1 /*
2 * Copyright 2013 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 "GrDistanceFieldGeoProc.h"
9
10 #include "GrTexture.h"
11 #include "SkDistanceFieldGen.h"
12 #include "glsl/GrGLSLFragmentShaderBuilder.h"
13 #include "glsl/GrGLSLGeometryProcessor.h"
14 #include "glsl/GrGLSLProgramDataManager.h"
15 #include "glsl/GrGLSLUniformHandler.h"
16 #include "glsl/GrGLSLUtil.h"
17 #include "glsl/GrGLSLVarying.h"
18 #include "glsl/GrGLSLVertexShaderBuilder.h"
19
20 // Assuming a radius of a little less than the diagonal of the fragment
21 #define SK_DistanceFieldAAFactor "0.65"
22
23 class GrGLDistanceFieldA8TextGeoProc : public GrGLSLGeometryProcessor {
24 public:
GrGLDistanceFieldA8TextGeoProc()25 GrGLDistanceFieldA8TextGeoProc()
26 : fViewMatrix(SkMatrix::InvalidMatrix())
27 #ifdef SK_GAMMA_APPLY_TO_A8
28 , fDistanceAdjust(-1.0f)
29 #endif
30 {}
31
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)32 void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
33 const GrDistanceFieldA8TextGeoProc& dfTexEffect =
34 args.fGP.cast<GrDistanceFieldA8TextGeoProc>();
35 GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
36
37 GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
38 GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
39 GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
40
41 // emit attributes
42 varyingHandler->emitAttributes(dfTexEffect);
43
44 #ifdef SK_GAMMA_APPLY_TO_A8
45 // adjust based on gamma
46 const char* distanceAdjustUniName = nullptr;
47 // width, height, 1/(3*width)
48 fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
49 kFloat_GrSLType, kDefault_GrSLPrecision,
50 "DistanceAdjust", &distanceAdjustUniName);
51 #endif
52
53 // Setup pass through color
54 varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
55
56 // Setup position
57 this->setupPosition(vertBuilder,
58 uniformHandler,
59 gpArgs,
60 dfTexEffect.inPosition()->fName,
61 dfTexEffect.viewMatrix(),
62 &fViewMatrixUniform);
63
64 // emit transforms
65 this->emitTransforms(vertBuilder,
66 varyingHandler,
67 uniformHandler,
68 gpArgs->fPositionVar,
69 dfTexEffect.inPosition()->fName,
70 args.fFPCoordTransformHandler);
71
72 // add varyings
73 GrGLSLVertToFrag recipScale(kFloat_GrSLType);
74 GrGLSLVertToFrag uv(kVec2f_GrSLType);
75 bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
76 kUniformScale_DistanceFieldEffectMask;
77 bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
78 bool isGammaCorrect =
79 SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
80 varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
81 vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
82
83 // compute numbers to be hardcoded to convert texture coordinates from float to int
84 SkASSERT(dfTexEffect.numTextureSamplers() == 1);
85 GrTexture* atlas = dfTexEffect.textureSampler(0).texture();
86 SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
87
88 GrGLSLVertToFrag st(kVec2f_GrSLType);
89 varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
90 vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
91 atlas->width(), atlas->height(),
92 dfTexEffect.inTextureCoords()->fName);
93
94 // Use highp to work around aliasing issues
95 fragBuilder->codeAppendf("highp vec2 uv = %s;\n", uv.fsIn());
96
97 fragBuilder->codeAppend("\tfloat texColor = ");
98 fragBuilder->appendTextureLookup(args.fTexSamplers[0],
99 "uv",
100 kVec2f_GrSLType);
101 fragBuilder->codeAppend(".r;\n");
102 fragBuilder->codeAppend("\tfloat distance = "
103 SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
104 #ifdef SK_GAMMA_APPLY_TO_A8
105 // adjust width based on gamma
106 fragBuilder->codeAppendf("distance -= %s;", distanceAdjustUniName);
107 #endif
108
109 fragBuilder->codeAppend("float afwidth;");
110 if (isUniformScale) {
111 // For uniform scale, we adjust for the effect of the transformation on the distance
112 // by using the length of the gradient of the t coordinate in the y direction.
113 // We use st coordinates to ensure we're mapping 1:1 from texel space to pixel space.
114
115 // this gives us a smooth step across approximately one fragment
116 #ifdef SK_VULKAN
117 fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdx(%s.x));",
118 st.fsIn());
119 #else
120 // We use the y gradient because there is a bug in the Mali 400 in the x direction.
121 fragBuilder->codeAppendf("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(%s.y));",
122 st.fsIn());
123 #endif
124 } else if (isSimilarity) {
125 // For similarity transform, we adjust the effect of the transformation on the distance
126 // by using the length of the gradient of the texture coordinates. We use st coordinates
127 // to ensure we're mapping 1:1 from texel space to pixel space.
128 // We use the y gradient because there is a bug in the Mali 400 in the x direction.
129
130 // this gives us a smooth step across approximately one fragment
131 #ifdef SK_VULKAN
132 fragBuilder->codeAppendf("float st_grad_len = length(dFdx(%s));", st.fsIn());
133 #else
134 // We use the y gradient because there is a bug in the Mali 400 in the x direction.
