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 "SkDisplacementMapEffect.h"
9 #include "SkDevice.h"
10 #include "SkReadBuffer.h"
11 #include "SkWriteBuffer.h"
12 #include "SkUnPreMultiply.h"
13 #include "SkColorPriv.h"
14 #if SK_SUPPORT_GPU
15 #include "GrContext.h"
16 #include "GrDrawContext.h"
17 #include "GrCoordTransform.h"
18 #include "GrInvariantOutput.h"
19 #include "SkGr.h"
20 #include "effects/GrTextureDomain.h"
21 #include "glsl/GrGLSLFragmentProcessor.h"
22 #include "glsl/GrGLSLFragmentShaderBuilder.h"
23 #include "glsl/GrGLSLProgramDataManager.h"
24 #include "glsl/GrGLSLUniformHandler.h"
25 #endif
26 
27 namespace {
28 
29 #define kChannelSelectorKeyBits 3; // Max value is 4, so 3 bits are required at most
30 
31 template<SkDisplacementMapEffect::ChannelSelectorType type>
getValue(SkColor,const SkUnPreMultiply::Scale *)32 uint32_t getValue(SkColor, const SkUnPreMultiply::Scale*) {
33     SkDEBUGFAIL("Unknown channel selector");
34     return 0;
35 }
36 
getValue(SkColor l,const SkUnPreMultiply::Scale * table)37 template<> uint32_t getValue<SkDisplacementMapEffect::kR_ChannelSelectorType>(
38     SkColor l, const SkUnPreMultiply::Scale* table) {
39     return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedR32(l));
40 }
41 
getValue(SkColor l,const SkUnPreMultiply::Scale * table)42 template<> uint32_t getValue<SkDisplacementMapEffect::kG_ChannelSelectorType>(
43     SkColor l, const SkUnPreMultiply::Scale* table) {
44     return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedG32(l));
45 }
46 
getValue(SkColor l,const SkUnPreMultiply::Scale * table)47 template<> uint32_t getValue<SkDisplacementMapEffect::kB_ChannelSelectorType>(
48     SkColor l, const SkUnPreMultiply::Scale* table) {
49     return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedB32(l));
50 }
51 
getValue(SkColor l,const SkUnPreMultiply::Scale *)52 template<> uint32_t getValue<SkDisplacementMapEffect::kA_ChannelSelectorType>(
53     SkColor l, const SkUnPreMultiply::Scale*) {
54     return SkGetPackedA32(l);
55 }
56 
57 template<SkDisplacementMapEffect::ChannelSelectorType typeX,
58          SkDisplacementMapEffect::ChannelSelectorType typeY>
computeDisplacement(const SkVector & scale,SkBitmap * dst,SkBitmap * displ,const SkIPoint & offset,SkBitmap * src,const SkIRect & bounds)59 void computeDisplacement(const SkVector& scale, SkBitmap* dst,
60                          SkBitmap* displ, const SkIPoint& offset,
61                          SkBitmap* src,
62                          const SkIRect& bounds)
63 {
64     static const SkScalar Inv8bit = SkScalarInvert(255);
65     const int srcW = src->width();
66     const int srcH = src->height();
67     const SkVector scaleForColor = SkVector::Make(SkScalarMul(scale.fX, Inv8bit),
68                                                   SkScalarMul(scale.fY, Inv8bit));
69     const SkVector scaleAdj = SkVector::Make(SK_ScalarHalf - SkScalarMul(scale.fX, SK_ScalarHalf),
70                                              SK_ScalarHalf - SkScalarMul(scale.fY, SK_ScalarHalf));
71     const SkUnPreMultiply::Scale* table = SkUnPreMultiply::GetScaleTable();
72     SkPMColor* dstPtr = dst->getAddr32(0, 0);
73     for (int y = bounds.top(); y < bounds.bottom(); ++y) {
74         const SkPMColor* displPtr = displ->getAddr32(bounds.left() + offset.fX,
75                                                      y + offset.fY);
76         for (int x = bounds.left(); x < bounds.right(); ++x, ++displPtr) {
77             const SkScalar displX = SkScalarMul(scaleForColor.fX,
78                 SkIntToScalar(getValue<typeX>(*displPtr, table))) + scaleAdj.fX;
79             const SkScalar displY = SkScalarMul(scaleForColor.fY,
80                 SkIntToScalar(getValue<typeY>(*displPtr, table))) + scaleAdj.fY;
81             // Truncate the displacement values
82             const int srcX = x + SkScalarTruncToInt(displX);
83             const int srcY = y + SkScalarTruncToInt(displY);
84             *dstPtr++ = ((srcX < 0) || (srcX >= srcW) || (srcY < 0) || (srcY >= srcH)) ?
