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      1 /*
      2  * Copyright (C) 2008 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 #ifndef SkFlipPixelRef_DEFINED
     18 #define SkFlipPixelRef_DEFINED
     19 
     20 #include "SkBitmap.h"
     21 #include "SkPageFlipper.h"
     22 #include "SkPixelRef.h"
     23 #include "SkThread.h"
     24 
     25 class SkRegion;
     26 
     27 class SkFlipPixelRef : public SkPixelRef {
     28 public:
     29             SkFlipPixelRef(SkBitmap::Config, int width, int height);
     30     virtual ~SkFlipPixelRef();
     31 
     32     bool isDirty() const { return fFlipper.isDirty(); }
     33     const SkRegion& dirtyRgn() const { return fFlipper.dirtyRgn(); }
     34 
     35     void inval() { fFlipper.inval(); }
     36     void inval(const SkIRect& rect) { fFlipper.inval(rect); }
     37     void inval(const SkRegion& rgn) { fFlipper.inval(rgn); }
     38     void inval(const SkRect& r, bool doAA) { fFlipper.inval(r, doAA); }
     39 
     40     const SkRegion& beginUpdate(SkBitmap* device);
     41     void endUpdate();
     42 
     43 private:
     44     void getFrontBack(const void** front, void** back) const {
     45         if (front) {
     46             *front = fPage0;
     47         }
     48         if (back) {
     49             *back = fPage1;
     50         }
     51     }
     52 
     53     void    swapPages();
     54 
     55     // Helper to copy pixels from srcAddr to the dst bitmap, clipped to clip.
     56     // srcAddr points to memory with the same config as dst.
     57     static void CopyBitsFromAddr(const SkBitmap& dst, const SkRegion& clip,
     58                                  const void* srcAddr);
     59 
     60     // serialization
     61 
     62 public:
     63     virtual Factory getFactory() const { return Create; }
     64     virtual void flatten(SkFlattenableWriteBuffer&) const;
     65     static SkPixelRef* Create(SkFlattenableReadBuffer& buffer);
     66 
     67 protected:
     68     virtual void* onLockPixels(SkColorTable**);
     69     virtual void onUnlockPixels();
     70 
     71     SkFlipPixelRef(SkFlattenableReadBuffer&);
     72 
     73 private:
     74     SkMutex         fMutex;
     75     SkPageFlipper   fFlipper;
     76 
     77     void*           fStorage;
     78     void*           fPage0; // points into fStorage;
     79     void*           fPage1; // points into fStorage;
     80     size_t          fSize;  // size of 1 page. fStorage holds 2 pages
     81     SkBitmap::Config fConfig;
     82 
     83     typedef SkPixelRef INHERITED;
     84 };
     85 
     86 class SkAutoFlipUpdate : SkNoncopyable {
     87 public:
     88     SkAutoFlipUpdate(SkFlipPixelRef* ref) : fRef(ref) {
     89         fDirty = &ref->beginUpdate(&fBitmap);
     90     }
     91     ~SkAutoFlipUpdate() {
     92         if (fRef) {
     93             fRef->endUpdate();
     94         }
     95     }
     96 
     97     const SkBitmap& bitmap() const { return fBitmap; }
     98     const SkRegion& dirty() const { return *fDirty; }
     99 
    100     // optional. This gets automatically called in the destructor (only once)
    101     void endUpdate() {
    102         if (fRef) {
    103             fRef->endUpdate();
    104             fRef = NULL;
    105         }
    106     }
    107 
    108 private:
    109     SkFlipPixelRef* fRef;
    110     SkBitmap        fBitmap;
    111     const SkRegion* fDirty;
    112 };
    113 
    114 #endif
    115