vector/Vlib/intersect.c File Reference

#include <stdlib.h>
#include <math.h>
#include <grass/gis.h>
#include <grass/Vect.h>
#include <grass/glocale.h>

Include dependency graph for vector/Vlib/intersect.c:

Go to the source code of this file.

Data Structures
struct	CROSS

Macros
#define	D   ((ax2-ax1)*(by1-by2) - (ay2-ay1)*(bx1-bx2))
#define	D1   ((bx1-ax1)*(by1-by2) - (by1-ay1)*(bx1-bx2))
#define	D2   ((ax2-ax1)*(by1-ay1) - (ay2-ay1)*(bx1-ax1))

Functions
int	Vect_segment_intersection (double ax1, double ay1, double az1, double ax2, double ay2, double az2, double bx1, double by1, double bz1, double bx2, double by2, double bz2, double *x1, double *y1, double *z1, double *x2, double *y2, double *z2, int with_z)
	Check for intersect of 2 line segments. More...
int	Vect_line_intersection (struct line_pnts *APoints, struct line_pnts *BPoints, struct line_pnts ***ALines, struct line_pnts ***BLines, int *nalines, int *nblines, int with_z)
	Intersect 2 lines. More...
int	Vect_line_check_intersection (struct line_pnts *APoints, struct line_pnts *BPoints, int with_z)
	Check if 2 lines intersect. More...
int	Vect_line_get_intersections (struct line_pnts *APoints, struct line_pnts *BPoints, struct line_pnts *IPoints, int with_z)
	Get 2 lines intersection points. More...

Macro Definition Documentation

#define D   ((ax2-ax1)*(by1-by2) - (ay2-ay1)*(bx1-bx2))

Definition at line 52 of file vector/Vlib/intersect.c.

Referenced by Vect_segment_intersection().

#define D1   ((bx1-ax1)*(by1-by2) - (by1-ay1)*(bx1-bx2))

Definition at line 53 of file vector/Vlib/intersect.c.

Referenced by Vect_segment_intersection().

#define D2   ((ax2-ax1)*(by1-ay1) - (ay2-ay1)*(bx1-ax1))

Definition at line 54 of file vector/Vlib/intersect.c.

Referenced by Vect_segment_intersection().

Function Documentation

int Vect_line_check_intersection	(	struct line_pnts *	APoints,
		struct line_pnts *	BPoints,
		int	with_z
	)

Check if 2 lines intersect.

Points (Points->n_points == 1) are also supported.

Parameters

[in]	APoints	first input line
[in]	BPoints	second input line
[in]	with_z	3D, not supported (only if one or both are points)!

Returns

0 no intersection

1 intersection found

Definition at line 1091 of file vector/Vlib/intersect.c.

References Rect::boundary, G_warning(), NULL, RTreeDestroyNode(), RTreeInsertRect(), RTreeNewIndex(), RTreeSearch(), Vect_copy_xyz_to_pnts(), Vect_line_distance(), and Vect_new_line_struct().

Referenced by wxdigit.IVDigit::OpenBackgroundMap(), Vect_line_get_intersections(), Vect_select_lines_by_polygon(), and Vedit_bulk_labeling().

int Vect_line_get_intersections	(	struct line_pnts *	APoints,
		struct line_pnts *	BPoints,
		struct line_pnts *	IPoints,
		int	with_z
	)

Get 2 lines intersection points.

A wrapper around Vect_line_check_intersection() function.

Parameters

[in]	APoints	first input line
[in]	BPoints	second input line
[out]	IPoints	output with intersection points
[in]	with_z	3D, not supported (only if one or both are points)!

Returns

0 no intersection

1 intersection found

Definition at line 1266 of file vector/Vlib/intersect.c.

References Vect_line_check_intersection().

int Vect_line_intersection	(	struct line_pnts *	APoints,
		struct line_pnts *	BPoints,
		struct line_pnts ***	ALines,
		struct line_pnts ***	BLines,
		int *	nalines,
		int *	nblines,
		int	with_z
	)

Intersect 2 lines.

Creates array of new lines created from original A line, by intersection with B line. Points (Points->n_points == 1) are not supported.

Parameters

[in]	APoints	first input line
[in]	BPoints	second input line
[out]	ALines	array of new lines created from original A line
[out]	BLines	array of new lines created from original B line
[out]	nalines	number of new lines (ALines)
[out]	nblines	number of new lines (BLines)
[in]	with_z	3D, not supported!

Returns

0 no intersection

1 intersection found

Definition at line 561 of file vector/Vlib/intersect.c.

References Rect::boundary, dig_line_degenerate(), CROSS::distance, G_debug(), l, RTreeDestroyNode(), RTreeInsertRect(), RTreeNewIndex(), RTreeSearch(), CROSS::segment, Vect_append_point(), Vect_destroy_line_struct(), Vect_new_line_struct(), CROSS::x, y, and CROSS::y.

Referenced by Vect_break_lines_list(), and Vedit_bulk_labeling().

int Vect_segment_intersection	(	double	ax1,
		double	ay1,
		double	az1,
		double	ax2,
		double	ay2,
		double	az2,
		double	bx1,
		double	by1,
		double	bz1,
		double	bx2,
		double	by2,
		double	bz2,
		double *	x1,
		double *	y1,
		double *	z1,
		double *	x2,
		double *	y2,
		double *	z2,
		int	with_z
	)

Check for intersect of 2 line segments.

Parameters

[in]	ax1,ay1,az1,ax2,ay2,az2	input line a
[in]	bx1,by1,bz1,bx2,by2,bz2	input line b
[out]	x1,y1,z1	intersection point1 (case 2-4)
[out]	x2,y2,z2	intersection point2 (case 2-4)
[in]	with_z	use z coordinate (3D) (TODO)

Returns

0 - do not intersect,

1 - intersect at one point,

2 - partial overlap,

3 - a contains b,

4 - b contains a,

5 - identical

Definition at line 109 of file vector/Vlib/intersect.c.

References D, D1, D2, G_debug(), and G_warning().