1 /*
2 * Copyright 2006 The Android Open Source Project
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "src/effects/SkEmbossMaskFilter.h"
9
10 #include "include/core/SkBlurTypes.h"
11 #include "include/core/SkMatrix.h"
12 #include "include/core/SkPoint.h"
13 #include "include/core/SkTypes.h"
14 #include "src/core/SkBlurMask.h"
15 #include "src/core/SkReadBuffer.h"
16 #include "src/core/SkWriteBuffer.h"
17 #include "src/effects/SkEmbossMask.h"
18
19 #if defined(SK_SUPPORT_LEGACY_EMBOSSMASKFILTER)
20 #include "include/effects/SkBlurMaskFilter.h"
21 #endif
22
23 #include <cstring>
24
normalize3(SkScalar dst[3],const SkScalar src[3])25 static void normalize3(SkScalar dst[3], const SkScalar src[3]) {
26 SkScalar mag = SkScalarSquare(src[0]) + SkScalarSquare(src[1]) + SkScalarSquare(src[2]);
27 SkScalar scale = SkScalarInvert(SkScalarSqrt(mag));
28
29 for (int i = 0; i < 3; i++) {
30 dst[i] = src[i] * scale;
31 }
32 }
33
Make(SkScalar blurSigma,const Light & light)34 sk_sp<SkMaskFilter> SkEmbossMaskFilter::Make(SkScalar blurSigma, const Light& light) {
35 if (!SkScalarIsFinite(blurSigma) || blurSigma <= 0) {
36 return nullptr;
37 }
38
39 Light newLight = light;
40 normalize3(newLight.fDirection, light.fDirection);
41 if (!SkScalarsAreFinite(newLight.fDirection, 3)) {
42 return nullptr;
43 }
44
45 return sk_sp<SkMaskFilter>(new SkEmbossMaskFilter(blurSigma, newLight));
46 }
47
48 #ifdef SK_SUPPORT_LEGACY_EMBOSSMASKFILTER
MakeEmboss(SkScalar blurSigma,const SkScalar direction[3],SkScalar ambient,SkScalar specular)49 sk_sp<SkMaskFilter> SkBlurMaskFilter::MakeEmboss(SkScalar blurSigma, const SkScalar direction[3],
50 SkScalar ambient, SkScalar specular) {
51 if (direction == nullptr) {
52 return nullptr;
53 }
54
55 SkEmbossMaskFilter::Light light;
56
57 memcpy(light.fDirection, direction, sizeof(light.fDirection));
58 // ambient should be 0...1 as a scalar
59 light.fAmbient = SkUnitScalarClampToByte(ambient);
60 // specular should be 0..15.99 as a scalar
61 static const SkScalar kSpecularMultiplier = SkIntToScalar(255) / 16;
62 light.fSpecular = static_cast<U8CPU>(SkTPin(specular, 0.0f, 16.0f) * kSpecularMultiplier + 0.5);
63
64 return SkEmbossMaskFilter::Make(blurSigma, light);
65 }
66 #endif
67
68 ///////////////////////////////////////////////////////////////////////////////
69
SkEmbossMaskFilter(SkScalar blurSigma,const Light & light)70 SkEmbossMaskFilter::SkEmbossMaskFilter(SkScalar blurSigma, const Light& light)
71 : fLight(light), fBlurSigma(blurSigma)
72 {
73 SkASSERT(fBlurSigma > 0);
74 SkASSERT(SkScalarsAreFinite(fLight.fDirection, 3));
75 }
76
getFormat() const77 SkMask::Format SkEmbossMaskFilter::getFormat() const {
78 return SkMask::k3D_Format;
79 }
80
filterMask(SkMask * dst,const SkMask & src,const SkMatrix & matrix,SkIPoint * margin) const81 bool SkEmbossMaskFilter::filterMask(SkMask* dst, const SkMask& src,
82 const SkMatrix& matrix, SkIPoint* margin) const {
83 if (src.fFormat != SkMask::kA8_Format) {
84 return false;
85 }
86
87 SkScalar sigma = matrix.mapRadius(fBlurSigma);
88
89 if (!SkBlurMask::BoxBlur(dst, src, sigma, kInner_SkBlurStyle)) {
90 return false;
91 }
92
93 dst->fFormat = SkMask::k3D_Format;
94 if (margin) {
95 margin->set(SkScalarCeilToInt(3*sigma), SkScalarCeilToInt(3*sigma));
96 }
97
98 if (src.fImage == nullptr) {
99 return true;
100 }
101
102 // create a larger buffer for the other two channels (should force fBlur to do this for us)
103
104 {
105 uint8_t* alphaPlane = dst->fImage;
106 size_t planeSize = dst->computeImageSize();
107 if (0 == planeSize) {
108 return false; // too big to allocate, abort
109 }
110 dst->fImage = SkMask::AllocImage(planeSize * 3);
111 memcpy(dst->fImage, alphaPlane, planeSize);
112 SkMask::FreeImage(alphaPlane);
113 }
114
115 // run the light direction through the matrix...
116 Light light = fLight;
117 matrix.mapVectors((SkVector*)(void*)light.fDirection,
118 (SkVector*)(void*)fLight.fDirection, 1);
119
120 // now restore the length of the XY component
121 // cast to SkVector so we can call setLength (this double cast silences alias warnings)
122 SkVector* vec = (SkVector*)(void*)light.fDirection;
123 vec->setLength(light.fDirection[0],
124 light.fDirection[1],
125 SkPoint::Length(fLight.fDirection[0], fLight.fDirection[1]));
126
127 SkEmbossMask::Emboss(dst, light);
128
129 // restore original alpha
130 memcpy(dst->fImage, src.fImage, src.computeImageSize());
131
132 return true;
133 }
134
CreateProc(SkReadBuffer & buffer)135 sk_sp<SkFlattenable> SkEmbossMaskFilter::CreateProc(SkReadBuffer& buffer) {
136 Light light;
137 if (buffer.readByteArray(&light, sizeof(Light))) {
138 light.fPad = 0; // for the font-cache lookup to be clean
139 const SkScalar sigma = buffer.readScalar();
140 return Make(sigma, light);
141 }
142 return nullptr;
143 }
144
flatten(SkWriteBuffer & buffer) const145 void SkEmbossMaskFilter::flatten(SkWriteBuffer& buffer) const {
146 Light tmpLight = fLight;
147 tmpLight.fPad = 0; // for the font-cache lookup to be clean
148 buffer.writeByteArray(&tmpLight, sizeof(tmpLight));
149 buffer.writeScalar(fBlurSigma);
150 }
151