agg_renderer_base.h

windows ce 下的画各种b样条曲线

                               cover_type cover = agg::cover_full)
        {
            if(y > ymax()) return;
            if(y < ymin()) return;

            if(x < xmin())
            {
                int d = xmin() - x;
                len -= d;
                if(len <= 0) return;
                if(covers) covers += d;
                colors += d;
                x = xmin();
            }
            if(x + len > xmax())
            {
                len = xmax() - x + 1;
                if(len <= 0) return;
            }
            m_ren->blend_color_hspan(x, y, len, colors, covers, cover);
        }

        //--------------------------------------------------------------------
        void blend_color_vspan(int x, int y, int len, 
                               const color_type* colors, 
                               const cover_type* covers,
                               cover_type cover = agg::cover_full)
        {
            if(x > xmax()) return;
            if(x < xmin()) return;

            if(y < ymin())
            {
                int d = ymin() - y;
                len -= d;
                if(len <= 0) return;
                if(covers) covers += d;
                colors += d;
                y = ymin();
            }
            if(y + len > ymax())
            {
                len = ymax() - y + 1;
                if(len <= 0) return;
            }
            m_ren->blend_color_vspan(x, y, len, colors, covers, cover);
        }

        //--------------------------------------------------------------------
        rect_i clip_rect_area(rect_i& dst, rect_i& src, int wsrc, int hsrc) const
        {
            rect_i rc(0,0,0,0);
            rect_i cb = clip_box();
            ++cb.x2;
            ++cb.y2;

            if(src.x1 < 0)
            {
                dst.x1 -= src.x1;
                src.x1 = 0;
            }
            if(src.y1 < 0)
            {
                dst.y1 -= src.y1;
                src.y1 = 0;
            }

            if(src.x2 > wsrc) src.x2 = wsrc;
            if(src.y2 > hsrc) src.y2 = hsrc;

            if(dst.x1 < cb.x1)
            {
                src.x1 += cb.x1 - dst.x1;
                dst.x1 = cb.x1;
            }
            if(dst.y1 < cb.y1)
            {
                src.y1 += cb.y1 - dst.y1;
                dst.y1 = cb.y1;
            }

            if(dst.x2 > cb.x2) dst.x2 = cb.x2;
            if(dst.y2 > cb.y2) dst.y2 = cb.y2;

            rc.x2 = dst.x2 - dst.x1;
            rc.y2 = dst.y2 - dst.y1;

            if(rc.x2 > src.x2 - src.x1) rc.x2 = src.x2 - src.x1;
            if(rc.y2 > src.y2 - src.y1) rc.y2 = src.y2 - src.y1;
            return rc;
        }

        //--------------------------------------------------------------------
        template<class RenBuf>
        void copy_from(const RenBuf& src, 
                       const rect_i* rect_src_ptr = 0, 
                       int dx = 0, 
                       int dy = 0)
        {
            rect_i rsrc(0, 0, src.width(), src.height());
            if(rect_src_ptr)
            {
                rsrc.x1 = rect_src_ptr->x1; 
                rsrc.y1 = rect_src_ptr->y1;
                rsrc.x2 = rect_src_ptr->x2 + 1;
                rsrc.y2 = rect_src_ptr->y2 + 1;
            }

            // Version with xdst, ydst (absolute positioning)
            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);

            // Version with dx, dy (relative positioning)
            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);

            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());

            if(rc.x2 > 0)
            {
                int incy = 1;
                if(rdst.y1 > rsrc.y1)
                {
                    rsrc.y1 += rc.y2 - 1;
                    rdst.y1 += rc.y2 - 1;
                    incy = -1;
                }
                while(rc.y2 > 0)
                {
                    m_ren->copy_from(src, 
                                     rdst.x1, rdst.y1,
                                     rsrc.x1, rsrc.y1,
                                     rc.x2);
                    rdst.y1 += incy;
                    rsrc.y1 += incy;
                    --rc.y2;
                }
            }
        }

        //--------------------------------------------------------------------
        template<class SrcPixelFormatRenderer>
        void blend_from(const SrcPixelFormatRenderer& src, 
                        const rect_i* rect_src_ptr = 0, 
                        int dx = 0, 
                        int dy = 0,
                        cover_type cover = agg::cover_full)
        {
            rect_i rsrc(0, 0, src.width(), src.height());
            if(rect_src_ptr)
            {
                rsrc.x1 = rect_src_ptr->x1; 
                rsrc.y1 = rect_src_ptr->y1;
                rsrc.x2 = rect_src_ptr->x2 + 1;
                rsrc.y2 = rect_src_ptr->y2 + 1;
            }

            // Version with xdst, ydst (absolute positioning)
            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);