85                       0 : *(src->getAddr32(srcX, srcY));
86         }
87     }
88 }
89 
90 template<SkDisplacementMapEffect::ChannelSelectorType typeX>
computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,const SkVector & scale,SkBitmap * dst,SkBitmap * displ,const SkIPoint & offset,SkBitmap * src,const SkIRect & bounds)91 void computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
92                          const SkVector& scale, SkBitmap* dst,
93                          SkBitmap* displ, const SkIPoint& offset,
94                          SkBitmap* src,
95                          const SkIRect& bounds)
96 {
97     switch (yChannelSelector) {
98       case SkDisplacementMapEffect::kR_ChannelSelectorType:
99         computeDisplacement<typeX, SkDisplacementMapEffect::kR_ChannelSelectorType>(
100             scale, dst, displ, offset, src, bounds);
101         break;
102       case SkDisplacementMapEffect::kG_ChannelSelectorType:
103         computeDisplacement<typeX, SkDisplacementMapEffect::kG_ChannelSelectorType>(
104             scale, dst, displ, offset, src, bounds);
105         break;
106       case SkDisplacementMapEffect::kB_ChannelSelectorType:
107         computeDisplacement<typeX, SkDisplacementMapEffect::kB_ChannelSelectorType>(
108             scale, dst, displ, offset, src, bounds);
109         break;
110       case SkDisplacementMapEffect::kA_ChannelSelectorType:
111         computeDisplacement<typeX, SkDisplacementMapEffect::kA_ChannelSelectorType>(
112             scale, dst, displ, offset, src, bounds);
113         break;
114       case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
115       default:
116         SkDEBUGFAIL("Unknown Y channel selector");
117     }
118 }
119 
computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,const SkVector & scale,SkBitmap * dst,SkBitmap * displ,const SkIPoint & offset,SkBitmap * src,const SkIRect & bounds)120 void computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
121                          SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
122                          const SkVector& scale, SkBitmap* dst,
123                          SkBitmap* displ, const SkIPoint& offset,
124                          SkBitmap* src,
125                          const SkIRect& bounds)
126 {
127     switch (xChannelSelector) {
128       case SkDisplacementMapEffect::kR_ChannelSelectorType:
129         computeDisplacement<SkDisplacementMapEffect::kR_ChannelSelectorType>(
130             yChannelSelector, scale, dst, displ, offset, src, bounds);
131         break;
132       case SkDisplacementMapEffect::kG_ChannelSelectorType:
133         computeDisplacement<SkDisplacementMapEffect::kG_ChannelSelectorType>(
134             yChannelSelector, scale, dst, displ, offset, src, bounds);
135         break;
136       case SkDisplacementMapEffect::kB_ChannelSelectorType:
137         computeDisplacement<SkDisplacementMapEffect::kB_ChannelSelectorType>(
138             yChannelSelector, scale, dst, displ, offset, src, bounds);
139         break;
140       case SkDisplacementMapEffect::kA_ChannelSelectorType:
141         computeDisplacement<SkDisplacementMapEffect::kA_ChannelSelectorType>(
142             yChannelSelector, scale, dst, displ, offset, src, bounds);
143         break;
144       case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
145       default:
146         SkDEBUGFAIL("Unknown X channel selector");
147     }
148 }
149 
channel_selector_type_is_valid(SkDisplacementMapEffect::ChannelSelectorType cst)150 bool channel_selector_type_is_valid(SkDisplacementMapEffect::ChannelSelectorType cst) {
151     switch (cst) {
152     case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
153     case SkDisplacementMapEffect::kR_ChannelSelectorType:
154     case SkDisplacementMapEffect::kG_ChannelSelectorType:
155     case SkDisplacementMapEffect::kB_ChannelSelectorType:
156     case SkDisplacementMapEffect::kA_ChannelSelectorType:
