OLD | NEW |
1 /* | 1 /* |
2 * Copyright 2011 Google Inc. | 2 * Copyright 2011 Google Inc. |
3 * | 3 * |
4 * Use of this source code is governed by a BSD-style license that can be | 4 * Use of this source code is governed by a BSD-style license that can be |
5 * found in the LICENSE file. | 5 * found in the LICENSE file. |
6 */ | 6 */ |
7 #include "SkColorMatrix.h" | 7 #include "SkColorMatrix.h" |
8 | 8 |
| 9 // To detect if we need to apply clamping after applying a matrix, we check if |
| 10 // any output component might go outside of [0, 255] for any combination of |
| 11 // input components in [0..255]. |
| 12 // Each output component is an affine transformation of the input component, so |
| 13 // the minimum and maximum values are for any combination of minimum or maximum |
| 14 // values of input components (i.e. 0 or 255). |
| 15 // E.g. if R' = x*R + y*G + z*B + w*A + t |
| 16 // Then the maximum value will be for R=255 if x>0 or R=0 if x<0, and the |
| 17 // minimum value will be for R=0 if x>0 or R=255 if x<0. |
| 18 // Same goes for all components. |
| 19 static bool component_needs_clamping(const SkScalar row[5]) { |
| 20 SkScalar maxValue = row[4] / 255; |
| 21 SkScalar minValue = row[4] / 255; |
| 22 for (int i = 0; i < 4; ++i) { |
| 23 if (row[i] > 0) |
| 24 maxValue += row[i]; |
| 25 else |
| 26 minValue += row[i]; |
| 27 } |
| 28 return (maxValue > 1) || (minValue < 0); |
| 29 } |
| 30 |
| 31 bool SkColorMatrix::NeedsClamping(const SkScalar matrix[20]) { |
| 32 return component_needs_clamping(matrix) |
| 33 || component_needs_clamping(matrix+5) |
| 34 || component_needs_clamping(matrix+10) |
| 35 || component_needs_clamping(matrix+15); |
| 36 } |
| 37 |
| 38 void SkColorMatrix::SetConcat(SkScalar result[20], |
| 39 const SkScalar outer[20], const SkScalar inner[20]
) { |
| 40 SkScalar tmp[20]; |
| 41 SkScalar* target; |
| 42 |
| 43 if (outer == result || inner == result) { |
| 44 target = tmp; // will memcpy answer when we're done into result |
| 45 } else { |
| 46 target = result; |
| 47 } |
| 48 |
| 49 int index = 0; |
| 50 for (int j = 0; j < 20; j += 5) { |
| 51 for (int i = 0; i < 4; i++) { |
| 52 target[index++] = outer[j + 0] * inner[i + 0] + |
| 53 outer[j + 1] * inner[i + 5] + |
| 54 outer[j + 2] * inner[i + 10] + |
| 55 outer[j + 3] * inner[i + 15]; |
| 56 } |
| 57 target[index++] = outer[j + 0] * inner[4] + |
| 58 outer[j + 1] * inner[9] + |
| 59 outer[j + 2] * inner[14] + |
| 60 outer[j + 3] * inner[19] + |
| 61 outer[j + 4]; |
| 62 } |
| 63 |
| 64 if (target != result) { |
| 65 memcpy(result, target, 20 * sizeof(SkScalar)); |
| 66 } |
| 67 } |
| 68 |
| 69 /////////////////////////////////////////////////////////////////////////////// |
| 70 |
9 void SkColorMatrix::setIdentity() { | 71 void SkColorMatrix::setIdentity() { |
10 memset(fMat, 0, sizeof(fMat)); | 72 memset(fMat, 0, sizeof(fMat)); |
11 fMat[kR_Scale] = fMat[kG_Scale] = fMat[kB_Scale] = fMat[kA_Scale] = 1; | 73 fMat[kR_Scale] = fMat[kG_Scale] = fMat[kB_Scale] = fMat[kA_Scale] = 1; |
12 } | 74 } |
13 | 75 |
14 void SkColorMatrix::setScale(SkScalar rScale, SkScalar gScale, SkScalar bScale, | 76 void SkColorMatrix::setScale(SkScalar rScale, SkScalar gScale, SkScalar bScale, |
