src/gpu/effects/generated/GrRRectBlurEffect.cpp

/*
 * 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.
 **************************************************************************************************/
#include "GrRRectBlurEffect.h"

#include "include/gpu/GrDirectContext.h"
#include "include/gpu/GrRecordingContext.h"
#include "src/core/SkAutoMalloc.h"
#include "src/core/SkGpuBlurUtils.h"
#include "src/core/SkRRectPriv.h"
#include "src/gpu/GrCaps.h"
#include "src/gpu/GrDirectContextPriv.h"
#include "src/gpu/GrPaint.h"
#include "src/gpu/GrProxyProvider.h"
#include "src/gpu/GrRecordingContextPriv.h"
#include "src/gpu/GrStyle.h"
#include "src/gpu/GrSurfaceDrawContext.h"
#include "src/gpu/GrThreadSafeCache.h"
#include "src/gpu/SkGr.h"
#include "src/gpu/effects/GrTextureEffect.h"

static constexpr auto kBlurredRRectMaskOrigin = kTopLeft_GrSurfaceOrigin;

static void make_blurred_rrect_key(GrUniqueKey* key,
                                   const SkRRect& rrectToDraw,
                                   float xformedSigma) {
    SkASSERT(!SkGpuBlurUtils::IsEffectivelyZeroSigma(xformedSigma));
    static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();

    GrUniqueKey::Builder builder(key, kDomain, 9, "RoundRect Blur Mask");
    builder[0] = SkScalarCeilToInt(xformedSigma - 1 / 6.0f);

    int index = 1;
    // TODO: this is overkill for _simple_ circular rrects
    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();
}

static bool fillin_view_on_gpu(GrDirectContext* dContext,
                               const GrSurfaceProxyView& lazyView,
                               sk_sp<GrThreadSafeCache::Trampoline> trampoline,
                               const SkRRect& rrectToDraw,
                               const SkISize& dimensions,
                               float xformedSigma) {
    SkASSERT(!SkGpuBlurUtils::IsEffectivelyZeroSigma(xformedSigma));

    // We cache blur masks. Use default surface props here so we can use the same cached mask
    // regardless of the final dst surface.
    SkSurfaceProps defaultSurfaceProps;

    std::unique_ptr<GrSurfaceDrawContext> rtc =
            GrSurfaceDrawContext::MakeWithFallback(dContext,
                                                   GrColorType::kAlpha_8,
                                                   nullptr,
                                                   SkBackingFit::kExact,
                                                   dimensions,
                                                   defaultSurfaceProps,
                                                   1,
                                                   GrMipmapped::kNo,
                                                   GrProtected::kNo,
                                                   kBlurredRRectMaskOrigin);
    if (!rtc) {
        return false;
    }

    GrPaint paint;

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

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

    auto view = rtc2->readSurfaceView();
    SkASSERT(view.swizzle() == lazyView.swizzle());
    SkASSERT(view.origin() == lazyView.origin());
    trampoline->fProxy = view.asTextureProxyRef();

    return true;
}

// Evaluate the vertical blur at the specified 'y' value given the location of the top of the
// rrect.
static uint8_t eval_V(float top, int y, const uint8_t* integral, int integralSize, float sixSigma) {
    if (top < 0) {
        return 0;  // an empty column
    }

    float fT = (top - y - 0.5f) * (integralSize / sixSigma);
    if (fT < 0) {
        return 255;
    } else if (fT >= integralSize - 1) {
        return 0;
    }

    int lower = (int)fT;
    float frac = fT - lower;

