root/Source/platform/graphics/filters/FELighting.cpp

DEFINITIONS

1. m_kernelUnitLengthY
2. mapPaintRect
3. topLeft
4. topRow
5. topRight
6. leftColumn
7. interior
8. rightColumn
9. bottomLeft
10. bottomRow
11. bottomRight
12. inlineSetPixel
13. setPixel
14. platformApplyGenericPaint
15. platformApplyGenericWorker
16. platformApplyGeneric
17. platformApply
18. getTransform
19. drawLighting
20. applySoftware
21. createImageFilter

/*
 * Copyright (C) 2010 University of Szeged
 * Copyright (C) 2010 Zoltan Herczeg
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "platform/graphics/filters/FELighting.h"

#include "SkLightingImageFilter.h"
#include "platform/graphics/cpu/arm/filters/FELightingNEON.h"
#include "platform/graphics/filters/DistantLightSource.h"
#include "platform/graphics/filters/ParallelJobs.h"
#include "platform/graphics/filters/SkiaImageFilterBuilder.h"
#include "platform/graphics/skia/NativeImageSkia.h"

namespace WebCore {

FELighting::FELighting(Filter* filter, LightingType lightingType, const Color& lightingColor, float surfaceScale,
    float diffuseConstant, float specularConstant, float specularExponent,
    float kernelUnitLengthX, float kernelUnitLengthY, PassRefPtr<LightSource> lightSource)
    : FilterEffect(filter)
    , m_lightingType(lightingType)
    , m_lightSource(lightSource)
    , m_lightingColor(lightingColor)
    , m_surfaceScale(surfaceScale)
    , m_diffuseConstant(std::max(diffuseConstant, 0.0f))
    , m_specularConstant(std::max(specularConstant, 0.0f))
    , m_specularExponent(std::min(std::max(specularExponent, 1.0f), 128.0f))
    , m_kernelUnitLengthX(kernelUnitLengthX)
    , m_kernelUnitLengthY(kernelUnitLengthY)
{
}

FloatRect FELighting::mapPaintRect(const FloatRect& rect, bool)
{
    FloatRect result = rect;
    // The areas affected need to be a pixel bigger to accommodate the Sobel kernel.
    result.inflate(1);
    return result;
}

const static int cPixelSize = 4;
const static int cAlphaChannelOffset = 3;
const static unsigned char cOpaqueAlpha = static_cast<unsigned char>(0xff);
const static float cFactor1div2 = -1 / 2.f;
const static float cFactor1div3 = -1 / 3.f;
const static float cFactor1div4 = -1 / 4.f;
const static float cFactor2div3 = -2 / 3.f;

// << 1 is signed multiply by 2
inline void FELighting::LightingData::topLeft(int offset, IntPoint& normalVector)
{
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int right = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset += widthMultipliedByPixelSize;
    int bottom = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int bottomRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    normalVector.setX(-(center << 1) + (right << 1) - bottom + bottomRight);
    normalVector.setY(-(center << 1) - right + (bottom << 1) + bottomRight);
}

inline void FELighting::LightingData::topRow(int offset, IntPoint& normalVector)
{
    int left = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int right = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset += widthMultipliedByPixelSize;
    int bottomLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int bottom = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int bottomRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    normalVector.setX(-(left << 1) + (right << 1) - bottomLeft + bottomRight);
    normalVector.setY(-left - (center << 1) - right + bottomLeft + (bottom << 1) + bottomRight);
}

inline void FELighting::LightingData::topRight(int offset, IntPoint& normalVector)
{
    int left = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    offset += widthMultipliedByPixelSize;
    int bottomLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int bottom = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    normalVector.setX(-(left << 1) + (center << 1) - bottomLeft + bottom);
    normalVector.setY(-left - (center << 1) + bottomLeft + (bottom << 1));
}

inline void FELighting::LightingData::leftColumn(int offset, IntPoint& normalVector)
{
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int right = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset -= widthMultipliedByPixelSize;
    int top = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int topRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset += widthMultipliedByPixelSize << 1;
    int bottom = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int bottomRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    normalVector.setX(-top + topRight - (center << 1) + (right << 1) - bottom + bottomRight);
    normalVector.setY(-(top << 1) - topRight + (bottom << 1) + bottomRight);
}

