Show agg_curves.h syntax highlighted
//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.3
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
// Copyright (C) 2005 Tony Juricic (tonygeek@yahoo.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 curve3 and curve4
//
//----------------------------------------------------------------------------
#ifndef AGG_CURVES_INCLUDED
#define AGG_CURVES_INCLUDED
#include "agg_basics.h"
namespace agg
{
// See Implemantation agg_curves.cpp
//------------------------------------------------------------------curve3
class curve3
{
public:
curve3() :
m_num_steps(0), m_step(0), m_scale(1.0) { }
curve3(double x1, double y1,
double x2, double y2,
double x3, double y3) :
m_num_steps(0), m_step(0), m_scale(1.0)
{
init(x1, y1, x2, y2, x3, y3);
}
void reset() { m_num_steps = 0; m_step = -1; }
void init(double x1, double y1,
double x2, double y2,
double x3, double y3);
void approximation_scale(double s) { m_scale = s; }
double approximation_scale() const { return m_scale; }
void rewind(unsigned path_id);
unsigned vertex(double* x, double* y);
private:
int m_num_steps;
int m_step;
double m_scale;
double m_start_x;
double m_start_y;
double m_end_x;
double m_end_y;
double m_fx;
double m_fy;
double m_dfx;
double m_dfy;
double m_ddfx;
double m_ddfy;
double m_saved_fx;
double m_saved_fy;
double m_saved_dfx;
double m_saved_dfy;
};
//-----------------------------------------------------------------curve4
class curve4
{
public:
struct points
{
double cp[8];
points() {}
points(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4)
{
cp[0] = x1; cp[1] = y1; cp[2] = x2; cp[3] = y2;
cp[4] = x3; cp[5] = y3; cp[6] = x4; cp[7] = y4;
}
double operator [] (unsigned i) const { return cp[i]; }
double& operator [] (unsigned i) { return cp[i]; }
};
curve4() :
m_num_steps(0), m_step(0), m_scale(1.0) { }
curve4(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4) :
m_num_steps(0), m_step(0), m_scale(1.0)
{
init(x1, y1, x2, y2, x3, y3, x4, y4);
}
curve4(const points& cp) :
m_num_steps(0), m_step(0), m_scale(1.0)
{
init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
}
void reset() { m_num_steps = 0; m_step = -1; }
void init(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4);
void init(const points& cp)
{
init(cp[0], cp[1], cp[2], cp[3], cp[4], cp[5], cp[6], cp[7]);
}
void approximation_scale(double s) { m_scale = s; }
double approximation_scale() const { return m_scale; }
void rewind(unsigned path_id);
unsigned vertex(double* x, double* y);
private:
int m_num_steps;
int m_step;
double m_scale;
double m_start_x;
double m_start_y;
double m_end_x;
double m_end_y;
double m_fx;
double m_fy;
double m_dfx;
double m_dfy;
double m_ddfx;
double m_ddfy;
double m_dddfx;
double m_dddfy;
double m_saved_fx;
double m_saved_fy;
double m_saved_dfx;
double m_saved_dfy;
double m_saved_ddfx;
double m_saved_ddfy;
};
//-------------------------------------------------------catrom_to_bezier
inline curve4::points catrom_to_bezier(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4)
{
// Trans. matrix Catmull-Rom to Bezier
//
// 0 1 0 0
// -1/6 1 1/6 0
// 0 1/6 1 -1/6
// 0 0 1 0
//
return curve4::points(
x2,
y2,
(-x1 + 6*x2 + x3) / 6,
(-y1 + 6*y2 + y3) / 6,
( x2 + 6*x3 - x4) / 6,
( y2 + 6*y3 - y4) / 6,
x3,
y3);
}
//-----------------------------------------------------------------------
inline curve4::points
catrom_to_bezier(const curve4::points& cp)
{
return catrom_to_bezier(cp[0], cp[1], cp[2], cp[3],
cp[4], cp[5], cp[6], cp[7]);
}
//-----------------------------------------------------ubspline_to_bezier
inline curve4::points ubspline_to_bezier(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4)
{
// Trans. matrix Uniform BSpline to Bezier
//
// 1/6 4/6 1/6 0
// 0 4/6 2/6 0
// 0 2/6 4/6 0
// 0 1/6 4/6 1/6
//
return curve4::points(
(x1 + 4*x2 + x3) / 6,
(y1 + 4*y2 + y3) / 6,
(4*x2 + 2*x3) / 6,
(4*y2 + 2*y3) / 6,
(2*x2 + 4*x3) / 6,
(2*y2 + 4*y3) / 6,
(x2 + 4*x3 + x4) / 6,
(y2 + 4*y3 + y4) / 6);
}
//-----------------------------------------------------------------------
inline curve4::points
ubspline_to_bezier(const curve4::points& cp)
{
return ubspline_to_bezier(cp[0], cp[1], cp[2], cp[3],
cp[4], cp[5], cp[6], cp[7]);
}
//------------------------------------------------------hermite_to_bezier
inline curve4::points hermite_to_bezier(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4)
{
// Trans. matrix Hermite to Bezier
//
// 1 0 0 0
// 1 0 1/3 0
// 0 1 0 -1/3
// 0 1 0 0
//
return curve4::points(
x1,
y1,
(3*x1 + x3) / 3,
(3*y1 + y3) / 3,
(3*x2 - x4) / 3,
(3*y2 - y4) / 3,
x2,
y2);
}
//-----------------------------------------------------------------------
inline curve4::points
hermite_to_bezier(const curve4::points& cp)
{
return hermite_to_bezier(cp[0], cp[1], cp[2], cp[3],
cp[4], cp[5], cp[6], cp[7]);
}
}
#endif
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