    SkASSERT(lower + 1 < integralSize);

    return integral[lower] * (1.0f - frac) + integral[lower + 1] * frac;
}

// Apply a gaussian 'kernel' horizontally at the specified 'x', 'y' location.
static uint8_t eval_H(int x,
                      int y,
                      const std::vector<float>& topVec,
                      const float* kernel,
                      int kernelSize,
                      const uint8_t* integral,
                      int integralSize,
                      float sixSigma) {
    SkASSERT(0 <= x && x < (int)topVec.size());
    SkASSERT(kernelSize % 2);

    float accum = 0.0f;

    int xSampleLoc = x - (kernelSize / 2);
    for (int i = 0; i < kernelSize; ++i, ++xSampleLoc) {
        if (xSampleLoc < 0 || xSampleLoc >= (int)topVec.size()) {
            continue;
        }

        accum += kernel[i] * eval_V(topVec[xSampleLoc], y, integral, integralSize, sixSigma);
    }

    return accum + 0.5f;
}

// Create a cpu-side blurred-rrect mask that is close to the version the gpu would've produced.
// The match needs to be close bc the cpu- and gpu-generated version must be interchangeable.
static GrSurfaceProxyView create_mask_on_cpu(GrRecordingContext* rContext,
                                             const SkRRect& rrectToDraw,
                                             const SkISize& dimensions,
                                             float xformedSigma) {
    SkASSERT(!SkGpuBlurUtils::IsEffectivelyZeroSigma(xformedSigma));
    int radius = SkGpuBlurUtils::SigmaRadius(xformedSigma);
    int kernelSize = 2 * radius + 1;

    SkASSERT(kernelSize % 2);
    SkASSERT(dimensions.width() % 2);
    SkASSERT(dimensions.height() % 2);

    SkVector radii = rrectToDraw.getSimpleRadii();
    SkASSERT(SkScalarNearlyEqual(radii.fX, radii.fY));

    const int halfWidthPlus1 = (dimensions.width() / 2) + 1;
    const int halfHeightPlus1 = (dimensions.height() / 2) + 1;

    std::unique_ptr<float[]> kernel(new float[kernelSize]);

    SkGpuBlurUtils::Compute1DGaussianKernel(kernel.get(), xformedSigma, radius);

    SkBitmap integral;
    if (!SkGpuBlurUtils::CreateIntegralTable(6 * xformedSigma, &integral)) {
        return {};
    }

    SkBitmap result;
    if (!result.tryAllocPixels(SkImageInfo::MakeA8(dimensions.width(), dimensions.height()))) {
        return {};
    }

    std::vector<float> topVec;
    topVec.reserve(dimensions.width());
    for (int x = 0; x < dimensions.width(); ++x) {
        if (x < rrectToDraw.rect().fLeft || x > rrectToDraw.rect().fRight) {
            topVec.push_back(-1);
        } else {
            if (x + 0.5f < rrectToDraw.rect().fLeft + radii.fX) {  // in the circular section
                float xDist = rrectToDraw.rect().fLeft + radii.fX - x - 0.5f;
                float h = sqrtf(radii.fX * radii.fX - xDist * xDist);
                SkASSERT(0 <= h && h < radii.fY);
                topVec.push_back(rrectToDraw.rect().fTop + radii.fX - h + 3 * xformedSigma);
            } else {
                topVec.push_back(rrectToDraw.rect().fTop + 3 * xformedSigma);
            }
        }
    }

    for (int y = 0; y < halfHeightPlus1; ++y) {
        uint8_t* scanline = result.getAddr8(0, y);

        for (int x = 0; x < halfWidthPlus1; ++x) {
            scanline[x] = eval_H(x,
                                 y,
                                 topVec,
                                 kernel.get(),
                                 kernelSize,
                                 integral.getAddr8(0, 0),
                                 integral.width(),
                                 6 * xformedSigma);
            scanline[dimensions.width() - x - 1] = scanline[x];
        }

        memcpy(result.getAddr8(0, dimensions.height() - y - 1), scanline, result.rowBytes());
    }

    result.setImmutable();

    auto view = std::get<0>(GrMakeUncachedBitmapProxyView(rContext, result));
    if (!view) {
        return {};
    }

