ebiten/audio/internal/oboe/oboe_fifo_FifoControllerBase_android.cpp

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/*
* Copyright 2015 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 <algorithm>
#include <cassert>
#include <stdint.h>
#include "oboe_fifo_FifoControllerBase_android.h"
namespace oboe {
FifoControllerBase::FifoControllerBase(uint32_t capacityInFrames)
: mTotalFrames(capacityInFrames)
{
// Avoid ridiculously large buffers and the arithmetic wraparound issues that can follow.
assert(capacityInFrames <= (UINT32_MAX / 4));
}
uint32_t FifoControllerBase::getFullFramesAvailable() const {
uint64_t writeCounter = getWriteCounter();
uint64_t readCounter = getReadCounter();
if (readCounter > writeCounter) {
return 0;
}
uint64_t delta = writeCounter - readCounter;
if (delta >= mTotalFrames) {
return mTotalFrames;
}
// delta is now guaranteed to fit within the range of a uint32_t
return static_cast<uint32_t>(delta);
}
uint32_t FifoControllerBase::getReadIndex() const {
// % works with non-power of two sizes
return static_cast<uint32_t>(getReadCounter() % mTotalFrames);
}
void FifoControllerBase::advanceReadIndex(uint32_t numFrames) {
incrementReadCounter(numFrames);
}
uint32_t FifoControllerBase::getEmptyFramesAvailable() const {
return static_cast<uint32_t>(mTotalFrames - getFullFramesAvailable());
}
uint32_t FifoControllerBase::getWriteIndex() const {
// % works with non-power of two sizes
return static_cast<uint32_t>(getWriteCounter() % mTotalFrames);
}
void FifoControllerBase::advanceWriteIndex(uint32_t numFrames) {
incrementWriteCounter(numFrames);
}
} // namespace oboe