157         return true;
158     default:
159         break;
160     }
161     return false;
162 }
163 
164 } // end namespace
165 
166 ///////////////////////////////////////////////////////////////////////////////
167 
Create(ChannelSelectorType xChannelSelector,ChannelSelectorType yChannelSelector,SkScalar scale,SkImageFilter * displacement,SkImageFilter * color,const CropRect * cropRect)168 SkImageFilter* SkDisplacementMapEffect::Create(ChannelSelectorType xChannelSelector,
169                                                ChannelSelectorType yChannelSelector,
170                                                SkScalar scale,
171                                                SkImageFilter* displacement,
172                                                SkImageFilter* color,
173                                                const CropRect* cropRect) {
174     if (!channel_selector_type_is_valid(xChannelSelector) ||
175         !channel_selector_type_is_valid(yChannelSelector)) {
176         return nullptr;
177     }
178 
179     SkImageFilter* inputs[2] = { displacement, color };
180     return new SkDisplacementMapEffect(xChannelSelector, yChannelSelector, scale, inputs, cropRect);
181 }
182 
SkDisplacementMapEffect(ChannelSelectorType xChannelSelector,ChannelSelectorType yChannelSelector,SkScalar scale,SkImageFilter * inputs[2],const CropRect * cropRect)183 SkDisplacementMapEffect::SkDisplacementMapEffect(ChannelSelectorType xChannelSelector,
184                                                  ChannelSelectorType yChannelSelector,
185                                                  SkScalar scale,
186                                                  SkImageFilter* inputs[2],
187                                                  const CropRect* cropRect)
188   : INHERITED(2, inputs, cropRect)
189   , fXChannelSelector(xChannelSelector)
190   , fYChannelSelector(yChannelSelector)
191   , fScale(scale)
192 {
193 }
194 
~SkDisplacementMapEffect()195 SkDisplacementMapEffect::~SkDisplacementMapEffect() {
196 }
197 
CreateProc(SkReadBuffer & buffer)198 SkFlattenable* SkDisplacementMapEffect::CreateProc(SkReadBuffer& buffer) {
199     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 2);
200     ChannelSelectorType xsel = (ChannelSelectorType)buffer.readInt();
201     ChannelSelectorType ysel = (ChannelSelectorType)buffer.readInt();
202     SkScalar scale = buffer.readScalar();
203     return Create(xsel, ysel, scale, common.getInput(0), common.getInput(1), &common.cropRect());
204 }
205 
flatten(SkWriteBuffer & buffer) const206 void SkDisplacementMapEffect::flatten(SkWriteBuffer& buffer) const {
207     this->INHERITED::flatten(buffer);
208     buffer.writeInt((int) fXChannelSelector);
209     buffer.writeInt((int) fYChannelSelector);
210     buffer.writeScalar(fScale);
211 }
212 
onFilterImageDeprecated(Proxy * proxy,const SkBitmap & src,const Context & ctx,SkBitmap * dst,SkIPoint * offset) const213 bool SkDisplacementMapEffect::onFilterImageDeprecated(Proxy* proxy,
214                                                       const SkBitmap& src,
215                                                       const Context& ctx,
216                                                       SkBitmap* dst,
217                                                       SkIPoint* offset) const {
218     SkBitmap displ = src, color = src;
219     SkIPoint colorOffset = SkIPoint::Make(0, 0), displOffset = SkIPoint::Make(0, 0);
220     if (!this->filterInputDeprecated(1, proxy, src, ctx, &color, &colorOffset) ||
221         !this->filterInputDeprecated(0, proxy, src, ctx, &displ, &displOffset)) {
222         return false;
223     }
224     if ((displ.colorType() != kN32_SkColorType) ||
225         (color.colorType() != kN32_SkColorType)) {
226         return false;
227     }
228     SkIRect bounds;
229     // Since computeDisplacement does bounds checking on color pixel access, we don't need to pad
230     // the color bitmap to bounds here.