    SkASSERT(view.origin() == kBlurredRRectMaskOrigin);
    return view;
}

static std::unique_ptr<GrFragmentProcessor> find_or_create_rrect_blur_mask_fp(
        GrRecordingContext* rContext,
        const SkRRect& rrectToDraw,
        const SkISize& dimensions,
        float xformedSigma) {
    SkASSERT(!SkGpuBlurUtils::IsEffectivelyZeroSigma(xformedSigma));
    GrUniqueKey key;
    make_blurred_rrect_key(&key, rrectToDraw, xformedSigma);

    auto threadSafeCache = rContext->priv().threadSafeCache();

    // 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());

    GrSurfaceProxyView view;

    if (GrDirectContext* dContext = rContext->asDirectContext()) {
        // The gpu thread gets priority over the recording threads. If the gpu thread is first,
        // it crams a lazy proxy into the cache and then fills it in later.
        auto[lazyView, trampoline] = GrThreadSafeCache::CreateLazyView(dContext,
                                                                       GrColorType::kAlpha_8,
                                                                       dimensions,
                                                                       kBlurredRRectMaskOrigin,
                                                                       SkBackingFit::kExact);
        if (!lazyView) {
            return nullptr;
        }

        view = threadSafeCache->findOrAdd(key, lazyView);
        if (view != lazyView) {
            SkASSERT(view.asTextureProxy());
            SkASSERT(view.origin() == kBlurredRRectMaskOrigin);
            return GrTextureEffect::Make(std::move(view), kPremul_SkAlphaType, m);
        }

        if (!fillin_view_on_gpu(dContext,
                                lazyView,
                                std::move(trampoline),
                                rrectToDraw,
                                dimensions,
                                xformedSigma)) {
            // In this case something has gone disastrously wrong so set up to drop the draw
            // that needed this resource and reduce future pollution of the cache.
            threadSafeCache->remove(key);
            return nullptr;
        }
    } else {
        view = threadSafeCache->find(key);
        if (view) {
            SkASSERT(view.asTextureProxy());
            SkASSERT(view.origin() == kBlurredRRectMaskOrigin);
            return GrTextureEffect::Make(std::move(view), kPremul_SkAlphaType, m);
        }

        view = create_mask_on_cpu(rContext, rrectToDraw, dimensions, xformedSigma);
        if (!view) {
            return nullptr;
        }

        view = threadSafeCache->add(key, view);
    }

    SkASSERT(view.asTextureProxy());
    SkASSERT(view.origin() == kBlurredRRectMaskOrigin);
    return GrTextureEffect::Make(std::move(view), kPremul_SkAlphaType, m);
}

std::unique_ptr<GrFragmentProcessor> GrRRectBlurEffect::Make(
        std::unique_ptr<GrFragmentProcessor> inputFP,
        GrRecordingContext* context,
        float sigma,
        float xformedSigma,
        const SkRRect& srcRRect,
        const SkRRect& devRRect) {
// Should've been caught up-stream
#ifdef SK_DEBUG
    SkASSERTF(!SkRRectPriv::IsCircle(devRRect),
              "Unexpected circle. %d\n\t%s\n\t%s",
              SkRRectPriv::IsCircle(srcRRect),
              srcRRect.dumpToString(true).c_str(),
              devRRect.dumpToString(true).c_str());
    SkASSERTF(!devRRect.isRect(),
              "Unexpected rect. %d\n\t%s\n\t%s",
              srcRRect.isRect(),
              srcRRect.dumpToString(true).c_str(),
              devRRect.dumpToString(true).c_str());
#endif
    // TODO: loosen this up
    if (!SkRRectPriv::IsSimpleCircular(devRRect)) {
        return nullptr;
    }

    if (SkGpuBlurUtils::IsEffectivelyZeroSigma(xformedSigma)) {
        return inputFP;
    }