135 fragBuilder->codeAppendf("float st_grad_len = length(dFdy(%s));", st.fsIn());
136 #endif
137 fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*st_grad_len);");
138 } else {
139 // For general transforms, to determine the amount of correction we multiply a unit
140 // vector pointing along the SDF gradient direction by the Jacobian of the st coords
141 // (which is the inverse transform for this fragment) and take the length of the result.
142 fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
143 // the length of the gradient may be 0, so we need to check for this
144 // this also compensates for the Adreno, which likes to drop tiles on division by 0
145 fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
146 fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
147 fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
148 fragBuilder->codeAppend("} else {");
149 fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
150 fragBuilder->codeAppend("}");
151
152 fragBuilder->codeAppendf("vec2 Jdx = dFdx(%s);", st.fsIn());
153 fragBuilder->codeAppendf("vec2 Jdy = dFdy(%s);", st.fsIn());
154 fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
155 fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
156
157 // this gives us a smooth step across approximately one fragment
158 fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
159 }
160
161 // The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
162 // doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
163 // mapped linearly to coverage, so use a linear step:
164 if (isGammaCorrect) {
165 fragBuilder->codeAppend(
166 "float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
167 } else {
168 fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
169 }
170
171 fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
172 }
173
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor & proc,FPCoordTransformIter && transformIter)174 void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& proc,
175 FPCoordTransformIter&& transformIter) override {
176 #ifdef SK_GAMMA_APPLY_TO_A8
177 const GrDistanceFieldA8TextGeoProc& dfTexEffect = proc.cast<GrDistanceFieldA8TextGeoProc>();
178 float distanceAdjust = dfTexEffect.getDistanceAdjust();
179 if (distanceAdjust != fDistanceAdjust) {
180 pdman.set1f(fDistanceAdjustUni, distanceAdjust);
181 fDistanceAdjust = distanceAdjust;
182 }
183 #endif
184 const GrDistanceFieldA8TextGeoProc& dfa8gp = proc.cast<GrDistanceFieldA8TextGeoProc>();
185
186 if (!dfa8gp.viewMatrix().isIdentity() && !fViewMatrix.cheapEqualTo(dfa8gp.viewMatrix())) {
187 fViewMatrix = dfa8gp.viewMatrix();
188 float viewMatrix[3 * 3];
189 GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
190 pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
191 }
192 this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter);
193 }
194
GenKey(const GrGeometryProcessor & gp,const GrShaderCaps &,GrProcessorKeyBuilder * b)195 static inline void GenKey(const GrGeometryProcessor& gp,
196 const GrShaderCaps&,
197 GrProcessorKeyBuilder* b) {
198 const GrDistanceFieldA8TextGeoProc& dfTexEffect = gp.cast<GrDistanceFieldA8TextGeoProc>();
199 uint32_t key = dfTexEffect.getFlags();
200 key |= ComputePosKey(dfTexEffect.viewMatrix()) << 16;
201 b->add32(key);
202
203 // Currently we hardcode numbers to convert atlas coordinates to normalized floating point
204 SkASSERT(gp.numTextureSamplers() == 1);
205 GrTexture* atlas = gp.textureSampler(0).texture();
206 SkASSERT(atlas);
207 b->add32(atlas->width());
208 b->add32(atlas->height());
209 }
210
211 private:
212 SkMatrix fViewMatrix;
213 UniformHandle fViewMatrixUniform;
214 #ifdef SK_GAMMA_APPLY_TO_A8
215 float fDistanceAdjust;
216 UniformHandle fDistanceAdjustUni;
217 #endif
218
219 typedef GrGLSLGeometryProcessor INHERITED;
220 };
221
222 ///////////////////////////////////////////////////////////////////////////////
223
GrDistanceFieldA8TextGeoProc(GrResourceProvider * resourceProvider,GrColor color,const SkMatrix & viewMatrix,sk_sp<GrTextureProxy> proxy,const GrSamplerParams & params,float distanceAdjust,uint32_t flags,bool usesLocalCoords)224 GrDistanceFieldA8TextGeoProc::GrDistanceFieldA8TextGeoProc(GrResourceProvider* resourceProvider,
225 GrColor color,
226 const SkMatrix& viewMatrix,
227 sk_sp<GrTextureProxy> proxy,
228 const GrSamplerParams& params,
229 #ifdef SK_GAMMA_APPLY_TO_A8
230 float distanceAdjust,
231 #endif
232 uint32_t flags,
233 bool usesLocalCoords)
234 : fColor(color)
235 , fViewMatrix(viewMatrix)
236 , fTextureSampler(resourceProvider, std::move(proxy), params)
237 #ifdef SK_GAMMA_APPLY_TO_A8
238 , fDistanceAdjust(distanceAdjust)
239 #endif
240 , fFlags(flags & kNonLCD_DistanceFieldEffectMask)
241 , fInColor(nullptr)
242 , fUsesLocalCoords(usesLocalCoords) {
243 SkASSERT(!(flags & ~kNonLCD_DistanceFieldEffectMask));
244 this->initClassID<GrDistanceFieldA8TextGeoProc>();
245 fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
246 kHigh_GrSLPrecision);
