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//----------------------------------------------------------------------------
// 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
//----------------------------------------------------------------------------
#include <math.h>
#include "agg_line_aa_basics.h"
namespace agg
{
//-------------------------------------------------------------------------
// The number of the octant is determined as a 3-bit value as follows:
// bit 0 = vertical flag
// bit 1 = sx < 0
// bit 2 = sy < 0
//
// [N] shows the number of the orthogonal quadrant
// <M> shows the number of the diagonal quadrant
// <1>
// [1] | [0]
// . (3)011 | 001(1) .
// . | .
// . | .
// . | .
// (2)010 .|. 000(0)
// <2> ----------.+.----------- <0>
// (6)110 . | . 100(4)
// . | .
// . | .
// . | .
// (7)111 | 101(5)
// [2] | [3]
// <3>
// 0,1,2,3,4,5,6,7
int8u line_parameters::s_orthogonal_quadrant[8] = { 0,0,1,1,3,3,2,2 };
int8u line_parameters::s_diagonal_quadrant[8] = { 0,1,2,1,0,3,2,3 };
//-------------------------------------------------------------------------
void bisectrix(const line_parameters& l1,
const line_parameters& l2,
int* x, int* y)
{
double k = double(l2.len) / double(l1.len);
double tx = l2.x2 - (l2.x1 - l1.x1) * k;
double ty = l2.y2 - (l2.y1 - l1.y1) * k;
//All bisectrices must be on the right of the line
//If the next point is on the left (l1 => l2.2)
//then the bisectix should be rotated by 180 degrees.
if(double(l2.x2 - l2.x1) * double(l2.y1 - l1.y1) <
double(l2.y2 - l2.y1) * double(l2.x1 - l1.x1) + 100.0)
{
tx -= (tx - l2.x1) * 2.0;
ty -= (ty - l2.y1) * 2.0;
}
// Check if the bisectrix is too short
double dx = tx - l2.x1;
double dy = ty - l2.y1;
if((int)sqrt(dx * dx + dy * dy) < line_subpixel_size)
{
*x = (l2.x1 + l2.x1 + (l2.y1 - l1.y1) + (l2.y2 - l2.y1)) >> 1;
*y = (l2.y1 + l2.y1 - (l2.x1 - l1.x1) - (l2.x2 - l2.x1)) >> 1;
return;
}
*x = int(tx);
*y = int(ty);
}
}
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