src/gpu/effects/generated/GrRRectBlurEffect.h

/*
 * Copyright 2018 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

/**************************************************************************************************
 *** This file was autogenerated from GrRRectBlurEffect.fp; do not modify.
 **************************************************************************************************/
#ifndef GrRRectBlurEffect_DEFINED
#define GrRRectBlurEffect_DEFINED

#include "include/core/SkM44.h"
#include "include/core/SkTypes.h"

#include "include/gpu/GrRecordingContext.h"
#include "src/core/SkBlurPriv.h"
#include "src/core/SkGpuBlurUtils.h"
#include "src/core/SkRRectPriv.h"
#include "src/gpu/GrCaps.h"
#include "src/gpu/GrPaint.h"
#include "src/gpu/GrProxyProvider.h"
#include "src/gpu/GrRecordingContextPriv.h"
#include "src/gpu/GrRenderTargetContext.h"
#include "src/gpu/GrStyle.h"
#include "src/gpu/effects/GrTextureEffect.h"

#include "src/gpu/GrFragmentProcessor.h"

class GrRRectBlurEffect : public GrFragmentProcessor {
public:
    static std::unique_ptr<GrFragmentProcessor> find_or_create_rrect_blur_mask_fp(
            GrRecordingContext* context,
            const SkRRect& rrectToDraw,
            const SkISize& dimensions,
            float xformedSigma) {
        static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
        GrUniqueKey key;
        GrUniqueKey::Builder builder(&key, kDomain, 9, "RoundRect Blur Mask");
        builder[0] = SkScalarCeilToInt(xformedSigma - 1 / 6.0f);

        int index = 1;
        for (auto c : {SkRRect::kUpperLeft_Corner, SkRRect::kUpperRight_Corner,
                       SkRRect::kLowerRight_Corner, SkRRect::kLowerLeft_Corner}) {
            SkASSERT(SkScalarIsInt(rrectToDraw.radii(c).fX) &&
                     SkScalarIsInt(rrectToDraw.radii(c).fY));
            builder[index++] = SkScalarCeilToInt(rrectToDraw.radii(c).fX);
            builder[index++] = SkScalarCeilToInt(rrectToDraw.radii(c).fY);
        }
        builder.finish();

        // It seems like we could omit this matrix and modify the shader code to not normalize
        // the coords used to sample the texture effect. However, the "proxyDims" value in the
        // shader is not always the actual the proxy dimensions. This is because 'dimensions' here
        // was computed using integer corner radii as determined in
        // SkComputeBlurredRRectParams whereas the shader code uses the float radius to compute
        // 'proxyDims'. Why it draws correctly with these unequal values is a mystery for the ages.
        auto m = SkMatrix::Scale(dimensions.width(), dimensions.height());
        static constexpr auto kMaskOrigin = kBottomLeft_GrSurfaceOrigin;
        GrProxyProvider* proxyProvider = context->priv().proxyProvider();

        if (auto view = proxyProvider->findCachedProxyWithColorTypeFallback(
                    key, kMaskOrigin, GrColorType::kAlpha_8, 1)) {
            return GrTextureEffect::Make(std::move(view), kPremul_SkAlphaType, m);
        }

        auto rtc = GrRenderTargetContext::MakeWithFallback(
                context, GrColorType::kAlpha_8, nullptr, SkBackingFit::kExact, dimensions, 1,
                GrMipmapped::kNo, GrProtected::kNo, kMaskOrigin);
        if (!rtc) {
            return nullptr;
        }

        GrPaint paint;

        rtc->clear(SK_PMColor4fTRANSPARENT);
        rtc->drawRRect(nullptr, std::move(paint), GrAA::kYes, SkMatrix::I(), rrectToDraw,
                       GrStyle::SimpleFill());

        GrSurfaceProxyView srcView = rtc->readSurfaceView();
        if (!srcView) {
            return nullptr;
        }
        SkASSERT(srcView.asTextureProxy());
        auto rtc2 = SkGpuBlurUtils::GaussianBlur(context,
                                                 std::move(srcView),
                                                 rtc->colorInfo().colorType(),
                                                 rtc->colorInfo().alphaType(),
                                                 nullptr,
                                                 SkIRect::MakeSize(dimensions),
                                                 SkIRect::MakeSize(dimensions),
                                                 xformedSigma,
                                                 xformedSigma,
                                                 SkTileMode::kClamp,
                                                 SkBackingFit::kExact);
        if (!rtc2) {
            return nullptr;
        }

        GrSurfaceProxyView mask = rtc2->readSurfaceView();
        if (!mask) {
            return nullptr;
        }
        SkASSERT(mask.asTextureProxy());
        SkASSERT(mask.origin() == kMaskOrigin);
        proxyProvider->assignUniqueKeyToProxy(key, mask.asTextureProxy());
        return GrTextureEffect::Make(std::move(mask), kPremul_SkAlphaType, m);
    }

    static std::unique_ptr<GrFragmentProcessor> Make(std::unique_ptr<GrFragmentProcessor> inputFP,
                                                     GrRecordingContext* context,
                                                     float sigma,
                                                     float xformedSigma,
                                                     const SkRRect& srcRRect,
                                                     const SkRRect& devRRect);
    GrRRectBlurEffect(const GrRRectBlurEffect& src);
    std::unique_ptr<GrFragmentProcessor> clone() const override;
    const char* name() const override { return "RRectBlurEffect"; }
    float sigma;
    SkRect rect;
    float cornerRadius;

private:
    GrRRectBlurEffect(std::unique_ptr<GrFragmentProcessor> inputFP,
                      float sigma,
                      SkRect rect,
                      float cornerRadius,
                      std::unique_ptr<GrFragmentProcessor> ninePatchFP)
            : INHERITED(kGrRRectBlurEffect_ClassID,
                        (OptimizationFlags)(inputFP ? ProcessorOptimizationFlags(inputFP.get())
                                                    : kAll_OptimizationFlags) &
                                kCompatibleWithCoverageAsAlpha_OptimizationFlag)
            , sigma(sigma)
            , rect(rect)
            , cornerRadius(cornerRadius) {
        this->registerChild(std::move(inputFP), SkSL::SampleUsage::PassThrough());
        SkASSERT(ninePatchFP);
        this->registerChild(std::move(ninePatchFP), SkSL::SampleUsage::Explicit());
    }
    GrGLSLFragmentProcessor* onCreateGLSLInstance() const override;
    void onGetGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder*) const override;
    bool onIsEqual(const GrFragmentProcessor&) const override;
    GR_DECLARE_FRAGMENT_PROCESSOR_TEST
    typedef GrFragmentProcessor INHERITED;
};
#endif