Add audio API

CMakeLists.txt

@@ -66,6 +66,7 @@ include_directories(thirdparty/spimpl)
 target_link_libraries(scratchcpp PRIVATE nlohmann_json::nlohmann_json)
 target_link_libraries(scratchcpp PRIVATE utf8cpp)
 target_link_libraries(scratchcpp PRIVATE zip)
+target_link_libraries(scratchcpp PRIVATE scratchcpp-audio)
 
 if (LIBSCRATCHCPP_NETWORK_SUPPORT)
     include(FetchContent)

include/scratchcpp/sound.h

@@ -17,13 +17,24 @@ class LIBSCRATCHCPP_EXPORT Sound : public Asset
     public:
         Sound(const std::string &name, const std::string &id, const std::string &format);
         Sound(const Sound &) = delete;
+        virtual ~Sound() { }
 
         int rate() const;
         void setRate(int newRate);
 
         int sampleCount() const;
         void setSampleCount(int newSampleCount);
 
+        virtual void setVolume(double volume);
+
+        virtual void start();
+        virtual void stop();
+
+        virtual bool isPlaying();
+
+    protected:
+        void processData(unsigned int size, void *data) override;
+
     private:
         spimpl::unique_impl_ptr<SoundPrivate> impl;
 };

src/CMakeLists.txt

@@ -15,3 +15,4 @@ add_subdirectory(blocks)
 add_subdirectory(engine)
 add_subdirectory(internal)
 add_subdirectory(scratch)
+add_subdirectory(audio)

src/audio/CMakeLists.txt

@@ -0,0 +1,38 @@
+option(LIBSCRATCHCPP_AUDIO_SUPPORT "Audio support" ON)
+
+add_library(scratchcpp-audio STATIC)
+set(MINIAUDIO_SRC thirdparty/miniaudio)
+
+if (LIBSCRATCHCPP_AUDIO_SUPPORT)
+    add_library(miniaudio STATIC
+	    ${MINIAUDIO_SRC}/miniaudio.c
+	    ${MINIAUDIO_SRC}/miniaudio.h
+    )
+    target_include_directories(scratchcpp-audio PUBLIC ${CMAKE_CURRENT_LIST_DIR}/${MINIAUDIO_SRC})
+    target_link_libraries(scratchcpp-audio PRIVATE miniaudio)
+    target_compile_definitions(scratchcpp-audio PUBLIC LIBSCRATCHCPP_AUDIO_SUPPORT)
+endif()
+
+target_sources(scratchcpp-audio
+  PUBLIC
+    iaudioplayer.h
+    iaudioplayerfactory.h
+    audioplayerfactory.cpp
+    audioplayerfactory.h
+)
+
+if (LIBSCRATCHCPP_AUDIO_SUPPORT)
+    target_sources(scratchcpp-audio
+      PUBLIC
+        audioengine.cpp
+	audioengine.h
+	audioplayer.cpp
+	audioplayer.h
+    )
+else()
+    target_sources(scratchcpp-audio
+      PUBLIC
+        audioplayerstub.cpp
+	audioplayerstub.h
+    )
+endif()

src/audio/audioengine.cpp

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#include <iostream>
+
+#include "audioengine.h"
+
+using namespace libscratchcpp;
+
+AudioEngine AudioEngine::instance;
+
+ma_engine *AudioEngine::engine()
+{
+    return &instance.m_engine;
+}
+
+bool AudioEngine::initialized()
+{
+    return instance.m_initialized;
+}
+
+AudioEngine::AudioEngine()
+{
+    ma_result result;
+    result = ma_engine_init(NULL, &m_engine);
+
+    if (result != MA_SUCCESS) {
+        std::cerr << "Failed to initialize audio engine." << std::endl;
+        return;
+    }
+
+    m_initialized = true;
+}
+
+AudioEngine::~AudioEngine()
+{
+    if (m_initialized)
+        ma_engine_uninit(&m_engine);
+}

src/audio/audioengine.h

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include <memory>
+#include <miniaudio.h>
+
+namespace libscratchcpp
+{
+
+// This is a singleton which initializes and uninitializes the miniaudio engine
+class AudioEngine
+{
+    public:
+        static ma_engine *engine();
+        static bool initialized();
+
+    private:
+        AudioEngine();
+        ~AudioEngine();
+
+        static AudioEngine instance;
+        ma_engine m_engine;
+        bool m_initialized = false;
+};
+
+} // namespace libscratchcpp