231     SkIRect srcBounds = color.bounds();
232     srcBounds.offset(colorOffset);
233     if (!this->applyCropRect(ctx, srcBounds, &bounds)) {
234         return false;
235     }
236     SkIRect displBounds;
237     if (!this->applyCropRectDeprecated(ctx, proxy, displ, &displOffset, &displBounds, &displ)) {
238         return false;
239     }
240     if (!bounds.intersect(displBounds)) {
241         return false;
242     }
243     SkAutoLockPixels alp_displacement(displ), alp_color(color);
244     if (!displ.getPixels() || !color.getPixels()) {
245         return false;
246     }
247 
248     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
249     if (!device) {
250         return false;
251     }
252     *dst = device->accessBitmap(false);
253     SkAutoLockPixels alp_dst(*dst);
254 
255     SkVector scale = SkVector::Make(fScale, fScale);
256     ctx.ctm().mapVectors(&scale, 1);
257     SkIRect colorBounds = bounds;
258     colorBounds.offset(-colorOffset);
259 
260     computeDisplacement(fXChannelSelector, fYChannelSelector, scale, dst,
261                         &displ, colorOffset - displOffset, &color, colorBounds);
262 
263     offset->fX = bounds.left();
264     offset->fY = bounds.top();
265     return true;
266 }
267 
computeFastBounds(const SkRect & src,SkRect * dst) const268 void SkDisplacementMapEffect::computeFastBounds(const SkRect& src, SkRect* dst) const {
269     if (this->getColorInput()) {
270         this->getColorInput()->computeFastBounds(src, dst);
271     } else {
272         *dst = src;
273     }
274     dst->outset(SkScalarAbs(fScale) * SK_ScalarHalf, SkScalarAbs(fScale) * SK_ScalarHalf);
275 }
276 
onFilterNodeBounds(const SkIRect & src,const SkMatrix & ctm,SkIRect * dst,MapDirection) const277 void SkDisplacementMapEffect::onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm,
278                                    SkIRect* dst, MapDirection) const {
279     *dst = src;
280     SkVector scale = SkVector::Make(fScale, fScale);
281     ctm.mapVectors(&scale, 1);
282     dst->outset(SkScalarCeilToInt(SkScalarAbs(scale.fX) * SK_ScalarHalf),
283                 SkScalarCeilToInt(SkScalarAbs(scale.fY) * SK_ScalarHalf));
284 }
285 
onFilterBounds(const SkIRect & src,const SkMatrix & ctm,SkIRect * dst,MapDirection direction) const286 bool SkDisplacementMapEffect::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
287                                              SkIRect* dst, MapDirection direction) const {
288     // Recurse only into color input.
