src/effects/gradients/SkRadialGradient.cpp - platform/external/skqp - Gitiles

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkRadialGradient.h"
 #include "SkNx.h"

 namespace {

 // GCC doesn't like using static functions as template arguments.  So force these to be non-static.
 inline SkFixed mirror_tileproc_nonstatic(SkFixed x) {
     return mirror_tileproc(x);
 }

 inline SkFixed repeat_tileproc_nonstatic(SkFixed x) {
     return repeat_tileproc(x);
 }

 SkMatrix rad_to_unit_matrix(const SkPoint& center, SkScalar radius) {
     SkScalar    inv = SkScalarInvert(radius);

     SkMatrix matrix;
     matrix.setTranslate(-center.fX, -center.fY);
     matrix.postScale(inv, inv);
     return matrix;
 }


 }  // namespace

 /////////////////////////////////////////////////////////////////////

 SkRadialGradient::SkRadialGradient(const SkPoint& center, SkScalar radius, const Descriptor& desc)
     : SkGradientShaderBase(desc, rad_to_unit_matrix(center, radius))
     , fCenter(center)
     , fRadius(radius) {
 }

 size_t SkRadialGradient::onContextSize(const ContextRec&) const {
     return sizeof(RadialGradientContext);
 }

 SkShader::Context* SkRadialGradient::onCreateContext(const ContextRec& rec, void* storage) const {
     return new (storage) RadialGradientContext(*this, rec);
 }

 SkRadialGradient::RadialGradientContext::RadialGradientContext(
         const SkRadialGradient& shader, const ContextRec& rec)
     : INHERITED(shader, rec) {}

 SkShader::GradientType SkRadialGradient::asAGradient(GradientInfo* info) const {
     if (info) {
         commonAsAGradient(info);
         info->fPoint[0] = fCenter;
         info->fRadius[0] = fRadius;
     }
     return kRadial_GradientType;
 }

 sk_sp<SkFlattenable> SkRadialGradient::CreateProc(SkReadBuffer& buffer) {
     DescriptorScope desc;
     if (!desc.unflatten(buffer)) {
         return nullptr;
     }
     const SkPoint center = buffer.readPoint();
     const SkScalar radius = buffer.readScalar();
     return SkGradientShader::MakeRadial(center, radius, desc.fColors, std::move(desc.fColorSpace),
                                         desc.fPos, desc.fCount, desc.fTileMode, desc.fGradFlags,
                                         desc.fLocalMatrix);
 }

 void SkRadialGradient::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writePoint(fCenter);
     buffer.writeScalar(fRadius);
 }

 namespace {

 inline bool radial_completely_pinned(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy) {
     // fast, overly-conservative test: checks unit square instead of unit circle
     bool xClamped = (fx >= 1 && dx >= 0) || (fx <= -1 && dx <= 0);
     bool yClamped = (fy >= 1 && dy >= 0) || (fy <= -1 && dy <= 0);
     return xClamped || yClamped;
 }

 typedef void (* RadialShadeProc)(SkScalar sfx, SkScalar sdx,
         SkScalar sfy, SkScalar sdy,
         SkPMColor* dstC, const SkPMColor* cache,
         int count, int toggle);

 static inline Sk4f fast_sqrt(const Sk4f& R) {
     return R * R.rsqrt();
 }

 static inline Sk4f sum_squares(const Sk4f& a, const Sk4f& b) {
     return a * a + b * b;
 }

 void shadeSpan_radial_clamp2(SkScalar sfx, SkScalar sdx, SkScalar sfy, SkScalar sdy,
                              SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
                              int count, int toggle) {
     if (radial_completely_pinned(sfx, sdx, sfy, sdy)) {
         unsigned fi = SkGradientShaderBase::kCache32Count - 1;
         sk_memset32_dither(dstC,
                            cache[toggle + fi],
                            cache[next_dither_toggle(toggle) + fi],
                            count);
     } else {
         const Sk4f min(SK_ScalarNearlyZero);
         const Sk4f max(255);
         const float scale = 255;
         sfx *= scale;
         sfy *= scale;
         sdx *= scale;
         sdy *= scale;
         const Sk4f fx4(sfx, sfx + sdx, sfx + 2*sdx, sfx + 3*sdx);
         const Sk4f fy4(sfy, sfy + sdy, sfy + 2*sdy, sfy + 3*sdy);
         const Sk4f dx4(sdx * 4);
         const Sk4f dy4(sdy * 4);

