Added Sound Extension

OneLoneCoder_PGE_SoundTest.cpp

@@ -0,0 +1,269 @@
+/*
+	Simple example code for olcPGEX_Sound.h - Mind your speakers!
+
+	You will need SampleA.wav, SampleB.wav and SampleC.wav for this demo.
+
+	License (OLC-3)
+	~~~~~~~~~~~~~~~
+
+	Copyright 2018 OneLoneCoder.com
+
+	Redistribution and use in source and binary forms, with or without
+	modification, are permitted provided that the following conditions
+	are met:
+
+	1. Redistributions or derivations of source code must retain the above
+	copyright notice, this list of conditions and the following disclaimer.
+
+	2. Redistributions or derivative works in binary form must reproduce
+	the above copyright notice. This list of conditions and the following
+	disclaimer must be reproduced in the documentation and/or other
+	materials provided with the distribution.
+
+	3. Neither the name of the copyright holder nor the names of its
+	contributors may be used to endorse or promote products derived
+	from this software without specific prior written permission.
+
+	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+	Links
+	~~~~~
+	YouTube:	https://www.youtube.com/javidx9
+	Discord:	https://discord.gg/WhwHUMV
+	Twitter:	https://www.twitter.com/javidx9
+	Twitch:		https://www.twitch.tv/javidx9
+	GitHub:		https://www.github.com/onelonecoder
+	Homepage:	https://www.onelonecoder.com
+	Patreon:	https://www.patreon.com/javidx9
+
+	Author
+	~~~~~~
+	David Barr, aka javidx9, ©OneLoneCoder 2018
+*/
+
+#define OLC_PGE_APPLICATION
+#include "olcPixelGameEngine.h"
+#include "olcPGEX_Sound.h"
+
+#include <list>
+
+class SoundTest : public olc::PixelGameEngine
+{
+public:
+	SoundTest()
+	{
+		sAppName = "Sound Test";
+	}
+
+private:
+	int sndSampleA;
+	int sndSampleB;
+	int sndSampleC;
+	bool bToggle = false;
+	static bool bSynthPlaying;
+	static float fSynthFrequency;
+	static float fFilterVolume;
+
+	const olc::Key keys[12] = { olc::Key::Z, olc::Key::S, olc::Key::X, olc::Key::D, olc::Key::C,
+				olc::Key::V, olc::Key::G, olc::Key::B, olc::Key::H, olc::Key::N, olc::Key::J, olc::Key::M};
+
+	static float fPreviousSamples[128];
+	static int nSamplePos;
+	
+
+private:
+
+	// This is an optional function that allows the user to generate or synthesize sounds
+	// in a custom way, it is fed into the output mixer bu the extension
+	static float MyCustomSynthFunction(int nChannel, float fGlobalTime, float fTimeStep)
+	{
+		// Just generate a sine wave of the appropriate frequency
+		if (bSynthPlaying)
+			return sin(fSynthFrequency * 2.0f * 3.14159f * fGlobalTime);
+		else
+			return 0.0f;
+	}
+
+	// This is an optional function that allows the user to filter the output from 
+	// the internal mixer of the extension. Here you could add effects or just
+	// control volume. I also like to use it to extract information about
+	// the currently playing output waveform
+	static float MyCustomFilterFunction(int nChannel, float fGlobalTime, float fSample)
+	{
+		// Fundamentally just control volume
+		float fOutput = fSample * fFilterVolume;
+
+		// But also add sample to list of previous samples for visualisation
+		fPreviousSamples[nSamplePos] = fOutput;
+		nSamplePos++;
+		nSamplePos %= 128;
+
+		return fOutput;
+	}
+
+
+	bool OnUserCreate()
+	{
+		olc::SOUND::InitialiseAudio();
+		sndSampleA = olc::SOUND::LoadAudioSample("SampleA.wav");
+		sndSampleB = olc::SOUND::LoadAudioSample("SampleB.wav");
