EllipticalRRectEffect::Impl Class Reference

Inheritance diagram for EllipticalRRectEffect::Impl:

Public Member Functions
void	emitCode (EmitArgs &) override
Public Member Functions inherited from GrFragmentProcessor::ProgramImpl
	ProgramImpl ()=default
virtual	~ProgramImpl ()=default
void	setData (const GrGLSLProgramDataManager &pdman, const GrFragmentProcessor &processor)
int	numChildProcessors () const
ProgramImpl *	childProcessor (int index) const
void	setFunctionName (SkString name)
const char *	functionName () const
SkString	invokeChild (int childIndex, EmitArgs &parentArgs, std::string_view skslCoords={})
SkString	invokeChildWithMatrix (int childIndex, EmitArgs &parentArgs)
SkString	invokeChild (int childIndex, const char *inputColor, EmitArgs &parentArgs, std::string_view skslCoords={})
SkString	invokeChildWithMatrix (int childIndex, const char *inputColor, EmitArgs &parentArgs)
SkString	invokeChild (int childIndex, const char *inputColor, const char *destColor, EmitArgs &parentArgs, std::string_view skslCoords={})
SkString	invokeChildWithMatrix (int childIndex, const char *inputColor, const char *destColor, EmitArgs &parentArgs)

Private Member Functions
void	onSetData (const GrGLSLProgramDataManager &, const GrFragmentProcessor &) override

Additional Inherited Members
Public Types inherited from GrFragmentProcessor::ProgramImpl
using	UniformHandle = GrGLSLUniformHandler::UniformHandle
using	SamplerHandle = GrGLSLUniformHandler::SamplerHandle

Detailed Description

Definition at line 532 of file GrRRectEffect.cpp.

Member Function Documentation

emitCode()

void EllipticalRRectEffect::Impl::emitCode ( EmitArgs &  args )

overridevirtual

Implements GrFragmentProcessor::ProgramImpl.

Definition at line 545 of file GrRRectEffect.cpp.

                                                       {
    const EllipticalRRectEffect& erre = args.fFp.cast<EllipticalRRectEffect>();
    GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
    const char *rectName;
    // The inner rect is the rrect bounds inset by the x/y radii
    fInnerRectUniform = uniformHandler->addUniform(&erre, kFragment_GrShaderFlag, SkSLType::kFloat4,
                                                   "innerRect", &rectName);
 
    GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
    // At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
    // to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
    // to that corner. This means that points near the interior near the rrect top edge will have
    // a vector that points straight up for both the TL left and TR corners. Computing an
    // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
    // fragments near the other three edges will get the correct AA. Fragments in the interior of
    // the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
    // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
    //
    // The code below is a simplified version of the above that performs maxs on the vector
    // components before computing distances and alpha values so that only one distance computation
    // need be computed to determine the min alpha.
    fragBuilder->codeAppendf("float2 dxy0 = %s.LT - sk_FragCoord.xy;", rectName);
    fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.RB;", rectName);
 
 
    const char* scaleName = nullptr;
    if (elliptical_effect_uses_scale(*args.fShaderCaps, erre.fRRect)) {
        fScaleUniform = uniformHandler->addUniform(&erre, kFragment_GrShaderFlag, SkSLType::kHalf2,
                                                   "scale", &scaleName);
    }
 
    // The uniforms with the inv squared radii are highp to prevent underflow.
    switch (erre.fRRect.getType()) {
        case SkRRect::kSimple_Type: {
            const char *invRadiiXYSqdName;
            fInvRadiiSqdUniform = uniformHandler->addUniform(&erre,
                                                             kFragment_GrShaderFlag,
                                                             SkSLType::kFloat2,
                                                             "invRadiiXY",
                                                             &invRadiiXYSqdName);
            fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
            if (scaleName) {
                fragBuilder->codeAppendf("dxy *= %s.y;", scaleName);
            }
            // Z is the x/y offsets divided by squared radii.
            fragBuilder->codeAppendf("float2 Z = dxy * %s.xy;", invRadiiXYSqdName);
            break;
        }
        case SkRRect::kNinePatch_Type: {
            const char *invRadiiLTRBSqdName;
            fInvRadiiSqdUniform = uniformHandler->addUniform(&erre,
                                                             kFragment_GrShaderFlag,
                                                             SkSLType::kFloat4,
                                                             "invRadiiLTRB",
                                                             &invRadiiLTRBSqdName);
            if (scaleName) {
                fragBuilder->codeAppendf("dxy0 *= %s.y;", scaleName);
                fragBuilder->codeAppendf("dxy1 *= %s.y;", scaleName);
            }
            fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
            // Z is the x/y offsets divided by squared radii. We only care about the (at most) one
            // corner where both the x and y offsets are positive, hence the maxes. (The inverse
            // squared radii will always be positive.)
            fragBuilder->codeAppendf("float2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);",
                                     invRadiiLTRBSqdName, invRadiiLTRBSqdName);
 