247 fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
248 fInTextureCoords = &this->addVertexAttrib("inTextureCoords", kVec2us_GrVertexAttribType,
249 kHigh_GrSLPrecision);
250 this->addTextureSampler(&fTextureSampler);
251 }
252
getGLSLProcessorKey(const GrShaderCaps & caps,GrProcessorKeyBuilder * b) const253 void GrDistanceFieldA8TextGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
254 GrProcessorKeyBuilder* b) const {
255 GrGLDistanceFieldA8TextGeoProc::GenKey(*this, caps, b);
256 }
257
258 GrGLSLPrimitiveProcessor*
createGLSLInstance(const GrShaderCaps &) const259 GrDistanceFieldA8TextGeoProc::createGLSLInstance(const GrShaderCaps&) const {
260 return new GrGLDistanceFieldA8TextGeoProc();
261 }
262
263 ///////////////////////////////////////////////////////////////////////////////
264
265 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrDistanceFieldA8TextGeoProc);
266
267 #if GR_TEST_UTILS
TestCreate(GrProcessorTestData * d)268 sk_sp<GrGeometryProcessor> GrDistanceFieldA8TextGeoProc::TestCreate(GrProcessorTestData* d) {
269 int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx
270 : GrProcessorUnitTest::kAlphaTextureIdx;
271 sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);
272
273 static const SkShader::TileMode kTileModes[] = {
274 SkShader::kClamp_TileMode,
275 SkShader::kRepeat_TileMode,
276 SkShader::kMirror_TileMode,
277 };
278 SkShader::TileMode tileModes[] = {
279 kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
280 kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
281 };
282 GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode
283 : GrSamplerParams::kNone_FilterMode);
284
285 uint32_t flags = 0;
286 flags |= d->fRandom->nextBool() ? kSimilarity_DistanceFieldEffectFlag : 0;
287 if (flags & kSimilarity_DistanceFieldEffectFlag) {
288 flags |= d->fRandom->nextBool() ? kScaleOnly_DistanceFieldEffectFlag : 0;
289 }
290
291 return GrDistanceFieldA8TextGeoProc::Make(d->resourceProvider(),
292 GrRandomColor(d->fRandom),
293 GrTest::TestMatrix(d->fRandom),
294 std::move(proxy), params,
295 #ifdef SK_GAMMA_APPLY_TO_A8
296 d->fRandom->nextF(),
297 #endif
298 flags,
299 d->fRandom->nextBool());
300 }
301 #endif
302
303 ///////////////////////////////////////////////////////////////////////////////
304
305 class GrGLDistanceFieldPathGeoProc : public GrGLSLGeometryProcessor {
306 public:
GrGLDistanceFieldPathGeoProc()307 GrGLDistanceFieldPathGeoProc()
308 : fViewMatrix(SkMatrix::InvalidMatrix())
309 , fTextureSize(SkISize::Make(-1, -1)) {}
310
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)311 void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
312 const GrDistanceFieldPathGeoProc& dfTexEffect = args.fGP.cast<GrDistanceFieldPathGeoProc>();
313
314 GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
315
316 GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
317 GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
318 GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
319
320 // emit attributes
321 varyingHandler->emitAttributes(dfTexEffect);
322
323 GrGLSLVertToFrag v(kVec2f_GrSLType);
324 varyingHandler->addVarying("TextureCoords", &v, kHigh_GrSLPrecision);
325
326 // setup pass through color
327 varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
328 vertBuilder->codeAppendf("%s = %s;", v.vsOut(), dfTexEffect.inTextureCoords()->fName);
329
330 // Setup position
331 this->setupPosition(vertBuilder,
332 uniformHandler,
333 gpArgs,
334 dfTexEffect.inPosition()->fName,
335 dfTexEffect.viewMatrix(),
336 &fViewMatrixUniform);
337
338 // emit transforms
339 this->emitTransforms(vertBuilder,
340 varyingHandler,
341 uniformHandler,
342 gpArgs->fPositionVar,
343 dfTexEffect.inPosition()->fName,
344 args.fFPCoordTransformHandler);
345
346 const char* textureSizeUniName = nullptr;
347 fTextureSizeUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
348 kVec2f_GrSLType, kDefault_GrSLPrecision,
349 "TextureSize", &textureSizeUniName);
350
351 // Use highp to work around aliasing issues
352 fragBuilder->codeAppendf("highp vec2 uv = %s;", v.fsIn());
353
354 fragBuilder->codeAppend("float texColor = ");
355 fragBuilder->appendTextureLookup(args.fTexSamplers[0],
356 "uv",
357 kVec2f_GrSLType);
358 fragBuilder->codeAppend(".r;");
359 fragBuilder->codeAppend("float distance = "
360 SK_DistanceFieldMultiplier "*(texColor - " SK_DistanceFieldThreshold ");");
361
362 fragBuilder->codeAppendf("highp vec2 st = uv*%s;", textureSizeUniName);
363 fragBuilder->codeAppend("float afwidth;");
364 bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
365 kUniformScale_DistanceFieldEffectMask;
366 bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
367 bool isGammaCorrect =
368 SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
369 if (isUniformScale) {
370 // For uniform scale, we adjust for the effect of the transformation on the distance
371 // by using the length of the gradient of the t coordinate in the y direction.