+		sndSampleC = olc::SOUND::LoadAudioSample("SampleC.wav");
+
+		// Give the sound engine a hook to a custom generation function
+		olc::SOUND::SetUserSynthFunction(MyCustomSynthFunction);
+
+		// Give the sound engine a hook to a custom filtering function
+		olc::SOUND::SetUserFilterFunction(MyCustomFilterFunction);
+
+		return true;
+	}
+
+	bool OnUserUpdate(float fElapsedTime)
+	{
+		//olc::SOUND::PlaySample(sndTest);
+
+		auto PointInRect = [&](int x, int y, int rx, int ry, int rw, int rh)
+		{
+			return x >= rx && x < (rx + rw) && y >= ry && y < (ry + rh);
+		};
+
+		int nMouseX = GetMouseX();
+		int nMouseY = GetMouseY();
+
+		if(GetMouse(0).bPressed && PointInRect(nMouseX, nMouseY, 16, 16, 128, 24))
+			olc::SOUND::PlaySample(sndSampleA); // Plays the sample once
+
+		if (GetMouse(0).bPressed && PointInRect(nMouseX, nMouseY, 16, 48, 128, 24))
+			olc::SOUND::PlaySample(sndSampleB);
+
+		if (GetMouse(0).bPressed && PointInRect(nMouseX, nMouseY, 16, 80, 128, 24))
+		{
+			bToggle = !bToggle;
+			if (bToggle)
+			{
+				olc::SOUND::PlaySample(sndSampleC, true); // Plays the sample in looping mode
+			}
+			else
+			{
+				olc::SOUND::StopSample(sndSampleC);
+			}
+		}
+
+		if (GetMouse(0).bHeld && PointInRect(nMouseX, nMouseY, 160, 16, 90, 24))
+			fFilterVolume += 2.0f * fElapsedTime;
+
+		if (GetMouse(0).bHeld && PointInRect(nMouseX, nMouseY, 160, 48, 90, 24))
+			fFilterVolume -= 2.0f * fElapsedTime;
+
+		if (fFilterVolume < 0.0f) fFilterVolume = 0.0f;
+		if (fFilterVolume > 1.0f) fFilterVolume = 1.0f;
+
+		// Detect keyboard - very simple synthesizer
+		if (IsFocused())
+		{
+			bool bKeyIsPressed = false;
+			float fFrequency = 0.0f;
+			for (int i = 0; i < 12; i++)
+			{
+				if (GetKey(keys[i]).bHeld)
+				{
+					bKeyIsPressed = true;
+					float fOctaveBaseFrequency = 220.0f; 
+					float f12thRootOf2 = pow(2.0f, 1.0f / 12.0f);
+					fFrequency = fOctaveBaseFrequency * powf(f12thRootOf2, (float)i);
+				}
+			}
+
+			fSynthFrequency = fFrequency;
+			bSynthPlaying = bKeyIsPressed;
+		}
+		
+
+		// Draw Buttons
+		Clear(olc::BLUE);
+
+		DrawRect(16, 16, 128, 24);
+		DrawString(20, 20, "Play Sample A");
+
+		DrawRect(16, 48, 128, 24);
+		DrawString(20, 52, "Play Sample B");
+
+		DrawRect(16, 80, 128, 24);
+		DrawString(20, 84, (bToggle ? "Stop Sample C" : "Loop Sample C"));
+
+
+		DrawRect(160, 16, 90, 24);
+		DrawString(164, 20, "Volume +");
+
+		DrawRect(160, 48, 90, 24);
+		DrawString(164, 52, "Volume -");
+
+
+		DrawString(164, 80, "Volume: " + std::to_string((int)(fFilterVolume * 10.0f)));
+
+		// Draw Keyboard
+
+		// White Keys
+		for (int i = 0; i < 7; i++)
+		{
+			FillRect(i * 16 + 8, 160, 16, 64);
+			DrawRect(i * 16 + 8, 160, 16, 64, olc::BLACK);
+			DrawString(i * 16 + 12, 212, std::string(1, "ZXCVBNM"[i]), olc::BLACK);
+		}
+
+		// Black Keys
+		for (int i = 0; i < 6; i++)
+		{
+			if (i != 2)
+			{
+				FillRect(i * 16 + 18, 160, 12, 32, olc::BLACK);
+				DrawString(i * 16 + 20, 180, std::string(1, "SDFGHJ"[i]), olc::WHITE);
+			}
+		}
+
+		// Draw visualisation
+		int nStartPos = (nSamplePos + 127) % 128;
+
+		for (int i = 127; i >= 0; i--)
+		{
+			float fSample = fPreviousSamples[(nSamplePos + i) % 128];
+			DrawLine(124 + i, 210, 124 + i, 210 + (int)(fSample * 20.0f), olc::RED);
+		}
+
+
+		return true;
+	}
+
+
+	// Note we must shut down the sound system too!!