289     if (this->getColorInput()) {
290         return this->getColorInput()->filterBounds(src, ctm, dst, direction);
291     }
292     *dst = src;
293     return true;
294 }
295 
296 #ifndef SK_IGNORE_TO_STRING
toString(SkString * str) const297 void SkDisplacementMapEffect::toString(SkString* str) const {
298     str->appendf("SkDisplacementMapEffect: (");
299     str->appendf("scale: %f ", fScale);
300     str->appendf("displacement: (");
301     if (this->getDisplacementInput()) {
302         this->getDisplacementInput()->toString(str);
303     }
304     str->appendf(") color: (");
305     if (this->getColorInput()) {
306         this->getColorInput()->toString(str);
307     }
308     str->appendf("))");
309 }
310 #endif
311 
312 ///////////////////////////////////////////////////////////////////////////////
313 
314 #if SK_SUPPORT_GPU
315 class GrGLDisplacementMapEffect : public GrGLSLFragmentProcessor {
316 public:
317     void emitCode(EmitArgs&) override;
318 
319     static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);
320 
321 protected:
322     void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;
323 
324 private:
325     GrGLSLProgramDataManager::UniformHandle fScaleUni;
326     GrTextureDomain::GLDomain fGLDomain;
327 
328     typedef GrGLSLFragmentProcessor INHERITED;
329 };
330 
331 ///////////////////////////////////////////////////////////////////////////////
332 
333 class GrDisplacementMapEffect : public GrFragmentProcessor {
334 public:
Create(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,SkVector scale,GrTexture * displacement,const SkMatrix & offsetMatrix,GrTexture * color,const SkISize & colorDimensions)335     static GrFragmentProcessor* Create(
336             SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
337             SkDisplacementMapEffect::ChannelSelectorType yChannelSelector, SkVector scale,
338             GrTexture* displacement, const SkMatrix& offsetMatrix, GrTexture* color,
339             const SkISize& colorDimensions) {
340         return new GrDisplacementMapEffect(xChannelSelector, yChannelSelector, scale, displacement,
341                                            offsetMatrix, color, colorDimensions);
342     }
343 
344     virtual ~GrDisplacementMapEffect();
345 
xChannelSelector() const346     SkDisplacementMapEffect::ChannelSelectorType xChannelSelector() const
347         { return fXChannelSelector; }
yChannelSelector() const348     SkDisplacementMapEffect::ChannelSelectorType yChannelSelector() const
349         { return fYChannelSelector; }
scale() const350     const SkVector& scale() const { return fScale; }
351 
name() const352     const char* name() const override { return "DisplacementMap"; }
domain() const353     const GrTextureDomain& domain() const { return fDomain; }
354 
355 private:
onCreateGLSLInstance() const356     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override {
357         return new GrGLDisplacementMapEffect;
358     }
359 
onGetGLSLProcessorKey(const GrGLSLCaps & caps,GrProcessorKeyBuilder * b) const360     void onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override {
361         GrGLDisplacementMapEffect::GenKey(*this, caps, b);
362     }
363 
364     bool onIsEqual(const GrFragmentProcessor&) const override;
365 
366     void onComputeInvariantOutput(GrInvariantOutput* inout) const override;
367 
368     GrDisplacementMapEffect(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
369                             SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
370                             const SkVector& scale,
371                             GrTexture* displacement, const SkMatrix& offsetMatrix,
372                             GrTexture* color,
373                             const SkISize& colorDimensions);
374 
375     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
376 
377     GrCoordTransform            fDisplacementTransform;
378     GrTextureAccess             fDisplacementAccess;
379     GrCoordTransform            fColorTransform;
380     GrTextureDomain             fDomain;
381     GrTextureAccess             fColorAccess;
382     SkDisplacementMapEffect::ChannelSelectorType fXChannelSelector;
383     SkDisplacementMapEffect::ChannelSelectorType fYChannelSelector;
384     SkVector fScale;
385 
386     typedef GrFragmentProcessor INHERITED;
387 };
388 
filterImageGPUDeprecated(Proxy * proxy,const SkBitmap & src,const Context & ctx,SkBitmap * result,SkIPoint * offset) const389 bool SkDisplacementMapEffect::filterImageGPUDeprecated(Proxy* proxy, const SkBitmap& src,
390                                                        const Context& ctx,
391                                                        SkBitmap* result, SkIPoint* offset) const {
392     SkBitmap colorBM = src;
393     SkIPoint colorOffset = SkIPoint::Make(0, 0);
394     if (!this->filterInputGPUDeprecated(1, proxy, src, ctx, &colorBM, &colorOffset)) {
395         return false;
396     }
397     SkBitmap displacementBM = src;
398     SkIPoint displacementOffset = SkIPoint::Make(0, 0);
399     if (!this->filterInputGPUDeprecated(0, proxy, src, ctx, &displacementBM, &displacementOffset)) {
400         return false;
401     }
402     SkIRect srcBounds = colorBM.bounds();
403     srcBounds.offset(colorOffset);
404     SkIRect bounds;
405     // Since GrDisplacementMapEffect does bounds checking on color pixel access, we don't need to
406     // pad the color bitmap to bounds here.