         Sk4f tmpxy = fx4 * dx4 + fy4 * dy4;
         Sk4f tmpdxdy = sum_squares(dx4, dy4);
         Sk4f R = Sk4f::Max(sum_squares(fx4, fy4), min);
         Sk4f dR = tmpxy + tmpxy + tmpdxdy;
         const Sk4f ddR = tmpdxdy + tmpdxdy;

         for (int i = 0; i < (count >> 2); ++i) {
             Sk4f dist = Sk4f::Min(fast_sqrt(R), max);
             R = Sk4f::Max(R + dR, min);
             dR = dR + ddR;

             uint8_t fi[4];
             SkNx_cast<uint8_t>(dist).store(fi);

             for (int i = 0; i < 4; i++) {
                 *dstC++ = cache[toggle + fi[i]];
                 toggle = next_dither_toggle(toggle);
             }
         }
         count &= 3;
         if (count) {
             Sk4f dist = Sk4f::Min(fast_sqrt(R), max);

             uint8_t fi[4];
             SkNx_cast<uint8_t>(dist).store(fi);
             for (int i = 0; i < count; i++) {
                 *dstC++ = cache[toggle + fi[i]];
                 toggle = next_dither_toggle(toggle);
             }
         }
     }
 }

 // Unrolling this loop doesn't seem to help (when float); we're stalling to
 // get the results of the sqrt (?), and don't have enough extra registers to
 // have many in flight.
 template <SkFixed (*TileProc)(SkFixed)>
 void shadeSpan_radial(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy,
                       SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
                       int count, int toggle) {
     do {
         const SkFixed dist = SkFloatToFixed(sk_float_sqrt(fx*fx + fy*fy));
         const unsigned fi = TileProc(dist);
         SkASSERT(fi <= 0xFFFF);
         *dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache32Shift)];
         toggle = next_dither_toggle(toggle);
         fx += dx;
         fy += dy;
     } while (--count != 0);
 }

 void shadeSpan_radial_mirror(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy,
                              SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
                              int count, int toggle) {
     shadeSpan_radial<mirror_tileproc_nonstatic>(fx, dx, fy, dy, dstC, cache, count, toggle);
 }

 void shadeSpan_radial_repeat(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy,
                              SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
                              int count, int toggle) {
     shadeSpan_radial<repeat_tileproc_nonstatic>(fx, dx, fy, dy, dstC, cache, count, toggle);
 }

 }  // namespace

 void SkRadialGradient::RadialGradientContext::shadeSpan(int x, int y,
                                                         SkPMColor* SK_RESTRICT dstC, int count) {
     SkASSERT(count > 0);

     const SkRadialGradient& radialGradient = static_cast<const SkRadialGradient&>(fShader);

     SkPoint             srcPt;
     SkMatrix::MapXYProc dstProc = fDstToIndexProc;
     TileProc            proc = radialGradient.fTileProc;
     const SkPMColor* SK_RESTRICT cache = fCache->getCache32();
     int toggle = init_dither_toggle(x, y);

     if (fDstToIndexClass != kPerspective_MatrixClass) {
         dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf,
                              SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
         SkScalar sdx = fDstToIndex.getScaleX();
         SkScalar sdy = fDstToIndex.getSkewY();

         if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
             const auto step = fDstToIndex.fixedStepInX(SkIntToScalar(y));
             sdx = step.fX;
             sdy = step.fY;
         } else {
             SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
         }