src/audio/audioplayer.cpp

@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#include <iostream>
+
+#include "audioplayer.h"
+#include "audioengine.h"
+
+using namespace libscratchcpp;
+
+AudioPlayer::AudioPlayer()
+{
+    m_decoder = new ma_decoder;
+    m_sound = new ma_sound;
+}
+
+AudioPlayer::~AudioPlayer()
+{
+    if (m_loaded) {
+        ma_sound_uninit(m_sound);
+        ma_decoder_uninit(m_decoder);
+    }
+
+    delete m_decoder;
+    delete m_sound;
+}
+
+bool AudioPlayer::load(unsigned int size, const void *data, unsigned long sampleRate)
+{
+    if (!AudioEngine::initialized())
+        return false;
+
+    ma_engine *engine = AudioEngine::engine();
+
+    if (!data || size == 0)
+        return false;
+
+    ma_decoder_config config = ma_decoder_config_init(ma_format_f32, 2, sampleRate);
+    ma_result result = ma_decoder_init_memory(data, size, &config, m_decoder);
+
+    if (result != MA_SUCCESS) {
+        std::cerr << "Failed to decode sound." << std::endl;
+        return false;
+    }
+
+    ma_result initResult = ma_sound_init_from_data_source(engine, m_decoder, MA_SOUND_FLAG_DECODE, NULL, m_sound);
+
+    if (initResult != MA_SUCCESS) {
+        std::cerr << "Failed to init sound." << std::endl;
+        ma_decoder_uninit(m_decoder);
+        return false;
+    }
+
+    m_loaded = true;
+    return true;
+}
+
+void AudioPlayer::setVolume(float volume)
+{
+    if (!AudioEngine::initialized())
+        return;
+
+    ma_sound_set_volume(m_sound, volume);
+}
+
+void AudioPlayer::start()
+{
+    if (!AudioEngine::initialized())
+        return;
+
+    ma_result result = ma_sound_start(m_sound);
+
+    if (result != MA_SUCCESS) {
+        std::cerr << "Failed to start sound." << std::endl;
+        m_started = false;
+    } else
+        m_started = true;
+}
+
+void AudioPlayer::stop()
+{
+    if (!AudioEngine::initialized())
+        return;
+
+    ma_result result = ma_sound_stop(m_sound);
+    m_started = false;
+
+    if (result != MA_SUCCESS)
+        std::cerr << "Failed to stop sound." << std::endl;
+}
+
+bool AudioPlayer::isPlaying() const
+{
+    if (!AudioEngine::initialized())
+        return false;
+
+    return m_started && !m_sound->atEnd;
+}

src/audio/audioplayer.h

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "iaudioplayer.h"
+
+struct ma_decoder;
+struct ma_sound;
+
+namespace libscratchcpp
+{
+
+class AudioPlayer : public IAudioPlayer
+{
+    public:
+        AudioPlayer();
+        ~AudioPlayer();
+
+        bool load(unsigned int size, const void *data, unsigned long sampleRate) override;
+        void setVolume(float volume) override;
+
+        void start() override;
+        void stop() override;
+
+        bool isPlaying() const override;
+
+    private:
+        ma_decoder *m_decoder = nullptr;
+        ma_sound *m_sound;
+        bool m_loaded = false;
+        bool m_started = false;
+};
+
+} // namespace libscratchcpp

src/audio/audioplayerfactory.cpp

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#include "audioplayerfactory.h"
+
+#ifdef LIBSCRATCHCPP_AUDIO_SUPPORT
+#include "audioplayer.h"
+#else
+#include "audioplayerstub.h"
+#endif
+
+using namespace libscratchcpp;
+
+std::shared_ptr<AudioPlayerFactory> AudioPlayerFactory::m_instance = std::make_shared<AudioPlayerFactory>();
+
+AudioPlayerFactory::AudioPlayerFactory()
+{
+}
+
+std::shared_ptr<AudioPlayerFactory> AudioPlayerFactory::instance()
+{
+    return m_instance;
+}
+
+std::shared_ptr<IAudioPlayer> AudioPlayerFactory::create() const
+{
+#ifdef LIBSCRATCHCPP_AUDIO_SUPPORT
+    return std::make_shared<AudioPlayer>();
+#else
+    return std::make_shared<AudioPlayerStub>();
+#endif
+}

src/audio/audioplayerfactory.h

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "iaudioplayerfactory.h"
+
+namespace libscratchcpp
+{
+
+class AudioPlayerFactory : public IAudioPlayerFactory
+{
+    public:
+        AudioPlayerFactory();
+
+        static std::shared_ptr<AudioPlayerFactory> instance();
+        std::shared_ptr<IAudioPlayer> create() const override;
+
+    private:
+        static std::shared_ptr<AudioPlayerFactory> m_instance;
+};
+
+} // namespace libscratchcpp

src/audio/audioplayerstub.cpp

@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#include "audioplayerstub.h"
+
+using namespace libscratchcpp;
+
+AudioPlayerStub::AudioPlayerStub()
+{
+}
+
+bool AudioPlayerStub::load(unsigned int size, const void *data, unsigned long sampleRate)
+{
+    return true;
+}
+
+void AudioPlayerStub::setVolume(float volume)
+{
+}
+
+void AudioPlayerStub::start()
+{
+}
+
+void AudioPlayerStub::stop()
+{
+}
+
+bool AudioPlayerStub::isPlaying() const
+{
+    return false;
+}

src/audio/audioplayerstub.h

@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+
+#include "iaudioplayer.h"
+
+namespace libscratchcpp
+{
+
+class AudioPlayerStub : public IAudioPlayer
+{
+    public:
+        AudioPlayerStub();
+
+        bool load(unsigned int size, const void *data, unsigned long sampleRate) override;
+        void setVolume(float volume) override;
+
+        void start() override;
+        void stop() override;
+
+        bool isPlaying() const override;
+};
+
+} // namespace libscratchcpp