add multi channel audio to raudio (#895)

* added multi channel sound replay to raudio
added -fPIC to Makefile for Linux
added simple lighting and audio multi channel to examples Makefile

* not properly reporting audio buffer pool size...

6 files changed, 259 insertions, 14 deletions

diff --git a/examples/Makefile b/examples/Makefile
index 218ed721..2731ee50 100644
--- a/examples/Makefile
+++ b/examples/Makefile
@@ -165,7 +165,7 @@ ifeq ($(PLATFORM),PLATFORM_RPI)
 endif
 ifeq ($(PLATFORM),PLATFORM_WEB)
     # HTML5 emscripten compiler
-    # WARNING: To compile to HTML5, code must be redesigned 
+    # WARNING: To compile to HTML5, code must be redesigned
     # to use emscripten.h and emscripten_set_main_loop()
     CC = emcc
 endif
@@ -303,12 +303,12 @@ ifeq ($(PLATFORM),PLATFORM_DESKTOP)
         # Libraries for Debian GNU/Linux desktop compiling
         # NOTE: Required packages: libegl1-mesa-dev
         LDLIBS = -lraylib -lGL -lm -lpthread -ldl -lrt
-        
+
         # On X11 requires also below libraries
         LDLIBS += -lX11
         # NOTE: It seems additional libraries are not required any more, latest GLFW just dlopen them
         #LDLIBS += -lXrandr -lXinerama -lXi -lXxf86vm -lXcursor
-        
+
         # On Wayland windowing system, additional libraries requires
         ifeq ($(USE_WAYLAND_DISPLAY),TRUE)
             LDLIBS += -lwayland-client -lwayland-cursor -lwayland-egl -lxkbcommon
@@ -435,10 +435,12 @@ EXAMPLES = \
     shaders/shaders_texture_waves \
     shaders/shaders_julia_set \
     shaders/shaders_eratosthenes \
+    shaders/shaders_basic_lighting \
     audio/audio_module_playing \
     audio/audio_music_stream \
     audio/audio_raw_stream \
     audio/audio_sound_loading \
+    audio/audio_multichannel_sound \
     physac/physics_demo \
     physac/physics_friction \
     physac/physics_movement \
diff --git a/examples/audio/audio_multichannel_sound.c b/examples/audio/audio_multichannel_sound.c
new file mode 100644
index 00000000..42c71704
--- /dev/null
+++ b/examples/audio/audio_multichannel_sound.c
@@ -0,0 +1,116 @@
+
+/*
+* This example was coded to demonstrate multi channel audio changes added to raylib
+*
+*   This example has been created using raylib (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   This example Copyright (c) 2018 Chris Camacho (codifies) http://bedroomcoders.co.uk/captcha/
+*
+* THIS EXAMPLE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+* OTHER DEALINGS IN THE SOFTWARE.
+*
+* This example may be freely redistributed.
+*/
+
+#include "raylib.h"
+#include <stdio.h> // sprintf
+
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [audio] abuse!");
+
+    InitAudioDevice();      // Initialize audio device
+
+    Sound fxWav = LoadSound("resources/sound.wav");         // Load WAV audio file
+    Sound fxOgg = LoadSound("resources/tanatana.ogg");      // Load OGG audio file
+
+
+    //InitPlayBufferPool();
+
+
+
+    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+    int frame = 0;
+    // Main game loop
+
+    // old system still works alongside
+    SetSoundVolume(fxWav, 0.2); // effects all mutltiplay replay (really annoying sound!!!)
+    PlaySound(fxOgg);
+
+    bool inhibitWav = false;
+    bool inhibitOgg = false;
+    int maxFrame = 60;
+    int numberPlaying = 0;
+
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        frame++;
+
+        if (IsKeyDown(KEY_ENTER)) { inhibitWav=true; } else { inhibitWav=false; }
+        if (IsKeyDown(KEY_SPACE)) { inhibitOgg=true; } else { inhibitOgg=false; }
+
+        // deliberatly hammer the play pool to see what dropping old
+        // pool entries sounds like....
+        if (frame % 5==0) {
+           if (!inhibitWav) PlaySoundEx(fxWav);
+        }
+        if (frame==maxFrame) {
+            if (!inhibitOgg) PlaySoundEx(fxOgg);
+            frame=0;
+            maxFrame = GetRandomValue(6,12);
+        }
+
+        numberPlaying = ConcurrentPlayChannels();
+
+        //----------------------------------------------------------------------------------
+
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+            char msg[1024];
+            DrawText("multichannel sound abuse!", 200, 180, 20, LIGHTGRAY);
+            DrawText("Space to inhibit new ogg triggering", 200, 200, 20, LIGHTGRAY);
+            DrawText("Enter to inhibit new wav triggering", 200, 220, 20, LIGHTGRAY);
+
+            sprintf(msg,"concurrently playing %i", numberPlaying);
+            DrawText(msg, 200, 280, 20, LIGHTGRAY);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+
+
+    // you MUST stop the buffer pool before unloading
+    // any Sounds it might have used...
+    StopPlayBufferPool();
+
+    UnloadSound(fxWav);     // Unload sound data
+    UnloadSound(fxOgg);     // Unload sound data
+
+    CloseAudioDevice();     // Close audio device
+
+    CloseWindow();          // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
diff --git a/src/Makefile b/src/Makefile
index ef8b438d..4af01d91 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -161,7 +161,7 @@ ifeq ($(PLATFORM),PLATFORM_ANDROID)
     # Starting at 2019 using ARM64 is mandatory for published apps
     ANDROID_ARCH ?= ARM
     ANDROID_API_VERSION = 21
-    
+
     # Android required path variables
     # NOTE: Android NDK is just required to generate the standalone toolchain,
     # in case is not already provided
@@ -169,7 +169,7 @@ ifeq ($(PLATFORM),PLATFORM_ANDROID)
 