372 // We use st coordinates to ensure we're mapping 1:1 from texel space to pixel space.
373
374 // this gives us a smooth step across approximately one fragment
375 #ifdef SK_VULKAN
376 fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdx(st.x));");
377 #else
378 // We use the y gradient because there is a bug in the Mali 400 in the x direction.
379 fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*dFdy(st.y));");
380 #endif
381 } else if (isSimilarity) {
382 // For similarity transform, we adjust the effect of the transformation on the distance
383 // by using the length of the gradient of the texture coordinates. We use st coordinates
384 // to ensure we're mapping 1:1 from texel space to pixel space.
385
386 // this gives us a smooth step across approximately one fragment
387 #ifdef SK_VULKAN
388 fragBuilder->codeAppend("float st_grad_len = length(dFdx(st));");
389 #else
390 // We use the y gradient because there is a bug in the Mali 400 in the x direction.
391 fragBuilder->codeAppend("float st_grad_len = length(dFdy(st));");
392 #endif
393 fragBuilder->codeAppend("afwidth = abs(" SK_DistanceFieldAAFactor "*st_grad_len);");
394 } else {
395 // For general transforms, to determine the amount of correction we multiply a unit
396 // vector pointing along the SDF gradient direction by the Jacobian of the st coords
397 // (which is the inverse transform for this fragment) and take the length of the result.
398 fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance), dFdy(distance));");
399 // the length of the gradient may be 0, so we need to check for this
400 // this also compensates for the Adreno, which likes to drop tiles on division by 0
401 fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
402 fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
403 fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
404 fragBuilder->codeAppend("} else {");
405 fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
406 fragBuilder->codeAppend("}");
407
408 fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
409 fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
410 fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
411 fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
412
413 // this gives us a smooth step across approximately one fragment
414 fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
415 }
416 // The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
417 // doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
418 // mapped linearly to coverage, so use a linear step:
419 if (isGammaCorrect) {
420 fragBuilder->codeAppend(
421 "float val = clamp(distance + afwidth / (2.0 * afwidth), 0.0, 1.0);");
422 } else {
423 fragBuilder->codeAppend("float val = smoothstep(-afwidth, afwidth, distance);");
424 }
425
426 fragBuilder->codeAppendf("%s = vec4(val);", args.fOutputCoverage);
427 }
428
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor & proc,FPCoordTransformIter && transformIter)429 void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& proc,
430 FPCoordTransformIter&& transformIter) override {
431 SkASSERT(fTextureSizeUni.isValid());
432
433 GrTexture* texture = proc.textureSampler(0).texture();
434 if (texture->width() != fTextureSize.width() ||
435 texture->height() != fTextureSize.height()) {
436 fTextureSize = SkISize::Make(texture->width(), texture->height());
437 pdman.set2f(fTextureSizeUni,
438 SkIntToScalar(fTextureSize.width()),
439 SkIntToScalar(fTextureSize.height()));
440 }
441
442 const GrDistanceFieldPathGeoProc& dfpgp = proc.cast<GrDistanceFieldPathGeoProc>();
443
444 if (!dfpgp.viewMatrix().isIdentity() && !fViewMatrix.cheapEqualTo(dfpgp.viewMatrix())) {
445 fViewMatrix = dfpgp.viewMatrix();
446 float viewMatrix[3 * 3];
447 GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
448 pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
449 }
450 this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter);
451 }
452
GenKey(const GrGeometryProcessor & gp,const GrShaderCaps &,GrProcessorKeyBuilder * b)453 static inline void GenKey(const GrGeometryProcessor& gp,
454 const GrShaderCaps&,
455 GrProcessorKeyBuilder* b) {
456 const GrDistanceFieldPathGeoProc& dfTexEffect = gp.cast<GrDistanceFieldPathGeoProc>();
457
458 uint32_t key = dfTexEffect.getFlags();
459 key |= ComputePosKey(dfTexEffect.viewMatrix()) << 16;
460 b->add32(key);
461 }
462
463 private:
464 UniformHandle fTextureSizeUni;
465 UniformHandle fViewMatrixUniform;
466 SkMatrix fViewMatrix;
467 SkISize fTextureSize;
468
469 typedef GrGLSLGeometryProcessor INHERITED;
470 };
471
472 ///////////////////////////////////////////////////////////////////////////////
