agg/include/agg_span_interpolator_linear.h

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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
//----------------------------------------------------------------------------
#ifndef AGG_SPAN_INTERPOLATOR_LINEAR_INCLUDED
#define AGG_SPAN_INTERPOLATOR_LINEAR_INCLUDED
#include "agg_basics.h"
#include "agg_dda_line.h"
#include "agg_trans_affine.h"
namespace agg
{
//================================================span_interpolator_linear
template<class Transformer = trans_affine, unsigned SubpixelShift = 8>
class span_interpolator_linear
{
public:
typedef Transformer trans_type;
enum subpixel_scale_e
{
subpixel_shift = SubpixelShift,
subpixel_scale = 1 << subpixel_shift
};
//--------------------------------------------------------------------
span_interpolator_linear() {}
span_interpolator_linear(trans_type& trans) : m_trans(&trans) {}
span_interpolator_linear(trans_type& trans,
double x, double y, unsigned len) :
m_trans(&trans)
{
begin(x, y, len);
}
//----------------------------------------------------------------
const trans_type& transformer() const { return *m_trans; }
void transformer(trans_type& trans) { m_trans = &trans; }
//----------------------------------------------------------------
void begin(double x, double y, unsigned len)
{
double tx;
double ty;
tx = x;
ty = y;
m_trans->transform(&tx, &ty);
int x1 = iround(tx * subpixel_scale);
int y1 = iround(ty * subpixel_scale);
tx = x + len;
ty = y;
m_trans->transform(&tx, &ty);
int x2 = iround(tx * subpixel_scale);
int y2 = iround(ty * subpixel_scale);
m_li_x = dda2_line_interpolator(x1, x2, len);
m_li_y = dda2_line_interpolator(y1, y2, len);
}
//----------------------------------------------------------------
void resynchronize(double xe, double ye, unsigned len)
{
m_trans->transform(&xe, &ye);
m_li_x = dda2_line_interpolator(m_li_x.y(), iround(xe * subpixel_scale), len);
m_li_y = dda2_line_interpolator(m_li_y.y(), iround(ye * subpixel_scale), len);
}
//----------------------------------------------------------------
void operator++()
{
++m_li_x;
++m_li_y;
}
//----------------------------------------------------------------
void coordinates(int* x, int* y) const
{
*x = m_li_x.y();
*y = m_li_y.y();
}
private:
trans_type* m_trans;
dda2_line_interpolator m_li_x;
dda2_line_interpolator m_li_y;
};
//=====================================span_interpolator_linear_subdiv
template<class Transformer = trans_affine, unsigned SubpixelShift = 8>
class span_interpolator_linear_subdiv
{
public:
typedef Transformer trans_type;
enum subpixel_scale_e
{
subpixel_shift = SubpixelShift,
subpixel_scale = 1 << subpixel_shift
};
//----------------------------------------------------------------
span_interpolator_linear_subdiv() :
m_subdiv_shift(4),
m_subdiv_size(1 << m_subdiv_shift),
m_subdiv_mask(m_subdiv_size - 1) {}
span_interpolator_linear_subdiv(trans_type& trans,
unsigned subdiv_shift = 4) :
m_subdiv_shift(subdiv_shift),
m_subdiv_size(1 << m_subdiv_shift),
m_subdiv_mask(m_subdiv_size - 1),
m_trans(&trans) {}
span_interpolator_linear_subdiv(trans_type& trans,
double x, double y, unsigned len,
unsigned subdiv_shift = 4) :
m_subdiv_shift(subdiv_shift),
m_subdiv_size(1 << m_subdiv_shift),
m_subdiv_mask(m_subdiv_size - 1),
m_trans(&trans)
{
begin(x, y, len);
}
//----------------------------------------------------------------
const trans_type& transformer() const { return *m_trans; }
void transformer(const trans_type& trans) { m_trans = &trans; }
//----------------------------------------------------------------
unsigned subdiv_shift() const { return m_subdiv_shift; }
void subdiv_shift(unsigned shift)
{
m_subdiv_shift = shift;
m_subdiv_size = 1 << m_subdiv_shift;
m_subdiv_mask = m_subdiv_size - 1;
}
//----------------------------------------------------------------
void begin(double x, double y, unsigned len)
{
double tx;
double ty;
m_pos = 1;
m_src_x = iround(x * subpixel_scale) + subpixel_scale;
m_src_y = y;
m_len = len;
if(len > m_subdiv_size) len = m_subdiv_size;
tx = x;
ty = y;
m_trans->transform(&tx, &ty);
int x1 = iround(tx * subpixel_scale);
int y1 = iround(ty * subpixel_scale);
tx = x + len;
ty = y;
m_trans->transform(&tx, &ty);
m_li_x = dda2_line_interpolator(x1, iround(tx * subpixel_scale), len);
m_li_y = dda2_line_interpolator(y1, iround(ty * subpixel_scale), len);
}
//----------------------------------------------------------------
void operator++()
{
++m_li_x;
++m_li_y;
if(m_pos >= m_subdiv_size)
{
unsigned len = m_len;
if(len > m_subdiv_size) len = m_subdiv_size;
double tx = double(m_src_x) / double(subpixel_scale) + len;
double ty = m_src_y;
m_trans->transform(&tx, &ty);
m_li_x = dda2_line_interpolator(m_li_x.y(), iround(tx * subpixel_scale), len);
m_li_y = dda2_line_interpolator(m_li_y.y(), iround(ty * subpixel_scale), len);
m_pos = 0;
}
m_src_x += subpixel_scale;
++m_pos;
--m_len;
}
//----------------------------------------------------------------
void coordinates(int* x, int* y) const
{
*x = m_li_x.y();
*y = m_li_y.y();
}
private:
unsigned m_subdiv_shift;
unsigned m_subdiv_size;
unsigned m_subdiv_mask;
trans_type* m_trans;
dda2_line_interpolator m_li_x;
dda2_line_interpolator m_li_y;
int m_src_x;
double m_src_y;
unsigned m_pos;
unsigned m_len;
};
}
#endif