     # Android standalone toolchain path
     ANDROID_TOOLCHAIN = C:/android_toolchain_$(ANDROID_ARCH)_API$(ANDROID_API_VERSION)
-    
+
     ifeq ($(ANDROID_ARCH),ARM)
         ANDROID_ARCH_NAME = armeabi-v7a
     endif
@@ -258,6 +258,10 @@ endif
 #  -fno-strict-aliasing     jar_xm.h does shady stuff (breaks strict aliasing)
 CFLAGS += -Wall -std=c99 -D_DEFAULT_SOURCE -Wno-missing-braces -Werror=pointer-arith -fno-strict-aliasing
 
+ifeq ($(PLATFORM_OS),LINUX)
+	CFLAGS += -fPIC
+endif
+
 ifeq ($(RAYLIB_BUILD_MODE),DEBUG)
     CFLAGS += -g
 endif
@@ -528,14 +532,14 @@ models.o : models.c raylib.h rlgl.h raymath.h
 # Compile audio module
 raudio.o : raudio.c raylib.h
 	$(CC) -c $< $(CFLAGS) $(INCLUDE_PATHS) -D$(PLATFORM)
-    
+
 # Compile raygui module
 # NOTE: raygui header should be distributed with raylib.h
 raygui.o : raygui.c raygui.h
 	@echo #define RAYGUI_IMPLEMENTATION > raygui.c
 	@echo #include "$(RAYLIB_MODULE_RAYGUI_PATH)/raygui.h" > raygui.c
 	$(CC) -c $< $(CFLAGS) $(INCLUDE_PATHS) -D$(PLATFORM) -DRAYGUI_IMPLEMENTATION
-    
+
 # Compile physac module
 # NOTE: physac header should be distributed with raylib.h
 physac.o : physac.c physac.h
diff --git a/src/raudio.c b/src/raudio.c
index 6ac0110c..2008c2bf 100644
--- a/src/raudio.c
+++ b/src/raudio.c
@@ -178,10 +178,11 @@ typedef enum {
 } TraceLogType;
 #endif
 
+
+
 //----------------------------------------------------------------------------------
 // Global Variables Definition
 //----------------------------------------------------------------------------------
-// ...
 