GrDistanceFieldPathGeoProc(GrResourceProvider * resourceProvider,GrColor color,const SkMatrix & viewMatrix,sk_sp<GrTextureProxy> proxy,const GrSamplerParams & params,uint32_t flags,bool usesLocalCoords)473 GrDistanceFieldPathGeoProc::GrDistanceFieldPathGeoProc(
474 GrResourceProvider* resourceProvider,
475 GrColor color,
476 const SkMatrix& viewMatrix,
477 sk_sp<GrTextureProxy> proxy,
478 const GrSamplerParams& params,
479 uint32_t flags,
480 bool usesLocalCoords)
481 : fColor(color)
482 , fViewMatrix(viewMatrix)
483 , fTextureSampler(resourceProvider, std::move(proxy), params)
484 , fFlags(flags & kNonLCD_DistanceFieldEffectMask)
485 , fInColor(nullptr)
486 , fUsesLocalCoords(usesLocalCoords) {
487 SkASSERT(!(flags & ~kNonLCD_DistanceFieldEffectMask));
488 this->initClassID<GrDistanceFieldPathGeoProc>();
489 fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
490 kHigh_GrSLPrecision);
491 fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
492 fInTextureCoords = &this->addVertexAttrib("inTextureCoords", kVec2us_GrVertexAttribType);
493 this->addTextureSampler(&fTextureSampler);
494 }
495
getGLSLProcessorKey(const GrShaderCaps & caps,GrProcessorKeyBuilder * b) const496 void GrDistanceFieldPathGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
497 GrProcessorKeyBuilder* b) const {
498 GrGLDistanceFieldPathGeoProc::GenKey(*this, caps, b);
499 }
500
501 GrGLSLPrimitiveProcessor*
createGLSLInstance(const GrShaderCaps &) const502 GrDistanceFieldPathGeoProc::createGLSLInstance(const GrShaderCaps&) const {
503 return new GrGLDistanceFieldPathGeoProc();
504 }
505
506 ///////////////////////////////////////////////////////////////////////////////
507
508 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrDistanceFieldPathGeoProc);
509
510 #if GR_TEST_UTILS
TestCreate(GrProcessorTestData * d)511 sk_sp<GrGeometryProcessor> GrDistanceFieldPathGeoProc::TestCreate(GrProcessorTestData* d) {
512 int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx
513 : GrProcessorUnitTest::kAlphaTextureIdx;
514 sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);
515
516 static const SkShader::TileMode kTileModes[] = {
517 SkShader::kClamp_TileMode,
518 SkShader::kRepeat_TileMode,
519 SkShader::kMirror_TileMode,
520 };
521 SkShader::TileMode tileModes[] = {
522 kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
523 kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
524 };
525 GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode
526 : GrSamplerParams::kNone_FilterMode);
527
528 uint32_t flags = 0;
529 flags |= d->fRandom->nextBool() ? kSimilarity_DistanceFieldEffectFlag : 0;
530 if (flags & kSimilarity_DistanceFieldEffectFlag) {
531 flags |= d->fRandom->nextBool() ? kScaleOnly_DistanceFieldEffectFlag : 0;
532 }
533
534 return GrDistanceFieldPathGeoProc::Make(d->resourceProvider(),
535 GrRandomColor(d->fRandom),
536 GrTest::TestMatrix(d->fRandom),
537 std::move(proxy),
538 params,
539 flags,
540 d->fRandom->nextBool());
541 }
542 #endif
543
544 ///////////////////////////////////////////////////////////////////////////////
545
546 class GrGLDistanceFieldLCDTextGeoProc : public GrGLSLGeometryProcessor {
547 public:
GrGLDistanceFieldLCDTextGeoProc()548 GrGLDistanceFieldLCDTextGeoProc()
549 : fViewMatrix(SkMatrix::InvalidMatrix()) {
550 fDistanceAdjust = GrDistanceFieldLCDTextGeoProc::DistanceAdjust::Make(1.0f, 1.0f, 1.0f);
551 }
552
onEmitCode(EmitArgs & args,GrGPArgs * gpArgs)553 void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override{
554 const GrDistanceFieldLCDTextGeoProc& dfTexEffect =
555 args.fGP.cast<GrDistanceFieldLCDTextGeoProc>();
556
557 GrGLSLVertexBuilder* vertBuilder = args.fVertBuilder;
558 GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
559 GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
560
561 // emit attributes
562 varyingHandler->emitAttributes(dfTexEffect);
563
564 GrGLSLPPFragmentBuilder* fragBuilder = args.fFragBuilder;
565
566 // setup pass through color
567 varyingHandler->addPassThroughAttribute(dfTexEffect.inColor(), args.fOutputColor);
568
569 // Setup position
570 this->setupPosition(vertBuilder,
571 uniformHandler,
572 gpArgs,
573 dfTexEffect.inPosition()->fName,
574 dfTexEffect.viewMatrix(),
575 &fViewMatrixUniform);
576
577 // emit transforms
578 this->emitTransforms(vertBuilder,
579 varyingHandler,
580 uniformHandler,
581 gpArgs->fPositionVar,
582 dfTexEffect.inPosition()->fName,
583 args.fFPCoordTransformHandler);
584
585 // set up varyings
586 bool isUniformScale = (dfTexEffect.getFlags() & kUniformScale_DistanceFieldEffectMask) ==
587 kUniformScale_DistanceFieldEffectMask;