407     if (!this->applyCropRect(ctx, srcBounds, &bounds)) {
408         return false;
409     }
410     SkIRect displBounds;
411     if (!this->applyCropRectDeprecated(ctx, proxy, displacementBM,
412                                        &displacementOffset, &displBounds, &displacementBM)) {
413         return false;
414     }
415     if (!bounds.intersect(displBounds)) {
416         return false;
417     }
418     GrTexture* color = colorBM.getTexture();
419     GrTexture* displacement = displacementBM.getTexture();
420     GrContext* context = color->getContext();
421 
422     GrSurfaceDesc desc;
423     desc.fFlags = kRenderTarget_GrSurfaceFlag;
424     desc.fWidth = bounds.width();
425     desc.fHeight = bounds.height();
426     desc.fConfig = kSkia8888_GrPixelConfig;
427 
428     SkAutoTUnref<GrTexture> dst(context->textureProvider()->createApproxTexture(desc));
429 
430     if (!dst) {
431         return false;
432     }
433 
434     SkVector scale = SkVector::Make(fScale, fScale);
435     ctx.ctm().mapVectors(&scale, 1);
436 
437     GrPaint paint;
438     SkMatrix offsetMatrix = GrCoordTransform::MakeDivByTextureWHMatrix(displacement);
439     offsetMatrix.preTranslate(SkIntToScalar(colorOffset.fX - displacementOffset.fX),
440                               SkIntToScalar(colorOffset.fY - displacementOffset.fY));
441 
442     paint.addColorFragmentProcessor(
443         GrDisplacementMapEffect::Create(fXChannelSelector,
444                                         fYChannelSelector,
445                                         scale,
446                                         displacement,
447                                         offsetMatrix,
448                                         color,
449                                         colorBM.dimensions()))->unref();
450     paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
451     SkIRect colorBounds = bounds;
452     colorBounds.offset(-colorOffset);
453     SkMatrix matrix;
454     matrix.setTranslate(-SkIntToScalar(colorBounds.x()),
455                         -SkIntToScalar(colorBounds.y()));
456 
457     SkAutoTUnref<GrDrawContext> drawContext(context->drawContext(dst->asRenderTarget()));
458     if (!drawContext) {
459         return false;
460     }
461 
462     drawContext->drawRect(GrClip::WideOpen(), paint, matrix, SkRect::Make(colorBounds));
463     offset->fX = bounds.left();
464     offset->fY = bounds.top();
465     GrWrapTextureInBitmap(dst, bounds.width(), bounds.height(), false, result);
466     return true;
467 }
468 
469 ///////////////////////////////////////////////////////////////////////////////
470 
GrDisplacementMapEffect(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,const SkVector & scale,GrTexture * displacement,const SkMatrix & offsetMatrix,GrTexture * color,const SkISize & colorDimensions)471 GrDisplacementMapEffect::GrDisplacementMapEffect(
472                              SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
473                              SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
474                              const SkVector& scale,
475                              GrTexture* displacement,
476                              const SkMatrix& offsetMatrix,
477                              GrTexture* color,
478                              const SkISize& colorDimensions)
479     : fDisplacementTransform(kLocal_GrCoordSet, offsetMatrix, displacement,
480                              GrTextureParams::kNone_FilterMode)
481     , fDisplacementAccess(displacement)
482     , fColorTransform(kLocal_GrCoordSet, color, GrTextureParams::kNone_FilterMode)
483     , fDomain(GrTextureDomain::MakeTexelDomain(color, SkIRect::MakeSize(colorDimensions)),
484               GrTextureDomain::kDecal_Mode)
485     , fColorAccess(color)
486     , fXChannelSelector(xChannelSelector)
487     , fYChannelSelector(yChannelSelector)
488     , fScale(scale) {
489     this->initClassID<GrDisplacementMapEffect>();
490     this->addCoordTransform(&fDisplacementTransform);
