GrFragmentProcessor.cpp File Reference

#include "src/gpu/ganesh/GrFragmentProcessor.h"
#include "include/core/SkM44.h"
#include "src/base/SkVx.h"
#include "src/core/SkRuntimeEffectPriv.h"
#include "src/gpu/KeyBuilder.h"
#include "src/gpu/ganesh/GrPipeline.h"
#include "src/gpu/ganesh/GrProcessorAnalysis.h"
#include "src/gpu/ganesh/GrShaderCaps.h"
#include "src/gpu/ganesh/effects/GrBlendFragmentProcessor.h"
#include "src/gpu/ganesh/effects/GrSkSLFP.h"
#include "src/gpu/ganesh/effects/GrTextureEffect.h"
#include "src/gpu/ganesh/glsl/GrGLSLFragmentShaderBuilder.h"
#include "src/gpu/ganesh/glsl/GrGLSLProgramBuilder.h"
#include "src/gpu/ganesh/glsl/GrGLSLProgramDataManager.h"
#include "src/gpu/ganesh/glsl/GrGLSLUniformHandler.h"

Go to the source code of this file.

Macros
#define	CLIP_EDGE_SKSL

Typedefs
using	ProgramImpl = GrFragmentProcessor::ProgramImpl

Macro Definition Documentation

CLIP_EDGE_SKSL

#define CLIP_EDGE_SKSL

Value:

    "const int kFillBW = 0;"        \
    "const int kFillAA = 1;"        \
    "const int kInverseFillBW = 2;" \
    "const int kInverseFillAA = 3;"

Definition at line 593 of file GrFragmentProcessor.cpp.

                                                                                          {
    static const SkRuntimeEffect* effect = SkMakeRuntimeEffect(SkRuntimeEffect::MakeForShader,
    CLIP_EDGE_SKSL
        "uniform int edgeType;"  // GrClipEdgeType, specialized
        "uniform float4 rectUniform;"
 
        "half4 main(float2 xy) {"
            "half coverage;"
            "if (edgeType == kFillBW || edgeType == kInverseFillBW) {"
                // non-AA
                "coverage = half(all(greaterThan(float4(sk_FragCoord.xy, rectUniform.zw),"
                                                "float4(rectUniform.xy, sk_FragCoord.xy))));"
            "} else {"
                // compute coverage relative to left and right edges, add, then subtract 1 to
                // account for double counting. And similar for top/bottom.
                "half4 dists4 = saturate(half4(1, 1, -1, -1) *"
                                        "half4(sk_FragCoord.xyxy - rectUniform));"
                "half2 dists2 = dists4.xy + dists4.zw - 1;"
                "coverage = dists2.x * dists2.y;"
            "}"
 
            "if (edgeType == kInverseFillBW || edgeType == kInverseFillAA) {"
                "coverage = 1.0 - coverage;"
            "}"
 
            "return half4(coverage);"
        "}"
    );
 
    SkASSERT(rect.isSorted());
    // The AA math in the shader evaluates to 0 at the uploaded coordinates, so outset by 0.5
    // to interpolate from 0 at a half pixel inset and 1 at a half pixel outset of rect.
    SkRect rectUniform = GrClipEdgeTypeIsAA(edgeType) ? rect.makeOutset(.5f, .5f) : rect;
 
    auto rectFP = GrSkSLFP::Make(effect, "Rect", /*inputFP=*/nullptr,
                                 GrSkSLFP::OptFlags::kCompatibleWithCoverageAsAlpha,
                                "edgeType", GrSkSLFP::Specialize(static_cast<int>(edgeType)),
                                "rectUniform", rectUniform);
    return GrBlendFragmentProcessor::Make<SkBlendMode::kModulate>(std::move(rectFP),
                                                                  std::move(inputFP));
}
 
GrFPResult GrFragmentProcessor::Circle(std::unique_ptr<GrFragmentProcessor> inputFP,
                                       GrClipEdgeType edgeType,
                                       SkPoint center,
                                       float radius) {
    // A radius below half causes the implicit insetting done by this processor to become
    // inverted. We could handle this case by making the processor code more complicated.
    if (radius < .5f && GrClipEdgeTypeIsInverseFill(edgeType)) {
        return GrFPFailure(std::move(inputFP));
    }
 
    static const SkRuntimeEffect* effect = SkMakeRuntimeEffect(SkRuntimeEffect::MakeForShader,
    CLIP_EDGE_SKSL
        "uniform int edgeType;"  // GrClipEdgeType, specialized
        // The circle uniform is (center.x, center.y, radius + 0.5, 1 / (radius + 0.5)) for regular
        // fills and (..., radius - 0.5, 1 / (radius - 0.5)) for inverse fills.
        "uniform float4 circle;"
 
