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
SkBlurDrawLooper(SkScalar radius,SkScalar dx,SkScalar dy,SkColor color,uint32_t flags)18 SkBlurDrawLooper::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
SkBlurDrawLooper(SkFlattenableReadBuffer & buffer)51 SkBlurDrawLooper::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
~SkBlurDrawLooper()62 SkBlurDrawLooper::~SkBlurDrawLooper() {
63 SkSafeUnref(fBlur);
64 SkSafeUnref(fColorFilter);
65 }
66
flatten(SkFlattenableWriteBuffer & buffer) const67 void 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
init(SkCanvas * canvas)77 void SkBlurDrawLooper::init(SkCanvas* canvas) {
78 fState = kBeforeEdge;
79 }
80
next(SkCanvas * canvas,SkPaint * paint)81 bool 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
toString(SkString * str) const122 void 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