inline void FELighting::LightingData::interior(int offset, IntPoint& normalVector)
{
    int left = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int right = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset -= widthMultipliedByPixelSize;
    int topLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int top = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int topRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset += widthMultipliedByPixelSize << 1;
    int bottomLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int bottom = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int bottomRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    normalVector.setX(-topLeft + topRight - (left << 1) + (right << 1) - bottomLeft + bottomRight);
    normalVector.setY(-topLeft - (top << 1) - topRight + bottomLeft + (bottom << 1) + bottomRight);
}

inline void FELighting::LightingData::rightColumn(int offset, IntPoint& normalVector)
{
    int left = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    offset -= widthMultipliedByPixelSize;
    int topLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int top = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    offset += widthMultipliedByPixelSize << 1;
    int bottomLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int bottom = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    normalVector.setX(-topLeft + top - (left << 1) + (center << 1) - bottomLeft + bottom);
    normalVector.setY(-topLeft - (top << 1) + bottomLeft + (bottom << 1));
}

inline void FELighting::LightingData::bottomLeft(int offset, IntPoint& normalVector)
{
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int right = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset -= widthMultipliedByPixelSize;
    int top = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int topRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    normalVector.setX(-top + topRight - (center << 1) + (right << 1));
    normalVector.setY(-(top << 1) - topRight + (center << 1) + right);
}

inline void FELighting::LightingData::bottomRow(int offset, IntPoint& normalVector)
{
    int left = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int right = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    offset -= widthMultipliedByPixelSize;
    int topLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int top = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    int topRight = static_cast<int>(pixels->item(offset + cPixelSize + cAlphaChannelOffset));
    normalVector.setX(-topLeft + topRight - (left << 1) + (right << 1));
    normalVector.setY(-topLeft - (top << 1) - topRight + left + (center << 1) + right);
}

inline void FELighting::LightingData::bottomRight(int offset, IntPoint& normalVector)
{
    int left = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int center = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    offset -= widthMultipliedByPixelSize;
    int topLeft = static_cast<int>(pixels->item(offset - cPixelSize + cAlphaChannelOffset));
    int top = static_cast<int>(pixels->item(offset + cAlphaChannelOffset));
    normalVector.setX(-topLeft + top - (left << 1) + (center << 1));
    normalVector.setY(-topLeft - (top << 1) + left + (center << 1));
}

inline void FELighting::inlineSetPixel(int offset, LightingData& data, LightSource::PaintingData& paintingData,
                                       int lightX, int lightY, float factorX, float factorY, IntPoint& normal2DVector)
{
    data.lightSource->updatePaintingData(paintingData, lightX, lightY, static_cast<float>(data.pixels->item(offset + cAlphaChannelOffset)) * data.surfaceScale);

    float lightStrength;
    if (!normal2DVector.x() && !normal2DVector.y()) {
        // Normal vector is (0, 0, 1). This is a quite frequent case.
        if (m_lightingType == FELighting::DiffuseLighting) {
            lightStrength = m_diffuseConstant * paintingData.lightVector.z() / paintingData.lightVectorLength;
        } else {
            FloatPoint3D halfwayVector = paintingData.lightVector;
            halfwayVector.setZ(halfwayVector.z() + paintingData.lightVectorLength);
            float halfwayVectorLength = halfwayVector.length();
            if (m_specularExponent == 1)
                lightStrength = m_specularConstant * halfwayVector.z() / halfwayVectorLength;
            else
                lightStrength = m_specularConstant * powf(halfwayVector.z() / halfwayVectorLength, m_specularExponent);
        }
    } else {
        FloatPoint3D normalVector;
        normalVector.setX(factorX * static_cast<float>(normal2DVector.x()) * data.surfaceScale);
        normalVector.setY(factorY * static_cast<float>(normal2DVector.y()) * data.surfaceScale);
        normalVector.setZ(1);
        float normalVectorLength = normalVector.length();

        if (m_lightingType == FELighting::DiffuseLighting) {
            lightStrength = m_diffuseConstant * (normalVector * paintingData.lightVector) / (normalVectorLength * paintingData.lightVectorLength);
        } else {
            FloatPoint3D halfwayVector = paintingData.lightVector;
            halfwayVector.setZ(halfwayVector.z() + paintingData.lightVectorLength);
            float halfwayVectorLength = halfwayVector.length();
            if (m_specularExponent == 1)
                lightStrength = m_specularConstant * (normalVector * halfwayVector) / (normalVectorLength * halfwayVectorLength);
            else
                lightStrength = m_specularConstant * powf((normalVector * halfwayVector) / (normalVectorLength * halfwayVectorLength), m_specularExponent);
        }
    }

