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/*
* 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 CheckedCreateContext<RadialGradientContext>(storage, *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 "GrShaderCaps.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 GrShaderCaps& 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 GrShaderCaps&, GrProcessorKeyBuilder* b) {
b->add32(GenBaseGradientKey(processor));
}
private:
typedef GrGradientEffect::GLSLProcessor INHERITED;
};
/////////////////////////////////////////////////////////////////////
GrGLSLFragmentProcessor* GrRadialGradient::onCreateGLSLInstance() const {
return new GrRadialGradient::GLSLRadialProcessor(*this);
}
void GrRadialGradient::onGetGLSLProcessorKey(const GrShaderCaps& 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();
RandomGradientParams params(d->fRandom);
auto shader = params.fUseColors4f ?
SkGradientShader::MakeRadial(center, radius, params.fColors4f, params.fColorSpace,
params.fStops, params.fColorCount, params.fTileMode) :
SkGradientShader::MakeRadial(center, radius, params.fColors,
params.fStops, params.fColorCount, params.fTileMode);
GrTest::TestAsFPArgs asFPArgs(d);
sk_sp<GrFragmentProcessor> fp = shader->asFragmentProcessor(asFPArgs.args());
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.fShaderCaps,
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