ChangeLog

2017-12-30  Simon Fraser  <simon.fraser@apple.com>

        SVG lighting colors need to be converted into linearSRGB

        https://bugs.webkit.org/show_bug.cgi?id=181196

        Reviewed by NOBODY (OOPS!).

        SVG filters, like feLighting, that poke values directly into buffers rather than going

        through CG like feFlood, need to convert colors into the operating color space. So add

        conversion functions to go between linear and sRGB colors, and use these in feLighting,

        and in ImageBuffer (which is only used for non-CG platforms).

        Tests: svg/filters/feSpotLight-color.svg

        * platform/graphics/ColorUtilities.cpp:

        (WebCore::linearToSRGBColorComponent):

        (WebCore::sRGBToLinearColorComponent):

        (WebCore::linearToSRGBColor):

        (WebCore::sRGBToLinearColor):

        * platform/graphics/ColorUtilities.h:

        * platform/graphics/ImageBuffer.cpp:

        (WebCore::ImageBuffer::transformColorSpace):

        * platform/graphics/filters/FELighting.cpp:

        (WebCore::FELighting::drawLighting):

2017-12-19  Jer Noble  <jer.noble@apple.com>

        Playing media elements which call "pause(); play()" will have the play promise rejected.

Source/WebCore/platform/graphics/ColorUtilities.cpp

#include "config.h"

#include "ColorUtilities.h"

#include "Color.h"

#include <wtf/MathExtras.h>

namespace WebCore {

ColorComponents::ColorComponents(const FloatComponents& floatComponents)

@@ColorComponents::ColorComponents(const FloatComponents& floatComponents)

    components[3] = clampedColorComponent(floatComponents.components[3]);

}

float linearToSRGBColorComponent(float c)

{

    if (c < 0.0031308)

        return 12.92 * c;

    return clampTo<float>(1.055 * powf(c, 1.0 / 2.4) - 0.055, 0, 1);

}

float sRGBToLinearColorComponent(float c)

{

    if (c <= 0.04045)

        return c / 12.92;

    return clampTo<float>(powf((c + 0.055) / 1.055, 2.4), 0, 1);

}

Color linearToSRGBColor(const Color& color)

{

    float r, g, b, a;

    color.getRGBA(r, g, b, a);

    r = linearToSRGBColorComponent(r);

    g = linearToSRGBColorComponent(g);

    b = linearToSRGBColorComponent(b);

    return Color(r, g, b, a);

}

Color sRGBToLinearColor(const Color& color)

{

    float r, g, b, a;

    color.getRGBA(r, g, b, a);

    r = sRGBToLinearColorComponent(r);

    g = sRGBToLinearColorComponent(g);

    b = sRGBToLinearColorComponent(b);

    return Color(r, g, b, a);

}

3980} // namespace WebCore

Source/WebCore/platform/graphics/ColorUtilities.h

#pragma once

28#include "Color.h"

#include <algorithm>

#include <math.h>

@@inline unsigned byteOffsetOfPixel(unsigned x, unsigned y, unsigned rowBytes)

    return x * bytesPerPixel + y * rowBytes;

}

// 0-1 components, result is clamped.

float linearToSRGBColorComponent(float);

float sRGBToLinearColorComponent(float);

Color linearToSRGBColor(const Color&);

Color sRGBToLinearColor(const Color&);

150158} // namespace WebCore

151159

Source/WebCore/platform/graphics/ImageBuffer.cpp

#include "config.h"

#include "ImageBuffer.h"

31#include "ColorUtilities.h"

#include "GraphicsContext.h"

#include "IntRect.h"

#include <wtf/MathExtras.h>

@@void ImageBuffer::transformColorSpace(ColorSpace srcColorSpace, ColorSpace dstCo

            std::array<uint8_t, 256> array;

            for (unsigned i = 0; i < 256; i++) {

                float color = i / 255.0f;

                color = (color <= 0.04045f ? color / 12.92f : pow((color + 0.055f) / 1.055f, 2.4f));

                color = std::max(0.0f, color);

                color = std::min(1.0f, color);

139 color = sRGBToLinearColorComponent(color);

                array[i] = static_cast<uint8_t>(round(color * 255));

            }

            return array;

@@void ImageBuffer::transformColorSpace(ColorSpace srcColorSpace, ColorSpace dstCo

            std::array<uint8_t, 256> array;

            for (unsigned i = 0; i < 256; i++) {

                float color = i / 255.0f;

                color = (powf(color, 1.0f / 2.4f) * 1.055f) - 0.055f;

                color = std::max(0.0f, color);

                color = std::min(1.0f, color);

150 color = linearToSRGBColorComponent(color);

                array[i] = static_cast<uint8_t>(round(color * 255));

            }

            return array;

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

#include "config.h"

#include "FELighting.h"

30#include "ColorUtilities.h"

#include "FELightingNEON.h"

#include <wtf/ParallelJobs.h>

@@bool FELighting::drawLighting(Uint8ClampedArray& pixels, int width, int height)

    data.widthMultipliedByPixelSize = width * cPixelSize;

    data.widthDecreasedByOne = width - 1;

    data.heightDecreasedByOne = height - 1;

400 paintingData.intialLightingData.colorVector = FloatPoint3D(m_lightingColor.red(), m_lightingColor.green(), m_lightingColor.blue());

    
    Color lightColor = (operatingColorSpace() == ColorSpaceLinearRGB) ? sRGBToLinearColor(m_lightingColor) : m_lightingColor;

    paintingData.intialLightingData.colorVector = FloatPoint3D(lightColor.red(), lightColor.green(), lightColor.blue());

    m_lightSource->initPaintingData(paintingData);

    // Top left.

LayoutTests/ChangeLog

2017-12-30  Simon Fraser  <simon.fraser@apple.com>

        SVG lighting colors need to be converted into linearSRGB

        https://bugs.webkit.org/show_bug.cgi?id=181196

        Reviewed by NOBODY (OOPS!).

        Compare a far-away green spotlight with a green flood. For some reason (a bug?)

        the bottom right pixel always has the wrong color, so mask it out.

        * svg/filters/feSpotLight-color-expected.svg: Added.

        * svg/filters/feSpotLight-color.svg: Added.

2017-12-19  Jer Noble  <jer.noble@apple.com>

        Playing media elements which call "pause(); play()" will have the play promise rejected.

LayoutTests/svg/filters/feSpotLight-color-expected.svg

<svg width="480px" height="600px" xmlns="http://www.w3.org/2000/svg">

<defs>

    <filter id="filter" filterUnits="objectBoundingBox" x="0" y="0" width="100%" height="100%">

        <feFlood flood-color="rgb(0, 128, 0)"/>

    </filter>

</defs>

<rect x="0" y="00" width="400" height="400" filter="url(#filter)"/>

<!-- Mask out a small difference in the bottom right corner -->

<rect x="385" y="385" width="20" height="20" fill="black"/>

</svg>

LayoutTests/svg/filters/feSpotLight-color.svg

<svg width="480px" height="600px" xmlns="http://www.w3.org/2000/svg">

<defs>

    <filter id="filter" filterUnits="objectBoundingBox" x="0" y="0" width="100%" height="100%">

        <feDiffuseLighting lighting-color="rgb(0, 128, 0)">

            <feSpotLight x="200" y="200" z="500000000" />

        </feDiffuseLighting>

    </filter>

</defs>

<rect x="0" y="0" width="400" height="400" filter="url(#filter)"/>

<!-- Mask out a small difference in the bottom right corner -->

<rect x="385" y="385" width="20" height="20" fill="black"/>

</svg>