skia2/src/effects/SkDisplacementMapEffect.cpp
brianosman eed6b0e1d8 Change SkSpecialImage::makeSurface and makeTightSurface to take output
properties (color space), bounds, and (optional) alphaType.

We were being pretty inconsistent before. Raster was honoring all
components of the info. GPU was using the supplied color type, but
propagating the source's color space. All call sites were saying N32.

What we want to do is propagate the original device's color space, and
pick a good format from that. Rather than force all the clients to
jump through hoops constructing an SkImageInfo that meets our criteria,
just have them supply the few bits we care about, and do everything else
internally.

This also lets us always use RGBA on GPU, but N32 on raster.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2349373004

Committed: https://skia.googlesource.com/skia/+/53c38087949252d27cde668368a3eeb59cc2eb00
Review-Url: https://codereview.chromium.org/2349373004
2016-09-23 13:04:05 -07:00

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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkDisplacementMapEffect.h"
#include "SkBitmap.h"
#include "SkReadBuffer.h"
#include "SkSpecialImage.h"
#include "SkWriteBuffer.h"
#include "SkUnPreMultiply.h"
#include "SkColorPriv.h"
#if SK_SUPPORT_GPU
#include "GrContext.h"
#include "GrDrawContext.h"
#include "GrCoordTransform.h"
#include "GrInvariantOutput.h"
#include "SkGr.h"
#include "SkGrPriv.h"
#include "effects/GrTextureDomain.h"
#include "glsl/GrGLSLFragmentProcessor.h"
#include "glsl/GrGLSLFragmentShaderBuilder.h"
#include "glsl/GrGLSLProgramDataManager.h"
#include "glsl/GrGLSLUniformHandler.h"
#endif
namespace {
#define kChannelSelectorKeyBits 3; // Max value is 4, so 3 bits are required at most
template<SkDisplacementMapEffect::ChannelSelectorType type>
uint32_t getValue(SkColor, const SkUnPreMultiply::Scale*) {
SkDEBUGFAIL("Unknown channel selector");
return 0;
}
template<> uint32_t getValue<SkDisplacementMapEffect::kR_ChannelSelectorType>(
SkColor l, const SkUnPreMultiply::Scale* table) {
return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedR32(l));
}
template<> uint32_t getValue<SkDisplacementMapEffect::kG_ChannelSelectorType>(
SkColor l, const SkUnPreMultiply::Scale* table) {
return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedG32(l));
}
template<> uint32_t getValue<SkDisplacementMapEffect::kB_ChannelSelectorType>(
SkColor l, const SkUnPreMultiply::Scale* table) {
return SkUnPreMultiply::ApplyScale(table[SkGetPackedA32(l)], SkGetPackedB32(l));
}
template<> uint32_t getValue<SkDisplacementMapEffect::kA_ChannelSelectorType>(
SkColor l, const SkUnPreMultiply::Scale*) {
return SkGetPackedA32(l);
}
template<SkDisplacementMapEffect::ChannelSelectorType typeX,
SkDisplacementMapEffect::ChannelSelectorType typeY>
void computeDisplacement(const SkVector& scale, SkBitmap* dst,
const SkBitmap& displ, const SkIPoint& offset,
const SkBitmap& src,
const SkIRect& bounds) {
static const SkScalar Inv8bit = SkScalarInvert(255);
const int srcW = src.width();
const int srcH = src.height();
const SkVector scaleForColor = SkVector::Make(SkScalarMul(scale.fX, Inv8bit),
SkScalarMul(scale.fY, Inv8bit));
const SkVector scaleAdj = SkVector::Make(SK_ScalarHalf - SkScalarMul(scale.fX, SK_ScalarHalf),
SK_ScalarHalf - SkScalarMul(scale.fY, SK_ScalarHalf));
const SkUnPreMultiply::Scale* table = SkUnPreMultiply::GetScaleTable();
SkPMColor* dstPtr = dst->getAddr32(0, 0);
for (int y = bounds.top(); y < bounds.bottom(); ++y) {
const SkPMColor* displPtr = displ.getAddr32(bounds.left() + offset.fX, y + offset.fY);
for (int x = bounds.left(); x < bounds.right(); ++x, ++displPtr) {
const SkScalar displX = SkScalarMul(scaleForColor.fX,
SkIntToScalar(getValue<typeX>(*displPtr, table))) + scaleAdj.fX;
const SkScalar displY = SkScalarMul(scaleForColor.fY,
SkIntToScalar(getValue<typeY>(*displPtr, table))) + scaleAdj.fY;
// Truncate the displacement values
const int srcX = x + SkScalarTruncToInt(displX);
const int srcY = y + SkScalarTruncToInt(displY);
*dstPtr++ = ((srcX < 0) || (srcX >= srcW) || (srcY < 0) || (srcY >= srcH)) ?
