SkBlurDrawLooper.cpp revision 4991b8f23482afc1494fd17647421ce68de53331
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 "SkColorFilter.h" 12#include "SkFlattenableBuffers.h" 13#include "SkMaskFilter.h" 14#include "SkPaint.h" 15#include "SkString.h" 16#include "SkStringUtils.h" 17 18SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, 19 SkColor color, uint32_t flags) 20 : fDx(dx), fDy(dy), fBlurColor(color), fBlurFlags(flags), fState(kDone) { 21 22 SkASSERT(flags <= kAll_BlurFlag); 23 if (radius > 0) { 24 uint32_t blurFlags = flags & kIgnoreTransform_BlurFlag ? 25 SkBlurMaskFilter::kIgnoreTransform_BlurFlag : 26 SkBlurMaskFilter::kNone_BlurFlag; 27 28 blurFlags |= flags & kHighQuality_BlurFlag ? 29 SkBlurMaskFilter::kHighQuality_BlurFlag : 30 SkBlurMaskFilter::kNone_BlurFlag; 31 32 fBlur = SkBlurMaskFilter::Create(radius, 33 SkBlurMaskFilter::kNormal_BlurStyle, 34 blurFlags); 35 } else { 36 fBlur = NULL; 37 } 38 39 if (flags & kOverrideColor_BlurFlag) { 40 // Set alpha to 1 for the override since transparency will already 41 // be baked into the blurred mask. 42 SkColor opaqueColor = SkColorSetA(color, 255); 43 //The SrcIn xfer mode will multiply 'color' by the incoming alpha 44 fColorFilter = SkColorFilter::CreateModeFilter(opaqueColor, 45 SkXfermode::kSrcIn_Mode); 46 } else { 47 fColorFilter = NULL; 48 } 49} 50 51SkBlurDrawLooper::SkBlurDrawLooper(SkFlattenableReadBuffer& buffer) 52: INHERITED(buffer) { 53 54 fDx = buffer.readScalar(); 55 fDy = buffer.readScalar(); 56 fBlurColor = buffer.readColor(); 57 fBlur = buffer.readFlattenableT<SkMaskFilter>(); 58 fColorFilter = buffer.readFlattenableT<SkColorFilter>(); 59 fBlurFlags = buffer.readUInt() & kAll_BlurFlag; 60} 61 62SkBlurDrawLooper::~SkBlurDrawLooper() { 63 SkSafeUnref(fBlur); 64 SkSafeUnref(fColorFilter); 65} 66 67void SkBlurDrawLooper::flatten(SkFlattenableWriteBuffer& buffer) const { 68 this->INHERITED::flatten(buffer); 69 buffer.writeScalar(fDx); 70 buffer.writeScalar(fDy); 71 buffer.writeColor(fBlurColor); 72 buffer.writeFlattenable(fBlur); 73 buffer.writeFlattenable(fColorFilter); 74 buffer.writeUInt(fBlurFlags); 75} 76 77void SkBlurDrawLooper::init(SkCanvas* canvas) { 78 fState = kBeforeEdge; 79} 80 81bool SkBlurDrawLooper::next(SkCanvas* canvas, SkPaint* paint) { 82 switch (fState) { 83 case kBeforeEdge: 84 // we do nothing if a maskfilter is already installed 85 if (paint->getMaskFilter()) { 86 fState = kDone; 87 return false; 88 } 89#ifdef SK_BUILD_FOR_ANDROID 90 SkColor blurColor; 91 blurColor = fBlurColor; 92 if (SkColorGetA(blurColor) == 255) { 93 blurColor = SkColorSetA(blurColor, paint->getAlpha()); 94 } 95 paint->setColor(blurColor); 96#else 97 paint->setColor(fBlurColor); 98#endif 99 paint->setMaskFilter(fBlur); 100 paint->setColorFilter(fColorFilter); 101 canvas->save(SkCanvas::kMatrix_SaveFlag); 102 if (fBlurFlags & kIgnoreTransform_BlurFlag) { 103 SkMatrix transform(canvas->getTotalMatrix()); 104 transform.postTranslate(fDx, fDy); 105 canvas->setMatrix(transform); 106 } else { 107 canvas->translate(fDx, fDy); 108 } 109 fState = kAfterEdge; 110 return true; 111 case kAfterEdge: 112 canvas->restore(); 113 fState = kDone; 114 return true; 115 default: 116 SkASSERT(kDone == fState); 117 return false; 118 } 119} 120 121#ifdef SK_DEVELOPER 122void SkBlurDrawLooper::toString(SkString* str) const { 123 str->append("SkBlurDrawLooper: "); 124 125 str->append("dx: "); 126 str->appendScalar(fDx); 127 128 str->append(" dy: "); 129 str->appendScalar(fDy); 130 131 str->append(" color: "); 132 str->appendHex(fBlurColor); 133 134 str->append(" flags: ("); 135 if (kNone_BlurFlag == fBlurFlags) { 136 str->append("None"); 137 } else { 138 bool needsSeparator = false; 139 SkAddFlagToString(str, SkToBool(kIgnoreTransform_BlurFlag & fBlurFlags), "IgnoreTransform", 140 &needsSeparator); 141 SkAddFlagToString(str, SkToBool(kOverrideColor_BlurFlag & fBlurFlags), "OverrideColor", 142 &needsSeparator); 143 SkAddFlagToString(str, SkToBool(kHighQuality_BlurFlag & fBlurFlags), "HighQuality", 144 &needsSeparator); 145 } 146 str->append(")"); 147 148 // TODO: add optional "fBlurFilter->toString(str);" when SkMaskFilter::toString is added 149 // alternatively we could cache the radius in SkBlurDrawLooper and just add it here 150} 151#endif 152