1
2 /*
3 * Copyright 2006 The Android Open Source Project
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
9
10 #include "SkEmbossMaskFilter.h"
11 #include "SkBlurMaskFilter.h"
12 #include "SkBlurMask.h"
13 #include "SkEmbossMask.h"
14 #include "SkFlattenableBuffers.h"
15
pin2byte(int n)16 static inline int pin2byte(int n) {
17 if (n < 0) {
18 n = 0;
19 } else if (n > 0xFF) {
20 n = 0xFF;
21 }
22 return n;
23 }
24
CreateEmboss(const SkScalar direction[3],SkScalar ambient,SkScalar specular,SkScalar blurRadius)25 SkMaskFilter* SkBlurMaskFilter::CreateEmboss(const SkScalar direction[3],
26 SkScalar ambient, SkScalar specular,
27 SkScalar blurRadius) {
28 if (direction == NULL) {
29 return NULL;
30 }
31
32 // ambient should be 0...1 as a scalar
33 int am = pin2byte(SkScalarToFixed(ambient) >> 8);
34
35 // specular should be 0..15.99 as a scalar
36 int sp = pin2byte(SkScalarToFixed(specular) >> 12);
37
38 SkEmbossMaskFilter::Light light;
39
40 memcpy(light.fDirection, direction, sizeof(light.fDirection));
41 light.fAmbient = SkToU8(am);
42 light.fSpecular = SkToU8(sp);
43
44 return SkNEW_ARGS(SkEmbossMaskFilter, (light, blurRadius));
45 }
46
47 ///////////////////////////////////////////////////////////////////////////////
48
normalize(SkScalar v[3])49 static void normalize(SkScalar v[3]) {
50 SkScalar mag = SkScalarSquare(v[0]) + SkScalarSquare(v[1]) + SkScalarSquare(v[2]);
51 mag = SkScalarSqrt(mag);
52
53 for (int i = 0; i < 3; i++) {
54 v[i] = SkScalarDiv(v[i], mag);
55 }
56 }
57
SkEmbossMaskFilter(const Light & light,SkScalar blurRadius)58 SkEmbossMaskFilter::SkEmbossMaskFilter(const Light& light, SkScalar blurRadius)
59 : fLight(light), fBlurRadius(blurRadius) {
60 normalize(fLight.fDirection);
61 }
62
getFormat() const63 SkMask::Format SkEmbossMaskFilter::getFormat() const {
64 return SkMask::k3D_Format;
65 }
66
filterMask(SkMask * dst,const SkMask & src,const SkMatrix & matrix,SkIPoint * margin) const67 bool SkEmbossMaskFilter::filterMask(SkMask* dst, const SkMask& src,
68 const SkMatrix& matrix, SkIPoint* margin) const {
69 SkScalar radius = matrix.mapRadius(fBlurRadius);
70
71 if (!SkBlurMask::Blur(dst, src, radius, SkBlurMask::kInner_Style,
72 SkBlurMask::kLow_Quality)) {
73 return false;
74 }
75
76 dst->fFormat = SkMask::k3D_Format;
77 if (margin) {
78 margin->set(SkScalarCeil(radius), SkScalarCeil(radius));
79 }
80
81 if (src.fImage == NULL) {
82 return true;
83 }
84
85 // create a larger buffer for the other two channels (should force fBlur to do this for us)
86
87 {
88 uint8_t* alphaPlane = dst->fImage;
89 size_t planeSize = dst->computeImageSize();
90 if (0 == planeSize) {
91 return false; // too big to allocate, abort
92 }
93 dst->fImage = SkMask::AllocImage(planeSize * 3);
94 memcpy(dst->fImage, alphaPlane, planeSize);
95 SkMask::FreeImage(alphaPlane);
96 }
97
98 // run the light direction through the matrix...
99 Light light = fLight;
100 matrix.mapVectors((SkVector*)(void*)light.fDirection,
101 (SkVector*)(void*)fLight.fDirection, 1);
102
103 // now restore the length of the XY component
104 // cast to SkVector so we can call setLength (this double cast silences alias warnings)
105 SkVector* vec = (SkVector*)(void*)light.fDirection;
106 vec->setLength(light.fDirection[0],
107 light.fDirection[1],
108 SkPoint::Length(fLight.fDirection[0], fLight.fDirection[1]));
109
110 SkEmbossMask::Emboss(dst, light);
111
112 // restore original alpha
113 memcpy(dst->fImage, src.fImage, src.computeImageSize());
114
115 return true;
116 }
117
SkEmbossMaskFilter(SkFlattenableReadBuffer & buffer)118 SkEmbossMaskFilter::SkEmbossMaskFilter(SkFlattenableReadBuffer& buffer)
119 : SkMaskFilter(buffer) {
120 SkASSERT(buffer.getArrayCount() == sizeof(Light));
121 buffer.readByteArray(&fLight);
122 SkASSERT(fLight.fPad == 0); // for the font-cache lookup to be clean
123 fBlurRadius = buffer.readScalar();
124 }
125
flatten(SkFlattenableWriteBuffer & buffer) const126 void SkEmbossMaskFilter::flatten(SkFlattenableWriteBuffer& buffer) const {
127 this->INHERITED::flatten(buffer);
128
129 Light tmpLight = fLight;
130 tmpLight.fPad = 0; // for the font-cache lookup to be clean
131 buffer.writeByteArray(&tmpLight, sizeof(tmpLight));
132 buffer.writeScalar(fBlurRadius);
133 }
134