/*
* This program source code file is part of KICAD, a free EDA CAD application.
*
* Copyright (C) 2016 Kicad Developers, see change_log.txt for contributors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
*/

#ifndef OPENGL_ANTIALIASING_H__
#define OPENGL_ANTIALIASING_H__

#include <memory>
#include <gal/opengl/shader.h>
#include <math/vector2d.h>

namespace KIGFX {

    class OPENGL_COMPOSITOR;

    class OPENGL_PRESENTOR
    {
    public:
        virtual ~OPENGL_PRESENTOR()
        {
        }

        virtual bool Init() = 0;
        virtual unsigned int CreateBuffer() = 0;

        virtual VECTOR2U GetInternalBufferSize() = 0;
        virtual void OnLostBuffers() = 0;

        virtual void Begin() = 0;
        virtual void DrawBuffer( GLuint aBuffer ) = 0;
        virtual void Present() = 0;
    };


    class ANTIALIASING_NONE : public OPENGL_PRESENTOR
    {
    public:
        ANTIALIASING_NONE( OPENGL_COMPOSITOR* aCompositor );

        bool Init() override;
        unsigned int CreateBuffer() override;

        VECTOR2U GetInternalBufferSize() override;
        void OnLostBuffers() override;

        void Begin() override;
        void DrawBuffer( GLuint aBuffer ) override;
        void Present() override;

    private:
        OPENGL_COMPOSITOR* compositor;
    };

    enum class SUPERSAMPLING_MODE {
        X2,
        X4
    };


    class ANTIALIASING_SUPERSAMPLING : public OPENGL_PRESENTOR
    {
    public:
        ANTIALIASING_SUPERSAMPLING( OPENGL_COMPOSITOR* aCompositor, SUPERSAMPLING_MODE aMode );

        bool Init() override;
        unsigned int CreateBuffer() override;

        VECTOR2U GetInternalBufferSize() override;
        void OnLostBuffers() override;

        void Begin() override;
        void DrawBuffer( GLuint ) override;
        void Present() override;

    private:
        OPENGL_COMPOSITOR* compositor;
        SUPERSAMPLING_MODE mode;

        unsigned int ssaaMainBuffer;
        bool areBuffersCreated;

        bool areShadersCreated;
        std::unique_ptr<SHADER> x4_shader;
    };

    enum class SMAA_QUALITY {
        HIGH,
        ULTRA
    };

    class ANTIALIASING_SMAA : public OPENGL_PRESENTOR
    {
    public:
        ANTIALIASING_SMAA( OPENGL_COMPOSITOR* aCompositor, SMAA_QUALITY aQuality );

        bool Init() override;
        unsigned int CreateBuffer () override;

        VECTOR2U GetInternalBufferSize() override;
        void OnLostBuffers() override;

        void Begin() override;
        void DrawBuffer( GLuint buffer ) override;
        void Present() override;

    private:
        void loadShaders();
        void updateUniforms();

        bool areBuffersInitialized;

        unsigned int smaaBaseBuffer;    // base + overlay temporary
        unsigned int smaaEdgesBuffer;
        unsigned int smaaBlendBuffer;

        // smaa shader lookup textures
        unsigned int smaaAreaTex;
        unsigned int smaaSearchTex;

        bool shadersLoaded;

        std::unique_ptr<SHADER> pass_1_shader;
        GLint pass_1_metrics;

        std::unique_ptr<SHADER> pass_2_shader;
        GLint pass_2_metrics;

        std::unique_ptr<SHADER> pass_3_shader;
        GLint pass_3_metrics;

        SMAA_QUALITY quality;
        OPENGL_COMPOSITOR* compositor;
    };

}

#endif