15 SkScalar aScale) { | 77 SkScalar aScale) { |
16 memset(fMat, 0, sizeof(fMat)); | 78 memset(fMat, 0, sizeof(fMat)); |
17 fMat[kR_Scale] = rScale; | 79 fMat[kR_Scale] = rScale; |
18 fMat[kG_Scale] = gScale; | 80 fMat[kG_Scale] = gScale; |
(...skipping 41 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
60 tmp.setRotate(axis, degrees); | 122 tmp.setRotate(axis, degrees); |
61 this->preConcat(tmp); | 123 this->preConcat(tmp); |
62 } | 124 } |
63 | 125 |
64 void SkColorMatrix::postRotate(Axis axis, SkScalar degrees) { | 126 void SkColorMatrix::postRotate(Axis axis, SkScalar degrees) { |
65 SkColorMatrix tmp; | 127 SkColorMatrix tmp; |
66 tmp.setRotate(axis, degrees); | 128 tmp.setRotate(axis, degrees); |
67 this->postConcat(tmp); | 129 this->postConcat(tmp); |
68 } | 130 } |
69 | 131 |
70 /////////////////////////////////////////////////////////////////////////////// | 132 void SkColorMatrix::setConcat(const SkColorMatrix& matA, const SkColorMatrix& ma
tB) { |
71 | 133 SetConcat(fMat, matA.fMat, matB.fMat); |
72 void SkColorMatrix::setConcat(const SkColorMatrix& matA, | |
73 const SkColorMatrix& matB) { | |
74 SkScalar tmp[20]; | |
75 SkScalar* result = fMat; | |
76 | |
77 if (&matA == this || &matB == this) { | |
78 result = tmp; | |
79 } | |
80 | |
81 const SkScalar* a = matA.fMat; | |
82 const SkScalar* b = matB.fMat; | |
83 | |
84 int index = 0; | |
85 for (int j = 0; j < 20; j += 5) { | |
86 for (int i = 0; i < 4; i++) { | |
87 result[index++] = SkScalarMul(a[j + 0], b[i + 0]) + | |
88 SkScalarMul(a[j + 1], b[i + 5]) + | |
89 SkScalarMul(a[j + 2], b[i + 10]) + | |
90 SkScalarMul(a[j + 3], b[i + 15]); | |
91 } | |
92 result[index++] = SkScalarMul(a[j + 0], b[4]) + | |
93 SkScalarMul(a[j + 1], b[9]) + | |
94 SkScalarMul(a[j + 2], b[14]) + | |
95 SkScalarMul(a[j + 3], b[19]) + | |
96 a[j + 4]; | |
97 } | |
98 | |
99 if (fMat != result) { | |
100 memcpy(fMat, result, sizeof(fMat)); | |
101 } | |
102 } | 134 } |
103 | 135 |
104 /////////////////////////////////////////////////////////////////////////////// | 136 /////////////////////////////////////////////////////////////////////////////// |
105 | 137 |
106 static void setrow(SkScalar row[], SkScalar r, SkScalar g, SkScalar b) { | 138 static void setrow(SkScalar row[], SkScalar r, SkScalar g, SkScalar b) { |
107 row[0] = r; | 139 row[0] = r; |
108 row[1] = g; | 140 row[1] = g; |
109 row[2] = b; | 141 row[2] = b; |
110 } | 142 } |
111 | 143 |
(...skipping 41 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
153 static const SkScalar kU2B = 1.772f; | 185 static const SkScalar kU2B = 1.772f; |
154 | 186 |
155 void SkColorMatrix::setYUV2RGB() { | 187 void SkColorMatrix::setYUV2RGB() { |
156 memset(fMat, 0, sizeof(fMat)); | 188 memset(fMat, 0, sizeof(fMat)); |
157 | 189 |
158 setrow(fMat + 0, 1, 0, kV2R); | 190 setrow(fMat + 0, 1, 0, kV2R); |
159 setrow(fMat + 5, 1, kU2G, kV2G); | 191 setrow(fMat + 5, 1, kU2G, kV2G); |
160 setrow(fMat + 10, 1, kU2B, 0); | 192 setrow(fMat + 10, 1, kU2B, 0); |
161 fMat[kA_Scale] = 1; | 193 fMat[kA_Scale] = 1; |
162 } | 194 } |
| 195 |
OLD | NEW |