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 "HWComposerBufferCache.h" 18 19 #include <gui/BufferQueue.h> 20 21 namespace android { 22 23 HWComposerBufferCache::HWComposerBufferCache() 24 { 25 mBuffers.reserve(BufferQueue::NUM_BUFFER_SLOTS); 26 } 27 28 void HWComposerBufferCache::getHwcBuffer(int slot, 29 const sp<GraphicBuffer>& buffer, 30 uint32_t* outSlot, sp<GraphicBuffer>* outBuffer) 31 { 32 if (slot == BufferQueue::INVALID_BUFFER_SLOT || slot < 0) { 33 // default to slot 0 34 slot = 0; 35 } 36 37 if (static_cast<size_t>(slot) >= mBuffers.size()) { 38 mBuffers.resize(slot + 1); 39 } 40 41 *outSlot = slot; 42 43 if (mBuffers[slot] == buffer) { 44 // already cached in HWC, skip sending the buffer 45 *outBuffer = nullptr; 46 } else { 47 *outBuffer = buffer; 48 49 // update cache 50 mBuffers[slot] = buffer; 51 } 52 } 53 54 } // namespace android 55