src/core/SkBitmapProcShader.cpp - skia - Git at Google

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */

 #include "SkBitmapProcShader.h"
 #include "SkBitmapProcState.h"
 #include "SkBitmapProvider.h"
 #include "SkColorPriv.h"
 #include "SkErrorInternals.h"
 #include "SkPixelRef.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"

 #if SK_SUPPORT_GPU
 #include "SkGrPriv.h"
 #include "effects/GrBicubicEffect.h"
 #include "effects/GrSimpleTextureEffect.h"
 #endif

 size_t SkBitmapProcShader::ContextSize() {
     // The SkBitmapProcState is stored outside of the context object, with the context holding
     // a pointer to it.
     return sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState);
 }

 SkBitmapProcShader::SkBitmapProcShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
                                        const SkMatrix* localMatrix)
         : INHERITED(localMatrix) {
     fRawBitmap = src;
     fTileModeX = (uint8_t)tmx;
     fTileModeY = (uint8_t)tmy;
 }

 bool SkBitmapProcShader::onIsABitmap(SkBitmap* texture, SkMatrix* texM, TileMode xy[]) const {
     if (texture) {
         *texture = fRawBitmap;
     }
     if (texM) {
         texM->reset();
     }
     if (xy) {
         xy[0] = (TileMode)fTileModeX;
         xy[1] = (TileMode)fTileModeY;
     }
     return true;
 }

 SkFlattenable* SkBitmapProcShader::CreateProc(SkReadBuffer& buffer) {
     SkMatrix lm;
     buffer.readMatrix(&lm);
     SkBitmap bm;
     if (!buffer.readBitmap(&bm)) {
         return nullptr;
     }
     bm.setImmutable();
     TileMode mx = (TileMode)buffer.readUInt();
     TileMode my = (TileMode)buffer.readUInt();
     return SkShader::CreateBitmapShader(bm, mx, my, &lm);
 }

 void SkBitmapProcShader::flatten(SkWriteBuffer& buffer) const {
     buffer.writeMatrix(this->getLocalMatrix());
     buffer.writeBitmap(fRawBitmap);
     buffer.writeUInt(fTileModeX);
     buffer.writeUInt(fTileModeY);
 }

 static bool only_scale_and_translate(const SkMatrix& matrix) {
     unsigned mask = SkMatrix::kTranslate_Mask | SkMatrix::kScale_Mask;
     return (matrix.getType() & ~mask) == 0;
 }

 bool SkBitmapProcShader::isOpaque() const {
     return fRawBitmap.isOpaque();
 }

 SkShader::Context* SkBitmapProcShader::MakeContext(const SkShader& shader,
                                                    TileMode tmx, TileMode tmy,
                                                    const SkBitmapProvider& provider,
                                                    const ContextRec& rec, void* storage) {
     SkMatrix totalInverse;
     // Do this first, so we know the matrix can be inverted.
     if (!shader.computeTotalInverse(rec, &totalInverse)) {
         return nullptr;
     }

     void* stateStorage = (char*)storage + sizeof(BitmapProcShaderContext);
     SkBitmapProcState* state = new (stateStorage) SkBitmapProcState(provider, tmx, tmy);

     SkASSERT(state);
     if (!state->chooseProcs(totalInverse, *rec.fPaint)) {
         state->~SkBitmapProcState();
         return nullptr;
     }

     return new (storage) BitmapProcShaderContext(shader, rec, state);
 }

 SkShader::Context* SkBitmapProcShader::onCreateContext(const ContextRec& rec, void* storage) const {
     return MakeContext(*this, (TileMode)fTileModeX, (TileMode)fTileModeY,
                        SkBitmapProvider(fRawBitmap), rec, storage);
 }

 SkBitmapProcShader::BitmapProcShaderContext::BitmapProcShaderContext(const SkShader& shader,
                                                                      const ContextRec& rec,
                                                                      SkBitmapProcState* state)
     : INHERITED(shader, rec)
     , fState(state)
 {
     const SkPixmap& pixmap = fState->fPixmap;
     bool isOpaque = pixmap.isOpaque();

