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comparison: gfx/skia/trunk/src/core/SkComposeShader.cpp
gfx/skia/trunk/src/core/SkComposeShader.cpp
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- TOR_BUG_9701
- changeset 8
- 97036ab72558
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| -1:000000000000 | 0:5b519f3a49a3 |
|---|---|
| 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 "SkComposeShader.h" | |
| 11 #include "SkColorFilter.h" | |
| 12 #include "SkColorPriv.h" | |
| 13 #include "SkColorShader.h" | |
| 14 #include "SkReadBuffer.h" | |
| 15 #include "SkWriteBuffer.h" | |
| 16 #include "SkXfermode.h" | |
| 17 #include "SkString.h" | |
| 18 | |
| 19 /////////////////////////////////////////////////////////////////////////////// | |
| 20 | |
| 21 SkComposeShader::SkComposeShader(SkShader* sA, SkShader* sB, SkXfermode* mode) { | |
| 22 fShaderA = sA; sA->ref(); | |
| 23 fShaderB = sB; sB->ref(); | |
| 24 // mode may be null | |
| 25 fMode = mode; | |
| 26 SkSafeRef(mode); | |
| 27 } | |
| 28 | |
| 29 SkComposeShader::SkComposeShader(SkReadBuffer& buffer) : | |
| 30 INHERITED(buffer) { | |
| 31 fShaderA = buffer.readShader(); | |
| 32 if (NULL == fShaderA) { | |
| 33 fShaderA = SkNEW_ARGS(SkColorShader, (0)); | |
| 34 } | |
| 35 fShaderB = buffer.readShader(); | |
| 36 if (NULL == fShaderB) { | |
| 37 fShaderB = SkNEW_ARGS(SkColorShader, (0)); | |
| 38 } | |
| 39 fMode = buffer.readXfermode(); | |
| 40 } | |
| 41 | |
| 42 SkComposeShader::~SkComposeShader() { | |
| 43 SkSafeUnref(fMode); | |
| 44 fShaderB->unref(); | |
| 45 fShaderA->unref(); | |
| 46 } | |
| 47 | |
| 48 class SkAutoAlphaRestore { | |
| 49 public: | |
| 50 SkAutoAlphaRestore(SkPaint* paint, uint8_t newAlpha) { | |
| 51 fAlpha = paint->getAlpha(); | |
| 52 fPaint = paint; | |
| 53 paint->setAlpha(newAlpha); | |
| 54 } | |
| 55 | |
| 56 ~SkAutoAlphaRestore() { | |
| 57 fPaint->setAlpha(fAlpha); | |
| 58 } | |
| 59 private: | |
| 60 SkPaint* fPaint; | |
| 61 uint8_t fAlpha; | |
| 62 }; | |
| 63 #define SkAutoAlphaRestore(...) SK_REQUIRE_LOCAL_VAR(SkAutoAlphaRestore) | |
| 64 | |
| 65 void SkComposeShader::flatten(SkWriteBuffer& buffer) const { | |
| 66 this->INHERITED::flatten(buffer); | |
| 67 buffer.writeFlattenable(fShaderA); | |
| 68 buffer.writeFlattenable(fShaderB); | |
| 69 buffer.writeFlattenable(fMode); | |
| 70 } | |
| 71 | |
| 72 /* We call setContext on our two worker shaders. However, we | |
| 73 always let them see opaque alpha, and if the paint really | |
| 74 is translucent, then we apply that after the fact. | |
| 75 | |
| 76 We need to keep the calls to setContext/endContext balanced, since if we | |
| 77 return false, our endContext() will not be called. | |
| 78 */ | |
| 79 bool SkComposeShader::setContext(const SkBitmap& device, | |
| 80 const SkPaint& paint, | |
| 81 const SkMatrix& matrix) { | |
| 82 if (!this->INHERITED::setContext(device, paint, matrix)) { | |
| 83 return false; | |
| 84 } | |
| 85 | |
| 86 // we preconcat our localMatrix (if any) with the device matrix | |
| 87 // before calling our sub-shaders | |
| 88 | |
| 89 SkMatrix tmpM; | |
| 90 | |
| 91 tmpM.setConcat(matrix, this->getLocalMatrix()); | |