         RadialShadeProc shadeProc = shadeSpan_radial_repeat;
         if (SkShader::kClamp_TileMode == radialGradient.fTileMode) {
             shadeProc = shadeSpan_radial_clamp2;
         } else if (SkShader::kMirror_TileMode == radialGradient.fTileMode) {
             shadeProc = shadeSpan_radial_mirror;
         } else {
             SkASSERT(SkShader::kRepeat_TileMode == radialGradient.fTileMode);
         }
         (*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC, cache, count, toggle);
     } else {    // perspective case
         SkScalar dstX = SkIntToScalar(x);
         SkScalar dstY = SkIntToScalar(y);
         do {
             dstProc(fDstToIndex, dstX, dstY, &srcPt);
             unsigned fi = proc(SkScalarToFixed(srcPt.length()));
             SkASSERT(fi <= 0xFFFF);
             *dstC++ = cache[fi >> SkGradientShaderBase::kCache32Shift];
             dstX += SK_Scalar1;
         } while (--count != 0);
     }
 }

 /////////////////////////////////////////////////////////////////////

 #if SK_SUPPORT_GPU

 #include "SkGr.h"
 #include "glsl/GrGLSLCaps.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"

 class GrRadialGradient : public GrGradientEffect {
 public:
     class GLSLRadialProcessor;

     static sk_sp<GrFragmentProcessor> Make(const CreateArgs& args) {
         return sk_sp<GrFragmentProcessor>(new GrRadialGradient(args));
     }

     virtual ~GrRadialGradient() { }

     const char* name() const override { return "Radial Gradient"; }

 private:
     GrRadialGradient(const CreateArgs& args)
         : INHERITED(args) {
         this->initClassID<GrRadialGradient>();
     }

     GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;

     virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
                                        GrProcessorKeyBuilder* b) const override;

     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

     typedef GrGradientEffect INHERITED;
 };

 /////////////////////////////////////////////////////////////////////

 class GrRadialGradient::GLSLRadialProcessor : public GrGradientEffect::GLSLProcessor {
 public:
     GLSLRadialProcessor(const GrProcessor&) {}
     virtual ~GLSLRadialProcessor() { }

     virtual void emitCode(EmitArgs&) override;

     static void GenKey(const GrProcessor& processor, const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
         b->add32(GenBaseGradientKey(processor));
     }

 private:
     typedef GrGradientEffect::GLSLProcessor INHERITED;

 };

 /////////////////////////////////////////////////////////////////////

 GrGLSLFragmentProcessor* GrRadialGradient::onCreateGLSLInstance() const {
     return new GrRadialGradient::GLSLRadialProcessor(*this);
 }

 void GrRadialGradient::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
                                              GrProcessorKeyBuilder* b) const {
     GrRadialGradient::GLSLRadialProcessor::GenKey(*this, caps, b);
 }

 /////////////////////////////////////////////////////////////////////

 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrRadialGradient);

 sk_sp<GrFragmentProcessor> GrRadialGradient::TestCreate(GrProcessorTestData* d) {
     SkPoint center = {d->fRandom->nextUScalar1(), d->fRandom->nextUScalar1()};
     SkScalar radius = d->fRandom->nextUScalar1();

     SkColor colors[kMaxRandomGradientColors];
     SkScalar stopsArray[kMaxRandomGradientColors];
     SkScalar* stops = stopsArray;
     SkShader::TileMode tm;
     int colorCount = RandomGradientParams(d->fRandom, colors, &stops, &tm);
     auto shader = SkGradientShader::MakeRadial(center, radius, colors, stops, colorCount, tm);
     SkMatrix viewMatrix = GrTest::TestMatrix(d->fRandom);
     sk_sp<GrFragmentProcessor> fp = shader->asFragmentProcessor(SkShader::AsFPArgs(
         d->fContext, &viewMatrix, NULL, kNone_SkFilterQuality, nullptr,
         SkSourceGammaTreatment::kRespect));
     GrAlwaysAssert(fp);
     return fp;
 }

 /////////////////////////////////////////////////////////////////////

 void GrRadialGradient::GLSLRadialProcessor::emitCode(EmitArgs& args) {
     const GrRadialGradient& ge = args.fFp.cast<GrRadialGradient>();
     this->emitUniforms(args.fUniformHandler, ge);
     SkString t("length(");
     t.append(args.fFragBuilder->ensureCoords2D(args.fTransformedCoords[0]));
     t.append(")");
     this->emitColor(args.fFragBuilder,
                     args.fUniformHandler,
                     args.fGLSLCaps,
                     ge, t.c_str(),
                     args.fOutputColor,
                     args.fInputColor,
                     args.fTexSamplers);
 }