     // update fFlags
     uint32_t flags = 0;
     if (isOpaque && (255 == this->getPaintAlpha())) {
         flags |= kOpaqueAlpha_Flag;
     }

     switch (pixmap.colorType()) {
         case kRGB_565_SkColorType:
             flags |= (kHasSpan16_Flag | kIntrinsicly16_Flag);
             break;
         case kIndex_8_SkColorType:
         case kN32_SkColorType:
             if (isOpaque) {
                 flags |= kHasSpan16_Flag;
             }
             break;
         case kAlpha_8_SkColorType:
             break;  // never set kHasSpan16_Flag
         default:
             break;
     }

     if (rec.fPaint->isDither() && pixmap.colorType() != kRGB_565_SkColorType) {
         // gradients can auto-dither in their 16bit sampler, but we don't so
         // we clear the flag here.
         flags &= ~kHasSpan16_Flag;
     }

     // if we're only 1-pixel high, and we don't rotate, then we can claim this
     if (1 == pixmap.height() &&
             only_scale_and_translate(this->getTotalInverse())) {
         flags |= kConstInY32_Flag;
         if (flags & kHasSpan16_Flag) {
             flags |= kConstInY16_Flag;
         }
     }

     fFlags = flags;
 }

 SkBitmapProcShader::BitmapProcShaderContext::~BitmapProcShaderContext() {
     // The bitmap proc state has been created outside of the context on memory that will be freed
     // elsewhere. Only call the destructor but leave the freeing of the memory to the caller.
     fState->~SkBitmapProcState();
 }

 #define BUF_MAX     128

 #define TEST_BUFFER_OVERRITEx

 #ifdef TEST_BUFFER_OVERRITE
     #define TEST_BUFFER_EXTRA   32
     #define TEST_PATTERN    0x88888888
 #else
     #define TEST_BUFFER_EXTRA   0
 #endif

 void SkBitmapProcShader::BitmapProcShaderContext::shadeSpan(int x, int y, SkPMColor dstC[],
                                                             int count) {
     const SkBitmapProcState& state = *fState;
     if (state.getShaderProc32()) {
         state.getShaderProc32()(&state, x, y, dstC, count);
         return;
     }

     uint32_t buffer[BUF_MAX + TEST_BUFFER_EXTRA];
     SkBitmapProcState::MatrixProc   mproc = state.getMatrixProc();
     SkBitmapProcState::SampleProc32 sproc = state.getSampleProc32();
     int max = state.maxCountForBufferSize(sizeof(buffer[0]) * BUF_MAX);

     SkASSERT(state.fPixmap.addr());

     for (;;) {
         int n = count;
         if (n > max) {
             n = max;
         }
         SkASSERT(n > 0 && n < BUF_MAX*2);
 #ifdef TEST_BUFFER_OVERRITE
         for (int i = 0; i < TEST_BUFFER_EXTRA; i++) {
             buffer[BUF_MAX + i] = TEST_PATTERN;
         }
 #endif
         mproc(state, buffer, n, x, y);
 #ifdef TEST_BUFFER_OVERRITE
         for (int j = 0; j < TEST_BUFFER_EXTRA; j++) {
             SkASSERT(buffer[BUF_MAX + j] == TEST_PATTERN);
         }
 #endif
         sproc(state, buffer, n, dstC);

         if ((count -= n) == 0) {
             break;
         }
         SkASSERT(count > 0);
         x += n;
         dstC += n;
     }
 }

 SkShader::Context::ShadeProc SkBitmapProcShader::BitmapProcShaderContext::asAShadeProc(void** ctx) {
     if (fState->getShaderProc32()) {
         *ctx = fState;
         return (ShadeProc)fState->getShaderProc32();
     }
     return nullptr;
 }

 void SkBitmapProcShader::BitmapProcShaderContext::shadeSpan16(int x, int y, uint16_t dstC[],
                                                               int count) {
     const SkBitmapProcState& state = *fState;
     if (state.getShaderProc16()) {
         state.getShaderProc16()(&state, x, y, dstC, count);
         return;
     }

     uint32_t buffer[BUF_MAX];
     SkBitmapProcState::MatrixProc   mproc = state.getMatrixProc();
     SkBitmapProcState::SampleProc16 sproc = state.getSampleProc16();
     int max = state.maxCountForBufferSize(sizeof(buffer));