0 : *(src.getAddr32(srcX, srcY));
}
}
}
template<SkDisplacementMapEffect::ChannelSelectorType typeX>
void computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
const SkVector& scale, SkBitmap* dst,
const SkBitmap& displ, const SkIPoint& offset,
const SkBitmap& src,
const SkIRect& bounds) {
switch (yChannelSelector) {
case SkDisplacementMapEffect::kR_ChannelSelectorType:
computeDisplacement<typeX, SkDisplacementMapEffect::kR_ChannelSelectorType>(
scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kG_ChannelSelectorType:
computeDisplacement<typeX, SkDisplacementMapEffect::kG_ChannelSelectorType>(
scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kB_ChannelSelectorType:
computeDisplacement<typeX, SkDisplacementMapEffect::kB_ChannelSelectorType>(
scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kA_ChannelSelectorType:
computeDisplacement<typeX, SkDisplacementMapEffect::kA_ChannelSelectorType>(
scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
default:
SkDEBUGFAIL("Unknown Y channel selector");
}
}
void computeDisplacement(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
const SkVector& scale, SkBitmap* dst,
const SkBitmap& displ, const SkIPoint& offset,
const SkBitmap& src,
const SkIRect& bounds) {
switch (xChannelSelector) {
case SkDisplacementMapEffect::kR_ChannelSelectorType:
computeDisplacement<SkDisplacementMapEffect::kR_ChannelSelectorType>(
yChannelSelector, scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kG_ChannelSelectorType:
computeDisplacement<SkDisplacementMapEffect::kG_ChannelSelectorType>(
yChannelSelector, scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kB_ChannelSelectorType:
computeDisplacement<SkDisplacementMapEffect::kB_ChannelSelectorType>(
yChannelSelector, scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kA_ChannelSelectorType:
computeDisplacement<SkDisplacementMapEffect::kA_ChannelSelectorType>(
yChannelSelector, scale, dst, displ, offset, src, bounds);
break;
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
default:
SkDEBUGFAIL("Unknown X channel selector");
}
}
bool channel_selector_type_is_valid(SkDisplacementMapEffect::ChannelSelectorType cst) {
switch (cst) {
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
case SkDisplacementMapEffect::kR_ChannelSelectorType:
case SkDisplacementMapEffect::kG_ChannelSelectorType:
case SkDisplacementMapEffect::kB_ChannelSelectorType:
case SkDisplacementMapEffect::kA_ChannelSelectorType:
return true;
default:
break;
}
return false;
}
} // end namespace
///////////////////////////////////////////////////////////////////////////////
sk_sp<SkImageFilter> SkDisplacementMapEffect::Make(ChannelSelectorType xChannelSelector,
ChannelSelectorType yChannelSelector,
SkScalar scale,
sk_sp<SkImageFilter> displacement,
sk_sp<SkImageFilter> color,
const CropRect* cropRect) {
if (!channel_selector_type_is_valid(xChannelSelector) ||
!channel_selector_type_is_valid(yChannelSelector)) {
return nullptr;
}
sk_sp<SkImageFilter> inputs[2] = { std::move(displacement), std::move(color) };
return sk_sp<SkImageFilter>(new SkDisplacementMapEffect(xChannelSelector,
yChannelSelector,
scale, inputs, cropRect));
}
SkDisplacementMapEffect::SkDisplacementMapEffect(ChannelSelectorType xChannelSelector,
ChannelSelectorType yChannelSelector,
SkScalar scale,
sk_sp<SkImageFilter> inputs[2],
const CropRect* cropRect)
: INHERITED(inputs, 2, cropRect)
, fXChannelSelector(xChannelSelector)
, fYChannelSelector(yChannelSelector)
, fScale(scale) {
}
SkDisplacementMapEffect::~SkDisplacementMapEffect() {
}
sk_sp<SkFlattenable> SkDisplacementMapEffect::CreateProc(SkReadBuffer& buffer) {
SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 2);
ChannelSelectorType xsel = (ChannelSelectorType)buffer.readInt();