+	bool OnUserDestroy()
+	{
+		olc::SOUND::DestroyAudio();
+		return true;
+	}
+};
+
+bool SoundTest::bSynthPlaying = false;
+float SoundTest::fSynthFrequency = 0.0f;
+float SoundTest::fFilterVolume = 1.0f;
+int SoundTest::nSamplePos = 0;
+float SoundTest::fPreviousSamples[128];
+
+int main()
+{
+	SoundTest demo;
+	if(demo.Construct(256, 240, 4, 4))
+		demo.Start();
+
+	return 0;
+}

olcPGEX_Sound.h

@@ -0,0 +1,513 @@
+/*
+	olcPGEX_Sound.h
+
+	+-------------------------------------------------------------+
+	|         OneLoneCoder Pixel Game Engine Extension            |
+	|                       Sound - v0.2                          |
+	+-------------------------------------------------------------+
+
+	What is this?
+	~~~~~~~~~~~~~
+	This is an extension to the olcPixelGameEngine, which provides
+	sound generation and wave playing routines.
+
+	License (OLC-3)
+	~~~~~~~~~~~~~~~
+
+	Copyright 2018 OneLoneCoder.com
+
+	Redistribution and use in source and binary forms, with or without
+	modification, are permitted provided that the following conditions
+	are met:
+
+	1. Redistributions or derivations of source code must retain the above
+	copyright notice, this list of conditions and the following disclaimer.
+
+	2. Redistributions or derivative works in binary form must reproduce
+	the above copyright notice. This list of conditions and the following
+	disclaimer must be reproduced in the documentation and/or other
+	materials provided with the distribution.
+
+	3. Neither the name of the copyright holder nor the names of its
+	contributors may be used to endorse or promote products derived
+	from this software without specific prior written permission.
+
+	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+	"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+	LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+	A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+	HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+	SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+	LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+	OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+	Links
+	~~~~~
+	YouTube:	https://www.youtube.com/javidx9
+	Discord:	https://discord.gg/WhwHUMV
+	Twitter:	https://www.twitter.com/javidx9
+	Twitch:		https://www.twitch.tv/javidx9
+	GitHub:		https://www.github.com/onelonecoder
+	Homepage:	https://www.onelonecoder.com
+	Patreon:	https://www.patreon.com/javidx9
+
+	Author
+	~~~~~~
+	David Barr, aka javidx9, ©OneLoneCoder 2018
+*/
+
+
+#ifndef OLC_PGEX_SOUND
+#define OLC_PGEX_SOUND
+
+#include <istream>
+
+#include <algorithm>
+#undef min
+#undef max
+
+namespace olc
+{
+	// Container class for Advanced 2D Drawing functions
+	class SOUND : public olc::PGEX
+	{
+		// A representation of an affine transform, used to rotate, scale, offset & shear space
+	public:
+		class AudioSample
+		{			
+		public:
+			AudioSample();
+			AudioSample(std::string sWavFile, olc::ResourcePack *pack = nullptr);
+			olc::rcode LoadFromFile(std::string sWavFile, olc::ResourcePack *pack = nullptr);
+				
+		public:
+			WAVEFORMATEX wavHeader;
+			float *fSample = nullptr;
+			long nSamples = 0;
+			int nChannels = 0;
+			bool bSampleValid = false;			
+		};
+
+		struct sCurrentlyPlayingSample
+		{
+			int nAudioSampleID = 0;
+			long nSamplePosition = 0;
+			bool bFinished = false;
+			bool bLoop = false;
+			bool bFlagForStop = false;
+		};
+
+		static std::list<sCurrentlyPlayingSample> listActiveSamples;
+
+	public:
