Changes based on PC version 0.2.

PlumbersDontWearTies/Audio.cpp

@@ -0,0 +1,120 @@
+#include "Audio.h"
+
+#include "Log.h"
+
+SDL_AudioDeviceID Audio::audioDeviceId = 0;
+std::ifstream Audio::currentAudioStream = std::ifstream();
+int32_t Audio::currentAudioStreamLegth = 0;
+
+bool Audio::Initialize()
+{
+	if (IsInitialized()) return false;
+
+	SDL_AudioSpec desiredAudioSpec, obtainedAudioSpec;
+	SDL_memset(&desiredAudioSpec, 0, sizeof(desiredAudioSpec));
+	desiredAudioSpec.freq = WAV_FREQUENCY;
+	desiredAudioSpec.format = WAV_FORMAT;
+	desiredAudioSpec.channels = WAV_CHANNELS;
+	desiredAudioSpec.samples = WAV_SAMPLES;
+	desiredAudioSpec.callback = AudioCallback;
+	audioDeviceId = SDL_OpenAudioDevice(NULL, 0, &desiredAudioSpec, &obtainedAudioSpec, /*SDL_AUDIO_ALLOW_FORMAT_CHANGE*/ 0);
+
+	if (audioDeviceId == 0)
+	{
+		Log::Print(LogTypes::Error, "Can't open audio device: %s", SDL_GetError());
+		return false;
+	}
+	else
+	{
+		Log::Print(LogTypes::Info, "Audio Initialized: frequency %i, channels %u, samples %u, buffer size %u.", obtainedAudioSpec.freq, obtainedAudioSpec.channels, obtainedAudioSpec.samples, obtainedAudioSpec.size);
+	}
+
+	SDL_PauseAudioDevice(audioDeviceId, 0);
+
+	return true;
+}
+
+void Audio::Dispose()
+{
+	StopAudio();
+
+	if (audioDeviceId > 0)
+	{
+		SDL_CloseAudioDevice(audioDeviceId);
+		audioDeviceId = 0;
+	}
+}
+
+bool Audio::LoadAudioFromWAV(const std::string baseDataPath, const std::string fileName)
+{
+	if (!IsInitialized()) return false;
+
+	StopAudio();
+
+	currentAudioStream = std::ifstream(baseDataPath + fileName, std::ios::binary);
+
+	if (!currentAudioStream.is_open())
+	{
+		Log::Print(LogTypes::Error, "Can't load audio file: %s", SDL_GetError());
+		return false;
+	}
+
+	currentAudioStream.seekg(0, std::ios_base::end);
+	currentAudioStreamLegth = static_cast<int32_t>(currentAudioStream.tellg());
+
+	// TODO: Does audio data in a WAV always start in the same offset?
+	currentAudioStream.seekg(WAV_DATA_START_POSITION, std::ios_base::beg);
+
+	Log::Print(LogTypes::Info, "Playing audio %s...", fileName.c_str());
+
+	return true;
+}
+
+void Audio::StopAudio()
+{
+	if (!currentAudioStream.is_open()) return;
+
+	currentAudioStream.close();
+	currentAudioStream = std::ifstream();
+	currentAudioStreamLegth = 0;
+}
+
+void Audio::SetAudioPlaybackTime(const double elapsedTime)
+{
+	if (!IsInitialized()) return;
+	if (!currentAudioStream.is_open()) return;
+
+	int32_t samplePosition = static_cast<int32_t>(elapsedTime * WAV_FREQUENCY * WAV_FORMAT_BYTES * WAV_CHANNELS);
+
+	// Make sure samplePosition is even, not odd, as audio is 16bit.
+	samplePosition &= ~1;
+
+	currentAudioStream.seekg(WAV_DATA_START_POSITION + samplePosition, std::ios_base::beg);
+}
+
+void Audio::AudioCallback(void* userdata, uint8_t* stream, int32_t len)
+{
+	if (currentAudioStream.is_open())
+	{
+		currentAudioStream.read((char*)stream, len);
+
+		int32_t bytesRead = static_cast<int32_t>(currentAudioStream.gcount());
+		int32_t remainingBytes = len - bytesRead;
+
+		if (remainingBytes > 0)
+		{
+			SDL_memset(stream + bytesRead, 0, remainingBytes);
+
+			// We have finished reading the audio file,
+			// don't need to keep it open.
+
+			currentAudioStream.close();
+			currentAudioStream = std::ifstream();
+			currentAudioStreamLegth = 0;
+		}
+	}
+	else
+	{
+		SDL_memset(stream, 0, len);
+	}
+}

PlumbersDontWearTies/Audio.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <fstream>
+
+#include <SDL.h>
+
+// Format of game's WAV files
+
+constexpr int32_t WAV_FREQUENCY = 11025; // Hz
+constexpr SDL_AudioFormat WAV_FORMAT = AUDIO_S16; // 16 bits
+constexpr int32_t WAV_FORMAT_BYTES = 2; // 16 bits
+constexpr int32_t WAV_CHANNELS = 2; // Stereo
+constexpr int32_t WAV_SAMPLES = 256;
+
+// TODO: Does audio data in a WAV always start in the same offset?
+
+constexpr int32_t WAV_DATA_START_POSITION = 0x2c;
+
+class Audio
+{
+private:
+	static SDL_AudioDeviceID audioDeviceId;
+	static std::ifstream currentAudioStream;
+	static int32_t currentAudioStreamLegth;
+
+public:
+	static bool Initialize();
+	static void Dispose();
+
+	static bool LoadAudioFromWAV(const std::string baseDataPath, const std::string fileName);
+	static void StopAudio();
+	static void SetAudioPlaybackTime(const double elapsedTime);
+
+	inline static bool IsInitialized() { return audioDeviceId > 0; }
+
+private:
+	static void AudioCallback(void* userdata, uint8_t* stream, int32_t len);
+};