491     this->addTextureAccess(&fDisplacementAccess);
492     this->addCoordTransform(&fColorTransform);
493     this->addTextureAccess(&fColorAccess);
494 }
495 
~GrDisplacementMapEffect()496 GrDisplacementMapEffect::~GrDisplacementMapEffect() {
497 }
498 
onIsEqual(const GrFragmentProcessor & sBase) const499 bool GrDisplacementMapEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
500     const GrDisplacementMapEffect& s = sBase.cast<GrDisplacementMapEffect>();
501     return fXChannelSelector == s.fXChannelSelector &&
502            fYChannelSelector == s.fYChannelSelector &&
503            fScale == s.fScale;
504 }
505 
onComputeInvariantOutput(GrInvariantOutput * inout) const506 void GrDisplacementMapEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
507     // Any displacement offset bringing a pixel out of bounds will output a color of (0,0,0,0),
508     // so the only way we'd get a constant alpha is if the input color image has a constant alpha
509     // and no displacement offset push any texture coordinates out of bounds OR if the constant
510     // alpha is 0. Since this isn't trivial to compute at this point, let's assume the output is
511     // not of constant color when a displacement effect is applied.
512     inout->setToUnknown(GrInvariantOutput::kWillNot_ReadInput);
513 }
514 
515 ///////////////////////////////////////////////////////////////////////////////
516 
517 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrDisplacementMapEffect);
518 
TestCreate(GrProcessorTestData * d)519 const GrFragmentProcessor* GrDisplacementMapEffect::TestCreate(GrProcessorTestData* d) {
520     int texIdxDispl = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
521                                                GrProcessorUnitTest::kAlphaTextureIdx;
522     int texIdxColor = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
523                                                GrProcessorUnitTest::kAlphaTextureIdx;
524     static const int kMaxComponent = 4;
525     SkDisplacementMapEffect::ChannelSelectorType xChannelSelector =
526         static_cast<SkDisplacementMapEffect::ChannelSelectorType>(
527                 d->fRandom->nextRangeU(1, kMaxComponent));
528     SkDisplacementMapEffect::ChannelSelectorType yChannelSelector =
529         static_cast<SkDisplacementMapEffect::ChannelSelectorType>(
530                 d->fRandom->nextRangeU(1, kMaxComponent));
531     SkVector scale = SkVector::Make(d->fRandom->nextRangeScalar(0, 100.0f),
532                                     d->fRandom->nextRangeScalar(0, 100.0f));
533     SkISize colorDimensions;
534     colorDimensions.fWidth = d->fRandom->nextRangeU(0, d->fTextures[texIdxColor]->width());
535     colorDimensions.fHeight = d->fRandom->nextRangeU(0, d->fTextures[texIdxColor]->height());
536     return GrDisplacementMapEffect::Create(xChannelSelector, yChannelSelector, scale,
537                                            d->fTextures[texIdxDispl], SkMatrix::I(),
538                                            d->fTextures[texIdxColor], colorDimensions);
539 }
540 
541 ///////////////////////////////////////////////////////////////////////////////
542 
emitCode(EmitArgs & args)543 void GrGLDisplacementMapEffect::emitCode(EmitArgs& args) {
544     const GrDisplacementMapEffect& displacementMap = args.fFp.cast<GrDisplacementMapEffect>();
545     const GrTextureDomain& domain = displacementMap.domain();
546 
547     fScaleUni = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
548                                                  kVec2f_GrSLType, kDefault_GrSLPrecision, "Scale");
549     const char* scaleUni = args.fUniformHandler->getUniformCStr(fScaleUni);
550     const char* dColor = "dColor";
551     const char* cCoords = "cCoords";
552     const char* nearZero = "1e-6"; // Since 6.10352e−5 is the smallest half float, use
553                                    // a number smaller than that to approximate 0, but
554                                    // leave room for 32-bit float GPU rounding errors.