     SkASSERT(state.fPixmap.addr());

     for (;;) {
         int n = count;
         if (n > max) {
             n = max;
         }
         mproc(state, buffer, n, x, y);
         sproc(state, buffer, n, dstC);

         if ((count -= n) == 0) {
             break;
         }
         x += n;
         dstC += n;
     }
 }

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

 #include "SkUnPreMultiply.h"
 #include "SkColorShader.h"
 #include "SkEmptyShader.h"

 // returns true and set color if the bitmap can be drawn as a single color
 // (for efficiency)
 static bool can_use_color_shader(const SkBitmap& bm, SkColor* color) {
 #ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
     // HWUI does not support color shaders (see b/22390304)
     return false;
 #endif

     if (1 != bm.width() || 1 != bm.height()) {
         return false;
     }

     SkAutoLockPixels alp(bm);
     if (!bm.readyToDraw()) {
         return false;
     }

     switch (bm.colorType()) {
         case kN32_SkColorType:
             *color = SkUnPreMultiply::PMColorToColor(*bm.getAddr32(0, 0));
             return true;
         case kRGB_565_SkColorType:
             *color = SkPixel16ToColor(*bm.getAddr16(0, 0));
             return true;
         case kIndex_8_SkColorType:
             *color = SkUnPreMultiply::PMColorToColor(bm.getIndex8Color(0, 0));
             return true;
         default: // just skip the other configs for now
             break;
     }
     return false;
 }

 static bool bitmap_is_too_big(const SkBitmap& bm) {
     // SkBitmapProcShader stores bitmap coordinates in a 16bit buffer, as it
     // communicates between its matrix-proc and its sampler-proc. Until we can
     // widen that, we have to reject bitmaps that are larger.
     //
     static const int kMaxSize = 65535;

     return bm.width() > kMaxSize || bm.height() > kMaxSize;
 }

 SkShader* SkCreateBitmapShader(const SkBitmap& src, SkShader::TileMode tmx,
                                SkShader::TileMode tmy, const SkMatrix* localMatrix,
                                SkTBlitterAllocator* allocator) {
     SkShader* shader;
     SkColor color;
     if (src.isNull() || bitmap_is_too_big(src)) {
         if (nullptr == allocator) {
             shader = new SkEmptyShader;
         } else {
             shader = allocator->createT<SkEmptyShader>();
         }
     } else if (can_use_color_shader(src, &color)) {
         if (nullptr == allocator) {
             shader = new SkColorShader(color);
         } else {
             shader = allocator->createT<SkColorShader>(color);
         }
     } else {
         if (nullptr == allocator) {
             shader = new SkBitmapProcShader(src, tmx, tmy, localMatrix);
         } else {
             shader = allocator->createT<SkBitmapProcShader>(src, tmx, tmy, localMatrix);
         }
     }
     return shader;
 }

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

 #ifndef SK_IGNORE_TO_STRING
 void SkBitmapProcShader::toString(SkString* str) const {
     static const char* gTileModeName[SkShader::kTileModeCount] = {
         "clamp", "repeat", "mirror"
     };

     str->append("BitmapShader: (");

     str->appendf("(%s, %s)",
                  gTileModeName[fTileModeX],
                  gTileModeName[fTileModeY]);

     str->append(" ");
     fRawBitmap.toString(str);

     this->INHERITED::toString(str);

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

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

 #if SK_SUPPORT_GPU

 #include "GrTextureAccess.h"
 #include "SkGr.h"
 #include "effects/GrSimpleTextureEffect.h"

 const GrFragmentProcessor* SkBitmapProcShader::asFragmentProcessor(GrContext* context,
                                              const SkMatrix& viewM, const SkMatrix* localMatrix,
                                              SkFilterQuality filterQuality) const {
     SkMatrix matrix;
     matrix.setIDiv(fRawBitmap.width(), fRawBitmap.height());

     SkMatrix lmInverse;
     if (!this->getLocalMatrix().invert(&lmInverse)) {
         return nullptr;
     }
     if (localMatrix) {
         SkMatrix inv;
         if (!localMatrix->invert(&inv)) {
             return nullptr;
         }
         lmInverse.postConcat(inv);
     }
     matrix.preConcat(lmInverse);

     SkShader::TileMode tm[] = {
         (TileMode)fTileModeX,
         (TileMode)fTileModeY,
     };

     // Must set wrap and filter on the sampler before requesting a texture. In two places below
     // we check the matrix scale factors to determine how to interpret the filter quality setting.
     // This completely ignores the complexity of the drawVertices case where explicit local coords
     // are provided by the caller.
     bool doBicubic;
     GrTextureParams::FilterMode textureFilterMode =
             GrSkFilterQualityToGrFilterMode(filterQuality, viewM, this->getLocalMatrix(),
                                             &doBicubic);
     GrTextureParams params(tm, textureFilterMode);
     SkAutoTUnref<GrTexture> texture(GrRefCachedBitmapTexture(context, fRawBitmap, params));

     if (!texture) {
         SkErrorInternals::SetError( kInternalError_SkError,
                                     "Couldn't convert bitmap to texture.");
         return nullptr;
     }

     SkAutoTUnref<const GrFragmentProcessor> inner;
     if (doBicubic) {
         inner.reset(GrBicubicEffect::Create(texture, matrix, tm));
     } else {
         inner.reset(GrSimpleTextureEffect::Create(texture, matrix, params));
     }

     if (kAlpha_8_SkColorType == fRawBitmap.colorType()) {
         return GrFragmentProcessor::MulOutputByInputUnpremulColor(inner);
     }
     return GrFragmentProcessor::MulOutputByInputAlpha(inner);
 }

 #endif
	/*
	* Copyright 2011 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/

	#include "SkBitmapProcShader.h"
	#include "SkBitmapProcState.h"
	#include "SkBitmapProvider.h"
	#include "SkColorPriv.h"
	#include "SkErrorInternals.h"
	#include "SkPixelRef.h"
	#include "SkReadBuffer.h"
	#include "SkWriteBuffer.h"

	#if SK_SUPPORT_GPU
	#include "SkGrPriv.h"
	#include "effects/GrBicubicEffect.h"
	#include "effects/GrSimpleTextureEffect.h"
	#endif

	size_t SkBitmapProcShader::ContextSize() {
	// The SkBitmapProcState is stored outside of the context object, with the context holding
	// a pointer to it.
	return sizeof(BitmapProcShaderContext) + sizeof(SkBitmapProcState);
	}

	SkBitmapProcShader::SkBitmapProcShader(const SkBitmap& src, TileMode tmx, TileMode tmy,
	const SkMatrix* localMatrix)
	: INHERITED(localMatrix) {
	fRawBitmap = src;
	fTileModeX = (uint8_t)tmx;
	fTileModeY = (uint8_t)tmy;
	}

	bool SkBitmapProcShader::onIsABitmap(SkBitmap* texture, SkMatrix* texM, TileMode xy[]) const {
	if (texture) {
	*texture = fRawBitmap;
	}
	if (texM) {
	texM->reset();
	}
	if (xy) {
	xy[0] = (TileMode)fTileModeX;
	xy[1] = (TileMode)fTileModeY;
	}
	return true;
	}

