First stage of audio API update

Look over changes and give feedback please.

src/audio.c

@@ -97,6 +97,7 @@ typedef enum { INFO = 0, ERROR, WARNING, DEBUG, OTHER } TraceLogType;
 //----------------------------------------------------------------------------------
 // Global Variables Definition
 //----------------------------------------------------------------------------------
+static bool mixChannelsActive_g[4]; // What mix channels are currently active
 static bool musicEnabled = false;
 static Music currentMusic;        // Current music loaded
                                   // NOTE: Only one music file playing at a time
@@ -164,6 +165,53 @@ void CloseAudioDevice(void)
     alcCloseDevice(device);
 }
 
+// True if call to InitAudioDevice() was successful and CloseAudioDevice() has not been called yet
+bool AudioDeviceReady(void)
+{
+    ALCcontext *context = alcGetCurrentContext();
+    if (context == NULL) return false;
+    else{
+        ALCdevice *device = alcGetContextsDevice(context);
+        if (device == NULL) return false;
+        else return true;
+    }
+}
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - Custom audio output
+//----------------------------------------------------------------------------------
+
+// Audio contexts are for outputing custom audio waveforms, This will shut down any other sound sources currently playing
+// The mix_t is what mix channel you want to operate on, mixA->mixD are the ones available. Each mix channel can only be used one at a time.
+// exmple usage is InitAudioContext(48000, 16, mixA, stereo);
+AudioContext* InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSample, mix_t mixChannel, channel_t channels)
+{
+    if(!AudioDeviceReady()) InitAudioDevice();
+    else StopMusicStream();
+    
+    if(!mixChannelsActive_g[mixChannel]){
+        AudioContext *ac = malloc(sizeof(AudioContext));
+        ac->sampleRate = sampleRate;
+        ac->bitsPerSample = bitsPerSample;
+        ac->mixChannel = mixChannel;
+        ac->channels = channels;
+        mixChannelsActive_g[mixChannel] = true;
+        return ac;
+    }
+    return NULL;
+}
+
+// Frees buffer in audio context
+void CloseAudioContext(AudioContext *ctx)
+{
+    if(ctx){
+        mixChannelsActive_g[ctx->mixChannel] = false;
+        free(ctx);
+    }
+}
+
+
+
 //----------------------------------------------------------------------------------
 // Module Functions Definition - Sounds loading and playing (.WAV)
 //----------------------------------------------------------------------------------

src/audio.h

@@ -41,8 +41,12 @@
 //----------------------------------------------------------------------------------
 #ifndef __cplusplus
 // Boolean type
-typedef enum { false, true } bool;
+    #ifndef true
+        typedef enum { false, true } bool;
+    #endif
 #endif
+typedef enum { silence, mono, stereo } channel_t;
+typedef enum { mixA, mixB, mixC, mixD } mix_t; // Used for mixing/muxing up to four diferent audio streams
 
 // Sound source type
 typedef struct Sound {
@@ -59,6 +63,16 @@ typedef struct Wave {
     short channels;
 } Wave;
 
+// Audio Context, used to create custom audio streams that are not bound to a sound file. There can be
+// no more than 4 concurrent audio contexts in use. This is due to each active context being tied to
+// a dedicated mix channel.
+typedef struct AudioContext {
+    unsigned short sampleRate;         // default is 48000
+    unsigned char bitsPerSample;       // 16 is default
+    mix_t mixChannel;                  // 0-3 or mixA-mixD, each mix channel can receive up to one dedicated audio stream
+    channel_t channels;                // 1=mono, 2=stereo
+} AudioContext;
+
 #ifdef __cplusplus
 extern "C" {            // Prevents name mangling of functions
 #endif
@@ -73,6 +87,13 @@ extern "C" {            // Prevents name mangling of functions
 //----------------------------------------------------------------------------------
 void InitAudioDevice(void);                                     // Initialize audio device and context
 void CloseAudioDevice(void);                                    // Close the audio device and context (and music stream)
+bool AudioDeviceReady(void);                                    // True if call to InitAudioDevice() was successful and CloseAudioDevice() has not been called yet
+
+// Audio contexts are for outputing custom audio waveforms, This will shut down any other sound sources currently playing
+// The mix_t is what mix channel you want to operate on, mixA->mixD are the ones available. Each mix channel can only be used one at a time.
+// exmple usage is InitAudioContext(48000, 16, mixA, stereo);
+AudioContext* InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSample, mix_t mixChannel, channel_t channels);
+void CloseAudioContext(AudioContext *ctx);                      // Frees audio context
 
 Sound LoadSound(char *fileName);                                // Load sound to memory
 Sound LoadSoundFromWave(Wave wave);                             // Load sound to memory from wave data
@@ -92,7 +113,7 @@ void PauseMusicStream(void);                                    // Pause music p
 void ResumeMusicStream(void);                                   // Resume playing paused music
 bool MusicIsPlaying(void);                                      // Check if music is playing
 void SetMusicVolume(float volume);                              // Set volume for music (1.0 is max level)
-float GetMusicTimeLength(void);                                 // Get current music time length (in seconds)
+float GetMusicTimeLength(void);                                 // Get music time length (in seconds)
 float GetMusicTimePlayed(void);                                 // Get current music time played (in seconds)
 
 #ifdef __cplusplus

src/raylib.h

@@ -265,6 +265,8 @@
         typedef enum { false, true } bool;
     #endif
 #endif
+typedef enum { silence, mono, stereo } channel_t;
+typedef enum { mixA, mixB, mixC, mixD } mix_t; // Used for mixing/muxing up to four diferent audio streams
 
 // byte type
 typedef unsigned char byte;
@@ -446,6 +448,16 @@ typedef struct Wave {
     short channels;
 } Wave;
 
+// Audio Context, used to create custom audio streams that are not bound to a sound file. There can be
+// no more than 4 concurrent audio contexts in use. This is due to each active context being tied to
+// a dedicated mix channel.
+typedef struct AudioContext {
+    unsigned short sampleRate;         // default is 48000
+    unsigned char bitsPerSample;       // 16 is default
+    mix_t mixChannel;                  // 0-3 or mixA-mixD, each mix channel can receive up to one dedicated audio stream
+    channel_t channels;                // 1=mono, 2=stereo
+} AudioContext;
+
 // Texture formats
 // NOTE: Support depends on OpenGL version and platform
 typedef enum {
@@ -863,6 +875,13 @@ void DrawPhysicObjectInfo(PhysicObject *pObj, Vector2 position, int fontSize);
 //------------------------------------------------------------------------------------
 void InitAudioDevice(void);                                     // Initialize audio device and context
 void CloseAudioDevice(void);                                    // Close the audio device and context (and music stream)
+bool AudioDeviceReady(void);                                    // True if call to InitAudioDevice() was successful and CloseAudioDevice() has not been called yet
+
+// Audio contexts are for outputing custom audio waveforms, This will shut down any other sound sources currently playing
+// The mix_t is what mix channel you want to operate on, mixA->mixD are the ones available. Each mix channel can only be used one at a time.
+// exmple usage is InitAudioContext(48000, 16, mixA, stereo);
+AudioContext* InitAudioContext(unsigned short sampleRate, unsigned char bitsPerSample, mix_t mixChannel, channel_t channels);
+void CloseAudioContext(AudioContext *ctx);                      // Frees audio context
 
 Sound LoadSound(char *fileName);                                // Load sound to memory
 Sound LoadSoundFromWave(Wave wave);                             // Load sound to memory from wave data