vgl_clip.h File Reference

#include <vgl/vgl_box_2d.h>
#include <vgl/vgl_line_2d.h>
#include <vgl/vgl_line_segment_2d.h>
#include <vgl/vgl_polygon.h>

Go to the source code of this file.

Macros
#define	VGL_CLIP_INSTANTIATE(T)   extern "please include vgl/vgl_clip.hxx instead"

Enumerations
enum	vgl_clip_type { vgl_clip_type_intersect, vgl_clip_type_union, vgl_clip_type_difference, vgl_clip_type_xor }
	Type of polygon "clip" operations. More...

Functions
template<class T >
bool	vgl_clip_lineseg_to_line (T &x1, T &y1, T &x2, T &y2, T a, T b, T c)
	clips away the portion where ax+by+c<0. return false if nothing left. More...
template<class T >
bool	vgl_clip_line_to_box (T a, T b, T c, T x1, T y1, T x2, T y2, T &bx, T &by, T &ex, T &ey)
	clip line ax+by+c=0 to given box. return false if no intersection. More...
template<class T >
vgl_line_segment_2d< T >	vgl_clip_line_to_box (vgl_line_2d< T > const &l, vgl_box_2d< T > const &b)
	clip given line to given box, and return resulting line segment. More...
template<class T >
vgl_polygon< T >	vgl_clip (const vgl_polygon< T > &poly1, const vgl_polygon< T > &poly2, vgl_clip_type op=vgl_clip_type_intersect)
	Clip a polygon against another polygon. More...
template<class T >
vgl_polygon< T >	vgl_clip (vgl_polygon< T > const &poly1, vgl_polygon< T > const &poly2, vgl_clip_type op, int *p_retval)
	Clip a polygon against another polygon. More...

Detailed Description

Author

fsm

  Modifications
   29 Apr 2002: Amitha Perera: added a polygon clipper (a wrap around for
                               Alan Murt's Generic Polygon Clipper)
   12 Oct 2002: Peter Vanroose: vgl_clip_line_to_box completely re-implemented
   14 Nov 2003: Peter Vanroose: made all functions templated
   27 May 2015: Scott Richardson: added another polygon clipper library (a wrapper
                around Angus Johnson's Clipper library)

Definition in file vgl_clip.h.

Macro Definition Documentation

VGL_CLIP_INSTANTIATE

#define VGL_CLIP_INSTANTIATE

(

T

)

extern "please include vgl/vgl_clip.hxx instead"

Definition at line 97 of file vgl_clip.h.

Enumeration Type Documentation

vgl_clip_type

enum vgl_clip_type

Type of polygon "clip" operations.

Enumerator
vgl_clip_type_intersect
vgl_clip_type_union
vgl_clip_type_difference
vgl_clip_type_xor

Definition at line 23 of file vgl_clip.h.

Function Documentation

vgl_clip() [1/2]

template<class T >

vgl_polygon< T > vgl_clip	(	const vgl_polygon< T > &	poly1,
		const vgl_polygon< T > &	poly2,
		vgl_clip_type	op = vgl_clip_type_intersect
	)

Clip a polygon against another polygon.

The two polygons poly1 and poly2 are combined with each other. The operation (intersection, union, etc) is given by parameter op.

Note

The implementation of this code is based on Alan Murta's GPC library (http://www.cs.man.ac.uk/aig/staff/alan/software/gpc.html) which is free for non-commercial use.

In order to be able to use it, make sure to satisfy the copyright notice, then activate the "BUILD_NONCOMMERCIAL" compiler option.

Definition at line 333 of file vgl_clip.hxx.

vgl_clip() [2/2]

template<class T >

vgl_polygon< T > vgl_clip	(	vgl_polygon< T > const &	poly1,
		vgl_polygon< T > const &	poly2,
		vgl_clip_type	op,
		int *	p_retval
	)

Clip a polygon against another polygon.

Same as vgl_clip( const vgl_polygon<T>& poly1, const vgl_polygon<T>& poly2, vgl_clip_type op = vgl_clip_type_intersect ); but where the fourth parameter is a return flag which is 1 if success, or 0 if the operation faced a geometric degeneracy which could not be handled. In this case, it might be necessary to perturb the input with a tiny amount of random noise and try again.

Definition at line 207 of file vgl_clip.hxx.

vgl_clip_line_to_box() [1/2]

template<class T >

bool vgl_clip_line_to_box	(	T	a,
		T	b,
		T	c,
		T	x1,
		T	y1,
		T	x2,
		T	y2,
		T &	bx,
		T &	by,
		T &	ex,
		T &	ey
	)

clip line ax+by+c=0 to given box. return false if no intersection.

Definition at line 45 of file vgl_clip.hxx.

vgl_clip_line_to_box() [2/2]

template<class T >

vgl_line_segment_2d< T > vgl_clip_line_to_box ( vgl_line_2d< T > const &  l, vgl_box_2d< T > const &  b  )

inline

clip given line to given box, and return resulting line segment.

Definition at line 55 of file vgl_clip.h.

vgl_clip_lineseg_to_line()

template<class T >

bool vgl_clip_lineseg_to_line	(	T &	x1,
		T &	y1,
		T &	x2,
		T &	y2,
		T	a,
		T	b,
		T	c
	)

clips away the portion where ax+by+c<0. return false if nothing left.

Definition at line 19 of file vgl_clip.hxx.