agg_renderer_outline_aa.h

来自「这是VCF框架的代码」· C头文件 代码 · 共 1,846 行 · 第 1/5 页

        //---------------------------------------------------------------------
        void dec_x(int dy)
        {
            m_dist       -= m_dy; 
            m_dist_start -= m_dy_start; 
            m_dist_end   -= m_dy_end;
            if(dy > 0)
            {
                m_dist       -= m_dx; 
                m_dist_start -= m_dx_start; 
                m_dist_end   -= m_dx_end;
            }
            if(dy < 0)
            {
                m_dist       += m_dx; 
                m_dist_start += m_dx_start; 
                m_dist_end   += m_dx_end;
            }
        }

        //---------------------------------------------------------------------
        void inc_y(int dx)
        {
            m_dist       -= m_dx; 
            m_dist_start -= m_dx_start; 
            m_dist_end   -= m_dx_end;
            if(dx > 0)
            {
                m_dist       += m_dy; 
                m_dist_start += m_dy_start; 
                m_dist_end   += m_dy_end;
            }
            if(dx < 0)
            {
                m_dist       -= m_dy; 
                m_dist_start -= m_dy_start; 
                m_dist_end   -= m_dy_end;
            }
        }

        //---------------------------------------------------------------------
        void dec_y(int dx)
        {
            m_dist       += m_dx; 
            m_dist_start += m_dx_start; 
            m_dist_end   += m_dx_end;
            if(dx > 0)
            {
                m_dist       += m_dy; 
                m_dist_start += m_dy_start; 
                m_dist_end   += m_dy_end;
            }
            if(dx < 0)
            {
                m_dist       -= m_dy; 
                m_dist_start -= m_dy_start; 
                m_dist_end   -= m_dy_end;
            }
        }

        //---------------------------------------------------------------------
        int dist()       const { return m_dist;       }
        int dist_start() const { return m_dist_start; }
        int dist_end()   const { return m_dist_end;   }

        //---------------------------------------------------------------------
        int dx()       const { return m_dx;       }
        int dy()       const { return m_dy;       }
        int dx_start() const { return m_dx_start; }
        int dy_start() const { return m_dy_start; }
        int dx_end()   const { return m_dx_end;   }
        int dy_end()   const { return m_dy_end;   }

    private:
        //---------------------------------------------------------------------
        int m_dx;
        int m_dy;
        int m_dx_start;
        int m_dy_start;
        int m_dx_end;
        int m_dy_end;

        int m_dist;
        int m_dist_start;
        int m_dist_end;
    };




    
    //================================================line_interpolator_aa_base
    template<class Renderer> class line_interpolator_aa_base
    {
    public:
        typedef Renderer renderer_type;
        typedef typename Renderer::color_type color_type;

        //---------------------------------------------------------------------
        enum max_half_width_e
        { 
            max_half_width = 64
        };

        //---------------------------------------------------------------------
        line_interpolator_aa_base(renderer_type& ren, const line_parameters& lp) :
            m_lp(&lp),
            m_li(lp.vertical ? line_dbl_hr(lp.x2 - lp.x1) :
                               line_dbl_hr(lp.y2 - lp.y1),
                 lp.vertical ? abs(lp.y2 - lp.y1) : 
                               abs(lp.x2 - lp.x1) + 1),
            m_ren(ren),
            m_len((lp.vertical == (lp.inc > 0)) ? -lp.len : lp.len),
            m_x(lp.x1 >> line_subpixel_shift),
            m_y(lp.y1 >> line_subpixel_shift),
            m_old_x(m_x),
            m_old_y(m_y),
            m_count((lp.vertical ? abs((lp.y2 >> line_subpixel_shift) - m_y) :
                                   abs((lp.x2 >> line_subpixel_shift) - m_x))),
            m_width(ren.subpixel_width()),
            //m_max_extent(m_width >> (line_subpixel_shift - 2)),
            m_max_extent((m_width + line_subpixel_mask) >> line_subpixel_shift),
            m_step(0)
        {
            agg::dda2_line_interpolator li(0, lp.vertical ? 
                                              (lp.dy << agg::line_subpixel_shift) :
                                              (lp.dx << agg::line_subpixel_shift),
                                           lp.len);

