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      1 #include "SkBlurDrawLooper.h"
      2 #include "SkBlurMaskFilter.h"
      3 #include "SkCanvas.h"
      4 #include "SkPaint.h"
      5 #include "SkMaskFilter.h"
      6 #include "SkColorFilter.h"
      7 
      8 SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy,
      9                                    SkColor color, uint32_t flags)
     10     : fDx(dx), fDy(dy), fBlurColor(color), fBlurFlags(flags) {
     11 
     12     SkASSERT(flags <= kAll_BlurFlag);
     13     if (radius > 0) {
     14         uint32_t blurFlags = flags & kIgnoreTransform_BlurFlag ?
     15             SkBlurMaskFilter::kIgnoreTransform_BlurFlag :
     16             SkBlurMaskFilter::kNone_BlurFlag;
     17 
     18         blurFlags |= flags & kHighQuality_BlurFlag ?
     19             SkBlurMaskFilter::kHighQuality_BlurFlag :
     20             SkBlurMaskFilter::kNone_BlurFlag;
     21 
     22         fBlur = SkBlurMaskFilter::Create(radius,
     23                                          SkBlurMaskFilter::kNormal_BlurStyle,
     24                                          blurFlags);
     25     } else {
     26         fBlur = NULL;
     27     }
     28 
     29     if (flags & kOverrideColor_BlurFlag) {
     30         // Set alpha to 1 for the override since transparency will already
     31         // be baked into the blurred mask.
     32         SkColor opaqueColor = SkColorSetA(color, 255);
     33         //The SrcIn xfer mode will multiply 'color' by the incoming alpha
     34         fColorFilter = SkColorFilter::CreateModeFilter(opaqueColor,
     35                                                        SkXfermode::kSrcIn_Mode);
     36     } else {
     37         fColorFilter = NULL;
     38     }
     39 }
     40 
     41 SkBlurDrawLooper::SkBlurDrawLooper(SkFlattenableReadBuffer& buffer) {
     42     fDx = buffer.readScalar();
     43     fDy = buffer.readScalar();
     44     fBlurColor = buffer.readU32();
     45     fBlur = static_cast<SkMaskFilter*>(buffer.readFlattenable());
     46     fColorFilter = static_cast<SkColorFilter*>(buffer.readFlattenable());
     47     fBlurFlags = buffer.readU32() & kAll_BlurFlag;
     48 }
     49 
     50 SkBlurDrawLooper::~SkBlurDrawLooper() {
     51     SkSafeUnref(fBlur);
     52     SkSafeUnref(fColorFilter);
     53 }
     54 
     55 void SkBlurDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) {
     56     buffer.writeScalar(fDx);
     57     buffer.writeScalar(fDy);
     58     buffer.write32(fBlurColor);
     59     buffer.writeFlattenable(fBlur);
     60     buffer.writeFlattenable(fColorFilter);
     61     buffer.write32(fBlurFlags);
     62 }
     63 
     64 void SkBlurDrawLooper::init(SkCanvas* canvas) {
     65     fState = kBeforeEdge;
     66 }
     67 
     68 bool SkBlurDrawLooper::next(SkCanvas* canvas, SkPaint* paint) {
     69     switch (fState) {
     70         case kBeforeEdge:
     71             // we do nothing if a maskfilter is already installed
     72             if (paint->getMaskFilter()) {
     73                 fState = kDone;
     74                 return false;
     75             }
     76 #ifdef ANDROID
     77             SkColor blurColor;
     78             blurColor = fBlurColor;
     79             if (SkColorGetA(blurColor) == 255) {
     80                 blurColor = SkColorSetA(blurColor, paint->getAlpha());
     81             }
     82             paint->setColor(blurColor);
     83 #else
     84             paint->setColor(fBlurColor);
     85 #endif
     86             paint->setMaskFilter(fBlur);
     87             paint->setColorFilter(fColorFilter);
     88             canvas->save(SkCanvas::kMatrix_SaveFlag);
     89             if (fBlurFlags & kIgnoreTransform_BlurFlag) {
     90                 SkMatrix transform(canvas->getTotalMatrix());
     91                 transform.postTranslate(fDx, fDy);
     92                 canvas->setMatrix(transform);
     93             } else {
     94                 canvas->translate(fDx, fDy);
     95             }
     96             fState = kAfterEdge;
     97             return true;
     98         case kAfterEdge:
     99             canvas->restore();
    100             fState = kDone;
    101             return true;
    102         default:
    103             SkASSERT(kDone == fState);
    104             return false;
    105     }
    106 }
    107 
    108 ///////////////////////////////////////////////////////////////////////////////
    109 
    110 static SkFlattenable::Registrar gReg("SkBlurDrawLooper",
    111                                      SkBlurDrawLooper::CreateProc);
    112 
    113