen = this->spec.size > byte_len ? this->spec.size * 2 : byte_len * 2; |
| this->hidden->mixbuf = SDL_malloc(this->hidden->mixlen); |
| } |
| |
| /* copy existing data */ |
| byte_len = copyData(this); |
| |
| /* read more data*/ |
| while (byte_len < this->spec.size) { |
| (*this->spec.callback) (this->spec.userdata, |
| this->convert.buf, |
| this->convert.len); |
| SDL_ConvertAudio(&this->convert); |
| byte_len = copyData(this); |
| } |
| |
| byte_len = this->spec.size; |
| buf = this->hidden->mixbuf + this->hidden->read_off; |
| this->hidden->read_off += byte_len; |
| } |
| |
| } else { |
| if (!this->hidden->mixbuf) { |
| this->hidden->mixlen = this->spec.size; |
| this->hidden->mixbuf = SDL_malloc(this->hidden->mixlen); |
| } |
| (*this->spec.callback) (this->spec.userdata, |
| this->hidden->mixbuf, |
| this->hidden->mixlen); |
| buf = this->hidden->mixbuf; |
| byte_len = this->hidden->mixlen; |
| } |
| |
| if (buf) { |
| EM_ASM_ARGS({ |
| var numChannels = SDL2.audio.currentOutputBuffer['numberOfChannels']; |
| for (var c = 0; c < numChannels; ++c) { |
| var channelData = SDL2.audio.currentOutputBuffer['getChannelData'](c); |
| if (channelData.length != $1) { |
| throw 'Web Audio output buffer length mismatch! Destination size: ' + channelData.length + ' samples vs expected ' + $1 + ' samples!'; |
| } |
| |
| for (var j = 0; j < $1; ++j) { |
| channelData[j] = getValue($0 + (j*numChannels + c)*4, 'float'); |
| } |
| } |
| }, buf, byte_len / bytes / this->spec.channels); |
| } |
| } |
| |
| static void |
| Emscripten_CloseDevice(_THIS) |
| { |
| if (this->hidden != NULL) { |
| if (this->hidden->mixbuf != NULL) { |
| /* Clean up the audio buffer */ |
| SDL_free(this->hidden->mixbuf); |
| this->hidden->mixbuf = NULL; |
| } |
| |
| SDL_free(this->hidden); |
| this->hidden = NULL; |
| } |
| } |
| |
| static int |
| Emscripten_OpenDevice(_THIS, void *handle, const char *devname, int iscapture) |
| { |
| SDL_bool valid_format = SDL_FALSE; |
| SDL_AudioFormat test_format = SDL_FirstAudioFormat(this->spec.format); |
| int i; |
| float f; |
| int result; |
| |
| while ((!valid_format) && (test_format)) { |
| switch (test_format) { |
| case AUDIO_F32: /* web audio only supports floats */ |
| this->spec.format = test_format; |
| |
| valid_format = SDL_TRUE; |
| break; |
| } |
| test_format = SDL_NextAudioFormat(); |
| } |
| |
| if (!valid_format) { |
| /* Didn't find a compatible format :( */ |
| return SDL_SetError("No compatible audio format!"); |
| } |
| |
| /* Initialize all variables that we clean on shutdown */ |
| this->hidden = (struct SDL_PrivateAudioData *) |
| SDL_malloc((sizeof *this->hidden)); |
| if (this->hidden == NULL) { |
| return SDL_OutOfMemory(); |
| } |
| SDL_memset(this->hidden, 0, (sizeof *this->hidden)); |
| |
| /* based on parts of library_sdl.js */ |
| |
| /* create context (TODO: this puts stuff in the global namespace...)*/ |
| result = EM_ASM_INT_V({ |
| if(typeof(SDL2) === 'undefined') |
| SDL2 = {}; |
| |
| if(typeof(SDL2.audio) === 'undefined') |
| SDL2.audio = {}; |
| |
| if (!SDL2.audioContext) { |
| if (typeof(AudioContext) !== 'undefined') { |
| SDL2.audioContext = new AudioContext(); |
| } else if (typeof(webkitAudioContext) !== 'undefined') { |
| SDL2.audioContext = new webkitAudioContext(); |
| } else { |
| return -1; |
| } |
| } |
| return 0; |
| }); |
| if (result < 0) { |
| return SDL_SetError("Web Audio API is not available!"); |
| } |
| |
| /* limit to native freq */ |
| int sampleRate = EM_ASM_INT_V({ |
| return SDL2.audioContext['sampleRate']; |
| }); |
| |
| if(this->spec.freq != sampleRate) { |
| for (i = this->spec.samples; i > 0; i--) { |
| f = (float)i / (float)sampleRate * (float)this->spec.freq; |
| if (SDL_floor(f) == f) { |
| this->hidden->conv_in_len = SDL_floor(f); |
| break; |
| } |
| } |
| |
| this->spec.freq = sampleRate; |
| } |
| |
| SDL_CalculateAudioSpec(&this->spec); |
| |
| /* setup a ScriptProcessorNode */ |
| EM_ASM_ARGS({ |
| SDL2.audio.scriptProcessorNode = SDL2.audioContext['createScriptProcessor']($1, 0, $0); |
| SDL2.audio.scriptProcessorNode['onaudioprocess'] = function (e) { |
| SDL2.audio.currentOutputBuffer = e['outputBuffer']; |
| Runtime.dynCall('vi', $2, [$3]); |
| }; |
| SDL2.audio.scriptProcessorNode['connect'](SDL2.audioContext['destination']); |
| }, this->spec.channels, this->spec.samples, HandleAudioProcess, this); |
| return 0; |
| } |
| |
| static int |
| Emscripten_Init(SDL_AudioDriverImpl * impl) |
| { |
| /* Set the function pointers */ |
| impl->OpenDevice = Emscripten_OpenDevice; |
| impl->CloseDevice = Emscripten_CloseDevice; |
| |
| /* only one output */ |
| impl->OnlyHasDefaultOutputDevice = 1; |
| |
| /* no threads here */ |
| impl->SkipMixerLock = 1; |
| impl->ProvidesOwnCallbackThread = 1; |
| |
| /* check availability */ |
| int available = EM_ASM_INT_V({ |
| if (typeof(AudioContext) !== 'undefined') { |
| return 1; |
| } else if (typeof(webkitAudioContext) !== 'undefined') { |
| return 1; |
| } |
| return 0; |
| }); |
| |
| if (!available) { |
| SDL_SetError("No audio context available"); |
| } |
| |
| return available; |
| } |
| |
| AudioBootStrap EmscriptenAudio_bootstrap = { |
| "emscripten", "SDL emscripten audio driver", Emscripten_Init, 0 |
| }; |
| |
| #endif /* SDL_AUDIO_DRIVER_EMSCRIPTEN */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |