190 lines
6.6 KiB
C
190 lines
6.6 KiB
C
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//----------------------------------------------------------------------------
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// Anti-Grain Geometry - Version 2.4
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// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
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//
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// Permission to copy, use, modify, sell and distribute this software
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// is granted provided this copyright notice appears in all copies.
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// This software is provided "as is" without express or implied
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// warranty, and with no claim as to its suitability for any purpose.
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//
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//----------------------------------------------------------------------------
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// Contact: mcseem@antigrain.com
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// mcseemagg@yahoo.com
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// http://www.antigrain.com
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//----------------------------------------------------------------------------
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#ifndef AGG_LINE_AA_BASICS_INCLUDED
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#define AGG_LINE_AA_BASICS_INCLUDED
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#include <stdlib.h>
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#include "agg_basics.h"
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namespace agg
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{
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// See Implementation agg_line_aa_basics.cpp
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//-------------------------------------------------------------------------
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enum line_subpixel_scale_e
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{
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line_subpixel_shift = 8, //----line_subpixel_shift
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line_subpixel_scale = 1 << line_subpixel_shift, //----line_subpixel_scale
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line_subpixel_mask = line_subpixel_scale - 1, //----line_subpixel_mask
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line_max_coord = (1 << 28) - 1, //----line_max_coord
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line_max_length = 1 << (line_subpixel_shift + 10) //----line_max_length
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};
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//-------------------------------------------------------------------------
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enum line_mr_subpixel_scale_e
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{
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line_mr_subpixel_shift = 4, //----line_mr_subpixel_shift
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line_mr_subpixel_scale = 1 << line_mr_subpixel_shift, //----line_mr_subpixel_scale
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line_mr_subpixel_mask = line_mr_subpixel_scale - 1 //----line_mr_subpixel_mask
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};
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//------------------------------------------------------------------line_mr
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AGG_INLINE int line_mr(int x)
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{
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return x >> (line_subpixel_shift - line_mr_subpixel_shift);
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}
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//-------------------------------------------------------------------line_hr
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AGG_INLINE int line_hr(int x)
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{
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return x << (line_subpixel_shift - line_mr_subpixel_shift);
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}
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//---------------------------------------------------------------line_dbl_hr
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AGG_INLINE int line_dbl_hr(int x)
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{
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return x << line_subpixel_shift;
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}
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//---------------------------------------------------------------line_coord
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struct line_coord
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{
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AGG_INLINE static int conv(double x)
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{
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return iround(x * line_subpixel_scale);
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}
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};
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//-----------------------------------------------------------line_coord_sat
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struct line_coord_sat
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{
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AGG_INLINE static int conv(double x)
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{
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return saturation<line_max_coord>::iround(x * line_subpixel_scale);
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}
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};
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//==========================================================line_parameters
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struct line_parameters
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{
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//---------------------------------------------------------------------
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line_parameters() {}
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line_parameters(int x1_, int y1_, int x2_, int y2_, int len_) :
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x1(x1_), y1(y1_), x2(x2_), y2(y2_),
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dx(abs(x2_ - x1_)),
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dy(abs(y2_ - y1_)),
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sx((x2_ > x1_) ? 1 : -1),
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sy((y2_ > y1_) ? 1 : -1),
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vertical(dy >= dx),
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inc(vertical ? sy : sx),
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len(len_),
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octant((sy & 4) | (sx & 2) | int(vertical))
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{
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}
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//---------------------------------------------------------------------
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unsigned orthogonal_quadrant() const { return s_orthogonal_quadrant[octant]; }
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unsigned diagonal_quadrant() const { return s_diagonal_quadrant[octant]; }
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//---------------------------------------------------------------------
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bool same_orthogonal_quadrant(const line_parameters& lp) const
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{
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return s_orthogonal_quadrant[octant] == s_orthogonal_quadrant[lp.octant];
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}
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//---------------------------------------------------------------------
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bool same_diagonal_quadrant(const line_parameters& lp) const
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{
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return s_diagonal_quadrant[octant] == s_diagonal_quadrant[lp.octant];
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}
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//---------------------------------------------------------------------
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void divide(line_parameters& lp1, line_parameters& lp2) const
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{
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int xmid = (x1 + x2) >> 1;
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int ymid = (y1 + y2) >> 1;
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int len2 = len >> 1;
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lp1 = *this;
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lp2 = *this;
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lp1.x2 = xmid;
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lp1.y2 = ymid;
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lp1.len = len2;
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lp1.dx = abs(lp1.x2 - lp1.x1);
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lp1.dy = abs(lp1.y2 - lp1.y1);
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lp2.x1 = xmid;
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lp2.y1 = ymid;
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lp2.len = len2;
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lp2.dx = abs(lp2.x2 - lp2.x1);
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lp2.dy = abs(lp2.y2 - lp2.y1);
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}
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//---------------------------------------------------------------------
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int x1, y1, x2, y2, dx, dy, sx, sy;
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bool vertical;
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int inc;
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int len;
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int octant;
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//---------------------------------------------------------------------
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static const int8u s_orthogonal_quadrant[8];
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static const int8u s_diagonal_quadrant[8];
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};
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// See Implementation agg_line_aa_basics.cpp
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//----------------------------------------------------------------bisectrix
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void bisectrix(const line_parameters& l1,
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const line_parameters& l2,
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int* x, int* y);
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//-------------------------------------------fix_degenerate_bisectrix_start
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void inline fix_degenerate_bisectrix_start(const line_parameters& lp,
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int* x, int* y)
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{
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int d = iround((double(*x - lp.x2) * double(lp.y2 - lp.y1) -
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double(*y - lp.y2) * double(lp.x2 - lp.x1)) / lp.len);
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if(d < line_subpixel_scale/2)
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{
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*x = lp.x1 + (lp.y2 - lp.y1);
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*y = lp.y1 - (lp.x2 - lp.x1);
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}
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}
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//---------------------------------------------fix_degenerate_bisectrix_end
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void inline fix_degenerate_bisectrix_end(const line_parameters& lp,
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int* x, int* y)
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{
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int d = iround((double(*x - lp.x2) * double(lp.y2 - lp.y1) -
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double(*y - lp.y2) * double(lp.x2 - lp.x1)) / lp.len);
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if(d < line_subpixel_scale/2)
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{
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*x = lp.x2 + (lp.y2 - lp.y1);
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*y = lp.y2 - (lp.x2 - lp.x1);
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}
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}
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}
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#endif
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