    if (lightStrength > 1)
        lightStrength = 1;
    if (lightStrength < 0)
        lightStrength = 0;

    data.pixels->set(offset, static_cast<unsigned char>(lightStrength * paintingData.colorVector.x()));
    data.pixels->set(offset + 1, static_cast<unsigned char>(lightStrength * paintingData.colorVector.y()));
    data.pixels->set(offset + 2, static_cast<unsigned char>(lightStrength * paintingData.colorVector.z()));
}

void FELighting::setPixel(int offset, LightingData& data, LightSource::PaintingData& paintingData,
                          int lightX, int lightY, float factorX, float factorY, IntPoint& normalVector)
{
    inlineSetPixel(offset, data, paintingData, lightX, lightY, factorX, factorY, normalVector);
}

inline void FELighting::platformApplyGenericPaint(LightingData& data, LightSource::PaintingData& paintingData, int startY, int endY)
{
    IntPoint normalVector;
    int offset = 0;

    for (int y = startY; y < endY; ++y) {
        offset = y * data.widthMultipliedByPixelSize + cPixelSize;
        for (int x = 1; x < data.widthDecreasedByOne; ++x, offset += cPixelSize) {
            data.interior(offset, normalVector);
            inlineSetPixel(offset, data, paintingData, x, y, cFactor1div4, cFactor1div4, normalVector);
        }
    }
}

void FELighting::platformApplyGenericWorker(PlatformApplyGenericParameters* parameters)
{
    parameters->filter->platformApplyGenericPaint(parameters->data, parameters->paintingData, parameters->yStart, parameters->yEnd);
}

inline void FELighting::platformApplyGeneric(LightingData& data, LightSource::PaintingData& paintingData)
{
    int optimalThreadNumber = ((data.widthDecreasedByOne - 1) * (data.heightDecreasedByOne - 1)) / s_minimalRectDimension;
    if (optimalThreadNumber > 1) {
        // Initialize parallel jobs
        ParallelJobs<PlatformApplyGenericParameters> parallelJobs(&platformApplyGenericWorker, optimalThreadNumber);

        // Fill the parameter array
        int job = parallelJobs.numberOfJobs();
        if (job > 1) {
            // Split the job into "yStep"-sized jobs but there a few jobs that need to be slightly larger since
            // yStep * jobs < total size. These extras are handled by the remainder "jobsWithExtra".
            const int yStep = (data.heightDecreasedByOne - 1) / job;
            const int jobsWithExtra = (data.heightDecreasedByOne - 1) % job;

            int yStart = 1;
            for (--job; job >= 0; --job) {
                PlatformApplyGenericParameters& params = parallelJobs.parameter(job);
                params.filter = this;
                params.data = data;
                params.paintingData = paintingData;
                params.yStart = yStart;
                yStart += job < jobsWithExtra ? yStep + 1 : yStep;
                params.yEnd = yStart;
            }
            parallelJobs.execute();
            return;
        }
        // Fallback to single threaded mode.
    }

    platformApplyGenericPaint(data, paintingData, 1, data.heightDecreasedByOne);
}

inline void FELighting::platformApply(LightingData& data, LightSource::PaintingData& paintingData)
{
    // The selection here eventually should happen dynamically on some platforms.
#if CPU(ARM_NEON) && CPU(ARM_TRADITIONAL) && COMPILER(GCC)
    platformApplyNeon(data, paintingData);
#else
    platformApplyGeneric(data, paintingData);
#endif
}

void FELighting::getTransform(FloatPoint3D* scale, FloatSize* offset) const
{
    FloatRect initialEffectRect = effectBoundaries();
    FloatRect absoluteEffectRect = filter()->mapLocalRectToAbsoluteRect(initialEffectRect);
    FloatPoint absoluteLocation(absolutePaintRect().location());
    FloatSize positionOffset(absoluteLocation - absoluteEffectRect.location());
    offset->setWidth(positionOffset.width());
    offset->setHeight(positionOffset.height());
    scale->setX(initialEffectRect.width() > 0.0f && initialEffectRect.width() > 0.0f ? absoluteEffectRect.width() / initialEffectRect.width() : 1.0f);
    scale->setY(initialEffectRect.height() > 0.0f && initialEffectRect.height() > 0.0f ? absoluteEffectRect.height() / initialEffectRect.height() : 1.0f);
    // X and Y scale should be the same, but, if not, do a best effort by averaging the 2 for Z scale
    scale->setZ(0.5f * (scale->x() + scale->y()));
}

bool FELighting::drawLighting(Uint8ClampedArray* pixels, int width, int height)
{
    LightSource::PaintingData paintingData;
    LightingData data;

    if (!m_lightSource)
        return false;