ChannelSelectorType ysel = (ChannelSelectorType)buffer.readInt();
SkScalar scale = buffer.readScalar();
return Make(xsel, ysel, scale,
common.getInput(0), common.getInput(1),
&common.cropRect());
}
void SkDisplacementMapEffect::flatten(SkWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeInt((int) fXChannelSelector);
buffer.writeInt((int) fYChannelSelector);
buffer.writeScalar(fScale);
}
#if SK_SUPPORT_GPU
class GrDisplacementMapEffect : public GrFragmentProcessor {
public:
static sk_sp<GrFragmentProcessor> Make(
SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
SkDisplacementMapEffect::ChannelSelectorType yChannelSelector, SkVector scale,
GrTexture* displacement, const SkMatrix& offsetMatrix, GrTexture* color,
const SkISize& colorDimensions) {
return sk_sp<GrFragmentProcessor>(
new GrDisplacementMapEffect(xChannelSelector, yChannelSelector, scale, displacement,
offsetMatrix, color, colorDimensions));
}
virtual ~GrDisplacementMapEffect();
SkDisplacementMapEffect::ChannelSelectorType xChannelSelector() const {
return fXChannelSelector;
}
SkDisplacementMapEffect::ChannelSelectorType yChannelSelector() const {
return fYChannelSelector;
}
const SkVector& scale() const { return fScale; }
const char* name() const override { return "DisplacementMap"; }
const GrTextureDomain& domain() const { return fDomain; }
private:
GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
void onGetGLSLProcessorKey(const GrGLSLCaps& caps, GrProcessorKeyBuilder* b) const override;
bool onIsEqual(const GrFragmentProcessor&) const override;
void onComputeInvariantOutput(GrInvariantOutput* inout) const override;
GrDisplacementMapEffect(SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
const SkVector& scale,
GrTexture* displacement, const SkMatrix& offsetMatrix,
GrTexture* color,
const SkISize& colorDimensions);
GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
GrCoordTransform fDisplacementTransform;
GrTextureAccess fDisplacementAccess;
GrCoordTransform fColorTransform;
GrTextureDomain fDomain;
GrTextureAccess fColorAccess;
SkDisplacementMapEffect::ChannelSelectorType fXChannelSelector;
SkDisplacementMapEffect::ChannelSelectorType fYChannelSelector;
SkVector fScale;
typedef GrFragmentProcessor INHERITED;
};
#endif
sk_sp<SkSpecialImage> SkDisplacementMapEffect::onFilterImage(SkSpecialImage* source,
const Context& ctx,
SkIPoint* offset) const {
SkIPoint colorOffset = SkIPoint::Make(0, 0);
sk_sp<SkSpecialImage> color(this->filterInput(1, source, ctx, &colorOffset));
if (!color) {
return nullptr;
}
SkIPoint displOffset = SkIPoint::Make(0, 0);
// Creation of the displacement map should happen in a non-colorspace aware context. This
// texture is a purely mathematical construct, so we want to just operate on the stored
// values. Consider:
// User supplies an sRGB displacement map. If we're rendering to a wider gamut, then we could
// end up filtering the displacement map into that gamut, which has the effect of reducing
// the amount of displacement that it represents (as encoded values move away from the
// primaries).
// With a more complex DAG attached to this input, it's not clear that working in ANY specific
// color space makes sense, so we ignore color spaces (and gamma) entirely. This may not be
// ideal, but it's at least consistent and predictable.
Context displContext(ctx.ctm(), ctx.clipBounds(), ctx.cache(), OutputProperties(nullptr));
sk_sp<SkSpecialImage> displ(this->filterInput(0, source, displContext, &displOffset));
if (!displ) {
return nullptr;
}
const SkIRect srcBounds = SkIRect::MakeXYWH(colorOffset.x(), colorOffset.y(),
color->width(), color->height());
// Both paths do bounds checking on color pixel access, we don't need to
// pad the color bitmap to bounds here.
