sky/engine/platform/graphics/filters/FEGaussianBlur.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) 2013 Google 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.
 */

#ifndef SKY_ENGINE_PLATFORM_GRAPHICS_FILTERS_FEGAUSSIANBLUR_H_
#define SKY_ENGINE_PLATFORM_GRAPHICS_FILTERS_FEGAUSSIANBLUR_H_

#include "sky/engine/platform/graphics/filters/Filter.h"
#include "sky/engine/platform/graphics/filters/FilterEffect.h"

namespace blink {

class PLATFORM_EXPORT FEGaussianBlur : public FilterEffect {
public:
    static PassRefPtr<FEGaussianBlur> create(Filter*, float, float);

    float stdDeviationX() const;
    void setStdDeviationX(float);

    float stdDeviationY() const;
    void setStdDeviationY(float);

    virtual FloatRect mapRect(const FloatRect&, bool forward = true) override final;
    virtual FloatRect determineAbsolutePaintRect(const FloatRect& requestedRect) override;
    static IntSize calculateKernelSize(Filter*, const FloatPoint& std);
    static IntSize calculateUnscaledKernelSize(const FloatPoint& std);

    virtual TextStream& externalRepresentation(TextStream&, int indention) const override;

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

    template<typename Type>
    friend class ParallelJobs;

    struct PlatformApplyParameters {
        FEGaussianBlur* filter;
        RefPtr<Uint8ClampedArray> srcPixelArray;
        RefPtr<Uint8ClampedArray> dstPixelArray;
        int width;
        int height;
        unsigned kernelSizeX;
        unsigned kernelSizeY;
    };

    FEGaussianBlur(Filter*, float, float);

    virtual void applySoftware() override;

    virtual PassRefPtr<SkImageFilter> createImageFilter(SkiaImageFilterBuilder*) override;

    float m_stdX;
    float m_stdY;
};

} // namespace blink

#endif  // SKY_ENGINE_PLATFORM_GRAPHICS_FILTERS_FEGAUSSIANBLUR_H_