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      1 #include "SkFlipPixelRef.h"
      2 #include "SkFlattenable.h"
      3 #include "SkRegion.h"
      4 
      5 SkFlipPixelRef::SkFlipPixelRef(SkBitmap::Config config, int width, int height)
      6 : fFlipper(width, height) {
      7     fConfig = config;
      8     fSize = SkBitmap::ComputeSize(config, width, height);
      9     fStorage = sk_malloc_throw(fSize << 1);
     10     fPage0 = fStorage;
     11     fPage1 = (char*)fStorage + fSize;
     12 }
     13 
     14 SkFlipPixelRef::~SkFlipPixelRef() {
     15     sk_free(fStorage);
     16 }
     17 
     18 const SkRegion& SkFlipPixelRef::beginUpdate(SkBitmap* device) {
     19     void*       writeAddr;
     20     const void* readAddr;
     21     this->getFrontBack(&readAddr, &writeAddr);
     22 
     23     device->setConfig(fConfig, fFlipper.width(), fFlipper.height());
     24     device->setPixels(writeAddr);
     25 
     26     SkRegion    copyBits;
     27     const SkRegion& dirty = fFlipper.update(&copyBits);
     28 
     29     SkFlipPixelRef::CopyBitsFromAddr(*device, copyBits, readAddr);
     30     return dirty;
     31 }
     32 
     33 void SkFlipPixelRef::endUpdate() {
     34     this->swapPages();
     35 }
     36 
     37 ///////////////////////////////////////////////////////////////////////////////
     38 
     39 void* SkFlipPixelRef::onLockPixels(SkColorTable** ct) {
     40     fMutex.acquire();
     41     *ct = NULL;
     42     return fPage0;
     43 }
     44 
     45 void SkFlipPixelRef::onUnlockPixels() {
     46     fMutex.release();
     47 }
     48 
     49 void SkFlipPixelRef::swapPages() {
     50     fMutex.acquire();
     51     SkTSwap<void*>(fPage0, fPage1);
     52     this->notifyPixelsChanged();
     53     fMutex.release();
     54 }
     55 
     56 void SkFlipPixelRef::flatten(SkFlattenableWriteBuffer& buffer) const {
     57     this->INHERITED::flatten(buffer);
     58 
     59     buffer.write32(fSize);
     60     // only need to write page0
     61     buffer.writePad(fPage0, fSize);
     62 }
     63 
     64 SkFlipPixelRef::SkFlipPixelRef(SkFlattenableReadBuffer& buffer)
     65         : INHERITED(buffer, NULL) {
     66     fSize = buffer.readU32();
     67     fStorage = sk_malloc_throw(fSize << 1);
     68     fPage0 = fStorage;
     69     fPage1 = (char*)fStorage + fSize;
     70     buffer.read(fPage0, fSize);
     71 }
     72 
     73 SkPixelRef* SkFlipPixelRef::Create(SkFlattenableReadBuffer& buffer) {
     74     return SkNEW_ARGS(SkFlipPixelRef, (buffer));
     75 }
     76 
     77 static SkPixelRef::Registrar reg("SkFlipPixelRef",
     78                                  SkFlipPixelRef::Create);
     79 
     80 ///////////////////////////////////////////////////////////////////////////////
     81 
     82 static void copyRect(const SkBitmap& dst, const SkIRect& rect,
     83                      const void* srcAddr, int shift) {
     84     const size_t offset = rect.fTop * dst.rowBytes() + (rect.fLeft << shift);
     85     char* dstP = static_cast<char*>(dst.getPixels()) + offset;
     86     const char* srcP = static_cast<const char*>(srcAddr) + offset;
     87     const size_t rb = dst.rowBytes();
     88     const size_t bytes = rect.width() << shift;
     89 
     90     int height = rect.height();
     91     while (--height >= 0) {
     92         memcpy(dstP, srcP, bytes);
     93         dstP += rb;
     94         srcP += rb;
     95     }
     96 }
     97 
     98 static int getShift(SkBitmap::Config config) {
     99     switch (config) {
    100         case SkBitmap::kARGB_8888_Config:
    101             return 2;
    102         case SkBitmap::kRGB_565_Config:
    103         case SkBitmap::kARGB_4444_Config:
    104             return 1;
    105         case SkBitmap::kIndex8_Config:
    106         case SkBitmap::kA8_Config:
    107             return 0;
    108         default:
    109             return -1;  // signal not supported
    110     }
    111 }
    112 
    113 void SkFlipPixelRef::CopyBitsFromAddr(const SkBitmap& dst, const SkRegion& clip,
    114                                       const void* srcAddr) {
    115     const int shift = getShift(dst.config());
    116     if (shift < 0) {
    117         return;
    118     }
    119 
    120     const SkIRect bounds = {0, 0, dst.width(), dst.height()};
    121     SkRegion::Cliperator iter(clip, bounds);
    122 
    123     while (!iter.done()) {
    124         copyRect(dst, iter.rect(), srcAddr, shift);
    125         iter.next();
    126     }
    127 }
    128