    // Make sure we can successfully ninepatch this rrect -- the blur sigma has to be
    // sufficiently small relative to both the size of the corner radius and the
    // width (and height) of the rrect.
    SkRRect rrectToDraw;
    SkISize dimensions;
    SkScalar ignored[SkGpuBlurUtils::kBlurRRectMaxDivisions];

    bool ninePatchable = SkGpuBlurUtils::ComputeBlurredRRectParams(srcRRect,
                                                                   devRRect,
                                                                   sigma,
                                                                   xformedSigma,
                                                                   &rrectToDraw,
                                                                   &dimensions,
                                                                   ignored,
                                                                   ignored,
                                                                   ignored,
                                                                   ignored);
    if (!ninePatchable) {
        return nullptr;
    }

    std::unique_ptr<GrFragmentProcessor> maskFP =
            find_or_create_rrect_blur_mask_fp(context, rrectToDraw, dimensions, xformedSigma);
    if (!maskFP) {
        return nullptr;
    }

    return std::unique_ptr<GrFragmentProcessor>(
            new GrRRectBlurEffect(std::move(inputFP),
                                  xformedSigma,
                                  devRRect.getBounds(),
                                  SkRRectPriv::GetSimpleRadii(devRRect).fX,
                                  std::move(maskFP)));
}
#include "src/core/SkUtils.h"
#include "src/gpu/GrTexture.h"
#include "src/gpu/glsl/GrGLSLFragmentProcessor.h"
#include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
#include "src/gpu/glsl/GrGLSLProgramBuilder.h"
#include "src/sksl/SkSLCPP.h"
#include "src/sksl/SkSLUtil.h"
class GrGLSLRRectBlurEffect : public GrGLSLFragmentProcessor {
public:
    GrGLSLRRectBlurEffect() {}
    void emitCode(EmitArgs& args) override {
        GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
        const GrRRectBlurEffect& _outer = args.fFp.cast<GrRRectBlurEffect>();
        (void)_outer;
        auto sigma = _outer.sigma;
        (void)sigma;
        auto rect = _outer.rect;
        (void)rect;
        auto cornerRadius = _outer.cornerRadius;
        (void)cornerRadius;
        cornerRadiusVar = args.fUniformHandler->addUniform(
                &_outer, kFragment_GrShaderFlag, kHalf_GrSLType, "cornerRadius");
        proxyRectVar = args.fUniformHandler->addUniform(
                &_outer, kFragment_GrShaderFlag, kFloat4_GrSLType, "proxyRect");
        blurRadiusVar = args.fUniformHandler->addUniform(
                &_outer, kFragment_GrShaderFlag, kHalf_GrSLType, "blurRadius");
        fragBuilder->codeAppendf(
                R"SkSL(float2 translatedFragPosFloat = sk_FragCoord.xy - %s.xy;
float2 proxyCenter = (%s.zw - %s.xy) * 0.5;
half edgeSize = (2.0 * %s + %s) + 0.5;
translatedFragPosFloat -= proxyCenter;
half2 fragDirection = half2(sign(translatedFragPosFloat));
translatedFragPosFloat = abs(translatedFragPosFloat);
half2 translatedFragPosHalf = half2(translatedFragPosFloat - (proxyCenter - float(edgeSize)));
translatedFragPosHalf = max(translatedFragPosHalf, 0.0);
translatedFragPosHalf *= fragDirection;
translatedFragPosHalf += half2(edgeSize);
half2 proxyDims = half2(2.0 * edgeSize);
half2 texCoord = translatedFragPosHalf / proxyDims;)SkSL",
                args.fUniformHandler->getUniformCStr(proxyRectVar),
                args.fUniformHandler->getUniformCStr(proxyRectVar),
                args.fUniformHandler->getUniformCStr(proxyRectVar),
                args.fUniformHandler->getUniformCStr(blurRadiusVar),
                args.fUniformHandler->getUniformCStr(cornerRadiusVar));
        SkString _sample0 = this->invokeChild(0, args);
        SkString _coords1("float2(texCoord)");
        SkString _sample1 = this->invokeChild(1, args, _coords1.c_str());
        fragBuilder->codeAppendf(
                R"SkSL(
return %s * %s.w;
)SkSL",
                _sample0.c_str(),
                _sample1.c_str());
    }

