gis/intersect.c File Reference

Go to the source code of this file.

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))
#define	SWAP(x, y)   {int t; t=x; x=y; y=t;}

Functions
int	G_intersect_line_segments (double ax1, double ay1, double ax2, double ay2, double bx1, double by1, double bx2, double by2, double *ra, double *rb, double *x, double *y)

Macro Definition Documentation

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

Definition at line 74 of file gis/intersect.c.

Referenced by D_a_to_d_col(), D_a_to_d_row(), D_d_to_a_col(), D_d_to_a_row(), D_d_to_u_col(), D_d_to_u_row(), D_do_conversions(), D_get_d(), D_get_d_east(), D_get_d_north(), D_get_d_south(), D_get_d_west(), D_u_to_d_col(), D_u_to_d_row(), G_intersect_line_segments(), mc33_test_face(), N_exp_upwinding(), and N_full_upwinding().

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

Definition at line 75 of file gis/intersect.c.

Referenced by G_intersect_line_segments().

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

Definition at line 76 of file gis/intersect.c.

Referenced by G_intersect_line_segments().

#define SWAP	(		x,
			y
	)		{int t; t=x; x=y; y=t;}

Definition at line 78 of file gis/intersect.c.

Referenced by G_intersect_line_segments().

Function Documentation

int G_intersect_line_segments	(	double	ax1,
		double	ay1,
		double	ax2,
		double	ay2,
		double	bx1,
		double	by1,
		double	bx2,
		double	by2,
		double *	ra,
		double *	rb,
		double *	x,
		double *	y
	)

Definition at line 80 of file gis/intersect.c.

References D, D1, D2, and SWAP.

Referenced by G_distance_between_line_segments(), and G_distance_point_to_line_segment().