eden/externals/oboe/samples/shared/Mixer.h
swurl 6c655321e6
Move dead submodules in-tree
Signed-off-by: swurl <swurl@swurl.xyz>
2025-05-31 02:33:02 -04:00

70 lines
2.1 KiB
C++

/*
* 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.
*/
#ifndef SHARED_MIXER_H
#define SHARED_MIXER_H
#include <array>
#include "IRenderableAudio.h"
/**
* A Mixer object which sums the output from multiple tracks into a single output. The number of
* input channels on each track must match the number of output channels (default 1=mono). This can
* be changed by calling `setChannelCount`.
* The inputs to the mixer are not owned by the mixer, they should not be deleted while rendering.
*/
class Mixer : public IRenderableAudio {
public:
void renderAudio(float *audioData, int32_t numFrames) {
int numSamples = numFrames * mChannelCount;
if (numSamples > mBufferSize) {
mMixingBuffer = std::make_unique<float[]>(numSamples);
mBufferSize = numSamples;
}
// Zero out the incoming container array
memset(audioData, 0, sizeof(float) * numSamples);
for (int i = 0; i < mTracks.size(); ++i) {
mTracks[i]->renderAudio(mMixingBuffer.get(), numFrames);
for (int j = 0; j < numSamples; ++j) {
audioData[j] += mMixingBuffer[j];
}
}
}
void addTrack(IRenderableAudio *renderer){
mTracks.push_back(renderer);
}
void setChannelCount(int32_t channelCount){ mChannelCount = channelCount; }
void removeAllTracks(){
mTracks.clear();
}
private:
int32_t mBufferSize = 0;
std::unique_ptr<float[]> mMixingBuffer;
std::vector<IRenderableAudio*> mTracks;
int32_t mChannelCount = 1; // Default to mono
};
#endif //SHARED_MIXER_H