sky/engine/platform/graphics/filters/FELighting.h

/*
 * 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.
 */

#ifndef SKY_ENGINE_PLATFORM_GRAPHICS_FILTERS_FELIGHTING_H_
#define SKY_ENGINE_PLATFORM_GRAPHICS_FILTERS_FELIGHTING_H_

#include "sky/engine/platform/graphics/Color.h"
#include "sky/engine/platform/graphics/filters/Filter.h"
#include "sky/engine/platform/graphics/filters/FilterEffect.h"
#include "sky/engine/platform/graphics/filters/LightSource.h"
#include "sky/engine/platform/graphics/filters/PointLightSource.h"
#include "sky/engine/platform/graphics/filters/SpotLightSource.h"
#include "sky/engine/wtf/Uint8ClampedArray.h"

// Common base class for FEDiffuseLighting and FESpecularLighting

namespace blink {

class PLATFORM_EXPORT FELighting : public FilterEffect {
public:
    virtual PassRefPtr<SkImageFilter> createImageFilter(SkiaImageFilterBuilder*) override;

protected:
    static const int s_minimalRectDimension = 100 * 100; // Empirical data limit for parallel jobs

    enum LightingType {
        DiffuseLighting,
        SpecularLighting
    };

    struct LightingData {
        // This structure contains only read-only (SMP safe) data
        Uint8ClampedArray* pixels;
        float surfaceScale;
        int widthMultipliedByPixelSize;
        int widthDecreasedByOne;
        int heightDecreasedByOne;
        const LightSource* lightSource;

        inline void topLeft(int offset, IntPoint& normalVector);
        inline void topRow(int offset, IntPoint& normalVector);
        inline void topRight(int offset, IntPoint& normalVector);
        inline void leftColumn(int offset, IntPoint& normalVector);
        inline void interior(int offset, IntPoint& normalVector);
        inline void rightColumn(int offset, IntPoint& normalVector);
        inline void bottomLeft(int offset, IntPoint& normalVector);
        inline void bottomRow(int offset, IntPoint& normalVector);
        inline void bottomRight(int offset, IntPoint& normalVector);
    };

    template<typename Type>
    friend class ParallelJobs;

    struct PlatformApplyGenericParameters {
        FELighting* filter;
        LightingData data;
        LightSource::PaintingData paintingData;
        int yStart;
        int yEnd;
    };

    virtual FloatRect mapPaintRect(const FloatRect&, bool forward = true) override final;
    virtual bool affectsTransparentPixels() override { return true; }

    static void platformApplyGenericWorker(PlatformApplyGenericParameters*);

    FELighting(Filter*, LightingType, const Color&, float, float, float, float, float, float, PassRefPtr<LightSource>);

    bool drawLighting(Uint8ClampedArray*, int, int);
    inline void inlineSetPixel(int offset, LightingData&, LightSource::PaintingData&,
                               int lightX, int lightY, float factorX, float factorY, IntPoint& normalVector);

    // Not worth to inline every occurence of setPixel.
    void setPixel(int offset, LightingData&, LightSource::PaintingData&,
                  int lightX, int lightY, float factorX, float factorY, IntPoint& normalVector);

    inline void platformApply(LightingData&, LightSource::PaintingData&);

    inline void platformApplyGenericPaint(LightingData&, LightSource::PaintingData&, int startX, int startY);
    inline void platformApplyGeneric(LightingData&, LightSource::PaintingData&);

    LightingType m_lightingType;
    RefPtr<LightSource> m_lightSource;

    Color m_lightingColor;
    float m_surfaceScale;
    float m_diffuseConstant;
    float m_specularConstant;
    float m_specularExponent;
    float m_kernelUnitLengthX;
    float m_kernelUnitLengthY;

private:
    virtual void applySoftware() override;

    void getTransform(FloatPoint3D* scale, FloatSize* offset) const;
};

} // namespace blink

#endif  // SKY_ENGINE_PLATFORM_GRAPHICS_FILTERS_FELIGHTING_H_