//----------------------------------------------------------------------------
// Anti-Grain Geometry (AGG) - Version 2.5
// A high quality rendering engine for C++
// Copyright (C) 2002-2006 Maxim Shemanarev
// Contact: mcseem@antigrain.com
//          mcseemagg@yahoo.com
//          http://antigrain.com
// 
// AGG 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.
// 
// AGG 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 AGG; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
// MA 02110-1301, USA.
//----------------------------------------------------------------------------

#ifndef AGG_PIXFMT_BGRA32_LCD_INCLUDED
#define AGG_PIXFMT_BGRA32_LCD_INCLUDED

#include <string.h>
#include "agg_basics.h"
#include "agg_color_rgba.h"
#include "agg_rendering_buffer.h"

namespace agg
{
 

    //=====================================================lcd_distribution_lut
    class lcd_distribution_lut
    {
    public:
        lcd_distribution_lut(double prim, double second, double tert)
        {
            double norm = 1.0 / (prim + second*2 + tert*2);
            prim   *= norm;
            second *= norm;
            tert   *= norm;
            for(unsigned i = 0; i < 256; i++)
            {
                unsigned b = (i << 8);
                unsigned s = round(second * b);
                unsigned t = round(tert   * b);
                unsigned p = b - (2*s + 2*t);

                m_data[3*i + 1] = s; /* secondary */
                m_data[3*i + 2] = t; /* tertiary */
                m_data[3*i    ] = p; /* primary */
            }
        }

        unsigned convolution(const int8u* covers, int i0, int i_min, int i_max) const
        {
            unsigned sum = 0;
            int k_min = (i0 >= i_min + 2 ? -2 : i_min - i0);
            int k_max = (i0 <= i_max - 2 ?  2 : i_max - i0);
            for (int k = k_min; k <= k_max; k++)
            {
                /* select the primary, secondary or tertiary channel */
                int channel = abs(k) % 3;
                int8u c = covers[i0 + k];
                sum += m_data[3*c + channel];
            }

            return (sum + 128) >> 8;
        }

    private:
        unsigned short m_data[256*3];
    };


    //========================================================pixfmt_bgra32_lcd
    class pixfmt_bgra32_lcd
    {
    public:
        typedef rgba8 color_type;
        typedef rendering_buffer::row_data row_data;
        typedef color_type::value_type value_type;
        typedef color_type::calc_type calc_type;

        //--------------------------------------------------------------------
        pixfmt_bgra32_lcd(rendering_buffer& rb, const lcd_distribution_lut& lut)
            : m_rbuf(&rb), m_lut(&lut)
        {
        }

        //--------------------------------------------------------------------
        unsigned width()  const {
            return m_rbuf->width() * 3;
        }
        unsigned height() const {
            return m_rbuf->height();
        }


        // This method should never be called when using the scanline_u8.
        // The use of scanline_p8 should be avoided because if does not works
        // properly for rendering fonts because single hspan are split in many
        // hline/hspan elements and pixel whitening happens.
        void blend_hline(int x, int y, unsigned len,
                         const color_type& c, int8u cover)
        { }

        void copy_hline(int x, int y, unsigned len, const color_type& c)
        {
            int8u* p = m_rbuf->row_ptr(y) + (x / 3) * 4;
            for (int ilen = len; ilen > 0; p += 4, ilen -= 3)
            {
                p[0] = c.b;
                p[1] = c.g;
                p[2] = c.r;
                p[3] = 0xff;
            }
        }

        //--------------------------------------------------------------------
        void blend_solid_hspan(int x, int y,
                               unsigned len,
                               const color_type& c,
                               const int8u* covers)
        {
            unsigned rowlen = width();
            int cx = (x - 2 >= 0 ? -2 : -x);
            int cx_max = (len + 2 <= rowlen ? len + 1 : rowlen - 1);

            int i = (x + cx) % 3;

            const int8u rgb[3] = { c.r, c.g, c.b };
            int8u* p = m_rbuf->row_ptr(y) + (x + cx);

            const int pixel_index[3] = {2, 1, 0};
            for (/* */; cx <= cx_max; cx += 3)
            {
                unsigned c_conv, alpha, dst_col, src_col;
                c_conv = m_lut->convolution(covers, cx, 0, len - 1);
                alpha = (c_conv + 1) * (c.a + 1);
                dst_col = rgb[i];
                src_col = *(p + pixel_index[i]);
                *(p + pixel_index[i]) = (int8u)((((dst_col - src_col) * alpha) + (src_col << 16)) >> 16);
                i = (i + 1) % 3;