+		static bool InitialiseAudio(unsigned int nSampleRate = 44100, unsigned int nChannels = 1, unsigned int nBlocks = 8, unsigned int nBlockSamples = 512);
+		static bool DestroyAudio();
+		static void SetUserSynthFunction(std::function<float(int, float, float)> func);
+		static void SetUserFilterFunction(std::function<float(int, float, float)> func);
+
+	public:
+		static unsigned int LoadAudioSample(std::string sWavFile, olc::ResourcePack *pack = nullptr);
+		static void PlaySample(int id, bool bLoop = false);
+		static void StopSample(int id);
+		static void StopAll();
+		static float GetMixerOutput(int nChannel, float fGlobalTime, float fTimeStep);
+
+#ifdef WIN32
+	private:
+		static void CALLBACK waveOutProc(HWAVEOUT hWaveOut, UINT uMsg, DWORD dwParam1, DWORD dwParam2);
+		static void AudioThread();
+		static unsigned int m_nSampleRate;
+		static unsigned int m_nChannels;
+		static unsigned int m_nBlockCount;
+		static unsigned int m_nBlockSamples;
+		static unsigned int m_nBlockCurrent;
+		static short* m_pBlockMemory;
+		static WAVEHDR *m_pWaveHeaders;
+		static HWAVEOUT m_hwDevice;
+		static std::thread m_AudioThread;
+		static std::atomic<bool> m_bAudioThreadActive;
+		static std::atomic<unsigned int> m_nBlockFree;
+		static std::condition_variable m_cvBlockNotZero;
+		static std::mutex m_muxBlockNotZero;
+		static std::atomic<float> m_fGlobalTime;
+		static std::function<float(int, float, float)> funcUserSynth;
+		static std::function<float(int, float, float)> funcUserFilter;
+#endif
+		
+	};
+}
+
+
+#ifdef WIN32
+#pragma comment(lib, "winmm.lib")
+namespace olc
+{
+	SOUND::AudioSample::AudioSample()
+	{
+
+
+
+	}
+
+	SOUND::AudioSample::AudioSample(std::string sWavFile, olc::ResourcePack *pack)
+	{
+		LoadFromFile(sWavFile, pack);
+	}
+
+	olc::rcode SOUND::AudioSample::LoadFromFile(std::string sWavFile, olc::ResourcePack *pack)
+	{
+		auto ReadWave = [&](std::istream &is)
+		{
+			char dump[4];
+			is.read(dump, sizeof(char) * 4); // Read "RIFF"
+			if (strncmp(dump, "RIFF", 4) != 0) return olc::FAIL;
+			is.read(dump, sizeof(char) * 4); // Not Interested
+			is.read(dump, sizeof(char) * 4); // Read "WAVE"
+			if (strncmp(dump, "WAVE", 4) != 0) return olc::FAIL;
+
+			// Read Wave description chunk
+			is.read(dump, sizeof(char) * 4); // Read "fmt "
+			unsigned int nHeaderSize = 0;
+			is.read((char*)&nHeaderSize, sizeof(unsigned int)); // Not Interested
+			is.read((char*)&wavHeader, nHeaderSize);// sizeof(WAVEFORMATEX)); // Read Wave Format Structure chunk
+														// Note the -2, because the structure has 2 bytes to indicate its own size
+														// which are not in the wav file
+
+			// Just check if wave format is compatible with olcPGE
+			if (wavHeader.wBitsPerSample != 16 || wavHeader.nSamplesPerSec != 44100)		
+				return olc::FAIL;
+			
+			// Search for audio data chunk
+			long nChunksize = 0;
+			is.read(dump, sizeof(char) * 4); // Read chunk header
+			is.read((char*)&nChunksize, sizeof(long)); // Read chunk size
+			while (strncmp(dump, "data", 4) != 0)
+			{
+				// Not audio data, so just skip it
+				//std::fseek(f, nChunksize, SEEK_CUR);
+				is.seekg(nChunksize, std::istream::cur);
+				is.read(dump, sizeof(char) * 4);
+				is.read((char*)&nChunksize, sizeof(long));
+			}
+
+			// Finally got to data, so read it all in and convert to float samples
+			nSamples = nChunksize / (wavHeader.nChannels * (wavHeader.wBitsPerSample >> 3));
+			nChannels = wavHeader.nChannels;
+
+			// Create floating point buffer to hold audio sample