 //----------------------------------------------------------------------------------
 // Module specific Functions Declaration
@@ -230,7 +231,7 @@ struct rAudioBuffer {
     unsigned int bufferSizeInFrames;
     rAudioBuffer *next;
     rAudioBuffer *prev;
-    unsigned char buffer[1];
+    unsigned char *buffer;
 };
 
 // HACK: To avoid CoreAudio (macOS) symbol collision
@@ -268,6 +269,24 @@ void SetAudioBufferPitch(AudioBuffer *audioBuffer, float pitch);
 void TrackAudioBuffer(AudioBuffer *audioBuffer);
 void UntrackAudioBuffer(AudioBuffer *audioBuffer);
 
+
+//----------------------------------------------------------------------------------
+// multi channel playback globals
+//----------------------------------------------------------------------------------
+
+// number of channels in the pool
+#define PLAY_POOL_SIZE 16
+
+// the buffer pool
+AudioBuffer* PlayBufferPool[PLAY_POOL_SIZE];
+
+// these are used to determine the oldest playing channel
+unsigned long PlayPoolAge = 0;
+unsigned long PlayPoolAges[PLAY_POOL_SIZE] = {0};
+
+//----------------------------------------------------------------------------------
+
+
 // Log callback function
 static void OnLog(ma_context *pContext, ma_device *pDevice, ma_uint32 logLevel, const char *message)
 {
@@ -462,6 +481,15 @@ static void MixAudioFrames(float *framesOut, const float *framesIn, ma_uint32 fr
     }
 }
 
+// initialise the multichannel buffer pool
+static void InitPlayBufferPool()
+{
+    // dummy buffers
+    for (int i=0; i<PLAY_POOL_SIZE; i++) {
+        PlayBufferPool[i] = CreateAudioBuffer(DEVICE_FORMAT, DEVICE_CHANNELS, DEVICE_SAMPLE_RATE, 0, AUDIO_BUFFER_USAGE_STATIC);
+    }
+}
+
 //----------------------------------------------------------------------------------
 // Module Functions Definition - Audio Device initialization and Closing
 //----------------------------------------------------------------------------------
@@ -526,9 +554,21 @@ void InitAudioDevice(void)
     TraceLog(LOG_INFO, "Audio sample rate: %d -> %d", device.sampleRate, device.playback.internalSampleRate);
     TraceLog(LOG_INFO, "Audio buffer size: %d", device.playback.internalBufferSizeInFrames);
 
+    InitPlayBufferPool();
+    TraceLog(LOG_INFO, "Audio multichannel pool size: %i", PLAY_POOL_SIZE);
+
     isAudioInitialized = MA_TRUE;
 }
 
+// internal
+static void FreePlayBufferPool() {
+    for (int i = 0; i < PLAY_POOL_SIZE; i++) {
+        // NB important free only the buffer struct not the attached data...!
+        RL_FREE(PlayBufferPool[i]);
+    }
+}
+
+
 // Close the audio device for all contexts
 void CloseAudioDevice(void)
 {
@@ -542,6 +582,8 @@ void CloseAudioDevice(void)
     ma_device_uninit(&device);
     ma_context_uninit(&context);
 
+    FreePlayBufferPool();
+
     TraceLog(LOG_INFO, "Audio device closed successfully");
 }
 
@@ -567,7 +609,8 @@ void SetMasterVolume(float volume)
 // Create a new audio buffer. Initially filled with silence
 AudioBuffer *CreateAudioBuffer(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, ma_uint32 bufferSizeInFrames, AudioBufferUsage usage)
 {
-    AudioBuffer *audioBuffer = (AudioBuffer *)RL_CALLOC(sizeof(*audioBuffer) + (bufferSizeInFrames*channels*ma_get_bytes_per_sample(format)), 1);
+    AudioBuffer *audioBuffer = (AudioBuffer *)RL_CALLOC(sizeof(*audioBuffer), 1);
+    audioBuffer->buffer = RL_CALLOC((bufferSizeInFrames*channels*ma_get_bytes_per_sample(format)), 1);
     if (audioBuffer == NULL)
     {
         TraceLog(LOG_ERROR, "CreateAudioBuffer() : Failed to allocate memory for audio buffer");
@@ -623,6 +666,7 @@ void DeleteAudioBuffer(AudioBuffer *audioBuffer)
     }
 