 /////////////////////////////////////////////////////////////////////

 sk_sp<GrFragmentProcessor> SkRadialGradient::asFragmentProcessor(const AsFPArgs& args) const {
     SkASSERT(args.fContext);

     SkMatrix matrix;
     if (!this->getLocalMatrix().invert(&matrix)) {
         return nullptr;
     }
     if (args.fLocalMatrix) {
         SkMatrix inv;
         if (!args.fLocalMatrix->invert(&inv)) {
             return nullptr;
         }
         matrix.postConcat(inv);
     }
     matrix.postConcat(fPtsToUnit);
     sk_sp<GrColorSpaceXform> colorSpaceXform = GrColorSpaceXform::Make(fColorSpace.get(),
                                                                        args.fDstColorSpace);
     sk_sp<GrFragmentProcessor> inner(GrRadialGradient::Make(
         GrGradientEffect::CreateArgs(args.fContext, this, &matrix, fTileMode,
                                      std::move(colorSpaceXform), SkToBool(args.fDstColorSpace))));
     return GrFragmentProcessor::MulOutputByInputAlpha(std::move(inner));
 }

 #endif

 #ifndef SK_IGNORE_TO_STRING
 void SkRadialGradient::toString(SkString* str) const {
     str->append("SkRadialGradient: (");

     str->append("center: (");
     str->appendScalar(fCenter.fX);
     str->append(", ");
     str->appendScalar(fCenter.fY);
     str->append(") radius: ");
     str->appendScalar(fRadius);
     str->append(" ");

     this->INHERITED::toString(str);

     str->append(")");
 }
 #endif
	/*
	* Copyright 2012 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkRadialGradient.h"
	#include "SkNx.h"

	namespace {

	// GCC doesn't like using static functions as template arguments. So force these to be non-static.
	inline SkFixed mirror_tileproc_nonstatic(SkFixed x) {
	return mirror_tileproc(x);
	}

	inline SkFixed repeat_tileproc_nonstatic(SkFixed x) {
	return repeat_tileproc(x);
	}

	SkMatrix rad_to_unit_matrix(const SkPoint& center, SkScalar radius) {
	SkScalar inv = SkScalarInvert(radius);

	SkMatrix matrix;
	matrix.setTranslate(-center.fX, -center.fY);
	matrix.postScale(inv, inv);
	return matrix;
	}


	} // namespace

	/////////////////////////////////////////////////////////////////////

	SkRadialGradient::SkRadialGradient(const SkPoint& center, SkScalar radius, const Descriptor& desc)
	: SkGradientShaderBase(desc, rad_to_unit_matrix(center, radius))
	, fCenter(center)
	, fRadius(radius) {
	}

	size_t SkRadialGradient::onContextSize(const ContextRec&) const {
	return sizeof(RadialGradientContext);
	}

	SkShader::Context* SkRadialGradient::onCreateContext(const ContextRec& rec, void* storage) const {
	return new (storage) RadialGradientContext(*this, rec);
	}

	SkRadialGradient::RadialGradientContext::RadialGradientContext(
	const SkRadialGradient& shader, const ContextRec& rec)
	: INHERITED(shader, rec) {}

	SkShader::GradientType SkRadialGradient::asAGradient(GradientInfo* info) const {
	if (info) {
	commonAsAGradient(info);
	info->fPoint[0] = fCenter;
	info->fRadius[0] = fRadius;
	}
	return kRadial_GradientType;
	}

	sk_sp<SkFlattenable> SkRadialGradient::CreateProc(SkReadBuffer& buffer) {
	DescriptorScope desc;
	if (!desc.unflatten(buffer)) {
	return nullptr;
	}
	const SkPoint center = buffer.readPoint();
	const SkScalar radius = buffer.readScalar();
	return SkGradientShader::MakeRadial(center, radius, desc.fColors, std::move(desc.fColorSpace),
	desc.fPos, desc.fCount, desc.fTileMode, desc.fGradFlags,
	desc.fLocalMatrix);
	}