| 92 | |
| 93 SkAutoAlphaRestore restore(const_cast<SkPaint*>(&paint), 0xFF); | |
| 94 | |
| 95 bool setContextA = fShaderA->setContext(device, paint, tmpM); | |
| 96 bool setContextB = fShaderB->setContext(device, paint, tmpM); | |
| 97 if (!setContextA || !setContextB) { | |
| 98 if (setContextB) { | |
| 99 fShaderB->endContext(); | |
| 100 } | |
| 101 else if (setContextA) { | |
| 102 fShaderA->endContext(); | |
| 103 } | |
| 104 this->INHERITED::endContext(); | |
| 105 return false; | |
| 106 } | |
| 107 return true; | |
| 108 } | |
| 109 | |
| 110 void SkComposeShader::endContext() { | |
| 111 fShaderB->endContext(); | |
| 112 fShaderA->endContext(); | |
| 113 this->INHERITED::endContext(); | |
| 114 } | |
| 115 | |
| 116 // larger is better (fewer times we have to loop), but we shouldn't | |
| 117 // take up too much stack-space (each element is 4 bytes) | |
| 118 #define TMP_COLOR_COUNT 64 | |
| 119 | |
| 120 void SkComposeShader::shadeSpan(int x, int y, SkPMColor result[], int count) { | |
| 121 SkShader* shaderA = fShaderA; | |
| 122 SkShader* shaderB = fShaderB; | |
| 123 SkXfermode* mode = fMode; | |
| 124 unsigned scale = SkAlpha255To256(this->getPaintAlpha()); | |
| 125 | |
| 126 SkPMColor tmp[TMP_COLOR_COUNT]; | |
| 127 | |
| 128 if (NULL == mode) { // implied SRC_OVER | |
| 129 // TODO: when we have a good test-case, should use SkBlitRow::Proc32 | |
| 130 // for these loops | |
| 131 do { | |
| 132 int n = count; | |
| 133 if (n > TMP_COLOR_COUNT) { | |
| 134 n = TMP_COLOR_COUNT; | |
| 135 } | |
| 136 | |
| 137 shaderA->shadeSpan(x, y, result, n); | |
| 138 shaderB->shadeSpan(x, y, tmp, n); | |
| 139 | |
| 140 if (256 == scale) { | |
| 141 for (int i = 0; i < n; i++) { | |
| 142 result[i] = SkPMSrcOver(tmp[i], result[i]); | |
| 143 } | |
| 144 } else { | |
| 145 for (int i = 0; i < n; i++) { | |
| 146 result[i] = SkAlphaMulQ(SkPMSrcOver(tmp[i], result[i]), | |
| 147 scale); | |
| 148 } | |
| 149 } | |
| 150 | |
| 151 result += n; | |
| 152 x += n; | |
| 153 count -= n; | |
| 154 } while (count > 0); | |
| 155 } else { // use mode for the composition | |
| 156 do { | |
| 157 int n = count; | |
| 158 if (n > TMP_COLOR_COUNT) { | |
| 159 n = TMP_COLOR_COUNT; | |
| 160 } | |
| 161 | |
| 162 shaderA->shadeSpan(x, y, result, n); | |
| 163 shaderB->shadeSpan(x, y, tmp, n); | |
| 164 mode->xfer32(result, tmp, n, NULL); | |
| 165 | |
| 166 if (256 == scale) { | |
| 167 for (int i = 0; i < n; i++) { | |
| 168 result[i] = SkAlphaMulQ(result[i], scale); | |
| 169 } | |
| 170 } | |
| 171 | |
| 172 result += n; | |
| 173 x += n; | |
| 174 count -= n; | |
| 175 } while (count > 0); | |
| 176 } | |
| 177 } | |
| 178 | |
| 179 #ifndef SK_IGNORE_TO_STRING | |
| 180 void SkComposeShader::toString(SkString* str) const { | |
| 181 str->append("SkComposeShader: ("); | |
| 182 | |
| 183 str->append("ShaderA: "); | |
| 184 fShaderA->toString(str); | |
| 185 str->append(" ShaderB: "); | |
| 186 fShaderB->toString(str); | |
| 187 str->append(" Xfermode: "); | |
| 188 fMode->toString(str); | |
| 189 | |
| 190 this->INHERITED::toString(str); | |
| 191 | |
| 192 str->append(")"); | |
| 193 } | |
| 194 #endif |