555 
556     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
557     fragBuilder->codeAppendf("\t\tvec4 %s = ", dColor);
558     fragBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str(),
559                                    args.fCoords[0].getType());
560     fragBuilder->codeAppend(";\n");
561 
562     // Unpremultiply the displacement
563     fragBuilder->codeAppendf(
564         "\t\t%s.rgb = (%s.a < %s) ? vec3(0.0) : clamp(%s.rgb / %s.a, 0.0, 1.0);",
565         dColor, dColor, nearZero, dColor, dColor);
566     SkString coords2D = fragBuilder->ensureFSCoords2D(args.fCoords, 1);
567     fragBuilder->codeAppendf("\t\tvec2 %s = %s + %s*(%s.",
568                              cCoords, coords2D.c_str(), scaleUni, dColor);
569 
570     switch (displacementMap.xChannelSelector()) {
571       case SkDisplacementMapEffect::kR_ChannelSelectorType:
572         fragBuilder->codeAppend("r");
573         break;
574       case SkDisplacementMapEffect::kG_ChannelSelectorType:
575         fragBuilder->codeAppend("g");
576         break;
577       case SkDisplacementMapEffect::kB_ChannelSelectorType:
578         fragBuilder->codeAppend("b");
579         break;
580       case SkDisplacementMapEffect::kA_ChannelSelectorType:
581         fragBuilder->codeAppend("a");
582         break;
583       case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
584       default:
585         SkDEBUGFAIL("Unknown X channel selector");
586     }
587 
588     switch (displacementMap.yChannelSelector()) {
589       case SkDisplacementMapEffect::kR_ChannelSelectorType:
590         fragBuilder->codeAppend("r");
591         break;
592       case SkDisplacementMapEffect::kG_ChannelSelectorType:
593         fragBuilder->codeAppend("g");
594         break;
595       case SkDisplacementMapEffect::kB_ChannelSelectorType:
596         fragBuilder->codeAppend("b");
597         break;
598       case SkDisplacementMapEffect::kA_ChannelSelectorType:
599         fragBuilder->codeAppend("a");
600         break;
601       case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
602       default:
603         SkDEBUGFAIL("Unknown Y channel selector");
604     }
605     fragBuilder->codeAppend("-vec2(0.5));\t\t");
606 
607     fGLDomain.sampleTexture(fragBuilder,
608                             args.fUniformHandler,
609                             args.fGLSLCaps,
610                             domain,
611                             args.fOutputColor,
612                             SkString(cCoords),
613                             args.fSamplers[1]);
614     fragBuilder->codeAppend(";\n");
615 }
616 
onSetData(const GrGLSLProgramDataManager & pdman,const GrProcessor & proc)617 void GrGLDisplacementMapEffect::onSetData(const GrGLSLProgramDataManager& pdman,
618                                           const GrProcessor& proc) {
619     const GrDisplacementMapEffect& displacementMap = proc.cast<GrDisplacementMapEffect>();
620     GrTexture* colorTex = displacementMap.texture(1);
621     SkScalar scaleX = displacementMap.scale().fX / colorTex->width();
622     SkScalar scaleY = displacementMap.scale().fY / colorTex->height();
623     pdman.set2f(fScaleUni, SkScalarToFloat(scaleX),
624                 colorTex->origin() == kTopLeft_GrSurfaceOrigin ?
625                 SkScalarToFloat(scaleY) : SkScalarToFloat(-scaleY));
626     fGLDomain.setData(pdman, displacementMap.domain(), colorTex->origin());
627 }
628 
GenKey(const GrProcessor & proc,const GrGLSLCaps &,GrProcessorKeyBuilder * b)629 void GrGLDisplacementMapEffect::GenKey(const GrProcessor& proc,
630                                        const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
631     const GrDisplacementMapEffect& displacementMap = proc.cast<GrDisplacementMapEffect>();
632 
633     uint32_t xKey = displacementMap.xChannelSelector();
634     uint32_t yKey = displacementMap.yChannelSelector() << kChannelSelectorKeyBits;
635 
636     b->add32(xKey | yKey);
637 }
638 #endif
639 
640