	void SkRadialGradient::flatten(SkWriteBuffer& buffer) const {
	this->INHERITED::flatten(buffer);
	buffer.writePoint(fCenter);
	buffer.writeScalar(fRadius);
	}

	namespace {

	inline bool radial_completely_pinned(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy) {
	// fast, overly-conservative test: checks unit square instead of unit circle
	bool xClamped = (fx >= 1 && dx >= 0) \|\| (fx <= -1 && dx <= 0);
	bool yClamped = (fy >= 1 && dy >= 0) \|\| (fy <= -1 && dy <= 0);
	return xClamped \|\| yClamped;
	}

	typedef void (* RadialShadeProc)(SkScalar sfx, SkScalar sdx,
	SkScalar sfy, SkScalar sdy,
	SkPMColor* dstC, const SkPMColor* cache,
	int count, int toggle);

	static inline Sk4f fast_sqrt(const Sk4f& R) {
	return R * R.rsqrt();
	}

	static inline Sk4f sum_squares(const Sk4f& a, const Sk4f& b) {
	return a * a + b * b;
	}

	void shadeSpan_radial_clamp2(SkScalar sfx, SkScalar sdx, SkScalar sfy, SkScalar sdy,
	SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
	int count, int toggle) {
	if (radial_completely_pinned(sfx, sdx, sfy, sdy)) {
	unsigned fi = SkGradientShaderBase::kCache32Count - 1;
	sk_memset32_dither(dstC,
	cache[toggle + fi],
	cache[next_dither_toggle(toggle) + fi],
	count);
	} else {
	const Sk4f min(SK_ScalarNearlyZero);
	const Sk4f max(255);
	const float scale = 255;
	sfx *= scale;
	sfy *= scale;
	sdx *= scale;
	sdy *= scale;
	const Sk4f fx4(sfx, sfx + sdx, sfx + 2sdx, sfx + 3sdx);
	const Sk4f fy4(sfy, sfy + sdy, sfy + 2sdy, sfy + 3sdy);
	const Sk4f dx4(sdx * 4);
	const Sk4f dy4(sdy * 4);

	Sk4f tmpxy = fx4 * dx4 + fy4 * dy4;
	Sk4f tmpdxdy = sum_squares(dx4, dy4);
	Sk4f R = Sk4f::Max(sum_squares(fx4, fy4), min);
	Sk4f dR = tmpxy + tmpxy + tmpdxdy;
	const Sk4f ddR = tmpdxdy + tmpdxdy;

	for (int i = 0; i < (count >> 2); ++i) {
	Sk4f dist = Sk4f::Min(fast_sqrt(R), max);
	R = Sk4f::Max(R + dR, min);
	dR = dR + ddR;

	uint8_t fi[4];
	SkNx_cast<uint8_t>(dist).store(fi);

	for (int i = 0; i < 4; i++) {
	*dstC++ = cache[toggle + fi[i]];
	toggle = next_dither_toggle(toggle);
	}
	}
	count &= 3;
	if (count) {
	Sk4f dist = Sk4f::Min(fast_sqrt(R), max);

	uint8_t fi[4];
	SkNx_cast<uint8_t>(dist).store(fi);
	for (int i = 0; i < count; i++) {
	*dstC++ = cache[toggle + fi[i]];
	toggle = next_dither_toggle(toggle);
	}
	}
	}
	}

	// Unrolling this loop doesn't seem to help (when float); we're stalling to
	// get the results of the sqrt (?), and don't have enough extra registers to
	// have many in flight.
	template <SkFixed (*TileProc)(SkFixed)>
	void shadeSpan_radial(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy,
	SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
	int count, int toggle) {
	do {
	const SkFixed dist = SkFloatToFixed(sk_float_sqrt(fxfx + fyfy));
	const unsigned fi = TileProc(dist);
	SkASSERT(fi <= 0xFFFF);
	*dstC++ = cache[toggle + (fi >> SkGradientShaderBase::kCache32Shift)];
	toggle = next_dither_toggle(toggle);
	fx += dx;
	fy += dy;
	} while (--count != 0);
	}