            unsigned i;
            int stop = m_width + line_subpixel_scale * 2;
            for(i = 0; i < max_half_width; ++i)
            {
                m_dist[i] = li.y();
                if(m_dist[i] >= stop) break;
                ++li;
            }
            m_dist[i++] = 0x7FFF0000;
        }

        //---------------------------------------------------------------------
        template<class DI> int step_hor_base(DI& di)
        {
            ++m_li;
            m_x += m_lp->inc;
            m_y = (m_lp->y1 + m_li.y()) >> line_subpixel_shift;

            if(m_lp->inc > 0) di.inc_x(m_y - m_old_y);
            else              di.dec_x(m_y - m_old_y);

            m_old_y = m_y;

            return di.dist() / m_len;
        }

        //---------------------------------------------------------------------
        template<class DI> int step_ver_base(DI& di)
        {
            ++m_li;
            m_y += m_lp->inc;
            m_x = (m_lp->x1 + m_li.y()) >> line_subpixel_shift;

            if(m_lp->inc > 0) di.inc_y(m_x - m_old_x);
            else              di.dec_y(m_x - m_old_x);

            m_old_x = m_x;

            return di.dist() / m_len;
        }

        //---------------------------------------------------------------------
        bool vertical() const { return m_lp->vertical; }
        int  width() const { return m_width; }
        int  count() const { return m_count; }

    private:
        line_interpolator_aa_base(const line_interpolator_aa_base<Renderer>&);
        const line_interpolator_aa_base<Renderer>& 
            operator = (const line_interpolator_aa_base<Renderer>&);

    protected:
        const line_parameters* m_lp;
        dda2_line_interpolator m_li;
        renderer_type&         m_ren;
        int m_len;
        int m_x;
        int m_y;
        int m_old_x;
        int m_old_y;
        int m_count;
        int m_width;
        int m_max_extent;
        int m_step;
        int m_dist[max_half_width + 1];
        cover_type m_covers[max_half_width * 2 + 4];
    };







    //====================================================line_interpolator_aa0
    template<class Renderer> class line_interpolator_aa0 :
    public line_interpolator_aa_base<Renderer>
    {
    public:
        typedef Renderer renderer_type;
        typedef typename Renderer::color_type color_type;
        typedef line_interpolator_aa_base<Renderer> base_type;

        //---------------------------------------------------------------------
        line_interpolator_aa0(renderer_type& ren, const line_parameters& lp) :
            line_interpolator_aa_base<Renderer>(ren, lp),
            m_di(lp.x1, lp.y1, lp.x2, lp.y2, 
                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask)
        {
            base_type::m_li.adjust_forward();
        }

        //---------------------------------------------------------------------
        bool step_hor()
        {
            int dist;
            int dy;
            int s1 = base_type::step_hor_base(m_di);
            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
            cover_type* p1 = p0;

            *p1++ = (cover_type)base_type::m_ren.cover(s1);

            dy = 1;
            while((dist = base_type::m_dist[dy] - s1) <= base_type::m_width)
            {
                *p1++ = (cover_type)base_type::m_ren.cover(dist);
                ++dy;
            }

            dy = 1;
            while((dist = base_type::m_dist[dy] + s1) <= base_type::m_width)
            {
                *--p0 = (cover_type)base_type::m_ren.cover(dist);
                ++dy;
            }
            base_type::m_ren.blend_solid_vspan(base_type::m_x, 
                                               base_type::m_y - dy + 1, 
                                               unsigned(p1 - p0), 
                                               p0);
            return ++base_type::m_step < base_type::m_count;
        }