+			fSample = new float[nSamples * nChannels];
+			float *pSample = fSample;
+
+			// Read in audio data and normalise
+			for (long i = 0; i < nSamples; i++)
+			{
+				for (int c = 0; c < nChannels; c++)
+				{
+					short s = 0;
+					if (!is.eof())
+					{
+						is.read((char*)&s, sizeof(short));
+
+						*pSample = (float)s / (float)(MAXSHORT);
+						pSample++;
+					}
+				}
+			}
+
+			// All done, flag sound as valid			
+			bSampleValid = true;
+			return olc::OK;
+		};
+		
+		if (pack != nullptr)
+		{
+			std::istream is(&(pack->GetStreamBuffer(sWavFile)));
+			return ReadWave(is);
+		}
+		else
+		{
+			// Read from file
+			std::ifstream ifs(sWavFile, std::ifstream::binary);
+			if (ifs.is_open())
+			{
+				return ReadWave(ifs);
+			}
+			else
+				return olc::FAIL;
+		}
+	}
+
+	bool SOUND::InitialiseAudio(unsigned int nSampleRate, unsigned int nChannels, unsigned int nBlocks, unsigned int nBlockSamples)
+	{
+		// Initialise Sound Engine
+		m_bAudioThreadActive = false;
+		m_nSampleRate = nSampleRate;
+		m_nChannels = nChannels;
+		m_nBlockCount = nBlocks;
+		m_nBlockSamples = nBlockSamples;
+		m_nBlockFree = m_nBlockCount;
+		m_nBlockCurrent = 0;
+		m_pBlockMemory = nullptr;
+		m_pWaveHeaders = nullptr;
+
+		// Device is available
+		WAVEFORMATEX waveFormat;
+		waveFormat.wFormatTag = WAVE_FORMAT_PCM;
+		waveFormat.nSamplesPerSec = m_nSampleRate;
+		waveFormat.wBitsPerSample = sizeof(short) * 8;
+		waveFormat.nChannels = m_nChannels;
+		waveFormat.nBlockAlign = (waveFormat.wBitsPerSample / 8) * waveFormat.nChannels;
+		waveFormat.nAvgBytesPerSec = waveFormat.nSamplesPerSec * waveFormat.nBlockAlign;
+		waveFormat.cbSize = 0;
+
+		listActiveSamples.clear();
+
+		// Open Device if valid
+		if (waveOutOpen(&m_hwDevice, WAVE_MAPPER, &waveFormat, (DWORD_PTR)SOUND::waveOutProc, (DWORD_PTR)0, CALLBACK_FUNCTION) != S_OK)
+			return DestroyAudio();
+
+		// Allocate Wave|Block Memory
+		m_pBlockMemory = new short[m_nBlockCount * m_nBlockSamples];
+		if (m_pBlockMemory == nullptr)
+			return DestroyAudio();
+		ZeroMemory(m_pBlockMemory, sizeof(short) * m_nBlockCount * m_nBlockSamples);
+
+		m_pWaveHeaders = new WAVEHDR[m_nBlockCount];
+		if (m_pWaveHeaders == nullptr)
+			return DestroyAudio();
+		ZeroMemory(m_pWaveHeaders, sizeof(WAVEHDR) * m_nBlockCount);
+
+		// Link headers to block memory
+		for (unsigned int n = 0; n < m_nBlockCount; n++)
+		{
+			m_pWaveHeaders[n].dwBufferLength = m_nBlockSamples * sizeof(short);
+			m_pWaveHeaders[n].lpData = (LPSTR)(m_pBlockMemory + (n * m_nBlockSamples));
+		}
+
+		m_bAudioThreadActive = true;
+		m_AudioThread = std::thread(&SOUND::AudioThread);
+
+		// Start the ball rolling with the sound delivery thread
+		std::unique_lock<std::mutex> lm(m_muxBlockNotZero);
+		m_cvBlockNotZero.notify_one();
+		return true;
+	}
+
+	// Stop and clean up audio system
+	bool SOUND::DestroyAudio()
+	{
+		m_bAudioThreadActive = false;
+		m_AudioThread.join();
+		return false;
+	}
+
+	// Handler for soundcard request for more data
+	void CALLBACK SOUND::waveOutProc(HWAVEOUT hWaveOut, UINT uMsg, DWORD dwParam1, DWORD dwParam2)
+	{
+		if (uMsg != WOM_DONE) return;
+		m_nBlockFree++;
+		std::unique_lock<std::mutex> lm(m_muxBlockNotZero);
+		m_cvBlockNotZero.notify_one();
+	}
+
+	// Audio thread. This loop responds to requests from the soundcard to fill 'blocks'
+	// with audio data. If no requests are available it goes dormant until the sound
+	// card is ready for more data. The block is fille by the "user" in some manner
+	// and then issued to the soundcard.