            // Version with dx, dy (relative positioning)
            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());

            if(rc.x2 > 0)
            {
                int incy = 1;
                if(rdst.y1 > rsrc.y1)
                {
                    rsrc.y1 += rc.y2 - 1;
                    rdst.y1 += rc.y2 - 1;
                    incy = -1;
                }
                while(rc.y2 > 0)
                {
                    typename SrcPixelFormatRenderer::row_data rw = src.row(rsrc.y1);
                    if(rw.ptr)
                    {
                        int x1src = rsrc.x1;
                        int x1dst = rdst.x1;
                        int len   = rc.x2;
                        if(rw.x1 > x1src)
                        {
                            x1dst += rw.x1 - x1src;
                            len   -= rw.x1 - x1src;
                            x1src  = rw.x1;
                        }
                        if(len > 0)
                        {
                            if(x1src + len-1 > rw.x2)
                            {
                                len -= x1src + len - rw.x2 - 1;
                            }
                            if(len > 0)
                            {
                                m_ren->blend_from(src,
                                                  x1dst, rdst.y1,
                                                  x1src, rsrc.y1,
                                                  len,
                                                  cover);
                            }
                        }
                    }
                    rdst.y1 += incy;
                    rsrc.y1 += incy;
                    --rc.y2;
                }
            }
        }

        //--------------------------------------------------------------------
        template<class SrcPixelFormatRenderer>
        void blend_from_color(const SrcPixelFormatRenderer& src, 
                              const color_type& color,
                              const rect_i* rect_src_ptr = 0, 
                              int dx = 0, 
                              int dy = 0,
                              cover_type cover = agg::cover_full)
        {
            rect_i rsrc(0, 0, src.width(), src.height());
            if(rect_src_ptr)
            {
                rsrc.x1 = rect_src_ptr->x1; 
                rsrc.y1 = rect_src_ptr->y1;
                rsrc.x2 = rect_src_ptr->x2 + 1;
                rsrc.y2 = rect_src_ptr->y2 + 1;
            }

            // Version with xdst, ydst (absolute positioning)
            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);

            // Version with dx, dy (relative positioning)
            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());

            if(rc.x2 > 0)
            {
                int incy = 1;
                if(rdst.y1 > rsrc.y1)
                {
                    rsrc.y1 += rc.y2 - 1;
                    rdst.y1 += rc.y2 - 1;
                    incy = -1;
                }
                while(rc.y2 > 0)
                {
                    typename SrcPixelFormatRenderer::row_data rw = src.row(rsrc.y1);
                    if(rw.ptr)
                    {
                        int x1src = rsrc.x1;
                        int x1dst = rdst.x1;
                        int len   = rc.x2;
                        if(rw.x1 > x1src)
                        {
                            x1dst += rw.x1 - x1src;
                            len   -= rw.x1 - x1src;
                            x1src  = rw.x1;
                        }
                        if(len > 0)
                        {
                            if(x1src + len-1 > rw.x2)
                            {
                                len -= x1src + len - rw.x2 - 1;
                            }
                            if(len > 0)
                            {
                                m_ren->blend_from_color(src,
                                                        color,
                                                        x1dst, rdst.y1,
                                                        x1src, rsrc.y1,
                                                        len,
                                                        cover);
                            }
                        }
                    }
                    rdst.y1 += incy;
                    rsrc.y1 += incy;
                    --rc.y2;
                }
            }
        }

        //--------------------------------------------------------------------
        template<class SrcPixelFormatRenderer>
        void blend_from_lut(const SrcPixelFormatRenderer& src, 
                            const color_type* color_lut,
                            const rect_i* rect_src_ptr = 0, 
                            int dx = 0, 
                            int dy = 0,
                            cover_type cover = agg::cover_full)
        {
            rect_i rsrc(0, 0, src.width(), src.height());
            if(rect_src_ptr)
            {
                rsrc.x1 = rect_src_ptr->x1; 
                rsrc.y1 = rect_src_ptr->y1;
                rsrc.x2 = rect_src_ptr->x2 + 1;
                rsrc.y2 = rect_src_ptr->y2 + 1;
            }

            // Version with xdst, ydst (absolute positioning)
            //rect_i rdst(xdst, ydst, xdst + rsrc.x2 - rsrc.x1, ydst + rsrc.y2 - rsrc.y1);

            // Version with dx, dy (relative positioning)
            rect_i rdst(rsrc.x1 + dx, rsrc.y1 + dy, rsrc.x2 + dx, rsrc.y2 + dy);
            rect_i rc = clip_rect_area(rdst, rsrc, src.width(), src.height());

            if(rc.x2 > 0)
            {
                int incy = 1;
                if(rdst.y1 > rsrc.y1)
                {
                    rsrc.y1 += rc.y2 - 1;
                    rdst.y1 += rc.y2 - 1;
                    incy = -1;
                }
                while(rc.y2 > 0)
                {
                    typename SrcPixelFormatRenderer::row_data rw = src.row(rsrc.y1);
                    if(rw.ptr)
                    {
                        int x1src = rsrc.x1;
                        int x1dst = rdst.x1;
                        int len   = rc.x2;
                        if(rw.x1 > x1src)
                        {
                            x1dst += rw.x1 - x1src;
                            len   -= rw.x1 - x1src;
                            x1src  = rw.x1;
                        }
                        if(len > 0)
                        {
                            if(x1src + len-1 > rw.x2)
                            {
                                len -= x1src + len - rw.x2 - 1;
                            }
                            if(len > 0)
                            {
                                m_ren->blend_from_lut(src,
                                                      color_lut,
                                                      x1dst, rdst.y1,
                                                      x1src, rsrc.y1,
                                                      len,
                                                      cover);
                            }
                        }
                    }
                    rdst.y1 += incy;
                    rsrc.y1 += incy;
                    --rc.y2;
                }
            }
        }

    private:
        pixfmt_type* m_ren;
        rect_i       m_clip_box;
    };


}

#endif