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

/*
 * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org>
 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org>
 * Copyright (C) 2005 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2021-2022 Apple Inc.  All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#pragma once

#include "FilterEffect.h"
#include <wtf/text/WTFString.h>

namespace WebCore {

enum CompositeOperationType {
    FECOMPOSITE_OPERATOR_UNKNOWN    = 0, 
    FECOMPOSITE_OPERATOR_OVER       = 1,
    FECOMPOSITE_OPERATOR_IN         = 2,
    FECOMPOSITE_OPERATOR_OUT        = 3,
    FECOMPOSITE_OPERATOR_ATOP       = 4,
    FECOMPOSITE_OPERATOR_XOR        = 5,
    FECOMPOSITE_OPERATOR_ARITHMETIC = 6,
    FECOMPOSITE_OPERATOR_LIGHTER    = 7
};

class FEComposite : public FilterEffect {
public:
    WEBCORE_EXPORT static Ref<FEComposite> create(const CompositeOperationType&, float k1, float k2, float k3, float k4);

    CompositeOperationType operation() const { return m_type; }
    bool setOperation(CompositeOperationType);

    float k1() const { return m_k1; }
    bool setK1(float);

    float k2() const { return m_k2; }
    bool setK2(float);

    float k3() const { return m_k3; }
    bool setK3(float);

    float k4() const { return m_k4; }
    bool setK4(float);

    template<class Encoder> void encode(Encoder&) const;
    template<class Decoder> static std::optional<Ref<FEComposite>> decode(Decoder&);

private:
    FEComposite(const CompositeOperationType&, float k1, float k2, float k3, float k4);

    unsigned numberOfEffectInputs() const override { return 2; }

    FloatRect calculateImageRect(const Filter&, const FilterImageVector& inputs, const FloatRect& primitiveSubregion) const override;

    bool resultIsValidPremultiplied() const override { return m_type != FECOMPOSITE_OPERATOR_ARITHMETIC; }

    std::unique_ptr<FilterEffectApplier> createSoftwareApplier() const override;

    WTF::TextStream& externalRepresentation(WTF::TextStream&, FilterRepresentation) const override;

#if HAVE(ARM_NEON_INTRINSICS)
    template <int b1, int b4>
    static inline void computeArithmeticPixelsNeon(const uint8_t* source, uint8_t* destination, unsigned pixelArrayLength, float k1, float k2, float k3, float k4);

    static inline void platformArithmeticNeon(const uint8_t* source, uint8_t* destination, unsigned pixelArrayLength, float k1, float k2, float k3, float k4);
#endif

    CompositeOperationType m_type;
    float m_k1;
    float m_k2;
    float m_k3;
    float m_k4;
};

template<class Encoder>
void FEComposite::encode(Encoder& encoder) const
{
    encoder << m_type;
    encoder << m_k1;
    encoder << m_k2;
    encoder << m_k3;
    encoder << m_k4;
}

template<class Decoder>
std::optional<Ref<FEComposite>> FEComposite::decode(Decoder& decoder)
{
    std::optional<CompositeOperationType> type;
    decoder >> type;
    if (!type)
        return std::nullopt;

    std::optional<float> k1;
    decoder >> k1;
    if (!k1)
        return std::nullopt;

    std::optional<float> k2;
    decoder >> k2;
    if (!k2)
        return std::nullopt;

    std::optional<float> k3;
    decoder >> k3;
    if (!k3)
        return std::nullopt;

    std::optional<float> k4;
    decoder >> k4;
    if (!k4)
        return std::nullopt;

    return FEComposite::create(*type, *k1, *k2, *k3, *k4);
}

} // namespace WebCore

namespace WTF {

template<> struct EnumTraits<WebCore::CompositeOperationType> {
    using values = EnumValues<
        WebCore::CompositeOperationType,

        WebCore::FECOMPOSITE_OPERATOR_UNKNOWN,
        WebCore::FECOMPOSITE_OPERATOR_OVER,
        WebCore::FECOMPOSITE_OPERATOR_IN,
        WebCore::FECOMPOSITE_OPERATOR_OUT,
        WebCore::FECOMPOSITE_OPERATOR_ATOP,
        WebCore::FECOMPOSITE_OPERATOR_XOR,
        WebCore::FECOMPOSITE_OPERATOR_ARITHMETIC,
        WebCore::FECOMPOSITE_OPERATOR_LIGHTER
    >;
};

} // namespace WTF

SPECIALIZE_TYPE_TRAITS_FILTER_EFFECT(FEComposite)