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https://github.com/hajimehoshi/ebiten.git
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69 lines
2.1 KiB
C++
Vendored
69 lines
2.1 KiB
C++
Vendored
/*
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* Copyright 2015 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <algorithm>
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#include <cassert>
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#include <stdint.h>
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#include "oboe_fifo_FifoControllerBase_android.h"
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namespace oboe {
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FifoControllerBase::FifoControllerBase(uint32_t capacityInFrames)
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: mTotalFrames(capacityInFrames)
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{
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// Avoid ridiculously large buffers and the arithmetic wraparound issues that can follow.
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assert(capacityInFrames <= (UINT32_MAX / 4));
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}
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uint32_t FifoControllerBase::getFullFramesAvailable() const {
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uint64_t writeCounter = getWriteCounter();
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uint64_t readCounter = getReadCounter();
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if (readCounter > writeCounter) {
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return 0;
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}
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uint64_t delta = writeCounter - readCounter;
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if (delta >= mTotalFrames) {
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return mTotalFrames;
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}
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// delta is now guaranteed to fit within the range of a uint32_t
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return static_cast<uint32_t>(delta);
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}
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uint32_t FifoControllerBase::getReadIndex() const {
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// % works with non-power of two sizes
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return static_cast<uint32_t>(getReadCounter() % mTotalFrames);
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}
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void FifoControllerBase::advanceReadIndex(uint32_t numFrames) {
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incrementReadCounter(numFrames);
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}
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uint32_t FifoControllerBase::getEmptyFramesAvailable() const {
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return static_cast<uint32_t>(mTotalFrames - getFullFramesAvailable());
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}
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uint32_t FifoControllerBase::getWriteIndex() const {
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// % works with non-power of two sizes
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return static_cast<uint32_t>(getWriteCounter() % mTotalFrames);
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}
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void FifoControllerBase::advanceWriteIndex(uint32_t numFrames) {
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incrementWriteCounter(numFrames);
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}
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} // namespace oboe
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