1 /* 2 * Copyright (C) 2017 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <compositionengine/impl/HwcBufferCache.h> 18 #include <gui/BufferQueue.h> 19 #include <ui/GraphicBuffer.h> 20 21 namespace android::compositionengine::impl { 22 23 HwcBufferCache::HwcBufferCache() { 24 std::fill(std::begin(mBuffers), std::end(mBuffers), wp<GraphicBuffer>(nullptr)); 25 } 26 27 void HwcBufferCache::getHwcBuffer(int slot, const sp<GraphicBuffer>& buffer, uint32_t* outSlot, 28 sp<GraphicBuffer>* outBuffer) { 29 // default is 0 30 if (slot == BufferQueue::INVALID_BUFFER_SLOT || slot < 0 || 31 slot >= BufferQueue::NUM_BUFFER_SLOTS) { 32 *outSlot = 0; 33 } else { 34 *outSlot = slot; 35 } 36 37 auto& currentBuffer = mBuffers[*outSlot]; 38 wp<GraphicBuffer> weakCopy(buffer); 39 if (currentBuffer == weakCopy) { 40 // already cached in HWC, skip sending the buffer 41 *outBuffer = nullptr; 42 } else { 43 *outBuffer = buffer; 44 45 // update cache 46 currentBuffer = buffer; 47 } 48 } 49 50 } // namespace android::compositionengine::impl 51