588 bool isSimilarity = SkToBool(dfTexEffect.getFlags() & kSimilarity_DistanceFieldEffectFlag);
589 bool isGammaCorrect =
590 SkToBool(dfTexEffect.getFlags() & kGammaCorrect_DistanceFieldEffectFlag);
591 GrGLSLVertToFrag recipScale(kFloat_GrSLType);
592 GrGLSLVertToFrag uv(kVec2f_GrSLType);
593 varyingHandler->addVarying("TextureCoords", &uv, kHigh_GrSLPrecision);
594 vertBuilder->codeAppendf("%s = %s;", uv.vsOut(), dfTexEffect.inTextureCoords()->fName);
595
596 // compute numbers to be hardcoded to convert texture coordinates from float to int
597 SkASSERT(dfTexEffect.numTextureSamplers() == 1);
598 GrTexture* atlas = dfTexEffect.textureSampler(0).texture();
599 SkASSERT(atlas && SkIsPow2(atlas->width()) && SkIsPow2(atlas->height()));
600
601 GrGLSLVertToFrag st(kVec2f_GrSLType);
602 varyingHandler->addVarying("IntTextureCoords", &st, kHigh_GrSLPrecision);
603 vertBuilder->codeAppendf("%s = vec2(%d, %d) * %s;", st.vsOut(),
604 atlas->width(), atlas->height(),
605 dfTexEffect.inTextureCoords()->fName);
606
607 // add frag shader code
608
609 // create LCD offset adjusted by inverse of transform
610 // Use highp to work around aliasing issues
611 fragBuilder->codeAppendf("highp vec2 uv = %s;\n", uv.fsIn());
612
613 SkScalar lcdDelta = 1.0f / (3.0f * atlas->width());
614 if (dfTexEffect.getFlags() & kBGR_DistanceFieldEffectFlag) {
615 fragBuilder->codeAppendf("highp float delta = -%.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
616 } else {
617 fragBuilder->codeAppendf("highp float delta = %.*f;\n", SK_FLT_DECIMAL_DIG, lcdDelta);
618 }
619 if (isUniformScale) {
620 #ifdef SK_VULKAN
621 fragBuilder->codeAppendf("float st_grad_len = abs(dFdx(%s.x));", st.fsIn());
622 #else
623 // We use the y gradient because there is a bug in the Mali 400 in the x direction.
624 fragBuilder->codeAppendf("float st_grad_len = abs(dFdy(%s.y));", st.fsIn());
625 #endif
626 fragBuilder->codeAppend("vec2 offset = vec2(st_grad_len*delta, 0.0);");
627 } else if (isSimilarity) {
628 // For a similarity matrix with rotation, the gradient will not be aligned
629 // with the texel coordinate axes, so we need to calculate it.
630 #ifdef SK_VULKAN
631 fragBuilder->codeAppendf("vec2 st_grad = dFdx(%s);", st.fsIn());
632 fragBuilder->codeAppend("vec2 offset = delta*st_grad;");
633 #else
634 // We use dFdy because of a Mali 400 bug, and rotate -90 degrees to
635 // get the gradient in the x direction.
636 fragBuilder->codeAppendf("vec2 st_grad = dFdy(%s);", st.fsIn());
637 fragBuilder->codeAppend("vec2 offset = delta*vec2(st_grad.y, -st_grad.x);");
638 #endif
639 fragBuilder->codeAppend("float st_grad_len = length(st_grad);");
640 } else {
641 fragBuilder->codeAppendf("vec2 st = %s;\n", st.fsIn());
642
643 fragBuilder->codeAppend("vec2 Jdx = dFdx(st);");
644 fragBuilder->codeAppend("vec2 Jdy = dFdy(st);");
645 fragBuilder->codeAppend("vec2 offset = delta*Jdx;");
646 }
647
648 // green is distance to uv center
649 fragBuilder->codeAppend("\tvec4 texColor = ");
650 fragBuilder->appendTextureLookup(args.fTexSamplers[0], "uv", kVec2f_GrSLType);
651 fragBuilder->codeAppend(";\n");
652 fragBuilder->codeAppend("\tvec3 distance;\n");
653 fragBuilder->codeAppend("\tdistance.y = texColor.r;\n");
654 // red is distance to left offset
655 fragBuilder->codeAppend("\tvec2 uv_adjusted = uv - offset;\n");
656 fragBuilder->codeAppend("\ttexColor = ");
657 fragBuilder->appendTextureLookup(args.fTexSamplers[0], "uv_adjusted", kVec2f_GrSLType);
658 fragBuilder->codeAppend(";\n");
659 fragBuilder->codeAppend("\tdistance.x = texColor.r;\n");
660 // blue is distance to right offset
661 fragBuilder->codeAppend("\tuv_adjusted = uv + offset;\n");
662 fragBuilder->codeAppend("\ttexColor = ");
663 fragBuilder->appendTextureLookup(args.fTexSamplers[0], "uv_adjusted", kVec2f_GrSLType);
664 fragBuilder->codeAppend(";\n");
665 fragBuilder->codeAppend("\tdistance.z = texColor.r;\n");
666
667 fragBuilder->codeAppend("\tdistance = "
668 "vec3(" SK_DistanceFieldMultiplier ")*(distance - vec3(" SK_DistanceFieldThreshold"));");
669
670 // adjust width based on gamma
671 const char* distanceAdjustUniName = nullptr;
672 fDistanceAdjustUni = uniformHandler->addUniform(kFragment_GrShaderFlag,
673 kVec3f_GrSLType, kDefault_GrSLPrecision,
674 "DistanceAdjust", &distanceAdjustUniName);
675 fragBuilder->codeAppendf("distance -= %s;", distanceAdjustUniName);
676
677 // To be strictly correct, we should compute the anti-aliasing factor separately
678 // for each color component. However, this is only important when using perspective
679 // transformations, and even then using a single factor seems like a reasonable
680 // trade-off between quality and speed.
