1 /*
2 * Copyright 2012 Google Inc.
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 "GrConfigConversionEffect.h"
9 #include "GrContext.h"
10 #include "GrTBackendEffectFactory.h"
11 #include "GrSimpleTextureEffect.h"
12 #include "gl/GrGLEffect.h"
13 #include "SkMatrix.h"
14
15 class GrGLConfigConversionEffect : public GrGLEffect {
16 public:
GrGLConfigConversionEffect(const GrBackendEffectFactory & factory,const GrDrawEffect & drawEffect)17 GrGLConfigConversionEffect(const GrBackendEffectFactory& factory,
18 const GrDrawEffect& drawEffect)
19 : INHERITED (factory) {
20 const GrConfigConversionEffect& effect = drawEffect.castEffect<GrConfigConversionEffect>();
21 fSwapRedAndBlue = effect.swapsRedAndBlue();
22 fPMConversion = effect.pmConversion();
23 }
24
emitCode(GrGLShaderBuilder * builder,const GrDrawEffect &,EffectKey key,const char * outputColor,const char * inputColor,const TransformedCoordsArray & coords,const TextureSamplerArray & samplers)25 virtual void emitCode(GrGLShaderBuilder* builder,
26 const GrDrawEffect&,
27 EffectKey key,
28 const char* outputColor,
29 const char* inputColor,
30 const TransformedCoordsArray& coords,
31 const TextureSamplerArray& samplers) SK_OVERRIDE {
32 builder->fsCodeAppendf("\t\t%s = ", outputColor);
33 builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
34 builder->fsCodeAppend(";\n");
35 if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
36 SkASSERT(fSwapRedAndBlue);
37 builder->fsCodeAppendf("\t%s = %s.bgra;\n", outputColor, outputColor);
38 } else {
39 const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
40 switch (fPMConversion) {
41 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
42 builder->fsCodeAppendf(
43 "\t\t%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
44 outputColor, outputColor, swiz, outputColor, outputColor);
45 break;
46 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
47 // Add a compensation(0.001) here to avoid the side effect of the floor operation.
48 // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
49 // is less than the integer value converted from %s.r by 1 when the %s.r is
50 // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
51 builder->fsCodeAppendf(
52 "\t\t%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);\n",
53 outputColor, outputColor, swiz, outputColor, outputColor);
54 break;
55 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
56 builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
57 outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
58 break;
59 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
60 builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
61 outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
62 break;
63 default:
64 SkFAIL("Unknown conversion op.");
65 break;
66 }
67 }
68 SkString modulate;
69 GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
70 builder->fsCodeAppend(modulate.c_str());
71 }
72
GenKey(const GrDrawEffect & drawEffect,const GrGLCaps &)73 static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
74 const GrConfigConversionEffect& conv = drawEffect.castEffect<GrConfigConversionEffect>();
75 return static_cast<EffectKey>(conv.swapsRedAndBlue()) | (conv.pmConversion() << 1);
76 }
77
78 private:
79 bool fSwapRedAndBlue;
80 GrConfigConversionEffect::PMConversion fPMConversion;
81
82 typedef GrGLEffect INHERITED;
83
84 };
85
86 ///////////////////////////////////////////////////////////////////////////////
87
GrConfigConversionEffect(GrTexture * texture,bool swapRedAndBlue,PMConversion pmConversion,const SkMatrix & matrix)88 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
89 bool swapRedAndBlue,
90 PMConversion pmConversion,
91 const SkMatrix& matrix)
92 : GrSingleTextureEffect(texture, matrix)
93 , fSwapRedAndBlue(swapRedAndBlue)
94 , fPMConversion(pmConversion) {
95 SkASSERT(kRGBA_8888_GrPixelConfig == texture->config() ||
96 kBGRA_8888_GrPixelConfig == texture->config());
97 // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
98 SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
99 }
100
getFactory() const101 const GrBackendEffectFactory& GrConfigConversionEffect::getFactory() const {
102 return GrTBackendEffectFactory<GrConfigConversionEffect>::getInstance();
103 }
104
onIsEqual(const GrEffect & s) const105 bool GrConfigConversionEffect::onIsEqual(const GrEffect& s) const {
106 const GrConfigConversionEffect& other = CastEffect<GrConfigConversionEffect>(s);
107 return this->texture(0) == s.texture(0) &&
108 other.fSwapRedAndBlue == fSwapRedAndBlue &&
109 other.fPMConversion == fPMConversion;
110 }
111
getConstantColorComponents(GrColor * color,uint32_t * validFlags) const112 void GrConfigConversionEffect::getConstantColorComponents(GrColor* color,
113 uint32_t* validFlags) const {
114 this->updateConstantColorComponentsForModulation(color, validFlags);
115 }
116
117 ///////////////////////////////////////////////////////////////////////////////
118
119 GR_DEFINE_EFFECT_TEST(GrConfigConversionEffect);
120
TestCreate(SkRandom * random,GrContext *,const GrDrawTargetCaps &,GrTexture * textures[])121 GrEffectRef* GrConfigConversionEffect::TestCreate(SkRandom* random,
122 GrContext*,
123 const GrDrawTargetCaps&,
124 GrTexture* textures[]) {
125 PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
126 bool swapRB;
127 if (kNone_PMConversion == pmConv) {
128 swapRB = true;
129 } else {
130 swapRB = random->nextBool();
131 }
132 AutoEffectUnref effect(SkNEW_ARGS(GrConfigConversionEffect,
133 (textures[GrEffectUnitTest::kSkiaPMTextureIdx],
134 swapRB,
135 pmConv,
136 GrEffectUnitTest::TestMatrix(random))));
137 return CreateEffectRef(effect);
138 }
139
140 ///////////////////////////////////////////////////////////////////////////////
TestForPreservingPMConversions(GrContext * context,PMConversion * pmToUPMRule,PMConversion * upmToPMRule)141 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
142 PMConversion* pmToUPMRule,
143 PMConversion* upmToPMRule) {
144 *pmToUPMRule = kNone_PMConversion;
145 *upmToPMRule = kNone_PMConversion;
146 SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
147 uint32_t* srcData = data.get();
148 uint32_t* firstRead = data.get() + 256 * 256;
149 uint32_t* secondRead = data.get() + 2 * 256 * 256;
150
151 // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
152 // values in row y. We set r,g, and b to the same value since they are handled identically.
