發現一個比較好的介紹graphic帖子， 后面會跟著帖子來梳理下graphic相關知識點
http://blog.csdn.net/u014409795/article/details/51276468

目前創新互聯已為千余家的企業提供了網站建設、域名、網頁空間、綿陽服務器托管、企業網站設計、昔陽網站維護等服務，公司將堅持客戶導向、應用為本的策略，正道將秉承"和諧、參與、激情"的文化，與客戶和合作伙伴齊心協力一起成長，共同發展。

1. BufferQueue

       class BufferQueue {
              class ProxyConsumerListener : public BnConsumerListener;
              static void createBufferQueue(sp<IGraphicBufferProducer>* outProducer,
                        sp<IGraphicBufferConsumer>* outConsumer,
                        const sp<IGraphicBufferAlloc>& allocator = NULL);
        private:
             BufferQueue(); // Create through createBufferQueue

     }

     //看起來只有consumer一個角色？

    void BufferQueue::createBufferQueue(sp<IGraphicBufferProducer>* outProducer,
        sp<IGraphicBufferConsumer>* outConsumer,
        const sp<IGraphicBufferAlloc>& allocator) {

        sp<BufferQueueCore> core(new BufferQueueCore(allocator));
        sp<IGraphicBufferProducer> producer(new BufferQueueProducer(core));

        sp<IGraphicBufferConsumer> consumer(new BufferQueueConsumer(core));

    

  BufferQueue核心是BufferQueueCore,

  看BufferQueueCore里面是管理什么的 

  class BufferQueueCore : public virtual RefBase {

          friend class BufferQueueProducer;
          friend class BufferQueueConsumer;

           typedef Vector<BufferItem> Fifo;  //一個BufferItem Vector

         private:

         // mAllocator is the connection to SurfaceFlinger that is used to allocate
         // new GraphicBuffer objects.
        sp<IGraphicBufferAlloc> mAllocator;
         // mSlots is an array of buffer slots that must be mirrored on the producer
        // side. This allows buffer ownership to be transferred between the producer
        // and consumer without sending a GraphicBuffer over Binder. The entire
       // array is initialized to NULL at construction time, and buffers are
       // allocated for a slot when requestBuffer is called with that slot's index.
        BufferQueueDefs::SlotsType mSlots;   //

        BufferSlot()
    : mEglDisplay(EGL_NO_DISPLAY),
      mBufferState(BufferSlot::FREE),   //state
      mRequestBufferCalled(false),
      mFrameNumber(0),
      mEglFence(EGL_NO_SYNC_KHR),
      mAcquireCalled(false),
      mNeedsCleanupOnRelease(false),
      mAttachedByConsumer(false) {
    }

    // mGraphicBuffer points to the buffer allocated for this slot or is NULL
    // if no buffer has been allocated.
    sp<GraphicBuffer> mGraphicBuffer;   //bufferslot中指向GraphicBuffer

  

    enum BufferState { // state 表示buffer state

     FREE = 0,  //FREE indicates that the buffer is available to be dequeued by the producer.
     // 允許produce獲取該buffer，填充數據，狀態變為dequeue    free 時表示該buffer還被bufferqueue 所有

   DEQUEUED = 1,// DEQUEUED indicates that the buffer has been dequeued by the  producer, but has not yet been queued or canceled. The slot is "owned" by the producer.  處于待填充數據狀態,被producer所有

  QUEUED = 2,//QUEUED indicates that the buffer has been filled by the producer and queued for use by the consumer; producer填充完數據，準備提供給consumer消費，被bufferqueue所有

   ACQUIRED = 3//ACQUIRED indicates that the buffer has been acquired by the  consumer.

   buffer被consumer獲取到，消費完后轉為free

   

   在bufferqueuecore中bufferItem又是什么
   class BufferItem : public Flattenable<BufferItem> {

   // mGraphicBuffer points to the buffer allocated for this slot, or is NULL
    // if the buffer in this slot has been acquired in the past (see
    // BufferSlot.mAcquireCalled).
    sp<GraphicBuffer> mGraphicBuffer; //也有GraphicBuffer指針 

     union {
        // mSlot is the slot index of this buffer (default INVALID_BUFFER_SLOT).
        int mSlot; // slot數組中索引

        // mBuf is the former name for mSlot
        int mBuf;  // 舊名字
    };

   

   BufferSlot 與 BufferItem 都指向GraphicBuffer,然后又 通過mSlot下標關聯起來，至于兩者使用場景再看
 

本文標題：Graphic學習筆記
當前URL：http://vcdvsql.cn/article42/peiphc.html

成都網站建設公司_創新互聯，為您提供App設計、響應式網站、關鍵詞優化、定制開發、建站公司、網站改版

廣告

聲明：本網站發布的內容（圖片、視頻和文字）以用戶投稿、用戶轉載內容為主，如果涉及侵權請盡快告知，我們將會在第一時間刪除。文章觀點不代表本網站立場，如需處理請聯系客服。電話：028-86922220；郵箱：631063699@qq.com。內容未經允許不得轉載，或轉載時需注明來源： 創新互聯