681 fragBuilder->codeAppend("float afwidth;");
682 if (isSimilarity) {
683 // For similarity transform (uniform scale-only is a subset of this), we adjust for the
684 // effect of the transformation on the distance by using the length of the gradient of
685 // the texture coordinates. We use st coordinates to ensure we're mapping 1:1 from texel
686 // space to pixel space.
687
688 // this gives us a smooth step across approximately one fragment
689 fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*st_grad_len;");
690 } else {
691 // For general transforms, to determine the amount of correction we multiply a unit
692 // vector pointing along the SDF gradient direction by the Jacobian of the st coords
693 // (which is the inverse transform for this fragment) and take the length of the result.
694 fragBuilder->codeAppend("vec2 dist_grad = vec2(dFdx(distance.r), dFdy(distance.r));");
695 // the length of the gradient may be 0, so we need to check for this
696 // this also compensates for the Adreno, which likes to drop tiles on division by 0
697 fragBuilder->codeAppend("float dg_len2 = dot(dist_grad, dist_grad);");
698 fragBuilder->codeAppend("if (dg_len2 < 0.0001) {");
699 fragBuilder->codeAppend("dist_grad = vec2(0.7071, 0.7071);");
700 fragBuilder->codeAppend("} else {");
701 fragBuilder->codeAppend("dist_grad = dist_grad*inversesqrt(dg_len2);");
702 fragBuilder->codeAppend("}");
703 fragBuilder->codeAppend("vec2 grad = vec2(dist_grad.x*Jdx.x + dist_grad.y*Jdy.x,");
704 fragBuilder->codeAppend(" dist_grad.x*Jdx.y + dist_grad.y*Jdy.y);");
705
706 // this gives us a smooth step across approximately one fragment
707 fragBuilder->codeAppend("afwidth = " SK_DistanceFieldAAFactor "*length(grad);");
708 }
709
710 // The smoothstep falloff compensates for the non-linear sRGB response curve. If we are
711 // doing gamma-correct rendering (to an sRGB or F16 buffer), then we actually want distance
712 // mapped linearly to coverage, so use a linear step:
713 if (isGammaCorrect) {
714 fragBuilder->codeAppend("vec4 val = "
715 "vec4(clamp(distance + vec3(afwidth) / vec3(2.0 * afwidth), 0.0, 1.0), 1.0);");
716 } else {
717 fragBuilder->codeAppend(
718 "vec4 val = vec4(smoothstep(vec3(-afwidth), vec3(afwidth), distance), 1.0);");
719 }
720
721 // set alpha to be max of rgb coverage
722 fragBuilder->codeAppend("val.a = max(max(val.r, val.g), val.b);");
723
724 fragBuilder->codeAppendf("%s = val;", args.fOutputCoverage);
725 }
726
setData(const GrGLSLProgramDataManager & pdman,const GrPrimitiveProcessor & processor,FPCoordTransformIter && transformIter)727 void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& processor,
728 FPCoordTransformIter&& transformIter) override {
729 SkASSERT(fDistanceAdjustUni.isValid());
730
731 const GrDistanceFieldLCDTextGeoProc& dflcd = processor.cast<GrDistanceFieldLCDTextGeoProc>();
732 GrDistanceFieldLCDTextGeoProc::DistanceAdjust wa = dflcd.getDistanceAdjust();
733 if (wa != fDistanceAdjust) {
734 pdman.set3f(fDistanceAdjustUni,
735 wa.fR,
736 wa.fG,
737 wa.fB);
738 fDistanceAdjust = wa;
739 }
740
741 if (!dflcd.viewMatrix().isIdentity() && !fViewMatrix.cheapEqualTo(dflcd.viewMatrix())) {
742 fViewMatrix = dflcd.viewMatrix();
743 float viewMatrix[3 * 3];
744 GrGLSLGetMatrix<3>(viewMatrix, fViewMatrix);
745 pdman.setMatrix3f(fViewMatrixUniform, viewMatrix);
746 }
747 this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter);
748 }
749
GenKey(const GrGeometryProcessor & gp,const GrShaderCaps &,GrProcessorKeyBuilder * b)750 static inline void GenKey(const GrGeometryProcessor& gp,
751 const GrShaderCaps&,
752 GrProcessorKeyBuilder* b) {
753 const GrDistanceFieldLCDTextGeoProc& dfTexEffect = gp.cast<GrDistanceFieldLCDTextGeoProc>();
754
755 uint32_t key = dfTexEffect.getFlags();
756 key |= ComputePosKey(dfTexEffect.viewMatrix()) << 16;
757 b->add32(key);
758
759 // Currently we hardcode numbers to convert atlas coordinates to normalized floating point