SkIRect bounds;
if (!this->applyCropRect(ctx, srcBounds, &bounds)) {
return nullptr;
}
SkIRect displBounds;
displ = this->applyCropRect(ctx, displ.get(), &displOffset, &displBounds);
if (!displ) {
return nullptr;
}
if (!bounds.intersect(displBounds)) {
return nullptr;
}
const SkIRect colorBounds = bounds.makeOffset(-colorOffset.x(), -colorOffset.y());
SkVector scale = SkVector::Make(fScale, fScale);
ctx.ctm().mapVectors(&scale, 1);
#if SK_SUPPORT_GPU
if (source->isTextureBacked()) {
GrContext* context = source->getContext();
sk_sp<GrTexture> colorTexture(color->asTextureRef(context));
sk_sp<GrTexture> displTexture(displ->asTextureRef(context));
if (!colorTexture || !displTexture) {
return nullptr;
}
GrPaint paint;
SkMatrix offsetMatrix = GrCoordTransform::MakeDivByTextureWHMatrix(displTexture.get());
offsetMatrix.preTranslate(SkIntToScalar(colorOffset.fX - displOffset.fX),
SkIntToScalar(colorOffset.fY - displOffset.fY));
paint.addColorFragmentProcessor(
GrDisplacementMapEffect::Make(fXChannelSelector,
fYChannelSelector,
scale,
displTexture.get(),
offsetMatrix,
colorTexture.get(),
SkISize::Make(color->width(), color->height())));
paint.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
SkMatrix matrix;
matrix.setTranslate(-SkIntToScalar(colorBounds.x()), -SkIntToScalar(colorBounds.y()));
SkColorSpace* colorSpace = ctx.outputProperties().colorSpace();
sk_sp<GrDrawContext> drawContext(
context->makeDrawContext(SkBackingFit::kApprox, bounds.width(), bounds.height(),
GrRenderableConfigForColorSpace(colorSpace),
sk_ref_sp(colorSpace)));
if (!drawContext) {
return nullptr;
}
paint.setGammaCorrect(drawContext->isGammaCorrect());
drawContext->drawRect(GrNoClip(), paint, matrix, SkRect::Make(colorBounds));
offset->fX = bounds.left();
offset->fY = bounds.top();
return SkSpecialImage::MakeFromGpu(SkIRect::MakeWH(bounds.width(), bounds.height()),
kNeedNewImageUniqueID_SpecialImage,
drawContext->asTexture(),
sk_ref_sp(drawContext->getColorSpace()));
}
#endif
SkBitmap colorBM, displBM;
if (!color->getROPixels(&colorBM) || !displ->getROPixels(&displBM)) {
return nullptr;
}
if ((colorBM.colorType() != kN32_SkColorType) ||
(displBM.colorType() != kN32_SkColorType)) {
return nullptr;
}
SkAutoLockPixels colorLock(colorBM), displLock(displBM);
if (!colorBM.getPixels() || !displBM.getPixels()) {
return nullptr;
}
SkImageInfo info = SkImageInfo::MakeN32(bounds.width(), bounds.height(),
colorBM.alphaType());
SkBitmap dst;
if (!dst.tryAllocPixels(info)) {
return nullptr;
}
SkAutoLockPixels dstLock(dst);
computeDisplacement(fXChannelSelector, fYChannelSelector, scale, &dst,
displBM, colorOffset - displOffset, colorBM, colorBounds);
offset->fX = bounds.left();
offset->fY = bounds.top();
return SkSpecialImage::MakeFromRaster(SkIRect::MakeWH(bounds.width(), bounds.height()),
dst);
}
SkRect SkDisplacementMapEffect::computeFastBounds(const SkRect& src) const {
SkRect bounds = this->getColorInput() ? this->getColorInput()->computeFastBounds(src) : src;
bounds.outset(SkScalarAbs(fScale) * SK_ScalarHalf, SkScalarAbs(fScale) * SK_ScalarHalf);
return bounds;
}
SkIRect SkDisplacementMapEffect::onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm,
MapDirection) const {
SkVector scale = SkVector::Make(fScale, fScale);
ctm.mapVectors(&scale, 1);
return src.makeOutset(SkScalarCeilToInt(SkScalarAbs(scale.fX) * SK_ScalarHalf),
SkScalarCeilToInt(SkScalarAbs(scale.fY) * SK_ScalarHalf));
}
SkIRect SkDisplacementMapEffect::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
MapDirection direction) const {
// Recurse only into color input.
