rotate.c File Reference

GIS Library - rotate. More...

#include <math.h>

Include dependency graph for rotate.c:

Go to the source code of this file.

Macros
#define	RpD   ((2 * M_PI) / 360.) /* radians/degree */
#define	D2R(d)   (double)(d * RpD) /* degrees->radians */
#define	R2D(d)   (double)(d / RpD) /* radians->degrees */

Functions
void	G_rotate_around_point (double X0, double Y0, double *X1, double *Y1, double angle)
	Rotate point (double version) More...
void	G_rotate_around_point_int (int X0, int Y0, int *X1, int *Y1, double angle)
	Rotate point (int version) More...

Detailed Description

GIS Library - rotate.

(C) 2001-2008 by the GRASS Development Team

This program is free software under the GNU General Public License (>=v2). Read the file COPYING that comes with GRASS for details.

Author

Hamish Bowman, Glynn Clements

Definition in file rotate.c.

Macro Definition Documentation

#define D2R

(

d

)

(double)(d * RpD) /* degrees->radians */

Definition at line 18 of file rotate.c.

Referenced by G_rotate_around_point().

#define R2D

(

d

)

(double)(d / RpD) /* radians->degrees */

Definition at line 19 of file rotate.c.

#define RpD   ((2 * M_PI) / 360.) /* radians/degree */

Definition at line 17 of file rotate.c.

Function Documentation

void G_rotate_around_point	(	double	X0,
		double	Y0,
		double *	X1,
		double *	Y1,
		double	angle
	)

Rotate point (double version)

Given a point, angle, and origin, rotate the point around the origin by the given angle. Coordinates and results are double prec floating point.

Parameters

	X0	X component of origin (center of circle)
	Y0	Y component of origin (center of circle)
[out]	X1	X component of point to be rotated (variable is modified!)
[out]	Y1	Y component of point to be rotated (variable is modified!)
	angle	in degrees, measured CCW from east

Definition at line 35 of file rotate.c.

References D2R, and dialogs::s.

Referenced by G_rotate_around_point_int(), and stroke_chain().

void G_rotate_around_point_int	(	int	X0,
		int	Y0,
		int *	X1,
		int *	Y1,
		double	angle
	)

Rotate point (int version)

Given a point, angle, and origin, rotate the point around the origin by the given angle. Coordinates are given in integer and results are rounded back to integer.

Parameters

	X0	X component of origin (center of circle)
	Y0	Y component of origin (center of circle)
[out]	X1	X component of point to be rotated (variable is modified!)
[out]	Y1	Y component of point to be rotated (variable is modified!)
	angle	in degrees, measured CCW from east

Definition at line 62 of file rotate.c.

References G_rotate_around_point(), int, and y.