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 "SkFlattenableBuffers.h"
14#include "SkMaskFilter.h"
15#include "SkPaint.h"
16#include "SkString.h"
17#include "SkStringUtils.h"
18
19SkBlurDrawLooper::SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy,
20                                   SkColor color, uint32_t flags) {
21    this->init(SkBlurMask::ConvertRadiusToSigma(radius), dx, dy, color, flags);
22}
23
24SkBlurDrawLooper::SkBlurDrawLooper(SkColor color, SkScalar sigma,
25                                   SkScalar dx, SkScalar dy, uint32_t flags) {
26    this->init(sigma, dx, dy, color, flags);
27}
28
29void SkBlurDrawLooper::init(SkScalar sigma, SkScalar dx, SkScalar dy,
30                            SkColor color, uint32_t flags) {
31    fDx = dx;
32    fDy = dy;
33    fBlurColor = color;
34    fBlurFlags = flags;
35    fState = kDone;
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(SkFlattenableReadBuffer& 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(SkFlattenableWriteBuffer& 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
92void SkBlurDrawLooper::init(SkCanvas*) {
93    fState = kBeforeEdge;
94}
95
96bool SkBlurDrawLooper::next(SkCanvas* canvas, SkPaint* paint) {
97    switch (fState) {
98        case kBeforeEdge:
99            // we do nothing if a maskfilter is already installed
100            if (paint->getMaskFilter()) {
101                fState = kDone;
102                return false;
103            }
104#ifdef SK_BUILD_FOR_ANDROID
105            SkColor blurColor;
106            blurColor = fBlurColor;
107            if (SkColorGetA(blurColor) == 255) {
108                blurColor = SkColorSetA(blurColor, paint->getAlpha());
109            }
110            paint->setColor(blurColor);
111#else
112            paint->setColor(fBlurColor);
113#endif
114            paint->setMaskFilter(fBlur);
115            paint->setColorFilter(fColorFilter);
116            canvas->save(SkCanvas::kMatrix_SaveFlag);
117            if (fBlurFlags & kIgnoreTransform_BlurFlag) {
118                SkMatrix transform(canvas->getTotalMatrix());
119                transform.postTranslate(fDx, fDy);
120                canvas->setMatrix(transform);
121            } else {
122                canvas->translate(fDx, fDy);
123            }
124            fState = kAfterEdge;
125            return true;
126        case kAfterEdge:
127            canvas->restore();
128            fState = kDone;
129            return true;
130        default:
131            SkASSERT(kDone == fState);
132            return false;
133    }
134}
135
136#ifdef SK_DEVELOPER
137void SkBlurDrawLooper::toString(SkString* str) const {
138    str->append("SkBlurDrawLooper: ");
139
140    str->append("dx: ");
141    str->appendScalar(fDx);
142
143    str->append(" dy: ");
144    str->appendScalar(fDy);
145
146    str->append(" color: ");
147    str->appendHex(fBlurColor);
148
149    str->append(" flags: (");
150    if (kNone_BlurFlag == fBlurFlags) {
151        str->append("None");
152    } else {
153        bool needsSeparator = false;
154        SkAddFlagToString(str, SkToBool(kIgnoreTransform_BlurFlag & fBlurFlags), "IgnoreTransform",
155                          &needsSeparator);
156        SkAddFlagToString(str, SkToBool(kOverrideColor_BlurFlag & fBlurFlags), "OverrideColor",
157                          &needsSeparator);
158        SkAddFlagToString(str, SkToBool(kHighQuality_BlurFlag & fBlurFlags), "HighQuality",
159                          &needsSeparator);
160    }
161    str->append(")");
162
163    // TODO: add optional "fBlurFilter->toString(str);" when SkMaskFilter::toString is added
164    // alternatively we could cache the radius in SkBlurDrawLooper and just add it here
165}
166#endif
167