     UntrackAudioBuffer(audioBuffer);
+    RL_FREE(audioBuffer->buffer);
     RL_FREE(audioBuffer);
 }
 
@@ -966,6 +1010,79 @@ void PlaySound(Sound sound)
     PlayAudioBuffer((AudioBuffer *)sound.audioBuffer);
 }
 
+// play a sound in the multichannel buffer pool
+void PlaySoundEx(Sound s)
+{
+    int found = -1;
+    unsigned long oldAge = 0;
+    int oldIndex = -1;
+
+    // find the first non playing pool entry
+    for (int i=0; i<PLAY_POOL_SIZE; i++) {
+        if (PlayPoolAges[i] > oldAge) {
+            oldAge = PlayPoolAges[i];
+            oldIndex = i;
+        }
+        if (!IsAudioBufferPlaying(PlayBufferPool[i])) {
+            found = i;
+            break;
+        }
+    }
+
+    // if no none playing pool members can be found choose the oldest
+    if (found == -1) {
+        TraceLog(LOG_WARNING,"pool age %i ended a sound early no room in buffer pool",PlayPoolAge);
+        if (oldIndex == -1) {
+            // shouldn't be able to get here... but just in case something odd happens!
+            TraceLog(LOG_ERROR,"sound buffer pool couldn't determine oldest buffer not playing sound");
+            return;
+        }
+        found = oldIndex;
+        // just in case...
+        StopAudioBuffer(PlayBufferPool[found]);
+    }
+
+    // experimentally mutex lock doesn't seem to be needed this makes sense
+    // as PlayBufferPool[found] isn't playing and the only stuff we're copying
+    // shouldn't be changing...
+
+    PlayPoolAges[found] = PlayPoolAge;
+    PlayPoolAge++;
+    PlayBufferPool[found]->volume = ((AudioBuffer*)s.audioBuffer)->volume;
+    PlayBufferPool[found]->pitch = ((AudioBuffer*)s.audioBuffer)->pitch;
+    PlayBufferPool[found]->looping = ((AudioBuffer*)s.audioBuffer)->looping;
+    PlayBufferPool[found]->usage = ((AudioBuffer*)s.audioBuffer)->usage;
+    PlayBufferPool[found]->isSubBufferProcessed[0] = false;
+    PlayBufferPool[found]->isSubBufferProcessed[1] = false;
+    PlayBufferPool[found]->bufferSizeInFrames = ((AudioBuffer*)s.audioBuffer)->bufferSizeInFrames;
+    PlayBufferPool[found]->buffer = ((AudioBuffer*)s.audioBuffer)->buffer;
+
+    PlayAudioBuffer(PlayBufferPool[found]);
+
+}
+
+// MUST be called before UnLoadSound is used on any sound played with PlaySoundEx
+void StopPlayBufferPool()
+{
+    for (int i = 0; i < PLAY_POOL_SIZE; i++) {
+        StopAudioBuffer(PlayBufferPool[i]);
+    }
+}
+
+// number of sounds playing in the multichannel buffer pool
+int ConcurrentPlayChannels()
+{
+    int n = 0;
+    for (int i=0; i<PLAY_POOL_SIZE; i++) {
+        if (IsAudioBufferPlaying(PlayBufferPool[i])) {
+            n++;
+        }
+    }
+    return n;
+}
+
+
+
 // Pause a sound
 void PauseSound(Sound sound)
 {
diff --git a/src/raudio.h b/src/raudio.h
index f71a3083..0077d8fa 100644
--- a/src/raudio.h
+++ b/src/raudio.h
@@ -139,6 +139,9 @@ void UpdateSound(Sound sound, const void *data, int samplesCount);// Update soun
 void UnloadWave(Wave wave);                                     // Unload wave data
 void UnloadSound(Sound sound);                                  // Unload sound
 void PlaySound(Sound sound);                                    // Play a sound
+void PlaySoundEx(Sound s);                                      // Play a sound using the multi channel buffer pool
+void StopPlayBufferPool();                                      // MUST be called before UnLoadSound is used on any sound played with PlaySoundEx
+int ConcurrentPlayChannels();                                   // Number of sounds playing in the multichannel buffer pool
 void PauseSound(Sound sound);                                   // Pause a sound
 void ResumeSound(Sound sound);                                  // Resume a paused sound
 void StopSound(Sound sound);                                    // Stop playing a sound
@@ -164,7 +167,7 @@ float GetMusicTimeLength(Music music);                          // Get music tim
 float GetMusicTimePlayed(Music music);                          // Get current music time played (in seconds)
 