153 for (int y = 0; y < 256; ++y) {
154 for (int x = 0; x < 256; ++x) {
155 uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
156 color[3] = y;
157 color[2] = SkTMin(x, y);
158 color[1] = SkTMin(x, y);
159 color[0] = SkTMin(x, y);
160 }
161 }
162
163 GrTextureDesc desc;
164 desc.fFlags = kRenderTarget_GrTextureFlagBit |
165 kNoStencil_GrTextureFlagBit;
166 desc.fWidth = 256;
167 desc.fHeight = 256;
168 desc.fConfig = kRGBA_8888_GrPixelConfig;
169
170 SkAutoTUnref<GrTexture> readTex(context->createUncachedTexture(desc, NULL, 0));
171 if (!readTex.get()) {
172 return;
173 }
174 SkAutoTUnref<GrTexture> tempTex(context->createUncachedTexture(desc, NULL, 0));
175 if (!tempTex.get()) {
176 return;
177 }
178 desc.fFlags = kNone_GrTextureFlags;
179 SkAutoTUnref<GrTexture> dataTex(context->createUncachedTexture(desc, data, 0));
180 if (!dataTex.get()) {
181 return;
182 }
183
184 static const PMConversion kConversionRules[][2] = {
185 {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
186 {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
187 };
188
189 GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
190
191 bool failed = true;
192
193 for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
194 *pmToUPMRule = kConversionRules[i][0];
195 *upmToPMRule = kConversionRules[i][1];
196
197 static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
198 static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
199 // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
200 // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
201 // We then verify that two reads produced the same values.
202
203 AutoEffectUnref pmToUPM1(SkNEW_ARGS(GrConfigConversionEffect, (dataTex,
204 false,
205 *pmToUPMRule,
206 SkMatrix::I())));
207 AutoEffectUnref upmToPM(SkNEW_ARGS(GrConfigConversionEffect, (readTex,
208 false,
209 *upmToPMRule,
210 SkMatrix::I())));
211 AutoEffectUnref pmToUPM2(SkNEW_ARGS(GrConfigConversionEffect, (tempTex,
212 false,
213 *pmToUPMRule,
214 SkMatrix::I())));
215
216 SkAutoTUnref<GrEffectRef> pmToUPMEffect1(CreateEffectRef(pmToUPM1));
217 SkAutoTUnref<GrEffectRef> upmToPMEffect(CreateEffectRef(upmToPM));
218 SkAutoTUnref<GrEffectRef> pmToUPMEffect2(CreateEffectRef(pmToUPM2));
219
220 context->setRenderTarget(readTex->asRenderTarget());
221 GrPaint paint1;
222 paint1.addColorEffect(pmToUPMEffect1);
223 context->drawRectToRect(paint1, kDstRect, kSrcRect);
224
225 readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
226
227 context->setRenderTarget(tempTex->asRenderTarget());
228 GrPaint paint2;
229 paint2.addColorEffect(upmToPMEffect);
230 context->drawRectToRect(paint2, kDstRect, kSrcRect);
231 context->setRenderTarget(readTex->asRenderTarget());
232
233 GrPaint paint3;
234 paint3.addColorEffect(pmToUPMEffect2);
235 context->drawRectToRect(paint3, kDstRect, kSrcRect);
236
237 readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
238
239 failed = false;
240 for (int y = 0; y < 256 && !failed; ++y) {
241 for (int x = 0; x <= y; ++x) {
242 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
243 failed = true;
244 break;
245 }
246 }
247 }
248 }
249 if (failed) {
250 *pmToUPMRule = kNone_PMConversion;
251 *upmToPMRule = kNone_PMConversion;
252 }
253 }
254
Create(GrTexture * texture,bool swapRedAndBlue,PMConversion pmConversion,const SkMatrix & matrix)255 const GrEffectRef* GrConfigConversionEffect::Create(GrTexture* texture,
256 bool swapRedAndBlue,
257 PMConversion pmConversion,
258 const SkMatrix& matrix) {
259 if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
260 // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
261 // then we may pollute our texture cache with redundant shaders. So in the case that no
262 // conversions were requested we instead return a GrSimpleTextureEffect.
263 return GrSimpleTextureEffect::Create(texture, matrix);
264 } else {
265 if (kRGBA_8888_GrPixelConfig != texture->config() &&
266 kBGRA_8888_GrPixelConfig != texture->config() &&
267 kNone_PMConversion != pmConversion) {
268 // The PM conversions assume colors are 0..255
269 return NULL;
270 }
271 AutoEffectUnref effect(SkNEW_ARGS(GrConfigConversionEffect, (texture,
272 swapRedAndBlue,
273 pmConversion,
274 matrix)));
275 return CreateEffectRef(effect);
276 }
277 }
278