Source/WebCore/platform/graphics/filters/FilterImage.h

/*
 * Copyright (C) 2021 Apple 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 APPLE INC. ``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 APPLE INC. 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
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "ImageBuffer.h"
#include "PixelBuffer.h"
#include <JavaScriptCore/Forward.h>
#include <wtf/RefCounted.h>
#include <wtf/Vector.h>

namespace WebCore {

class ImageBuffer;
class PixelBuffer;

class FilterImage : public RefCounted<FilterImage> {
public:
    static RefPtr<FilterImage> create(const FloatRect& primitiveSubregion, const IntRect& absoluteImageRect, bool isAlphaImage, RenderingMode, const DestinationColorSpace&);

    FloatRect primitiveSubregion() const { return m_primitiveSubregion; }
    IntRect absoluteImageRect() const { return m_absoluteImageRect; }

    bool isAlphaImage() const { return m_isAlphaImage; }
    RenderingMode renderingMode() const { return m_renderingMode; }
    const DestinationColorSpace& colorSpace() const { return m_colorSpace; }

    ImageBuffer* imageBuffer();
    PixelBuffer* pixelBuffer(AlphaPremultiplication);

    std::optional<PixelBuffer> getPixelBuffer(AlphaPremultiplication, const IntRect& sourceRect, std::optional<DestinationColorSpace> = std::nullopt);
    void copyPixelBuffer(PixelBuffer& destinationPixelBuffer, const IntRect& sourceRect);

    void correctPremultipliedPixelBuffer();
    void transformToColorSpace(const DestinationColorSpace&);

private:
    FilterImage(const FloatRect& primitiveSubregion, const IntRect& absoluteImageRect, bool isAlphaImage, RenderingMode, const DestinationColorSpace&);

    std::optional<PixelBuffer>& pixelBufferSlot(AlphaPremultiplication);

    bool requiresPixelBufferColorSpaceConversion(std::optional<DestinationColorSpace>) const;

    FloatRect m_primitiveSubregion;
    IntRect m_absoluteImageRect;

    bool m_isAlphaImage { false };
    RenderingMode m_renderingMode;
    DestinationColorSpace m_colorSpace;

    RefPtr<ImageBuffer> m_imageBuffer;
    std::optional<PixelBuffer> m_unpremultipliedPixelBuffer;
    std::optional<PixelBuffer> m_premultipliedPixelBuffer;
};

} // namespace WebCore