 // AudioStream management functions
-AudioStream InitAudioStream(unsigned int sampleRate, 
+AudioStream InitAudioStream(unsigned int sampleRate,
                             unsigned int sampleSize,
                             unsigned int channels);             // Init audio stream (to stream raw audio pcm data)
 void UpdateAudioStream(AudioStream stream, const void *data, int samplesCount); // Update audio stream buffers with data
@@ -182,4 +185,4 @@ void SetAudioStreamPitch(AudioStream stream, float pitch);      // Set pitch for
 }
 #endif
 
-#endif // RAUDIO_H
\ No newline at end of file
+#endif // RAUDIO_H
diff --git a/src/raylib.h b/src/raylib.h
index 9d0262c4..f40a30dc 100644
--- a/src/raylib.h
+++ b/src/raylib.h
@@ -631,7 +631,7 @@ typedef enum {
     GAMEPAD_BUTTON_LEFT_FACE_RIGHT,
     GAMEPAD_BUTTON_LEFT_FACE_DOWN,
     GAMEPAD_BUTTON_LEFT_FACE_LEFT,
-  
+
     // This is normally a DPAD
     GAMEPAD_BUTTON_RIGHT_FACE_UP,
     GAMEPAD_BUTTON_RIGHT_FACE_RIGHT,
@@ -1327,7 +1327,7 @@ RLAPI void EndScissorMode(void);                                          // End
 RLAPI void InitVrSimulator(void);                       // Init VR simulator for selected device parameters
 RLAPI void CloseVrSimulator(void);                      // Close VR simulator for current device
 RLAPI void UpdateVrTracking(Camera *camera);            // Update VR tracking (position and orientation) and camera
-RLAPI void SetVrConfiguration(VrDeviceInfo info, Shader distortion);      // Set stereo rendering configuration parameters 
+RLAPI void SetVrConfiguration(VrDeviceInfo info, Shader distortion);      // Set stereo rendering configuration parameters
 RLAPI bool IsVrSimulatorReady(void);                    // Detect if VR simulator is ready
 RLAPI void ToggleVrMode(void);                          // Enable/Disable VR experience
 RLAPI void BeginVrDrawing(void);                        // Begin VR simulator stereo rendering
@@ -1356,6 +1356,9 @@ RLAPI void ExportWaveAsCode(Wave wave, const char *fileName);         // Export
 
 // Wave/Sound management functions
 RLAPI void PlaySound(Sound sound);                                    // Play a sound
+RLAPI void PlaySoundEx(Sound s);                                      // Play a sound using the multi channel buffer pool
+RLAPI void StopPlayBufferPool();                                      // MUST be called before UnLoadSound is used on any sound played with PlaySoundEx
+RLAPI int ConcurrentPlayChannels();                                   // Number of sounds playing in the multichannel buffer pool
 RLAPI void PauseSound(Sound sound);                                   // Pause a sound
 RLAPI void ResumeSound(Sound sound);                                  // Resume a paused sound
 RLAPI void StopSound(Sound sound);                                    // Stop playing a sound