SkBlurDrawLooper.cpp revision fbfcd5602128ec010c82cb733c9cdc0a3254f9f3
1 2/* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8#include "SkBlurDrawLooper.h" 9#include "SkBlurMaskFilter.h" 10#include "SkCanvas.h" 11#include "SkFlattenableBuffers.h" 12#include "SkPaint.h" 13#include "SkMaskFilter.h" 14#include "SkColorFilter.h" 15 16SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, 17 SkColor color, uint32_t flags) 18 : fDx(dx), fDy(dy), fBlurColor(color), fBlurFlags(flags), fState(kDone) { 19 20 SkASSERT(flags <= kAll_BlurFlag); 21 if (radius > 0) { 22 uint32_t blurFlags = flags & kIgnoreTransform_BlurFlag ? 23 SkBlurMaskFilter::kIgnoreTransform_BlurFlag : 24 SkBlurMaskFilter::kNone_BlurFlag; 25 26 blurFlags |= flags & kHighQuality_BlurFlag ? 27 SkBlurMaskFilter::kHighQuality_BlurFlag : 28 SkBlurMaskFilter::kNone_BlurFlag; 29 30 fBlur = SkBlurMaskFilter::Create(radius, 31 SkBlurMaskFilter::kNormal_BlurStyle, 32 blurFlags); 33 } else { 34 fBlur = NULL; 35 } 36 37 if (flags & kOverrideColor_BlurFlag) { 38 // Set alpha to 1 for the override since transparency will already 39 // be baked into the blurred mask. 40 SkColor opaqueColor = SkColorSetA(color, 255); 41 //The SrcIn xfer mode will multiply 'color' by the incoming alpha 42 fColorFilter = SkColorFilter::CreateModeFilter(opaqueColor, 43 SkXfermode::kSrcIn_Mode); 44 } else { 45 fColorFilter = NULL; 46 } 47} 48 49SkBlurDrawLooper::SkBlurDrawLooper(SkFlattenableReadBuffer& buffer) 50: INHERITED(buffer) { 51 52 fDx = buffer.readScalar(); 53 fDy = buffer.readScalar(); 54 fBlurColor = buffer.readColor(); 55 fBlur = buffer.readFlattenableT<SkMaskFilter>(); 56 fColorFilter = buffer.readFlattenableT<SkColorFilter>(); 57 fBlurFlags = buffer.readUInt() & kAll_BlurFlag; 58} 59 60SkBlurDrawLooper::~SkBlurDrawLooper() { 61 SkSafeUnref(fBlur); 62 SkSafeUnref(fColorFilter); 63} 64 65void SkBlurDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) const { 66 this->INHERITED::flatten(buffer); 67 buffer.writeScalar(fDx); 68 buffer.writeScalar(fDy); 69 buffer.writeColor(fBlurColor); 70 buffer.writeFlattenable(fBlur); 71 buffer.writeFlattenable(fColorFilter); 72 buffer.writeUInt(fBlurFlags); 73} 74 75void SkBlurDrawLooper::init(SkCanvas* canvas) { 76 fState = kBeforeEdge; 77} 78 79bool SkBlurDrawLooper::next(SkCanvas* canvas, SkPaint* paint) { 80 switch (fState) { 81 case kBeforeEdge: 82 // we do nothing if a maskfilter is already installed 83 if (paint->getMaskFilter()) { 84 fState = kDone; 85 return false; 86 } 87#ifdef SK_BUILD_FOR_ANDROID 88 SkColor blurColor; 89 blurColor = fBlurColor; 90 if (SkColorGetA(blurColor) == 255) { 91 blurColor = SkColorSetA(blurColor, paint->getAlpha()); 92 } 93 paint->setColor(blurColor); 94#else 95 paint->setColor(fBlurColor); 96#endif 97 paint->setMaskFilter(fBlur); 98 paint->setColorFilter(fColorFilter); 99 canvas->save(SkCanvas::kMatrix_SaveFlag); 100 if (fBlurFlags & kIgnoreTransform_BlurFlag) { 101 SkMatrix transform(canvas->getTotalMatrix()); 102 transform.postTranslate(fDx, fDy); 103 canvas->setMatrix(transform); 104 } else { 105 canvas->translate(fDx, fDy); 106 } 107 fState = kAfterEdge; 108 return true; 109 case kAfterEdge: 110 canvas->restore(); 111 fState = kDone; 112 return true; 113 default: 114 SkASSERT(kDone == fState); 115 return false; 116 } 117} 118 119/////////////////////////////////////////////////////////////////////////////// 120 121SK_DEFINE_FLATTENABLE_REGISTRAR(SkBlurDrawLooper) 122 123