	SkFlattenable* SkBitmapProcShader::CreateProc(SkReadBuffer& buffer) {
	SkMatrix lm;
	buffer.readMatrix(&lm);
	SkBitmap bm;
	if (!buffer.readBitmap(&bm)) {
	return nullptr;
	}
	bm.setImmutable();
	TileMode mx = (TileMode)buffer.readUInt();
	TileMode my = (TileMode)buffer.readUInt();
	return SkShader::CreateBitmapShader(bm, mx, my, &lm);
	}

	void SkBitmapProcShader::flatten(SkWriteBuffer& buffer) const {
	buffer.writeMatrix(this->getLocalMatrix());
	buffer.writeBitmap(fRawBitmap);
	buffer.writeUInt(fTileModeX);
	buffer.writeUInt(fTileModeY);
	}

	static bool only_scale_and_translate(const SkMatrix& matrix) {
	unsigned mask = SkMatrix::kTranslate_Mask \| SkMatrix::kScale_Mask;
	return (matrix.getType() & ~mask) == 0;
	}

	bool SkBitmapProcShader::isOpaque() const {
	return fRawBitmap.isOpaque();
	}

	SkShader::Context* SkBitmapProcShader::MakeContext(const SkShader& shader,
	TileMode tmx, TileMode tmy,
	const SkBitmapProvider& provider,
	const ContextRec& rec, void* storage) {
	SkMatrix totalInverse;
	// Do this first, so we know the matrix can be inverted.
	if (!shader.computeTotalInverse(rec, &totalInverse)) {
	return nullptr;
	}

	void* stateStorage = (char*)storage + sizeof(BitmapProcShaderContext);
	SkBitmapProcState* state = new (stateStorage) SkBitmapProcState(provider, tmx, tmy);

	SkASSERT(state);
	if (!state->chooseProcs(totalInverse, *rec.fPaint)) {
	state->~SkBitmapProcState();
	return nullptr;
	}

	return new (storage) BitmapProcShaderContext(shader, rec, state);
	}

	SkShader::Context* SkBitmapProcShader::onCreateContext(const ContextRec& rec, void* storage) const {
	return MakeContext(*this, (TileMode)fTileModeX, (TileMode)fTileModeY,
	SkBitmapProvider(fRawBitmap), rec, storage);
	}

	SkBitmapProcShader::BitmapProcShaderContext::BitmapProcShaderContext(const SkShader& shader,
	const ContextRec& rec,
	SkBitmapProcState* state)
	: INHERITED(shader, rec)
	, fState(state)
	{
	const SkPixmap& pixmap = fState->fPixmap;
	bool isOpaque = pixmap.isOpaque();

	// update fFlags
	uint32_t flags = 0;
	if (isOpaque && (255 == this->getPaintAlpha())) {
	flags \|= kOpaqueAlpha_Flag;
	}

	switch (pixmap.colorType()) {
	case kRGB_565_SkColorType:
	flags \|= (kHasSpan16_Flag \| kIntrinsicly16_Flag);
	break;
	case kIndex_8_SkColorType:
	case kN32_SkColorType:
	if (isOpaque) {
	flags \|= kHasSpan16_Flag;
	}
	break;
	case kAlpha_8_SkColorType:
	break; // never set kHasSpan16_Flag
	default:
	break;
	}

	if (rec.fPaint->isDither() && pixmap.colorType() != kRGB_565_SkColorType) {
	// gradients can auto-dither in their 16bit sampler, but we don't so
	// we clear the flag here.
	flags &= ~kHasSpan16_Flag;
	}

	// if we're only 1-pixel high, and we don't rotate, then we can claim this
	if (1 == pixmap.height() &&
	only_scale_and_translate(this->getTotalInverse())) {
	flags \|= kConstInY32_Flag;
	if (flags & kHasSpan16_Flag) {
	flags \|= kConstInY16_Flag;
	}
	}

	fFlags = flags;
	}

	SkBitmapProcShader::BitmapProcShaderContext::~BitmapProcShaderContext() {
	// The bitmap proc state has been created outside of the context on memory that will be freed
	// elsewhere. Only call the destructor but leave the freeing of the memory to the caller.
	fState->~SkBitmapProcState();
	}

