1 files changed, 276 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/effects/gradients/SkSweepGradient.cpp b/gfx/skia/skia/src/effects/gradients/SkSweepGradient.cpp
new file mode 100644
index 000000000..d1fe269b9
--- /dev/null
+++ b/gfx/skia/skia/src/effects/gradients/SkSweepGradient.cpp
@@ -0,0 +1,276 @@
+/*
+ * 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 "SkSweepGradient.h"
+
+static SkMatrix translate(SkScalar dx, SkScalar dy) {
+    SkMatrix matrix;
+    matrix.setTranslate(dx, dy);
+    return matrix;
+}
+
+SkSweepGradient::SkSweepGradient(SkScalar cx, SkScalar cy, const Descriptor& desc)
+    : SkGradientShaderBase(desc, translate(-cx, -cy))
+    , fCenter(SkPoint::Make(cx, cy))
+{
+    // overwrite the tilemode to a canonical value (since sweep ignores it)
+    fTileMode = SkShader::kClamp_TileMode;
+}
+
+SkShader::GradientType SkSweepGradient::asAGradient(GradientInfo* info) const {
+    if (info) {
+        commonAsAGradient(info);
+        info->fPoint[0] = fCenter;
+    }
+    return kSweep_GradientType;
+}
+
+sk_sp<SkFlattenable> SkSweepGradient::CreateProc(SkReadBuffer& buffer) {
+    DescriptorScope desc;
+    if (!desc.unflatten(buffer)) {
+        return nullptr;
+    }
+    const SkPoint center = buffer.readPoint();
+    return SkGradientShader::MakeSweep(center.x(), center.y(), desc.fColors,
+                                       std::move(desc.fColorSpace), desc.fPos, desc.fCount,
+                                       desc.fGradFlags, desc.fLocalMatrix);
+}
+
+void SkSweepGradient::flatten(SkWriteBuffer& buffer) const {
+    this->INHERITED::flatten(buffer);
+    buffer.writePoint(fCenter);
+}
+
+size_t SkSweepGradient::onContextSize(const ContextRec&) const {
+    return sizeof(SweepGradientContext);
+}
+
+SkShader::Context* SkSweepGradient::onCreateContext(const ContextRec& rec, void* storage) const {
+    return CheckedCreateContext<SweepGradientContext>(storage, *this, rec);
+}
+
+SkSweepGradient::SweepGradientContext::SweepGradientContext(
+        const SkSweepGradient& shader, const ContextRec& rec)
+    : INHERITED(shader, rec) {}
+
+//  returns angle in a circle [0..2PI) -> [0..255]
+static unsigned SkATan2_255(float y, float x) {
+    //    static const float g255Over2PI = 255 / (2 * SK_ScalarPI);
+    static const float g255Over2PI = 40.584510488433314f;
+
+    float result = sk_float_atan2(y, x);
+    if (!SkScalarIsFinite(result)) {
+        return 0;
+    }
+    if (result < 0) {
+        result += 2 * SK_ScalarPI;
+    }
+    SkASSERT(result >= 0);
+    // since our value is always >= 0, we can cast to int, which is faster than
+    // calling floorf()
+    int ir = (int)(result * g255Over2PI);
+    SkASSERT(ir >= 0 && ir <= 255);
+    return ir;
+}
+
+void SkSweepGradient::SweepGradientContext::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC,
+                                                      int count) {
+    SkMatrix::MapXYProc proc = fDstToIndexProc;
+    const SkMatrix&     matrix = fDstToIndex;
+    const SkPMColor* SK_RESTRICT cache = fCache->getCache32();
+    int                 toggle = init_dither_toggle(x, y);
+    SkPoint             srcPt;
+
+    if (fDstToIndexClass != kPerspective_MatrixClass) {
+        proc(matrix, SkIntToScalar(x) + SK_ScalarHalf,
+                     SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
+        SkScalar dx, fx = srcPt.fX;
+        SkScalar dy, fy = srcPt.fY;
+
+        if (fDstToIndexClass == kFixedStepInX_MatrixClass) {
+            const auto step = matrix.fixedStepInX(SkIntToScalar(y) + SK_ScalarHalf);
+            dx = step.fX;
+            dy = step.fY;
+        } else {
+            SkASSERT(fDstToIndexClass == kLinear_MatrixClass);
+            dx = matrix.getScaleX();
+            dy = matrix.getSkewY();
+        }
+
+        for (; count > 0; --count) {
+            *dstC++ = cache[toggle + SkATan2_255(fy, fx)];
+            fx += dx;
+            fy += dy;
+            toggle = next_dither_toggle(toggle);
+        }
+    } else {  // perspective case
+        for (int stop = x + count; x < stop; x++) {
+            proc(matrix, SkIntToScalar(x) + SK_ScalarHalf,
+                         SkIntToScalar(y) + SK_ScalarHalf, &srcPt);
+            *dstC++ = cache[toggle + SkATan2_255(srcPt.fY, srcPt.fX)];
+            toggle = next_dither_toggle(toggle);
+        }
+    }
+}
+
+/////////////////////////////////////////////////////////////////////
+
+#if SK_SUPPORT_GPU
+
+#include "SkGr.h"
+#include "gl/GrGLContext.h"
+#include "glsl/GrGLSLCaps.h"
+#include "glsl/GrGLSLFragmentShaderBuilder.h"
+
+class GrSweepGradient : public GrGradientEffect {
