1 files changed, 130 insertions, 0 deletions
diff --git a/externals/oboe/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp b/externals/oboe/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp
new file mode 100644
index 0000000000..defb6dcb42
--- /dev/null
+++ b/externals/oboe/samples/SoundBoard/src/main/cpp/SoundBoardEngine.cpp
@@ -0,0 +1,130 @@
+/*
+ * Copyright 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#include <memory>
+#include "SoundBoardEngine.h"
+
+/**
+ * Main audio engine for the SoundBoard sample. It is responsible for:
+ *
+ * - Creating the callback object which will be supplied when constructing the audio stream
+ * - Creating the playback stream, including setting the callback object
+ * - Creating `Synth` which will render the audio inside the callback
+ * - Starting the playback stream
+ * - Restarting the playback stream when `restart()` is called by the callback object
+ *
+ * @param numSignals
+ */
+SoundBoardEngine::SoundBoardEngine(int32_t numSignals) {
+    createCallback(numSignals);
+}
+
+SoundBoardEngine::~SoundBoardEngine() {
+    if (mStream) {
+        LOGE("SoundBoardEngine destructor was called without calling stop()."
+             "Please call stop() to ensure stream resources are not leaked.");
+        stop();
+    }
+}
+
+void SoundBoardEngine::noteOff(int32_t noteIndex) {
+    mSynth->noteOff(noteIndex);
+}
+
+void SoundBoardEngine::noteOn(int32_t noteIndex) {
+    mSynth->noteOn(noteIndex);
+}
+
+void SoundBoardEngine::tap(bool isDown) {
+    mSynth->tap(isDown);
+}
+
+void SoundBoardEngine::restart() {
+    stop();
+    start();
+}
+// Create the playback stream
+oboe::Result SoundBoardEngine::createPlaybackStream() {
+    oboe::AudioStreamBuilder builder;
+    return builder.setSharingMode(oboe::SharingMode::Exclusive)
+            ->setPerformanceMode(oboe::PerformanceMode::LowLatency)
+            ->setFormat(oboe::AudioFormat::Float)
+            ->setDataCallback(mDataCallback)
+            ->setErrorCallback(mErrorCallback)
+            ->openStream(mStream);
+}
+
+// Create the callback and set its thread affinity to the supplied CPU core IDs
+void SoundBoardEngine::createCallback(int32_t numSignals){
+
+    mDataCallback = std::make_shared<DefaultDataCallback>();
+
+    // Create the error callback, we supply ourselves as the parent so that we can restart the stream
+    // when it's disconnected
+    mErrorCallback = std::make_shared<DefaultErrorCallback>(*this);
+
+    mNumSignals = numSignals;
+}
+
+bool SoundBoardEngine::start() {
+    // It is possible for a stream's device to become disconnected during stream open or between
+    // stream open and stream start.
+    // If the stream fails to start, close the old stream and try again.
+    bool didStart = false;
+    int tryCount = 0;
+    do {
+        if (tryCount > 0) {
+            usleep(20 * 1000); // Sleep between tries to give the system time to settle.
+        }
+        didStart = attemptStart();
+    } while (!didStart && tryCount++ < 3);
+    if (!didStart) {
+        LOGE("Failed at starting the stream");
+    }
+    return didStart;
+}
+
+bool SoundBoardEngine::attemptStart() {
+    auto result = createPlaybackStream();
+
+    if (result == Result::OK) {
+        // Create our synthesizer audio source using the properties of the stream
+        mSynth = Synth::create(mStream->getSampleRate(), mStream->getChannelCount(), mNumSignals);
+        mDataCallback->reset();
+        mDataCallback->setSource(std::dynamic_pointer_cast<IRenderableAudio>(mSynth));
+        result = mStream->start();
+        if (result == Result::OK) {
+            return true;
+        } else {
+            LOGW("Failed attempt at starting the playback stream. Error: %s", convertToText(result));
+            return false;
+        }
+    } else {
+        LOGW("Failed attempt at creating the playback stream. Error: %s", convertToText(result));
+        return false;
+    }
+}
+
+bool SoundBoardEngine::stop() {
+    if(mStream && mStream->getState() != oboe::StreamState::Closed) {
+        mStream->stop();
+        mStream->close();
+    }
+    mStream.reset();
+    return true;
+}
+