	#define BUF_MAX 128

	#define TEST_BUFFER_OVERRITEx

	#ifdef TEST_BUFFER_OVERRITE
	#define TEST_BUFFER_EXTRA 32
	#define TEST_PATTERN 0x88888888
	#else
	#define TEST_BUFFER_EXTRA 0
	#endif

	void SkBitmapProcShader::BitmapProcShaderContext::shadeSpan(int x, int y, SkPMColor dstC[],
	int count) {
	const SkBitmapProcState& state = *fState;
	if (state.getShaderProc32()) {
	state.getShaderProc32()(&state, x, y, dstC, count);
	return;
	}

	uint32_t buffer[BUF_MAX + TEST_BUFFER_EXTRA];
	SkBitmapProcState::MatrixProc mproc = state.getMatrixProc();
	SkBitmapProcState::SampleProc32 sproc = state.getSampleProc32();
	int max = state.maxCountForBufferSize(sizeof(buffer[0]) * BUF_MAX);

	SkASSERT(state.fPixmap.addr());

	for (;;) {
	int n = count;
	if (n > max) {
	n = max;
	}
	SkASSERT(n > 0 && n < BUF_MAX*2);
	#ifdef TEST_BUFFER_OVERRITE
	for (int i = 0; i < TEST_BUFFER_EXTRA; i++) {
	buffer[BUF_MAX + i] = TEST_PATTERN;
	}
	#endif
	mproc(state, buffer, n, x, y);
	#ifdef TEST_BUFFER_OVERRITE
	for (int j = 0; j < TEST_BUFFER_EXTRA; j++) {
	SkASSERT(buffer[BUF_MAX + j] == TEST_PATTERN);
	}
	#endif
	sproc(state, buffer, n, dstC);

	if ((count -= n) == 0) {
	break;
	}
	SkASSERT(count > 0);
	x += n;
	dstC += n;
	}
	}

	SkShader::Context::ShadeProc SkBitmapProcShader::BitmapProcShaderContext::asAShadeProc(void** ctx) {
	if (fState->getShaderProc32()) {
	*ctx = fState;
	return (ShadeProc)fState->getShaderProc32();
	}
	return nullptr;
	}

	void SkBitmapProcShader::BitmapProcShaderContext::shadeSpan16(int x, int y, uint16_t dstC[],
	int count) {
	const SkBitmapProcState& state = *fState;
	if (state.getShaderProc16()) {
	state.getShaderProc16()(&state, x, y, dstC, count);
	return;
	}

	uint32_t buffer[BUF_MAX];
	SkBitmapProcState::MatrixProc mproc = state.getMatrixProc();
	SkBitmapProcState::SampleProc16 sproc = state.getSampleProc16();
	int max = state.maxCountForBufferSize(sizeof(buffer));

	SkASSERT(state.fPixmap.addr());

	for (;;) {
	int n = count;
	if (n > max) {
	n = max;
	}
	mproc(state, buffer, n, x, y);
	sproc(state, buffer, n, dstC);

	if ((count -= n) == 0) {
	break;
	}
	x += n;
	dstC += n;
	}
	}

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

	#include "SkUnPreMultiply.h"
	#include "SkColorShader.h"
	#include "SkEmptyShader.h"

	// returns true and set color if the bitmap can be drawn as a single color
	// (for efficiency)
	static bool can_use_color_shader(const SkBitmap& bm, SkColor* color) {
	#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
	// HWUI does not support color shaders (see b/22390304)
	return false;
	#endif

	if (1 != bm.width() \|\| 1 != bm.height()) {
	return false;
	}

	SkAutoLockPixels alp(bm);
	if (!bm.readyToDraw()) {
	return false;
	}

	switch (bm.colorType()) {
	case kN32_SkColorType:
	color = SkUnPreMultiply::PMColorToColor(bm.getAddr32(0, 0));
	return true;
	case kRGB_565_SkColorType:
	color = SkPixel16ToColor(bm.getAddr16(0, 0));
	return true;
	case kIndex_8_SkColorType:
	*color = SkUnPreMultiply::PMColorToColor(bm.getIndex8Color(0, 0));
	return true;
	default: // just skip the other configs for now
	break;
	}
	return false;
	}

	static bool bitmap_is_too_big(const SkBitmap& bm) {
	// SkBitmapProcShader stores bitmap coordinates in a 16bit buffer, as it
	// communicates between its matrix-proc and its sampler-proc. Until we can
	// widen that, we have to reject bitmaps that are larger.
	//
	static const int kMaxSize = 65535;