private:
    void onSetData(const GrGLSLProgramDataManager& pdman,
                   const GrFragmentProcessor& _proc) override {
        const GrRRectBlurEffect& _outer = _proc.cast<GrRRectBlurEffect>();
        { pdman.set1f(cornerRadiusVar, _outer.cornerRadius); }
        auto sigma = _outer.sigma;
        (void)sigma;
        auto rect = _outer.rect;
        (void)rect;
        UniformHandle& cornerRadius = cornerRadiusVar;
        (void)cornerRadius;
        UniformHandle& proxyRect = proxyRectVar;
        (void)proxyRect;
        UniformHandle& blurRadius = blurRadiusVar;
        (void)blurRadius;

        float blurRadiusValue = 3.f * SkScalarCeilToScalar(sigma - 1 / 6.0f);
        pdman.set1f(blurRadius, blurRadiusValue);

        SkRect outset = rect;
        outset.outset(blurRadiusValue, blurRadiusValue);
        pdman.set4f(proxyRect, outset.fLeft, outset.fTop, outset.fRight, outset.fBottom);
    }
    UniformHandle proxyRectVar;
    UniformHandle blurRadiusVar;
    UniformHandle cornerRadiusVar;
};
std::unique_ptr<GrGLSLFragmentProcessor> GrRRectBlurEffect::onMakeProgramImpl() const {
    return std::make_unique<GrGLSLRRectBlurEffect>();
}
void GrRRectBlurEffect::onGetGLSLProcessorKey(const GrShaderCaps& caps,
                                              GrProcessorKeyBuilder* b) const {}
bool GrRRectBlurEffect::onIsEqual(const GrFragmentProcessor& other) const {
    const GrRRectBlurEffect& that = other.cast<GrRRectBlurEffect>();
    (void)that;
    if (sigma != that.sigma) return false;
    if (rect != that.rect) return false;
    if (cornerRadius != that.cornerRadius) return false;
    return true;
}
GrRRectBlurEffect::GrRRectBlurEffect(const GrRRectBlurEffect& src)
        : INHERITED(kGrRRectBlurEffect_ClassID, src.optimizationFlags())
        , sigma(src.sigma)
        , rect(src.rect)
        , cornerRadius(src.cornerRadius) {
    this->cloneAndRegisterAllChildProcessors(src);
}
std::unique_ptr<GrFragmentProcessor> GrRRectBlurEffect::clone() const {
    return std::make_unique<GrRRectBlurEffect>(*this);
}
#if GR_TEST_UTILS
SkString GrRRectBlurEffect::onDumpInfo() const {
    return SkStringPrintf("(sigma=%f, rect=float4(%f, %f, %f, %f), cornerRadius=%f)",
                          sigma,
                          rect.left(),
                          rect.top(),
                          rect.right(),
                          rect.bottom(),
                          cornerRadius);
}
#endif
GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrRRectBlurEffect);
#if GR_TEST_UTILS
std::unique_ptr<GrFragmentProcessor> GrRRectBlurEffect::TestCreate(GrProcessorTestData* d) {
    SkScalar w = d->fRandom->nextRangeScalar(100.f, 1000.f);
    SkScalar h = d->fRandom->nextRangeScalar(100.f, 1000.f);
    SkScalar r = d->fRandom->nextRangeF(1.f, 9.f);
    SkScalar sigma = d->fRandom->nextRangeF(1.f, 10.f);
    SkRRect rrect;
    rrect.setRectXY(SkRect::MakeWH(w, h), r, r);
    return GrRRectBlurEffect::Make(d->inputFP(), d->context(), sigma, sigma, rrect, rrect);
}
#endif