        "half4 main(float2 xy) {"
            // TODO: Right now the distance to circle calculation is performed in a space normalized
            // to the radius and then denormalized. This is to mitigate overflow on devices that
            // don't have full float.
            "half d;"
            "if (edgeType == kInverseFillBW || edgeType == kInverseFillAA) {"
                "d = half((length((circle.xy - sk_FragCoord.xy) * circle.w) - 1.0) * circle.z);"
            "} else {"
                "d = half((1.0 - length((circle.xy - sk_FragCoord.xy) * circle.w)) * circle.z);"
            "}"
            "return half4((edgeType == kFillAA || edgeType == kInverseFillAA)"
                              "? saturate(d)"
                              ": (d > 0.5 ? 1 : 0));"
        "}"
    );
 
    SkScalar effectiveRadius = radius;
    if (GrClipEdgeTypeIsInverseFill(edgeType)) {
        effectiveRadius -= 0.5f;
        // When the radius is 0.5 effectiveRadius is 0 which causes an inf * 0 in the shader.
        effectiveRadius = std::max(0.001f, effectiveRadius);
    } else {
        effectiveRadius += 0.5f;
    }
    SkV4 circle = {center.fX, center.fY, effectiveRadius, SkScalarInvert(effectiveRadius)};
 
    auto circleFP = GrSkSLFP::Make(effect, "Circle", /*inputFP=*/nullptr,
                                   GrSkSLFP::OptFlags::kCompatibleWithCoverageAsAlpha,
                                   "edgeType", GrSkSLFP::Specialize(static_cast<int>(edgeType)),
                                   "circle", circle);
    return GrFPSuccess(GrBlendFragmentProcessor::Make<SkBlendMode::kModulate>(std::move(inputFP),
                                                                              std::move(circleFP)));
}
 
GrFPResult GrFragmentProcessor::Ellipse(std::unique_ptr<GrFragmentProcessor> inputFP,
                                        GrClipEdgeType edgeType,
                                        SkPoint center,
                                        SkPoint radii,
                                        const GrShaderCaps& caps) {
    const bool medPrecision = !caps.fFloatIs32Bits;
 
    // Small radii produce bad results on devices without full float.
    if (medPrecision && (radii.fX < 0.5f || radii.fY < 0.5f)) {
        return GrFPFailure(std::move(inputFP));
    }
    // Very narrow ellipses produce bad results on devices without full float
    if (medPrecision && (radii.fX > 255*radii.fY || radii.fY > 255*radii.fX)) {
        return GrFPFailure(std::move(inputFP));
    }
    // Very large ellipses produce bad results on devices without full float
    if (medPrecision && (radii.fX > 16384 || radii.fY > 16384)) {
        return GrFPFailure(std::move(inputFP));
    }
 
    static const SkRuntimeEffect* effect = SkMakeRuntimeEffect(SkRuntimeEffect::MakeForShader,
    CLIP_EDGE_SKSL
        "uniform int edgeType;"      // GrClipEdgeType, specialized
        "uniform int medPrecision;"  // !sk_Caps.floatIs32Bits, specialized
 
        "uniform float4 ellipse;"
        "uniform float2 scale;"    // only for medPrecision
 
        "half4 main(float2 xy) {"
            // d is the offset to the ellipse center
            "float2 d = sk_FragCoord.xy - ellipse.xy;"
            // If we're on a device with a "real" mediump then we'll do the distance computation in
            // a space that is normalized by the larger radius or 128, whichever is smaller. The
            // scale uniform will be scale, 1/scale. The inverse squared radii uniform values are
            // already in this normalized space. The center is not.
            "if (bool(medPrecision)) {"
                "d *= scale.y;"
            "}"
            "float2 Z = d * ellipse.zw;"
            // implicit is the evaluation of (x/rx)^2 + (y/ry)^2 - 1.
            "float implicit = dot(Z, d) - 1;"
            // grad_dot is the squared length of the gradient of the implicit.
            "float grad_dot = 4 * dot(Z, Z);"
            // Avoid calling inversesqrt on zero.
            "if (bool(medPrecision)) {"
                "grad_dot = max(grad_dot, 6.1036e-5);"
            "} else {"
                "grad_dot = max(grad_dot, 1.1755e-38);"
            "}"
            "float approx_dist = implicit * inversesqrt(grad_dot);"
            "if (bool(medPrecision)) {"
                "approx_dist *= scale.x;"
            "}"
 