+public:
+    class GLSLSweepProcessor;
+
+    static sk_sp<GrFragmentProcessor> Make(const CreateArgs& args) {
+        return sk_sp<GrFragmentProcessor>(new GrSweepGradient(args));
+    }
+    virtual ~GrSweepGradient() { }
+
+    const char* name() const override { return "Sweep Gradient"; }
+
+private:
+    GrSweepGradient(const CreateArgs& args)
+    : INHERITED(args) {
+        this->initClassID<GrSweepGradient>();
+    }
+
+    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
+
+    virtual void onGetGLSLProcessorKey(const GrGLSLCaps& caps,
+                                       GrProcessorKeyBuilder* b) const override;
+
+    GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
+
+    typedef GrGradientEffect INHERITED;
+};
+
+/////////////////////////////////////////////////////////////////////
+
+class GrSweepGradient::GLSLSweepProcessor : public GrGradientEffect::GLSLProcessor {
+public:
+    GLSLSweepProcessor(const GrProcessor&) {}
+    virtual ~GLSLSweepProcessor() { }
+
+    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* GrSweepGradient::onCreateGLSLInstance() const {
+    return new GrSweepGradient::GLSLSweepProcessor(*this);
+}
+
+void GrSweepGradient::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
+                                            GrProcessorKeyBuilder* b) const {
+    GrSweepGradient::GLSLSweepProcessor::GenKey(*this, caps, b);
+}
+
+
+/////////////////////////////////////////////////////////////////////
+
+GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrSweepGradient);
+
+sk_sp<GrFragmentProcessor> GrSweepGradient::TestCreate(GrProcessorTestData* d) {
+    SkPoint center = {d->fRandom->nextUScalar1(), d->fRandom->nextUScalar1()};
+
+    SkColor colors[kMaxRandomGradientColors];
+    SkScalar stopsArray[kMaxRandomGradientColors];
+    SkScalar* stops = stopsArray;
+    SkShader::TileMode tmIgnored;
+    int colorCount = RandomGradientParams(d->fRandom, colors, &stops, &tmIgnored);
+    sk_sp<SkShader> shader(SkGradientShader::MakeSweep(center.fX, center.fY,  colors, stops,
+                                                       colorCount));
+    SkMatrix viewMatrix = GrTest::TestMatrix(d->fRandom);
+    auto dstColorSpace = GrTest::TestColorSpace(d->fRandom);
+    sk_sp<GrFragmentProcessor> fp = shader->asFragmentProcessor(SkShader::AsFPArgs(
+        d->fContext, &viewMatrix, NULL, kNone_SkFilterQuality, dstColorSpace.get(),
+        SkSourceGammaTreatment::kRespect));
+    GrAlwaysAssert(fp);
+    return fp;
+}
+
+/////////////////////////////////////////////////////////////////////
+
+void GrSweepGradient::GLSLSweepProcessor::emitCode(EmitArgs& args) {
+    const GrSweepGradient& ge = args.fFp.cast<GrSweepGradient>();
+    this->emitUniforms(args.fUniformHandler, ge);
+    SkString coords2D = args.fFragBuilder->ensureCoords2D(args.fTransformedCoords[0]);
+    SkString t;
+    // 0.1591549430918 is 1/(2*pi), used since atan returns values [-pi, pi]
+    // On Intel GPU there is an issue where it reads the second arguement to atan "- %s.x" as an int
+    // thus must us -1.0 * %s.x to work correctly
+    if (args.fGLSLCaps->mustForceNegatedAtanParamToFloat()){
+        t.printf("(atan(- %s.y, -1.0 * %s.x) * 0.1591549430918 + 0.5)",
+                 coords2D.c_str(), coords2D.c_str());
+    } else {
+        t.printf("(atan(- %s.y, - %s.x) * 0.1591549430918 + 0.5)",
+                 coords2D.c_str(), coords2D.c_str());
+    }
+    this->emitColor(args.fFragBuilder,
+                    args.fUniformHandler,
+                    args.fGLSLCaps,
+                    ge, t.c_str(),
+                    args.fOutputColor,
+                    args.fInputColor,
+                    args.fTexSamplers);
+}
+
+/////////////////////////////////////////////////////////////////////
+
+sk_sp<GrFragmentProcessor> SkSweepGradient::asFragmentProcessor(const AsFPArgs& args) const {
+
+    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(GrSweepGradient::Make(
+        GrGradientEffect::CreateArgs(args.fContext, this, &matrix, SkShader::kClamp_TileMode,
+                                     std::move(colorSpaceXform), SkToBool(args.fDstColorSpace))));
+    return GrFragmentProcessor::MulOutputByInputAlpha(std::move(inner));
+}
+
+#endif
+
+#ifndef SK_IGNORE_TO_STRING
+void SkSweepGradient::toString(SkString* str) const {
+    str->append("SkSweepGradient: (");
+
+    str->append("center: (");
+    str->appendScalar(fCenter.fX);
+    str->append(", ");
+    str->appendScalar(fCenter.fY);
+    str->append(") ");
+
+    this->INHERITED::toString(str);
+
+    str->append(")");
+}
+#endif