+	void SOUND::AudioThread()
+	{
+		m_fGlobalTime = 0.0f;
+		static float fTimeStep = 1.0f / (float)m_nSampleRate;
+
+		// Goofy hack to get maximum integer for a type at run-time
+		short nMaxSample = (short)pow(2, (sizeof(short) * 8) - 1) - 1;
+		float fMaxSample = (float)nMaxSample;
+		short nPreviousSample = 0;
+
+		while (m_bAudioThreadActive)
+		{
+			// Wait for block to become available
+			if (m_nBlockFree == 0)
+			{
+				std::unique_lock<std::mutex> lm(m_muxBlockNotZero);
+				while (m_nBlockFree == 0) // sometimes, Windows signals incorrectly
+					m_cvBlockNotZero.wait(lm);
+			}
+
+			// Block is here, so use it
+			m_nBlockFree--;
+
+			// Prepare block for processing
+			if (m_pWaveHeaders[m_nBlockCurrent].dwFlags & WHDR_PREPARED)
+				waveOutUnprepareHeader(m_hwDevice, &m_pWaveHeaders[m_nBlockCurrent], sizeof(WAVEHDR));
+
+			short nNewSample = 0;
+			int nCurrentBlock = m_nBlockCurrent * m_nBlockSamples;
+
+			auto clip = [](float fSample, float fMax)
+			{
+				if (fSample >= 0.0)
+					return fmin(fSample, fMax);
+				else
+					return fmax(fSample, -fMax);
+			};
+
+			for (unsigned int n = 0; n < m_nBlockSamples; n += m_nChannels)
+			{
+				// User Process
+				for (unsigned int c = 0; c < m_nChannels; c++)
+				{
+					nNewSample = (short)(clip(GetMixerOutput(c, m_fGlobalTime, fTimeStep), 1.0) * fMaxSample);
+					m_pBlockMemory[nCurrentBlock + n + c] = nNewSample;
+					nPreviousSample = nNewSample;
+				}
+
+				m_fGlobalTime = m_fGlobalTime + fTimeStep;
+			}
+
+			// Send block to sound device
+			waveOutPrepareHeader(m_hwDevice, &m_pWaveHeaders[m_nBlockCurrent], sizeof(WAVEHDR));
+			waveOutWrite(m_hwDevice, &m_pWaveHeaders[m_nBlockCurrent], sizeof(WAVEHDR));
+			m_nBlockCurrent++;
+			m_nBlockCurrent %= m_nBlockCount;
+		}
+	}
+
+	// This vector holds all loaded sound samples in memory
+	std::vector<olc::SOUND::AudioSample> vecAudioSamples;
+
+	// This structure represents a sound that is currently playing. It only
+	// holds the sound ID and where this instance of it is up to for its
+	// current playback
+	
+	void SOUND::SetUserSynthFunction(std::function<float(int, float, float)> func)
+	{
+		funcUserSynth = func;
+	}
+
+	void SOUND::SetUserFilterFunction(std::function<float(int, float, float)> func)
+	{
+		funcUserFilter = func;
+	}
+
+	// Load a 16-bit WAVE file @ 44100Hz ONLY into memory. A sample ID
+	// number is returned if successful, otherwise -1
+	unsigned int SOUND::LoadAudioSample(std::string sWavFile, olc::ResourcePack *pack)
+	{
+
+		olc::SOUND::AudioSample a(sWavFile, pack);
+		if (a.bSampleValid)
+		{
+			vecAudioSamples.push_back(a);
+			return vecAudioSamples.size();
+		}
+		else
+			return -1;
+	}
+
+	// Add sample 'id' to the mixers sounds to play list
+	void SOUND::PlaySample(int id, bool bLoop)
+	{
+		olc::SOUND::sCurrentlyPlayingSample a;
+		a.nAudioSampleID = id;
+		a.nSamplePosition = 0;
+		a.bFinished = false;
+		a.bFlagForStop = false;