            "half alpha;"
            "if (edgeType == kFillBW) {"
                "alpha = approx_dist > 0.0 ? 0.0 : 1.0;"
            "} else if (edgeType == kFillAA) {"
                "alpha = saturate(0.5 - half(approx_dist));"
            "} else if (edgeType == kInverseFillBW) {"
                "alpha = approx_dist > 0.0 ? 1.0 : 0.0;"
            "} else {"  // edgeType == kInverseFillAA
                "alpha = saturate(0.5 + half(approx_dist));"
            "}"
            "return half4(alpha);"
        "}"
    );
 
    float invRXSqd;
    float invRYSqd;
    SkV2 scale = {1, 1};
    // If we're using a scale factor to work around precision issues, choose the larger radius as
    // the scale factor. The inv radii need to be pre-adjusted by the scale factor.
    if (medPrecision) {
        if (radii.fX > radii.fY) {
            invRXSqd = 1.f;
            invRYSqd = (radii.fX * radii.fX) / (radii.fY * radii.fY);
            scale = {radii.fX, 1.f / radii.fX};
        } else {
            invRXSqd = (radii.fY * radii.fY) / (radii.fX * radii.fX);
            invRYSqd = 1.f;
            scale = {radii.fY, 1.f / radii.fY};
        }
    } else {
        invRXSqd = 1.f / (radii.fX * radii.fX);
        invRYSqd = 1.f / (radii.fY * radii.fY);
    }
    SkV4 ellipse = {center.fX, center.fY, invRXSqd, invRYSqd};
 
    auto ellipseFP = GrSkSLFP::Make(effect, "Ellipse", /*inputFP=*/nullptr,
                                    GrSkSLFP::OptFlags::kCompatibleWithCoverageAsAlpha,
                                    "edgeType", GrSkSLFP::Specialize(static_cast<int>(edgeType)),
                                    "medPrecision",  GrSkSLFP::Specialize<int>(medPrecision),
                                    "ellipse", ellipse,
                                    "scale", scale);
    return GrFPSuccess(GrBlendFragmentProcessor::Make<SkBlendMode::kModulate>(std::move(ellipseFP),
                                                                              std::move(inputFP)));
}
 
//////////////////////////////////////////////////////////////////////////////
 
std::unique_ptr<GrFragmentProcessor> GrFragmentProcessor::HighPrecision(
        std::unique_ptr<GrFragmentProcessor> fp) {
    class HighPrecisionFragmentProcessor : public GrFragmentProcessor {
    public:
        static std::unique_ptr<GrFragmentProcessor> Make(std::unique_ptr<GrFragmentProcessor> fp) {
            return std::unique_ptr<GrFragmentProcessor>(
                    new HighPrecisionFragmentProcessor(std::move(fp)));
        }
 
        const char* name() const override { return "HighPrecision"; }
 
        std::unique_ptr<GrFragmentProcessor> clone() const override {
            return Make(this->childProcessor(0)->clone());
        }
 
    private:
        HighPrecisionFragmentProcessor(std::unique_ptr<GrFragmentProcessor> fp)
                : INHERITED(kHighPrecisionFragmentProcessor_ClassID,
                            ProcessorOptimizationFlags(fp.get())) {
            this->registerChild(std::move(fp));
        }
 
        std::unique_ptr<ProgramImpl> onMakeProgramImpl() const override {
            class Impl : public ProgramImpl {
            public:
                void emitCode(EmitArgs& args) override {
                    SkString childColor = this->invokeChild(0, args);
 
                    args.fFragBuilder->forceHighPrecision();
                    args.fFragBuilder->codeAppendf("return %s;", childColor.c_str());
                }
            };
            return std::make_unique<Impl>();
        }
 
        void onAddToKey(const GrShaderCaps&, skgpu::KeyBuilder*) const override {}
        bool onIsEqual(const GrFragmentProcessor& other) const override { return true; }
 
        SkPMColor4f constantOutputForConstantInput(const SkPMColor4f& input) const override {
            return ConstantOutputForConstantInput(this->childProcessor(0), input);
        }
 
        using INHERITED = GrFragmentProcessor;
    };
 
    return HighPrecisionFragmentProcessor::Make(std::move(fp));
}
 
//////////////////////////////////////////////////////////////////////////////
 
using ProgramImpl = GrFragmentProcessor::ProgramImpl;
 
void ProgramImpl::setData(const GrGLSLProgramDataManager& pdman,
                          const GrFragmentProcessor& processor) {
    this->onSetData(pdman, processor);
}
 