	void shadeSpan_radial_mirror(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy,
	SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
	int count, int toggle) {
	shadeSpan_radial<mirror_tileproc_nonstatic>(fx, dx, fy, dy, dstC, cache, count, toggle);
	}

	void shadeSpan_radial_repeat(SkScalar fx, SkScalar dx, SkScalar fy, SkScalar dy,
	SkPMColor* SK_RESTRICT dstC, const SkPMColor* SK_RESTRICT cache,
	int count, int toggle) {
	shadeSpan_radial<repeat_tileproc_nonstatic>(fx, dx, fy, dy, dstC, cache, count, toggle);
	}

	} // namespace

	void SkRadialGradient::RadialGradientContext::shadeSpan(int x, int y,
	SkPMColor* SK_RESTRICT dstC, int count) {
	SkASSERT(count > 0);

	const SkRadialGradient& radialGradient = static_cast<const SkRadialGradient&>(fShader);

	SkPoint srcPt;
	SkMatrix::MapXYProc dstProc = fDstToIndexProc;
	TileProc proc = radialGradient.fTileProc;
	const SkPMColor* SK_RESTRICT cache = fCache->getCache32();
	int toggle = init_dither_toggle(x, y);

	if (fDstToIndexClass != kPerspective_MatrixClass) {
	dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf,
	SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
	SkScalar sdx = fDstToIndex.getScaleX();
	SkScalar sdy = fDstToIndex.getSkewY();

	if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
	const auto step = fDstToIndex.fixedStepInX(SkIntToScalar(y));
	sdx = step.fX;
	sdy = step.fY;
	} else {
	SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
	}

	RadialShadeProc shadeProc = shadeSpan_radial_repeat;
	if (SkShader::kClamp_TileMode == radialGradient.fTileMode) {
	shadeProc = shadeSpan_radial_clamp2;
	} else if (SkShader::kMirror_TileMode == radialGradient.fTileMode) {
	shadeProc = shadeSpan_radial_mirror;
	} else {
	SkASSERT(SkShader::kRepeat_TileMode == radialGradient.fTileMode);
	}
	(*shadeProc)(srcPt.fX, sdx, srcPt.fY, sdy, dstC, cache, count, toggle);
	} else { // perspective case
	SkScalar dstX = SkIntToScalar(x);
	SkScalar dstY = SkIntToScalar(y);
	do {
	dstProc(fDstToIndex, dstX, dstY, &srcPt);
	unsigned fi = proc(SkScalarToFixed(srcPt.length()));
	SkASSERT(fi <= 0xFFFF);
	*dstC++ = cache[fi >> SkGradientShaderBase::kCache32Shift];
	dstX += SK_Scalar1;
	} while (--count != 0);
	}
	}

	/////////////////////////////////////////////////////////////////////

	#if SK_SUPPORT_GPU

	#include "SkGr.h"
	#include "glsl/GrGLSLCaps.h"
	#include "glsl/GrGLSLFragmentShaderBuilder.h"

	class GrRadialGradient : public GrGradientEffect {
	public:
	class GLSLRadialProcessor;

	static sk_sp<GrFragmentProcessor> Make(const CreateArgs& args) {
	return sk_sp<GrFragmentProcessor>(new GrRadialGradient(args));
	}

	virtual ~GrRadialGradient() { }

	const char* name() const override { return "Radial Gradient"; }

	private:
	GrRadialGradient(const CreateArgs& args)
	: INHERITED(args) {
	this->initClassID<GrRadialGradient>();
	}

	GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;

	virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
	GrProcessorKeyBuilder* b) const override;

	GR_DECLARE_FRAGMENT_PROCESSOR_TEST;

	typedef GrGradientEffect INHERITED;
	};

	/////////////////////////////////////////////////////////////////////

	class GrRadialGradient::GLSLRadialProcessor : public GrGradientEffect::GLSLProcessor {
	public:
	GLSLRadialProcessor(const GrProcessor&) {}
	virtual ~GLSLRadialProcessor() { }

	virtual void emitCode(EmitArgs&) override;

	static void GenKey(const GrProcessor& processor, const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
	b->add32(GenBaseGradientKey(processor));
	}

	private:
	typedef GrGradientEffect::GLSLProcessor INHERITED;