    // FIXME: do something if width or height (or both) is 1 pixel.
    // The W3 spec does not define this case. Now the filter just returns.
    if (width <= 2 || height <= 2)
        return false;

    data.pixels = pixels;
    data.surfaceScale = m_surfaceScale / 255.0f;
    data.widthMultipliedByPixelSize = width * cPixelSize;
    data.widthDecreasedByOne = width - 1;
    data.heightDecreasedByOne = height - 1;
    FloatPoint3D worldScale;
    FloatSize originOffset;
    getTransform(&worldScale, &originOffset);
    RefPtr<LightSource> lightSource = m_lightSource->create(worldScale, originOffset);
    data.lightSource = lightSource.get();
    Color lightColor = adaptColorToOperatingColorSpace(m_lightingColor);
    paintingData.colorVector = FloatPoint3D(lightColor.red(), lightColor.green(), lightColor.blue());
    data.lightSource->initPaintingData(paintingData);

    // Top/Left corner.
    IntPoint normalVector;
    int offset = 0;
    data.topLeft(offset, normalVector);
    setPixel(offset, data, paintingData, 0, 0, cFactor2div3, cFactor2div3, normalVector);

    // Top/Right pixel.
    offset = data.widthMultipliedByPixelSize - cPixelSize;
    data.topRight(offset, normalVector);
    setPixel(offset, data, paintingData, data.widthDecreasedByOne, 0, cFactor2div3, cFactor2div3, normalVector);

    // Bottom/Left pixel.
    offset = data.heightDecreasedByOne * data.widthMultipliedByPixelSize;
    data.bottomLeft(offset, normalVector);
    setPixel(offset, data, paintingData, 0, data.heightDecreasedByOne, cFactor2div3, cFactor2div3, normalVector);

    // Bottom/Right pixel.
    offset = height * data.widthMultipliedByPixelSize - cPixelSize;
    data.bottomRight(offset, normalVector);
    setPixel(offset, data, paintingData, data.widthDecreasedByOne, data.heightDecreasedByOne, cFactor2div3, cFactor2div3, normalVector);

    if (width >= 3) {
        // Top row.
        offset = cPixelSize;
        for (int x = 1; x < data.widthDecreasedByOne; ++x, offset += cPixelSize) {
            data.topRow(offset, normalVector);
            inlineSetPixel(offset, data, paintingData, x, 0, cFactor1div3, cFactor1div2, normalVector);
        }
        // Bottom row.
        offset = data.heightDecreasedByOne * data.widthMultipliedByPixelSize + cPixelSize;
        for (int x = 1; x < data.widthDecreasedByOne; ++x, offset += cPixelSize) {
            data.bottomRow(offset, normalVector);
            inlineSetPixel(offset, data, paintingData, x, data.heightDecreasedByOne, cFactor1div3, cFactor1div2, normalVector);
        }
    }

    if (height >= 3) {
        // Left column.
        offset = data.widthMultipliedByPixelSize;
        for (int y = 1; y < data.heightDecreasedByOne; ++y, offset += data.widthMultipliedByPixelSize) {
            data.leftColumn(offset, normalVector);
            inlineSetPixel(offset, data, paintingData, 0, y, cFactor1div2, cFactor1div3, normalVector);
        }
        // Right column.
        offset = (data.widthMultipliedByPixelSize << 1) - cPixelSize;
        for (int y = 1; y < data.heightDecreasedByOne; ++y, offset += data.widthMultipliedByPixelSize) {
            data.rightColumn(offset, normalVector);
            inlineSetPixel(offset, data, paintingData, data.widthDecreasedByOne, y, cFactor1div2, cFactor1div3, normalVector);
        }
    }

    if (width >= 3 && height >= 3) {
        // Interior pixels.
        platformApply(data, paintingData);
    }

    int lastPixel = data.widthMultipliedByPixelSize * height;
    if (m_lightingType == DiffuseLighting) {
        for (int i = cAlphaChannelOffset; i < lastPixel; i += cPixelSize)
            data.pixels->set(i, cOpaqueAlpha);
    } else {
        for (int i = 0; i < lastPixel; i += cPixelSize) {
            unsigned char a1 = data.pixels->item(i);
            unsigned char a2 = data.pixels->item(i + 1);
            unsigned char a3 = data.pixels->item(i + 2);
            // alpha set to set to max(a1, a2, a3)
            data.pixels->set(i + 3, a1 >= a2 ? (a1 >= a3 ? a1 : a3) : (a2 >= a3 ? a2 : a3));
        }
    }

    return true;
}

void FELighting::applySoftware()
{
    FilterEffect* in = inputEffect(0);

