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Diffstat (limited to 'agg/inc/agg_span_gouraud_gray.h')
| -rwxr-xr-x | agg/inc/agg_span_gouraud_gray.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/agg/inc/agg_span_gouraud_gray.h b/agg/inc/agg_span_gouraud_gray.h new file mode 100755 index 000000000000..caf288919e93 --- /dev/null +++ b/agg/inc/agg_span_gouraud_gray.h @@ -0,0 +1,185 @@ +//---------------------------------------------------------------------------- +// Anti-Grain Geometry - Version 2.3 +// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com) +// +// Permission to copy, use, modify, sell and distribute this software +// is granted provided this copyright notice appears in all copies. +// This software is provided "as is" without express or implied +// warranty, and with no claim as to its suitability for any purpose. +// +//---------------------------------------------------------------------------- +// Contact: mcseem@antigrain.com +// mcseemagg@yahoo.com +// http://www.antigrain.com +//---------------------------------------------------------------------------- +// +// Adaptation for high precision colors has been sponsored by +// Liberty Technology Systems, Inc., visit http://lib-sys.com +// +// Liberty Technology Systems, Inc. is the provider of +// PostScript and PDF technology for software developers. +// +//---------------------------------------------------------------------------- + +#ifndef AGG_SPAN_GOURAUD_GRAY_INCLUDED +#define AGG_SPAN_GOURAUD_GRAY_INCLUDED + +#include "agg_basics.h" +#include "agg_color_gray.h" +#include "agg_dda_line.h" +#include "agg_span_gouraud.h" + +namespace agg +{ + + //=======================================================span_gouraud_gray + template<class ColorT, class Allocator = span_allocator<ColorT> > + class span_gouraud_gray : public span_gouraud<ColorT, Allocator> + { + public: + typedef Allocator alloc_type; + typedef ColorT color_type; + typedef typename color_type::value_type value_type; + typedef span_gouraud<color_type, alloc_type> base_type; + typedef typename base_type::coord_type coord_type; + + private: + //-------------------------------------------------------------------- + struct gray_calc + { + void init(const coord_type& c1, const coord_type& c2) + { + m_x1 = c1.x; + m_y1 = c1.y; + m_dx = c2.x - c1.x; + m_dy = 1.0 / (c2.y - c1.y); + m_v1 = c1.color.v; + m_a1 = c1.color.a; + m_dv = c2.color.v - m_v1; + m_da = c2.color.a - m_a1; + } + + void calc(int y) + { + double k = 0.0; + if(y > m_y1) k = (y - m_y1) * m_dy; + gray8 c; + m_v = m_v1 + int(m_dv * k); + m_a = m_a1 + int(m_da * k); + m_x = int(m_x1 + m_dx * k); + } + + double m_x1; + double m_y1; + double m_dx; + double m_dy; + int m_v1; + int m_a1; + int m_dv; + int m_da; + int m_v; + int m_a; + int m_x; + }; + + + public: + //-------------------------------------------------------------------- + span_gouraud_gray(alloc_type& alloc) : base_type(alloc) {} + + //-------------------------------------------------------------------- + span_gouraud_gray(alloc_type& alloc, + const color_type& c1, + const color_type& c2, + const color_type& c3, + double x1, double y1, + double x2, double y2, + double x3, double y3, + double d = 0) : + base_type(alloc, c1, c2, c3, x1, y1, x2, y2, x3, y3, d) + {} + + //-------------------------------------------------------------------- + void prepare(unsigned max_span_len) + { + base_type::prepare(max_span_len); + + coord_type coord[3]; + arrange_vertices(coord); + + m_y2 = int(coord[1].y); + + m_swap = calc_point_location(coord[0].x, coord[0].y, + coord[2].x, coord[2].y, + coord[1].x, coord[1].y) < 0.0; + + m_c1.init(coord[0], coord[2]); + m_c2.init(coord[0], coord[1]); + m_c3.init(coord[1], coord[2]); + } + + //-------------------------------------------------------------------- + color_type* generate(int x, int y, unsigned len) + { + m_c1.calc(y); + const gray_calc* pc1 = &m_c1; + const gray_calc* pc2 = &m_c2; + + if(y < m_y2) + { + m_c2.calc(y+1); + } + else + { + m_c3.calc(y); + pc2 = &m_c3; + } + + if(m_swap) + { + const gray_calc* t = pc2; + pc2 = pc1; + pc1 = t; + } + + int nx = pc1->m_x; + unsigned nlen = pc2->m_x - pc1->m_x + 1; + + if(nlen < len) nlen = len; + + dda_line_interpolator<14> v(pc1->m_v, pc2->m_v, nlen); + dda_line_interpolator<14> a(pc1->m_a, pc2->m_a, nlen); + + if(nx < x) + { + unsigned d = unsigned(x - nx); + v += d; + a += d; + } + + color_type* span = base_type::allocator().span(); + do + { + span->v = (value_type)v.y(); + span->a = (value_type)a.y(); + ++v; + ++a; + ++span; + } + while(--len); + return base_type::allocator().span(); + } + + + private: + bool m_swap; + int m_y2; + gray_calc m_c1; + gray_calc m_c2; + gray_calc m_c3; + }; + + +} + +#endif |