GRASS GIS 7 Programmer's Manual  7.5.svn(2018)-r72636
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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)   {double 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 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,
 
)    {double 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().