    Uint8ClampedArray* srcPixelArray = createPremultipliedImageResult();
    if (!srcPixelArray)
        return;

    setIsAlphaImage(false);

    IntRect effectDrawingRect = requestedRegionOfInputImageData(in->absolutePaintRect());
    in->copyPremultipliedImage(srcPixelArray, effectDrawingRect);

    // FIXME: support kernelUnitLengths other than (1,1). The issue here is that the W3
    // standard has no test case for them, and other browsers (like Firefox) has strange
    // output for various kernelUnitLengths, and I am not sure they are reliable.
    // Anyway, feConvolveMatrix should also use the implementation

    IntSize absolutePaintSize = absolutePaintRect().size();
    drawLighting(srcPixelArray, absolutePaintSize.width(), absolutePaintSize.height());
}

PassRefPtr<SkImageFilter> FELighting::createImageFilter(SkiaImageFilterBuilder* builder)
{
    SkImageFilter::CropRect rect = getCropRect(builder ? builder->cropOffset() : FloatSize());
    Color lightColor = adaptColorToOperatingColorSpace(m_lightingColor);
    RefPtr<SkImageFilter> input(builder ? builder->build(inputEffect(0), operatingColorSpace()) : nullptr);
    switch (m_lightSource->type()) {
    case LS_DISTANT: {
        DistantLightSource* distantLightSource = static_cast<DistantLightSource*>(m_lightSource.get());
        float azimuthRad = deg2rad(distantLightSource->azimuth());
        float elevationRad = deg2rad(distantLightSource->elevation());
        SkPoint3 direction(cosf(azimuthRad) * cosf(elevationRad),
                           sinf(azimuthRad) * cosf(elevationRad),
                           sinf(elevationRad));
        if (m_specularConstant > 0)
            return adoptRef(SkLightingImageFilter::CreateDistantLitSpecular(direction, lightColor.rgb(), m_surfaceScale, m_specularConstant, m_specularExponent, input.get(), &rect));
        return adoptRef(SkLightingImageFilter::CreateDistantLitDiffuse(direction, lightColor.rgb(), m_surfaceScale, m_diffuseConstant, input.get(), &rect));
    }
    case LS_POINT: {
        PointLightSource* pointLightSource = static_cast<PointLightSource*>(m_lightSource.get());
        FloatPoint3D position = pointLightSource->position();
        SkPoint3 skPosition(position.x(), position.y(), position.z());
        if (m_specularConstant > 0)
            return adoptRef(SkLightingImageFilter::CreatePointLitSpecular(skPosition, lightColor.rgb(), m_surfaceScale, m_specularConstant, m_specularExponent, input.get(), &rect));
        return adoptRef(SkLightingImageFilter::CreatePointLitDiffuse(skPosition, lightColor.rgb(), m_surfaceScale, m_diffuseConstant, input.get(), &rect));
    }
    case LS_SPOT: {
        SpotLightSource* spotLightSource = static_cast<SpotLightSource*>(m_lightSource.get());
        SkPoint3 location(spotLightSource->position().x(), spotLightSource->position().y(), spotLightSource->position().z());
        SkPoint3 target(spotLightSource->direction().x(), spotLightSource->direction().y(), spotLightSource->direction().z());
        float specularExponent = spotLightSource->specularExponent();
        float limitingConeAngle = spotLightSource->limitingConeAngle();
        if (!limitingConeAngle || limitingConeAngle > 90 || limitingConeAngle < -90)
            limitingConeAngle = 90;
        if (m_specularConstant > 0)
            return adoptRef(SkLightingImageFilter::CreateSpotLitSpecular(location, target, specularExponent, limitingConeAngle, lightColor.rgb(), m_surfaceScale, m_specularConstant, m_specularExponent, input.get(), &rect));
        return adoptRef(SkLightingImageFilter::CreateSpotLitDiffuse(location, target, specularExponent, limitingConeAngle, lightColor.rgb(), m_surfaceScale, m_diffuseConstant, input.get(), &rect));
    }
    default:
        ASSERT_NOT_REACHED();
        return nullptr;
    }
}

} // namespace WebCore