            break;
        }
        default:
            SK_ABORT("RRect should always be simple or nine-patch.");
    }
    // implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
    fragBuilder->codeAppend("half implicit = half(dot(Z, dxy) - 1.0);");
    // grad_dot is the squared length of the gradient of the implicit.
    fragBuilder->codeAppend("half grad_dot = half(4.0 * dot(Z, Z));");
    // avoid calling inversesqrt on zero.
    fragBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
    fragBuilder->codeAppend("half approx_dist = implicit * half(inversesqrt(grad_dot));");
    if (scaleName) {
        fragBuilder->codeAppendf("approx_dist *= %s.x;", scaleName);
    }
 
    if (erre.fEdgeType == GrClipEdgeType::kFillAA) {
        fragBuilder->codeAppend("half alpha = clamp(0.5 - approx_dist, 0.0, 1.0);");
    } else {
        fragBuilder->codeAppend("half alpha = clamp(0.5 + approx_dist, 0.0, 1.0);");
    }
 
    SkString inputSample = this->invokeChild(/*childIndex=*/0, args);
 
    fragBuilder->codeAppendf("return %s * alpha;", inputSample.c_str());
}

onSetData()

void EllipticalRRectEffect::Impl::onSetData ( const GrGLSLProgramDataManager &  , const GrFragmentProcessor &    )

overrideprivatevirtual

A ProgramImpl instance can be reused with any GrFragmentProcessor that produces the same the same key; this function reads data from a GrFragmentProcessor and uploads any uniform variables required by the shaders created in emitCode(). The GrFragmentProcessor parameter is guaranteed to be of the same type that created this ProgramImpl and to have an identical key as the one that created this ProgramImpl.

Reimplemented from GrFragmentProcessor::ProgramImpl.

Definition at line 638 of file GrRRectEffect.cpp.

                                                                               {
    const EllipticalRRectEffect& erre = effect.cast<EllipticalRRectEffect>();
    const SkRRect& rrect = erre.fRRect;
    // If we're using a scale factor to work around precision issues, choose the largest radius
    // as the scale factor. The inv radii need to be pre-adjusted by the scale factor.
    if (rrect != fPrevRRect) {
        SkRect rect = rrect.getBounds();
        const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
        SkASSERT(r0.fX >= kRadiusMin);
        SkASSERT(r0.fY >= kRadiusMin);
        switch (rrect.getType()) {
            case SkRRect::kSimple_Type:
                rect.inset(r0.fX, r0.fY);
                if (fScaleUniform.isValid()) {
                    if (r0.fX > r0.fY) {
                        pdman.set2f(fInvRadiiSqdUniform, 1.f, (r0.fX * r0.fX) / (r0.fY * r0.fY));
                        pdman.set2f(fScaleUniform, r0.fX, 1.f / r0.fX);
                    } else {
                        pdman.set2f(fInvRadiiSqdUniform, (r0.fY * r0.fY) / (r0.fX * r0.fX), 1.f);
                        pdman.set2f(fScaleUniform, r0.fY, 1.f / r0.fY);
                    }
                } else {
                    pdman.set2f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
                                                     1.f / (r0.fY * r0.fY));
                }
                break;
            case SkRRect::kNinePatch_Type: {
                const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
                SkASSERT(r1.fX >= kRadiusMin);
                SkASSERT(r1.fY >= kRadiusMin);
                rect.fLeft += r0.fX;
                rect.fTop += r0.fY;
                rect.fRight -= r1.fX;
                rect.fBottom -= r1.fY;
                if (fScaleUniform.isValid()) {
                    float scale = std::max(std::max(r0.fX, r0.fY), std::max(r1.fX, r1.fY));
                    float scaleSqd = scale * scale;
                    pdman.set4f(fInvRadiiSqdUniform, scaleSqd / (r0.fX * r0.fX),
                                                     scaleSqd / (r0.fY * r0.fY),
                                                     scaleSqd / (r1.fX * r1.fX),
                                                     scaleSqd / (r1.fY * r1.fY));
                    pdman.set2f(fScaleUniform, scale, 1.f / scale);
                } else {
                    pdman.set4f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
                                                     1.f / (r0.fY * r0.fY),
                                                     1.f / (r1.fX * r1.fX),
                                                     1.f / (r1.fY * r1.fY));
                }
                break;
            }
        default:
            SK_ABORT("RRect should always be simple or nine-patch.");
        }
        pdman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
        fPrevRRect = rrect;
    }
}

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The documentation for this class was generated from the following file:

• third_party/skia/src/gpu/ganesh/effects/GrRRectEffect.cpp