760 SkASSERT(gp.numTextureSamplers() == 1);
761 GrTexture* atlas = gp.textureSampler(0).texture();
762 SkASSERT(atlas);
763 b->add32(atlas->width());
764 b->add32(atlas->height());
765 }
766
767 private:
768 SkMatrix fViewMatrix;
769 UniformHandle fViewMatrixUniform;
770 UniformHandle fColorUniform;
771 GrDistanceFieldLCDTextGeoProc::DistanceAdjust fDistanceAdjust;
772 UniformHandle fDistanceAdjustUni;
773
774 typedef GrGLSLGeometryProcessor INHERITED;
775 };
776
777 ///////////////////////////////////////////////////////////////////////////////
GrDistanceFieldLCDTextGeoProc(GrResourceProvider * resourceProvider,GrColor color,const SkMatrix & viewMatrix,sk_sp<GrTextureProxy> proxy,const GrSamplerParams & params,DistanceAdjust distanceAdjust,uint32_t flags,bool usesLocalCoords)778 GrDistanceFieldLCDTextGeoProc::GrDistanceFieldLCDTextGeoProc(
779 GrResourceProvider* resourceProvider,
780 GrColor color, const SkMatrix& viewMatrix,
781 sk_sp<GrTextureProxy> proxy,
782 const GrSamplerParams& params,
783 DistanceAdjust distanceAdjust,
784 uint32_t flags, bool usesLocalCoords)
785 : fColor(color)
786 , fViewMatrix(viewMatrix)
787 , fTextureSampler(resourceProvider, std::move(proxy), params)
788 , fDistanceAdjust(distanceAdjust)
789 , fFlags(flags & kLCD_DistanceFieldEffectMask)
790 , fUsesLocalCoords(usesLocalCoords) {
791 SkASSERT(!(flags & ~kLCD_DistanceFieldEffectMask) && (flags & kUseLCD_DistanceFieldEffectFlag));
792 this->initClassID<GrDistanceFieldLCDTextGeoProc>();
793 fInPosition = &this->addVertexAttrib("inPosition", kVec2f_GrVertexAttribType,
794 kHigh_GrSLPrecision);
795 fInColor = &this->addVertexAttrib("inColor", kVec4ub_GrVertexAttribType);
796 fInTextureCoords = &this->addVertexAttrib("inTextureCoords", kVec2us_GrVertexAttribType,
797 kHigh_GrSLPrecision);
798 this->addTextureSampler(&fTextureSampler);
799 }
800
getGLSLProcessorKey(const GrShaderCaps & caps,GrProcessorKeyBuilder * b) const801 void GrDistanceFieldLCDTextGeoProc::getGLSLProcessorKey(const GrShaderCaps& caps,
802 GrProcessorKeyBuilder* b) const {
803 GrGLDistanceFieldLCDTextGeoProc::GenKey(*this, caps, b);
804 }
805
createGLSLInstance(const GrShaderCaps &) const806 GrGLSLPrimitiveProcessor* GrDistanceFieldLCDTextGeoProc::createGLSLInstance(const GrShaderCaps&) const {
807 return new GrGLDistanceFieldLCDTextGeoProc();
808 }
809
810 ///////////////////////////////////////////////////////////////////////////////
811
812 GR_DEFINE_GEOMETRY_PROCESSOR_TEST(GrDistanceFieldLCDTextGeoProc);
813
814 #if GR_TEST_UTILS
TestCreate(GrProcessorTestData * d)815 sk_sp<GrGeometryProcessor> GrDistanceFieldLCDTextGeoProc::TestCreate(GrProcessorTestData* d) {
816 int texIdx = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
817 GrProcessorUnitTest::kAlphaTextureIdx;
818 sk_sp<GrTextureProxy> proxy = d->textureProxy(texIdx);
819
820 static const SkShader::TileMode kTileModes[] = {
821 SkShader::kClamp_TileMode,
822 SkShader::kRepeat_TileMode,
823 SkShader::kMirror_TileMode,
824 };
825 SkShader::TileMode tileModes[] = {
826 kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
827 kTileModes[d->fRandom->nextULessThan(SK_ARRAY_COUNT(kTileModes))],
828 };
829 GrSamplerParams params(tileModes, d->fRandom->nextBool() ? GrSamplerParams::kBilerp_FilterMode
830 : GrSamplerParams::kNone_FilterMode);
831 DistanceAdjust wa = { 0.0f, 0.1f, -0.1f };
832 uint32_t flags = kUseLCD_DistanceFieldEffectFlag;
833 flags |= d->fRandom->nextBool() ? kSimilarity_DistanceFieldEffectFlag : 0;
834 if (flags & kSimilarity_DistanceFieldEffectFlag) {
835 flags |= d->fRandom->nextBool() ? kScaleOnly_DistanceFieldEffectFlag : 0;
836 }
837 flags |= d->fRandom->nextBool() ? kBGR_DistanceFieldEffectFlag : 0;
838 return GrDistanceFieldLCDTextGeoProc::Make(d->resourceProvider(),
839 GrRandomColor(d->fRandom),
840 GrTest::TestMatrix(d->fRandom),
841 std::move(proxy), params,
842 wa,
843 flags,
844 d->fRandom->nextBool());
845 }
846 #endif
847