SkBlurDrawLooper.cpp revision 0f10f7bf1fb43ca6346dc220a076773b1f19a367
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 "SkBlurMask.h" // just for SkBlurMask::ConvertRadiusToSigma 10#include "SkBlurMaskFilter.h" 11#include "SkCanvas.h" 12#include "SkColorFilter.h" 13#include "SkReadBuffer.h" 14#include "SkWriteBuffer.h" 15#include "SkMaskFilter.h" 16#include "SkPaint.h" 17#include "SkString.h" 18#include "SkStringUtils.h" 19 20SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, 21 SkColor color, uint32_t flags) { 22 this->init(SkBlurMask::ConvertRadiusToSigma(radius), dx, dy, color, flags); 23} 24 25SkBlurDrawLooper::SkBlurDrawLooper(SkColor color, SkScalar sigma, 26 SkScalar dx, SkScalar dy, uint32_t flags) { 27 this->init(sigma, dx, dy, color, flags); 28} 29 30void SkBlurDrawLooper::init(SkScalar sigma, SkScalar dx, SkScalar dy, 31 SkColor color, uint32_t flags) { 32 fDx = dx; 33 fDy = dy; 34 fBlurColor = color; 35 fBlurFlags = flags; 36 37 SkASSERT(flags <= kAll_BlurFlag); 38 if (sigma > 0) { 39 uint32_t blurFlags = flags & kIgnoreTransform_BlurFlag ? 40 SkBlurMaskFilter::kIgnoreTransform_BlurFlag : 41 SkBlurMaskFilter::kNone_BlurFlag; 42 43 blurFlags |= flags & kHighQuality_BlurFlag ? 44 SkBlurMaskFilter::kHighQuality_BlurFlag : 45 SkBlurMaskFilter::kNone_BlurFlag; 46 47 fBlur = SkBlurMaskFilter::Create(SkBlurMaskFilter::kNormal_BlurStyle, 48 sigma, 49 blurFlags); 50 } else { 51 fBlur = NULL; 52 } 53 54 if (flags & kOverrideColor_BlurFlag) { 55 // Set alpha to 1 for the override since transparency will already 56 // be baked into the blurred mask. 57 SkColor opaqueColor = SkColorSetA(color, 255); 58 //The SrcIn xfer mode will multiply 'color' by the incoming alpha 59 fColorFilter = SkColorFilter::CreateModeFilter(opaqueColor, 60 SkXfermode::kSrcIn_Mode); 61 } else { 62 fColorFilter = NULL; 63 } 64} 65 66SkBlurDrawLooper::SkBlurDrawLooper(SkReadBuffer& buffer) 67: INHERITED(buffer) { 68 69 fDx = buffer.readScalar(); 70 fDy = buffer.readScalar(); 71 fBlurColor = buffer.readColor(); 72 fBlur = buffer.readMaskFilter(); 73 fColorFilter = buffer.readColorFilter(); 74 fBlurFlags = buffer.readUInt() & kAll_BlurFlag; 75} 76 77SkBlurDrawLooper::~SkBlurDrawLooper() { 78 SkSafeUnref(fBlur); 79 SkSafeUnref(fColorFilter); 80} 81 82void SkBlurDrawLooper::flatten(SkWriteBuffer& buffer) const { 83 this->INHERITED::flatten(buffer); 84 buffer.writeScalar(fDx); 85 buffer.writeScalar(fDy); 86 buffer.writeColor(fBlurColor); 87 buffer.writeFlattenable(fBlur); 88 buffer.writeFlattenable(fColorFilter); 89 buffer.writeUInt(fBlurFlags); 90} 91 92SkDrawLooper::Context* SkBlurDrawLooper::createContext(SkCanvas*, void* storage) const { 93 return SkNEW_PLACEMENT_ARGS(storage, BlurDrawLooperContext, (this)); 94} 95 96SkBlurDrawLooper::BlurDrawLooperContext::BlurDrawLooperContext( 97 const SkBlurDrawLooper* looper) 98 : fLooper(looper), fState(SkBlurDrawLooper::kBeforeEdge) {} 99 100bool SkBlurDrawLooper::BlurDrawLooperContext::next(SkCanvas* canvas, 101 SkPaint* paint) { 102 switch (fState) { 103 case kBeforeEdge: 104 // we do nothing if a maskfilter is already installed 105 if (paint->getMaskFilter()) { 106 fState = kDone; 107 return false; 108 } 109#ifdef SK_BUILD_FOR_ANDROID 110 SkColor blurColor; 111 blurColor = fLooper->fBlurColor; 112 if (SkColorGetA(blurColor) == 255) { 113 blurColor = SkColorSetA(blurColor, paint->getAlpha()); 114 } 115 paint->setColor(blurColor); 116#else 117 paint->setColor(fLooper->fBlurColor); 118#endif 119 paint->setMaskFilter(fLooper->fBlur); 120 paint->setColorFilter(fLooper->fColorFilter); 121 canvas->save(SkCanvas::kMatrix_SaveFlag); 122 if (fLooper->fBlurFlags & kIgnoreTransform_BlurFlag) { 123 SkMatrix transform(canvas->getTotalMatrix()); 124 transform.postTranslate(fLooper->fDx, fLooper->fDy); 125 canvas->setMatrix(transform); 126 } else { 127 canvas->translate(fLooper->fDx, fLooper->fDy); 128 } 129 fState = kAfterEdge; 130 return true; 131 case kAfterEdge: 132 canvas->restore(); 133 fState = kDone; 134 return true; 135 default: 136 SkASSERT(kDone == fState); 137 return false; 138 } 139} 140 141#ifndef SK_IGNORE_TO_STRING 142void SkBlurDrawLooper::toString(SkString* str) const { 143 str->append("SkBlurDrawLooper: "); 144 145 str->append("dx: "); 146 str->appendScalar(fDx); 147 148 str->append(" dy: "); 149 str->appendScalar(fDy); 150 151 str->append(" color: "); 152 str->appendHex(fBlurColor); 153 154 str->append(" flags: ("); 155 if (kNone_BlurFlag == fBlurFlags) { 156 str->append("None"); 157 } else { 158 bool needsSeparator = false; 159 SkAddFlagToString(str, SkToBool(kIgnoreTransform_BlurFlag & fBlurFlags), "IgnoreTransform", 160 &needsSeparator); 161 SkAddFlagToString(str, SkToBool(kOverrideColor_BlurFlag & fBlurFlags), "OverrideColor", 162 &needsSeparator); 163 SkAddFlagToString(str, SkToBool(kHighQuality_BlurFlag & fBlurFlags), "HighQuality", 164 &needsSeparator); 165 } 166 str->append(")"); 167 168 // TODO: add optional "fBlurFilter->toString(str);" when SkMaskFilter::toString is added 169 // alternatively we could cache the radius in SkBlurDrawLooper and just add it here 170} 171#endif 172