        //---------------------------------------------------------------------
        bool step_ver()
        {
            int dist;
            int dx;
            int s1 = base_type::step_ver_base(m_di);
            cover_type* p0 = base_type::m_covers + base_type::max_half_width + 2;
            cover_type* p1 = p0;

            *p1++ = (cover_type)base_type::m_ren.cover(s1);

            dx = 1;
            while((dist = base_type::m_dist[dx] - s1) <= base_type::m_width)
            {
                *p1++ = (cover_type)base_type::m_ren.cover(dist);
                ++dx;
            }

            dx = 1;
            while((dist = base_type::m_dist[dx] + s1) <= base_type::m_width)
            {
                *--p0 = (cover_type)base_type::m_ren.cover(dist);
                ++dx;
            }
            base_type::m_ren.blend_solid_hspan(base_type::m_x - dx + 1, 
                                               base_type::m_y,
                                               unsigned(p1 - p0), 
                                               p0);
            return ++base_type::m_step < base_type::m_count;
        }

    private:
        line_interpolator_aa0(const line_interpolator_aa0<Renderer>&);
        const line_interpolator_aa0<Renderer>& 
            operator = (const line_interpolator_aa0<Renderer>&);

        //---------------------------------------------------------------------
        distance_interpolator1 m_di; 
    };






    //====================================================line_interpolator_aa1
    template<class Renderer> class line_interpolator_aa1 :
    public line_interpolator_aa_base<Renderer>
    {
    public:
        typedef Renderer renderer_type;
        typedef typename Renderer::color_type color_type;
        typedef line_interpolator_aa_base<Renderer> base_type;

        //---------------------------------------------------------------------
        line_interpolator_aa1(renderer_type& ren, const line_parameters& lp, 
                              int sx, int sy) :
            line_interpolator_aa_base<Renderer>(ren, lp),
            m_di(lp.x1, lp.y1, lp.x2, lp.y2, sx, sy,
                 lp.x1 & ~line_subpixel_mask, lp.y1 & ~line_subpixel_mask)
        {
            int dist1_start;
            int dist2_start;

            int npix = 1;

            if(lp.vertical)
            {
                do
                {
                    --base_type::m_li;
                    base_type::m_y -= lp.inc;
                    base_type::m_x = (base_type::m_lp->x1 + base_type::m_li.y()) >> line_subpixel_shift;

                    if(lp.inc > 0) m_di.dec_y(base_type::m_x - base_type::m_old_x);
                    else           m_di.inc_y(base_type::m_x - base_type::m_old_x);

                    base_type::m_old_x = base_type::m_x;

                    dist1_start = dist2_start = m_di.dist_start(); 

                    int dx = 0;
                    if(dist1_start < 0) ++npix;
                    do
                    {
                        dist1_start += m_di.dy_start();
                        dist2_start -= m_di.dy_start();
                        if(dist1_start < 0) ++npix;
                        if(dist2_start < 0) ++npix;
                        ++dx;
                    }
                    while(base_type::m_dist[dx] <= base_type::m_width);
                    --base_type::m_step;
                    if(npix == 0) break;
                    npix = 0;
                }
                while(base_type::m_step >= -base_type::m_max_extent);
            }
            else
            {
                do
                {
                    --base_type::m_li;
                    base_type::m_x -= lp.inc;
                    base_type::m_y = (base_type::m_lp->y1 + base_type::m_li.y()) >> line_subpixel_shift;

                    if(lp.inc > 0) m_di.dec_x(base_type::m_y - base_type::m_old_y);
                    else           m_di.inc_x(base_type::m_y - base_type::m_old_y);

                    base_type::m_old_y = base_type::m_y;

                    dist1_start = dist2_start = m_di.dist_start(); 

                    int dy = 0;
                    if(dist1_start < 0) ++npix;
                    do
                    {