	return bm.width() > kMaxSize \|\| bm.height() > kMaxSize;
	}

	SkShader* SkCreateBitmapShader(const SkBitmap& src, SkShader::TileMode tmx,
	SkShader::TileMode tmy, const SkMatrix* localMatrix,
	SkTBlitterAllocator* allocator) {
	SkShader* shader;
	SkColor color;
	if (src.isNull() \|\| bitmap_is_too_big(src)) {
	if (nullptr == allocator) {
	shader = new SkEmptyShader;
	} else {
	shader = allocator->createT<SkEmptyShader>();
	}
	} else if (can_use_color_shader(src, &color)) {
	if (nullptr == allocator) {
	shader = new SkColorShader(color);
	} else {
	shader = allocator->createT<SkColorShader>(color);
	}
	} else {
	if (nullptr == allocator) {
	shader = new SkBitmapProcShader(src, tmx, tmy, localMatrix);
	} else {
	shader = allocator->createT<SkBitmapProcShader>(src, tmx, tmy, localMatrix);
	}
	}
	return shader;
	}

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

	#ifndef SK_IGNORE_TO_STRING
	void SkBitmapProcShader::toString(SkString* str) const {
	static const char* gTileModeName[SkShader::kTileModeCount] = {
	"clamp", "repeat", "mirror"
	};

	str->append("BitmapShader: (");

	str->appendf("(%s, %s)",
	gTileModeName[fTileModeX],
	gTileModeName[fTileModeY]);

	str->append(" ");
	fRawBitmap.toString(str);

	this->INHERITED::toString(str);

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

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

	#if SK_SUPPORT_GPU

	#include "GrTextureAccess.h"
	#include "SkGr.h"
	#include "effects/GrSimpleTextureEffect.h"

	const GrFragmentProcessor* SkBitmapProcShader::asFragmentProcessor(GrContext* context,
	const SkMatrix& viewM, const SkMatrix* localMatrix,
	SkFilterQuality filterQuality) const {
	SkMatrix matrix;
	matrix.setIDiv(fRawBitmap.width(), fRawBitmap.height());

	SkMatrix lmInverse;
	if (!this->getLocalMatrix().invert(&lmInverse)) {
	return nullptr;
	}
	if (localMatrix) {
	SkMatrix inv;
	if (!localMatrix->invert(&inv)) {
	return nullptr;
	}
	lmInverse.postConcat(inv);
	}
	matrix.preConcat(lmInverse);

	SkShader::TileMode tm[] = {
	(TileMode)fTileModeX,
	(TileMode)fTileModeY,
	};

	// Must set wrap and filter on the sampler before requesting a texture. In two places below
	// we check the matrix scale factors to determine how to interpret the filter quality setting.
	// This completely ignores the complexity of the drawVertices case where explicit local coords
	// are provided by the caller.
	bool doBicubic;
	GrTextureParams::FilterMode textureFilterMode =
	GrSkFilterQualityToGrFilterMode(filterQuality, viewM, this->getLocalMatrix(),
	&doBicubic);
	GrTextureParams params(tm, textureFilterMode);
	SkAutoTUnref<GrTexture> texture(GrRefCachedBitmapTexture(context, fRawBitmap, params));

	if (!texture) {
	SkErrorInternals::SetError( kInternalError_SkError,
	"Couldn't convert bitmap to texture.");
	return nullptr;
	}

	SkAutoTUnref<const GrFragmentProcessor> inner;
	if (doBicubic) {
	inner.reset(GrBicubicEffect::Create(texture, matrix, tm));
	} else {
	inner.reset(GrSimpleTextureEffect::Create(texture, matrix, params));
	}

	if (kAlpha_8_SkColorType == fRawBitmap.colorType()) {
	return GrFragmentProcessor::MulOutputByInputUnpremulColor(inner);
	}
	return GrFragmentProcessor::MulOutputByInputAlpha(inner);
	}

	#endif