	};

	/////////////////////////////////////////////////////////////////////

	GrGLSLFragmentProcessor* GrRadialGradient::onCreateGLSLInstance() const {
	return new GrRadialGradient::GLSLRadialProcessor(*this);
	}

	void GrRadialGradient::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
	GrProcessorKeyBuilder* b) const {
	GrRadialGradient::GLSLRadialProcessor::GenKey(*this, caps, b);
	}

	/////////////////////////////////////////////////////////////////////

	GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrRadialGradient);

	sk_sp<GrFragmentProcessor> GrRadialGradient::TestCreate(GrProcessorTestData* d) {
	SkPoint center = {d->fRandom->nextUScalar1(), d->fRandom->nextUScalar1()};
	SkScalar radius = d->fRandom->nextUScalar1();

	SkColor colors[kMaxRandomGradientColors];
	SkScalar stopsArray[kMaxRandomGradientColors];
	SkScalar* stops = stopsArray;
	SkShader::TileMode tm;
	int colorCount = RandomGradientParams(d->fRandom, colors, &stops, &tm);
	auto shader = SkGradientShader::MakeRadial(center, radius, colors, stops, colorCount, tm);
	SkMatrix viewMatrix = GrTest::TestMatrix(d->fRandom);
	sk_sp<GrFragmentProcessor> fp = shader->asFragmentProcessor(SkShader::AsFPArgs(
	d->fContext, &viewMatrix, NULL, kNone_SkFilterQuality, nullptr,
	SkSourceGammaTreatment::kRespect));
	GrAlwaysAssert(fp);
	return fp;
	}

	/////////////////////////////////////////////////////////////////////

	void GrRadialGradient::GLSLRadialProcessor::emitCode(EmitArgs& args) {
	const GrRadialGradient& ge = args.fFp.cast<GrRadialGradient>();
	this->emitUniforms(args.fUniformHandler, ge);
	SkString t("length(");
	t.append(args.fFragBuilder->ensureCoords2D(args.fTransformedCoords[0]));
	t.append(")");
	this->emitColor(args.fFragBuilder,
	args.fUniformHandler,
	args.fGLSLCaps,
	ge, t.c_str(),
	args.fOutputColor,
	args.fInputColor,
	args.fTexSamplers);
	}

	/////////////////////////////////////////////////////////////////////

	sk_sp<GrFragmentProcessor> SkRadialGradient::asFragmentProcessor(const AsFPArgs& args) const {
	SkASSERT(args.fContext);

	SkMatrix matrix;
	if (!this->getLocalMatrix().invert(&matrix)) {
	return nullptr;
	}
	if (args.fLocalMatrix) {
	SkMatrix inv;
	if (!args.fLocalMatrix->invert(&inv)) {
	return nullptr;
	}
	matrix.postConcat(inv);
	}
	matrix.postConcat(fPtsToUnit);
	sk_sp<GrColorSpaceXform> colorSpaceXform = GrColorSpaceXform::Make(fColorSpace.get(),
	args.fDstColorSpace);
	sk_sp<GrFragmentProcessor> inner(GrRadialGradient::Make(
	GrGradientEffect::CreateArgs(args.fContext, this, &matrix, fTileMode,
	std::move(colorSpaceXform), SkToBool(args.fDstColorSpace))));
	return GrFragmentProcessor::MulOutputByInputAlpha(std::move(inner));
	}

	#endif

	#ifndef SK_IGNORE_TO_STRING
	void SkRadialGradient::toString(SkString* str) const {
	str->append("SkRadialGradient: (");

	str->append("center: (");
	str->appendScalar(fCenter.fX);
	str->append(", ");
	str->appendScalar(fCenter.fY);
	str->append(") radius: ");
	str->appendScalar(fRadius);
	str->append(" ");

	this->INHERITED::toString(str);

	str->append(")");
	}
	#endif