+		a.bLoop = bLoop;
+		SOUND::listActiveSamples.push_back(a);
+	}
+
+	void SOUND::StopSample(int id)
+	{
+		// Find first occurence of sample id
+		auto s = std::find_if(listActiveSamples.begin(), listActiveSamples.end(), [&](const olc::SOUND::sCurrentlyPlayingSample &s) { return s.nAudioSampleID == id; });
+		if(s != listActiveSamples.end())
+			s->bFlagForStop = true;		
+	}
+
+	void SOUND::StopAll()
+	{
+		for (auto &s : listActiveSamples)
+		{
+			s.bFlagForStop = true;
+		}
+	}
+
+	float SOUND::GetMixerOutput(int nChannel, float fGlobalTime, float fTimeStep)
+	{
+		// Accumulate sample for this channel
+		float fMixerSample = 0.0f;
+
+		for (auto &s : listActiveSamples)
+		{
+			if (m_bAudioThreadActive)
+			{
+				if (s.bFlagForStop)
+				{
+					s.bLoop = false;
+					s.bFinished = true;
+				}
+				else
+				{
+					// Calculate sample position
+					s.nSamplePosition += (long)((float)vecAudioSamples[s.nAudioSampleID - 1].wavHeader.nSamplesPerSec * fTimeStep);
+
+					// If sample position is valid add to the mix
+					if (s.nSamplePosition < vecAudioSamples[s.nAudioSampleID - 1].nSamples)
+						fMixerSample += vecAudioSamples[s.nAudioSampleID - 1].fSample[(s.nSamplePosition * vecAudioSamples[s.nAudioSampleID - 1].nChannels) + nChannel];
+					else
+					{
+						if (s.bLoop)
+						{
+							s.nSamplePosition = 0;
+						}
+						else
+							s.bFinished = true; // Else sound has completed
+					}
+				}
+			}
+			else
+				return 0.0f;
+		}
+
+		// If sounds have completed then remove them
+		listActiveSamples.remove_if([](const sCurrentlyPlayingSample &s) {return s.bFinished; });
+
+		// The users application might be generating sound, so grab that if it exists
+		if(funcUserSynth != nullptr)
+			fMixerSample += funcUserSynth(nChannel, fGlobalTime, fTimeStep);
+
+		// Return the sample via an optional user override to filter the sound		
+		if (funcUserFilter != nullptr)
+			return funcUserFilter(nChannel, fGlobalTime, fMixerSample);
+		else
+			return fMixerSample;
+	}
+
+
+	unsigned int SOUND::m_nSampleRate = 0;
+	unsigned int SOUND::m_nChannels = 0;
+	unsigned int SOUND::m_nBlockCount = 0;
+	unsigned int SOUND::m_nBlockSamples = 0;
+	unsigned int SOUND::m_nBlockCurrent = 0;
+	short* SOUND::m_pBlockMemory = nullptr;
+	WAVEHDR *SOUND::m_pWaveHeaders = nullptr;
+	HWAVEOUT SOUND::m_hwDevice;
+	std::thread SOUND::m_AudioThread;
+	std::atomic<bool> SOUND::m_bAudioThreadActive = false;
+	std::atomic<unsigned int> SOUND::m_nBlockFree = 0;
+	std::condition_variable SOUND::m_cvBlockNotZero;
+	std::mutex SOUND::m_muxBlockNotZero;
+	std::atomic<float> SOUND::m_fGlobalTime = 0.0f;
+	std::list<SOUND::sCurrentlyPlayingSample> SOUND::listActiveSamples;
+	std::function<float(int, float, float)> SOUND::funcUserSynth = nullptr;
+	std::function<float(int, float, float)> SOUND::funcUserFilter = nullptr;
+}
+#endif
+
+// Currently no Linux implementation so just go blank :(
+
+#endif