                c_conv = m_lut->convolution(covers, cx + 1, 0, len - 1);
                alpha = (c_conv + 1) * (c.a + 1);
                dst_col = rgb[i];
                src_col = *(p + pixel_index[i]);
                *(p + pixel_index[i]) = (int8u)((((dst_col - src_col) * alpha) + (src_col << 16)) >> 16);
                i = (i + 1) % 3;

                c_conv = m_lut->convolution(covers, cx + 2, 0, len - 1);
                alpha = (c_conv + 1) * (c.a + 1);
                dst_col = rgb[i];
                src_col = *(p + pixel_index[i]);
                *(p + pixel_index[i]) = (int8u)((((dst_col - src_col) * alpha) + (src_col << 16)) >> 16);
                i = (i + 1) % 3;

                p[3] = 0xff;
                p += 4;
            }
        }

    private:
        rendering_buffer* m_rbuf;
        const lcd_distribution_lut* m_lut;
    };


    template <class Gamma>
    class pixfmt_bgra32_lcd_gamma
    {
    public:
        typedef rgba8 color_type;
        typedef rendering_buffer::row_data row_data;
        typedef color_type::value_type value_type;
        typedef color_type::calc_type calc_type;

        //--------------------------------------------------------------------
        pixfmt_bgra32_lcd_gamma(rendering_buffer& rb, const lcd_distribution_lut& lut, const Gamma& gamma)
            : m_rbuf(&rb), m_lut(&lut), m_gamma(gamma)
        {
        }

        //--------------------------------------------------------------------
        unsigned width()  const {
            return m_rbuf->width() * 3;
        }
        unsigned height() const {
            return m_rbuf->height();
        }


        // This method should never be called when using the scanline_u8.
        // The use of scanline_p8 should be avoided because if does not works
        // properly for rendering fonts because single hspan are split in many
        // hline/hspan elements and pixel whitening happens.
        void blend_hline(int x, int y, unsigned len,
                         const color_type& c, int8u cover)
        { }

        void copy_hline(int x, int y, unsigned len, const color_type& c)
        {
            int8u* p = m_rbuf->row_ptr(y) + (x / 3) * 4;
            for (int ilen = len; ilen > 0; p += 4, ilen -= 3)
            {
                p[0] = c.r;
                p[1] = c.g;
                p[2] = c.b;
                p[3] = 0xff;
            }
        }

        //--------------------------------------------------------------------
        void blend_solid_hspan(int x, int y,
                               unsigned len,
                               const color_type& c,
                               const int8u* covers)
        {
            unsigned rowlen = width();
            int cx = (x - 2 >= 0 ? -2 : -x);
            int cx_max = (len + 2 <= rowlen ? len + 1 : rowlen - 1);

            int i = (x + cx) % 3;

            const int8u rgb[3] = { c.r, c.g, c.b };
            int8u* p = m_rbuf->row_ptr(y) + (x + cx);

            const int pixel_index[3] = {2, 1, 0};
            for (/* */; cx <= cx_max; cx += 3)
            {
                unsigned c_conv, alpha, dst_col, src_col;
                c_conv = m_lut->convolution(covers, cx, 0, len - 1);
                alpha = (c_conv + 1) * (c.a + 1);
                dst_col = m_gamma.dir(rgb[i]);
                src_col = m_gamma.dir(*(p + pixel_index[i]));
                *(p + pixel_index[i]) = m_gamma.inv((((dst_col - src_col) * alpha) + (src_col << 16)) >> 16);
                i = (i + 1) % 3;

                c_conv = m_lut->convolution(covers, cx + 1, 0, len - 1);
                alpha = (c_conv + 1) * (c.a + 1);
                dst_col = m_gamma.dir(rgb[i]);
                src_col = m_gamma.dir(*(p + pixel_index[i]));
                *(p + pixel_index[i]) = m_gamma.inv((((dst_col - src_col) * alpha) + (src_col << 16)) >> 16);
                i = (i + 1) % 3;

                c_conv = m_lut->convolution(covers, cx + 2, 0, len - 1);
                alpha = (c_conv + 1) * (c.a + 1);
                dst_col = m_gamma.dir(rgb[i]);
                src_col = m_gamma.dir(*(p + pixel_index[i]));
                *(p + pixel_index[i]) = m_gamma.inv((((dst_col - src_col) * alpha) + (src_col << 16)) >> 16);
                i = (i + 1) % 3;

                p[3] = 0xff;
                p += 4;
            }
        }

    private:
        rendering_buffer* m_rbuf;
        const lcd_distribution_lut* m_lut;
        const Gamma& m_gamma;
    };

}

#endif