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//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// 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
//----------------------------------------------------------------------------
//
// classes dda_line_interpolator, dda2_line_interpolator
//
//----------------------------------------------------------------------------
#ifndef AGG_DDA_LINE_INCLUDED
#define AGG_DDA_LINE_INCLUDED
#include <stdlib.h>
#include "agg_basics.h"
namespace agg
{
//===================================================dda_line_interpolator
template<int FractionShift, int YShift=0> class dda_line_interpolator
{
public:
//--------------------------------------------------------------------
dda_line_interpolator() {}
//--------------------------------------------------------------------
dda_line_interpolator(int y1, int y2, unsigned count) :
m_y(y1),
m_inc(((y2 - y1) << FractionShift) / int(count)),
m_dy(0)
{
}
//--------------------------------------------------------------------
void operator ++ ()
{
m_dy += m_inc;
}
//--------------------------------------------------------------------
void operator -- ()
{
m_dy -= m_inc;
}
//--------------------------------------------------------------------
void operator += (unsigned n)
{
m_dy += m_inc * n;
}
//--------------------------------------------------------------------
void operator -= (unsigned n)
{
m_dy -= m_inc * n;
}
//--------------------------------------------------------------------
int y() const { return m_y + (m_dy >> (FractionShift-YShift)); }
int dy() const { return m_dy; }
private:
int m_y;
int m_inc;
int m_dy;
};
//=================================================dda2_line_interpolator
class dda2_line_interpolator
{
public:
typedef int save_data_type;
enum save_size_e { save_size = 2 };
//--------------------------------------------------------------------
dda2_line_interpolator() {}
//-------------------------------------------- Forward-adjusted line
dda2_line_interpolator(int y1, int y2, int count) :
m_cnt(count <= 0 ? 1 : count),
m_lft((y2 - y1) / m_cnt),
m_rem((y2 - y1) % m_cnt),
m_mod(m_rem),
m_y(y1)
{
if(m_mod <= 0)
{
m_mod += count;
m_rem += count;
m_lft--;
}
m_mod -= count;
}
//-------------------------------------------- Backward-adjusted line
dda2_line_interpolator(int y1, int y2, int count, int) :
m_cnt(count <= 0 ? 1 : count),
m_lft((y2 - y1) / m_cnt),
m_rem((y2 - y1) % m_cnt),
m_mod(m_rem),
m_y(y1)
{
if(m_mod <= 0)
{
m_mod += count;
m_rem += count;
m_lft--;
}
}
//-------------------------------------------- Backward-adjusted line
dda2_line_interpolator(int y, int count) :
m_cnt(count <= 0 ? 1 : count),
m_lft(y / m_cnt),
m_rem(y % m_cnt),
m_mod(m_rem),
m_y(0)
{
if(m_mod <= 0)
{
m_mod += count;
m_rem += count;
m_lft--;
}
}
//--------------------------------------------------------------------
void save(save_data_type* data) const
{
data[0] = m_mod;
data[1] = m_y;
}
//--------------------------------------------------------------------
void load(const save_data_type* data)
{
m_mod = data[0];
m_y = data[1];
}
//--------------------------------------------------------------------
void operator++()
{
m_mod += m_rem;
m_y += m_lft;
if(m_mod > 0)
{
m_mod -= m_cnt;
m_y++;
}
}
//--------------------------------------------------------------------
void operator--()
{
if(m_mod <= m_rem)
{
m_mod += m_cnt;
m_y--;
}
m_mod -= m_rem;
m_y -= m_lft;
}
//--------------------------------------------------------------------
void adjust_forward()
{
m_mod -= m_cnt;
}
//--------------------------------------------------------------------
void adjust_backward()
{
m_mod += m_cnt;
}
//--------------------------------------------------------------------
int mod() const { return m_mod; }
int rem() const { return m_rem; }
int lft() const { return m_lft; }
//--------------------------------------------------------------------
int y() const { return m_y; }
private:
int m_cnt;
int m_lft;
int m_rem;
int m_mod;
int m_y;
};
//---------------------------------------------line_bresenham_interpolator
class line_bresenham_interpolator
{
public:
enum subpixel_scale_e
{
subpixel_shift = 8,
subpixel_scale = 1 << subpixel_shift,
subpixel_mask = subpixel_scale - 1
};
//--------------------------------------------------------------------
static int line_lr(int v) { return v >> subpixel_shift; }
//--------------------------------------------------------------------
line_bresenham_interpolator(int x1, int y1, int x2, int y2) :
m_x1_lr(line_lr(x1)),
m_y1_lr(line_lr(y1)),
m_x2_lr(line_lr(x2)),
m_y2_lr(line_lr(y2)),
m_ver(abs(m_x2_lr - m_x1_lr) < abs(m_y2_lr - m_y1_lr)),
m_len(m_ver ? abs(m_y2_lr - m_y1_lr) :
abs(m_x2_lr - m_x1_lr)),
m_inc(m_ver ? ((y2 > y1) ? 1 : -1) : ((x2 > x1) ? 1 : -1)),
m_interpolator(m_ver ? x1 : y1,
m_ver ? x2 : y2,
m_len)
{
}
//--------------------------------------------------------------------
bool is_ver() const { return m_ver; }
unsigned len() const { return m_len; }
int inc() const { return m_inc; }
//--------------------------------------------------------------------
void hstep()
{
++m_interpolator;
m_x1_lr += m_inc;
}
//--------------------------------------------------------------------
void vstep()
{
++m_interpolator;
m_y1_lr += m_inc;
}
//--------------------------------------------------------------------
int x1() const { return m_x1_lr; }
int y1() const { return m_y1_lr; }
int x2() const { return line_lr(m_interpolator.y()); }
int y2() const { return line_lr(m_interpolator.y()); }
int x2_hr() const { return m_interpolator.y(); }
int y2_hr() const { return m_interpolator.y(); }
private:
int m_x1_lr;
int m_y1_lr;
int m_x2_lr;
int m_y2_lr;
bool m_ver;
unsigned m_len;
int m_inc;
dda2_line_interpolator m_interpolator;
};
}
#endif
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