if (this->getColorInput()) {
return this->getColorInput()->filterBounds(src, ctm, direction);
}
return src;
}
#ifndef SK_IGNORE_TO_STRING
void SkDisplacementMapEffect::toString(SkString* str) const {
str->appendf("SkDisplacementMapEffect: (");
str->appendf("scale: %f ", fScale);
str->appendf("displacement: (");
if (this->getDisplacementInput()) {
this->getDisplacementInput()->toString(str);
}
str->appendf(") color: (");
if (this->getColorInput()) {
this->getColorInput()->toString(str);
}
str->appendf("))");
}
#endif
///////////////////////////////////////////////////////////////////////////////
#if SK_SUPPORT_GPU
class GrGLDisplacementMapEffect : public GrGLSLFragmentProcessor {
public:
void emitCode(EmitArgs&) override;
static inline void GenKey(const GrProcessor&, const GrGLSLCaps&, GrProcessorKeyBuilder*);
protected:
void onSetData(const GrGLSLProgramDataManager&, const GrProcessor&) override;
private:
GrGLSLProgramDataManager::UniformHandle fScaleUni;
GrTextureDomain::GLDomain fGLDomain;
typedef GrGLSLFragmentProcessor INHERITED;
};
///////////////////////////////////////////////////////////////////////////////
GrGLSLFragmentProcessor* GrDisplacementMapEffect::onCreateGLSLInstance() const {
return new GrGLDisplacementMapEffect;
}
void GrDisplacementMapEffect::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
GrProcessorKeyBuilder* b) const {
GrGLDisplacementMapEffect::GenKey(*this, caps, b);
}
GrDisplacementMapEffect::GrDisplacementMapEffect(
SkDisplacementMapEffect::ChannelSelectorType xChannelSelector,
SkDisplacementMapEffect::ChannelSelectorType yChannelSelector,
const SkVector& scale,
GrTexture* displacement,
const SkMatrix& offsetMatrix,
GrTexture* color,
const SkISize& colorDimensions)
: fDisplacementTransform(kLocal_GrCoordSet, offsetMatrix, displacement,
GrTextureParams::kNone_FilterMode)
, fDisplacementAccess(displacement)
, fColorTransform(kLocal_GrCoordSet, color, GrTextureParams::kNone_FilterMode)
, fDomain(GrTextureDomain::MakeTexelDomain(color, SkIRect::MakeSize(colorDimensions)),
GrTextureDomain::kDecal_Mode)
, fColorAccess(color)
, fXChannelSelector(xChannelSelector)
, fYChannelSelector(yChannelSelector)
, fScale(scale) {
this->initClassID<GrDisplacementMapEffect>();
this->addCoordTransform(&fDisplacementTransform);
this->addTextureAccess(&fDisplacementAccess);
this->addCoordTransform(&fColorTransform);
this->addTextureAccess(&fColorAccess);
}
GrDisplacementMapEffect::~GrDisplacementMapEffect() {
}
bool GrDisplacementMapEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
const GrDisplacementMapEffect& s = sBase.cast<GrDisplacementMapEffect>();
return fXChannelSelector == s.fXChannelSelector &&
fYChannelSelector == s.fYChannelSelector &&
fScale == s.fScale;
}
void GrDisplacementMapEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
// Any displacement offset bringing a pixel out of bounds will output a color of (0,0,0,0),
// so the only way we'd get a constant alpha is if the input color image has a constant alpha
// and no displacement offset push any texture coordinates out of bounds OR if the constant
// alpha is 0. Since this isn't trivial to compute at this point, let's assume the output is
// not of constant color when a displacement effect is applied.
inout->setToUnknown(GrInvariantOutput::kWillNot_ReadInput);
}
///////////////////////////////////////////////////////////////////////////////
GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrDisplacementMapEffect);
sk_sp<GrFragmentProcessor> GrDisplacementMapEffect::TestCreate(GrProcessorTestData* d) {
int texIdxDispl = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
GrProcessorUnitTest::kAlphaTextureIdx;
int texIdxColor = d->fRandom->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
GrProcessorUnitTest::kAlphaTextureIdx;
static const int kMaxComponent = 4;
SkDisplacementMapEffect::ChannelSelectorType xChannelSelector =
static_cast<SkDisplacementMapEffect::ChannelSelectorType>(
d->fRandom->nextRangeU(1, kMaxComponent));
SkDisplacementMapEffect::ChannelSelectorType yChannelSelector =
static_cast<SkDisplacementMapEffect::ChannelSelectorType>(
d->fRandom->nextRangeU(1, kMaxComponent));
SkVector scale = SkVector::Make(d->fRandom->nextRangeScalar(0, 100.0f),
d->fRandom->nextRangeScalar(0, 100.0f));
SkISize colorDimensions;
colorDimensions.fWidth = d->fRandom->nextRangeU(0, d->fTextures[texIdxColor]->width());
colorDimensions.fHeight = d->fRandom->nextRangeU(0, d->fTextures[texIdxColor]->height());
return GrDisplacementMapEffect::Make(xChannelSelector, yChannelSelector, scale,
d->fTextures[texIdxDispl], SkMatrix::I(),
d->fTextures[texIdxColor], colorDimensions);
}
///////////////////////////////////////////////////////////////////////////////
void GrGLDisplacementMapEffect::emitCode(EmitArgs& args) {
const GrDisplacementMapEffect& displacementMap = args.fFp.cast<GrDisplacementMapEffect>();
const GrTextureDomain& domain = displacementMap.domain();
fScaleUni = args.fUniformHandler->addUniform(kFragment_GrShaderFlag,
kVec2f_GrSLType, kDefault_GrSLPrecision, "Scale");
const char* scaleUni = args.fUniformHandler->getUniformCStr(fScaleUni);
const char* dColor = "dColor";
const char* cCoords = "cCoords";
const char* nearZero = "1e-6"; // Since 6.10352e5 is the smallest half float, use
// a number smaller than that to approximate 0, but
// leave room for 32-bit float GPU rounding errors.
GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
fragBuilder->codeAppendf("\t\tvec4 %s = ", dColor);
fragBuilder->appendTextureLookup(args.fTexSamplers[0], args.fTransformedCoords[0].c_str(),
args.fTransformedCoords[0].getType());
fragBuilder->codeAppend(";\n");
// Unpremultiply the displacement
fragBuilder->codeAppendf(
"\t\t%s.rgb = (%s.a < %s) ? vec3(0.0) : clamp(%s.rgb / %s.a, 0.0, 1.0);",
dColor, dColor, nearZero, dColor, dColor);
SkString coords2D = fragBuilder->ensureCoords2D(args.fTransformedCoords[1]);
fragBuilder->codeAppendf("\t\tvec2 %s = %s + %s*(%s.",
cCoords, coords2D.c_str(), scaleUni, dColor);
switch (displacementMap.xChannelSelector()) {
case SkDisplacementMapEffect::kR_ChannelSelectorType:
fragBuilder->codeAppend("r");
break;
case SkDisplacementMapEffect::kG_ChannelSelectorType:
fragBuilder->codeAppend("g");
break;
case SkDisplacementMapEffect::kB_ChannelSelectorType:
fragBuilder->codeAppend("b");
break;
case SkDisplacementMapEffect::kA_ChannelSelectorType:
fragBuilder->codeAppend("a");
break;
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
default:
SkDEBUGFAIL("Unknown X channel selector");
}
switch (displacementMap.yChannelSelector()) {
case SkDisplacementMapEffect::kR_ChannelSelectorType:
fragBuilder->codeAppend("r");
break;
case SkDisplacementMapEffect::kG_ChannelSelectorType:
fragBuilder->codeAppend("g");
break;
case SkDisplacementMapEffect::kB_ChannelSelectorType:
fragBuilder->codeAppend("b");
break;
case SkDisplacementMapEffect::kA_ChannelSelectorType:
fragBuilder->codeAppend("a");
break;
case SkDisplacementMapEffect::kUnknown_ChannelSelectorType:
default:
SkDEBUGFAIL("Unknown Y channel selector");
}
fragBuilder->codeAppend("-vec2(0.5));\t\t");
fGLDomain.sampleTexture(fragBuilder,
args.fUniformHandler,
args.fGLSLCaps,
domain,
args.fOutputColor,
SkString(cCoords),
args.fTexSamplers[1]);
fragBuilder->codeAppend(";\n");
}
void GrGLDisplacementMapEffect::onSetData(const GrGLSLProgramDataManager& pdman,
const GrProcessor& proc) {
const GrDisplacementMapEffect& displacementMap = proc.cast<GrDisplacementMapEffect>();
GrTexture* colorTex = displacementMap.texture(1);
SkScalar scaleX = displacementMap.scale().fX / colorTex->width();
SkScalar scaleY = displacementMap.scale().fY / colorTex->height();
pdman.set2f(fScaleUni, SkScalarToFloat(scaleX),
colorTex->origin() == kTopLeft_GrSurfaceOrigin ?
SkScalarToFloat(scaleY) : SkScalarToFloat(-scaleY));
fGLDomain.setData(pdman, displacementMap.domain(), colorTex->origin());
}
void GrGLDisplacementMapEffect::GenKey(const GrProcessor& proc,
const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
const GrDisplacementMapEffect& displacementMap = proc.cast<GrDisplacementMapEffect>();
uint32_t xKey = displacementMap.xChannelSelector();
uint32_t yKey = displacementMap.yChannelSelector() << kChannelSelectorKeyBits;
b->add32(xKey | yKey);
}
#endif