SkString ProgramImpl::invokeChild(int childIndex,
                                  const char* inputColor,
                                  const char* destColor,
                                  EmitArgs& args,
                                  std::string_view skslCoords) {
    SkASSERT(childIndex >= 0);
 
    if (!inputColor) {
        inputColor = args.fInputColor;
    }
 
    const GrFragmentProcessor* childProc = args.fFp.childProcessor(childIndex);
    if (!childProc) {
        // If no child processor is provided, return the input color as-is.
        return SkString(inputColor);
    }
 
    auto invocation = SkStringPrintf("%s(%s", this->childProcessor(childIndex)->functionName(),
                                     inputColor);
 
    if (childProc->isBlendFunction()) {
        if (!destColor) {
            destColor = args.fFp.isBlendFunction() ? args.fDestColor : "half4(1)";
        }
        invocation.appendf(", %s", destColor);
    }
 
    // Assert that the child has no sample matrix. A uniform matrix sample call would go through
    // invokeChildWithMatrix, not here.
    SkASSERT(!childProc->sampleUsage().isUniformMatrix());
 
    if (args.fFragBuilder->getProgramBuilder()->fragmentProcessorHasCoordsParam(childProc)) {
        SkASSERT(!childProc->sampleUsage().isFragCoord() || skslCoords == "sk_FragCoord.xy");
        // The child's function takes a half4 color and a float2 coordinate
        if (!skslCoords.empty()) {
            invocation.appendf(", %.*s", (int)skslCoords.size(), skslCoords.data());
        } else {
            invocation.appendf(", %s", args.fSampleCoord);
        }
    }
 
    invocation.append(")");
    return invocation;
}
 
SkString ProgramImpl::invokeChildWithMatrix(int childIndex,
                                            const char* inputColor,
                                            const char* destColor,
                                            EmitArgs& args) {
    SkASSERT(childIndex >= 0);
 
    if (!inputColor) {
        inputColor = args.fInputColor;
    }
 
    const GrFragmentProcessor* childProc = args.fFp.childProcessor(childIndex);
    if (!childProc) {
        // If no child processor is provided, return the input color as-is.
        return SkString(inputColor);
    }
 
    SkASSERT(childProc->sampleUsage().isUniformMatrix());
 
    // Every uniform matrix has the same (initial) name. Resolve that into the mangled name:
    GrShaderVar uniform = args.fUniformHandler->getUniformMapping(
            args.fFp, SkString(SkSL::SampleUsage::MatrixUniformName()));
    SkASSERT(uniform.getType() == SkSLType::kFloat3x3);
    const SkString& matrixName(uniform.getName());
 
    auto invocation = SkStringPrintf("%s(%s", this->childProcessor(childIndex)->functionName(),
                                     inputColor);
 
    if (childProc->isBlendFunction()) {
        if (!destColor) {
            destColor = args.fFp.isBlendFunction() ? args.fDestColor : "half4(1)";
        }
        invocation.appendf(", %s", destColor);
    }
 
    // Produce a string containing the call to the helper function. We have a uniform variable
    // containing our transform (matrixName). If the parent coords were produced by uniform
    // transforms, then the entire expression (matrixName * coords) is lifted to a vertex shader
    // and is stored in a varying. In that case, childProc will not be sampled explicitly, so its
    // function signature will not take in coords.
    //
    // In all other cases, we need to insert sksl to compute matrix * parent coords and then invoke
    // the function.
    if (args.fFragBuilder->getProgramBuilder()->fragmentProcessorHasCoordsParam(childProc)) {
        // Only check perspective for this specific matrix transform, not the aggregate FP property.
        // Any parent perspective will have already been applied when evaluated in the FS.
        if (childProc->sampleUsage().hasPerspective()) {
            invocation.appendf(", proj((%s) * %s.xy1)", matrixName.c_str(), args.fSampleCoord);
        } else if (args.fShaderCaps->fNonsquareMatrixSupport) {
            invocation.appendf(", float3x2(%s) * %s.xy1", matrixName.c_str(), args.fSampleCoord);
        } else {
            invocation.appendf(", ((%s) * %s.xy1).xy", matrixName.c_str(), args.fSampleCoord);
        }
    }
 
    invocation.append(")");
    return invocation;
}

Typedef Documentation

ProgramImpl

using ProgramImpl = GrFragmentProcessor::ProgramImpl

Definition at line 849 of file GrFragmentProcessor.cpp.