1 files changed, 146 insertions, 0 deletions

diff --git a/src/libjin/audio/SDL/sdl_audio.cpp b/src/libjin/audio/SDL/sdl_audio.cpp
new file mode 100644
index 0000000..4c4bcc2
--- /dev/null
+++ b/src/libjin/audio/SDL/sdl_audio.cpp
@@ -0,0 +1,146 @@
+#include "../../core/configuration.h"
+#if defined(jin_audio) && (jin_audio == jin_audio_sdl)
+
+#include <iostream>
+
+#include "../../math/math.h"
+#include "../../utils/log.h"
+
+#include "sdl_audio.h"
+#include "sdl_source.h"
+
+using namespace JinEngine::Math;
+
+namespace JinEngine
+{
+    namespace Audio
+    {
+        namespace SDL
+        {
+
+            /* ע��callback������Ƶ�̵߳��� */
+            static void defaultCallback(void *userdata, Uint8 *stream, int size)
+            {
+                static SDLAudio* audio = static_cast<SDLAudio*>(userdata);
+                if (!audio->goOnProcess())
+                    return;
+                audio->lock();
+                audio->processCommands();
+                audio->processSources(stream, size);
+                audio->processBuffer(stream, size);
+                audio->unlock();
+            }
+
+            /*call only once*/ bool SDLAudio::startSystem(const SettingBase* s)
+            {
+                jin_log_info("Initialize audio system.");
+
+                if (SDL_Init(SDL_INIT_AUDIO) < 0)
+                    return false;
+
+                SDL_AudioSpec spec;
+                Setting* setting = (Setting*)s;
+                if (setting == nullptr)
+                    return false;
+
+                unsigned int samplerate = setting->samplerate;
+                unsigned int samples = clamp<int>(setting->samples, 1, setting->samplerate);
+
+                spec.freq = samplerate;        // ÿ�������sample��,���õ��� 11025, 22050, 44100 and 48000 Hz. 
+                spec.format = AUDIO_S16SYS;      // signed 16-bit samples in native byte order
+                spec.channels = SDLAUDIO_CHANNELS; // ������
+                spec.samples = samples;           // ÿ�β���ʱ��һ�������ã����=setting->samplerate��ÿ��ֻ����1��
+                spec.userdata = this;
+                spec.callback = defaultCallback;
+
+                audioDevice = SDL_OpenAudioDevice(NULL, 0, &spec, NULL, 0);
+                if (audioDevice == 0)
+                    return false;
+                /* start audio */
+                SDL_PauseAudioDevice(audioDevice, 0);
+                return true;
+            }
+
+            /*call only once*/ void SDLAudio::quitSystem()
+            {
+                jin_log_info("Quit audio system.");
+                SDL_CloseAudio();
+            }
+
+            void SDLAudio::lock()
+            {
+                SDL_LockAudioDevice(audioDevice);
+            }
+
+            void SDLAudio::unlock()
+            {
+                SDL_UnlockAudioDevice(audioDevice);
+            }
+
+            bool SDLAudio::goOnProcess()
+            {
+                if (state == SDLAudio::State::STOP)
+                {
+                    SDLSourceManager::get()->removeAllSource();
+                    pause();
+                    return false;
+                }
+                else if (state == SDLAudio::State::PAUSE)
+                    return false;
+                else
+                    return true;
+            }
+
+            void SDLAudio::processCommands()
+            {
+                SDLSourceManager::get()->processCommands();
+            }
+
+            void SDLAudio::processSources(void* buffer, size_t len)
+            {
+                SDLSourceManager::get()->processSources(buffer, len);
+            }
+
+            void SDLAudio::processBuffer(void* buff, size_t len)
+            {
+                short* buffer = (short*)buff;
+                int samples = (len / SDLAUDIO_BYTEDEPTH) >> 1; // ˫����
+                const char L = 0, R = 1;
+                for (int i = 0; i < samples; ++i)
+                {
+                    short* clip = buffer + (i << 1);
+                    clip[L] *= volume;
+                    clip[R] *= volume;
+                }
+            }
+
+            void SDLAudio::play()
+            {
+                state = State::PLAY;
+            }
+
+            void SDLAudio::stop()
+            {
+                state = State::STOP;
+            }
+
+            void SDLAudio::pause()
+            {
+                state = State::PAUSE;
+            }
+
+            void SDLAudio::resume()
+            {
+                state = State::PLAY;
+            }
+
+            void SDLAudio::setVolume(float volume)
+            {
+                this->volume = clamp(volume, 0.0f, 1.0f);
+            }
+
+        } // namespace SDL
+    } // namespace Audio
+} // namespace JinEngine
+
+#endif // (jin_audio) && (jin_audio == jin_audio_sdl)
\ No newline at end of file