GIS Library - rotate. More...

#include <math.h>

Include dependency graph for rotate.c:

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)

void	G_rotate_around_point_int (int X0, int Y0, int X1, int Y1, double angle)
	Rotate point (int version)

Detailed Description

GIS Library - rotate.

SPDX-FileCopyrightText: 2001-2014 GRASS Development Team SPDX-License-Identifier: GPL-2.0-or-later

Author: Hamish Bowman, Glynn Clements

Definition in file rotate.c.

Macro Definition Documentation

◆ D2R

#define D2R ( d ) (double)(d * RpD) /* degrees->radians */

Definition at line 15 of file rotate.c.

◆ R2D

#define R2D ( d ) (double)(d / RpD) /* radians->degrees */

Definition at line 16 of file rotate.c.

◆ RpD

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

Definition at line 14 of file rotate.c.

Function Documentation

◆ G_rotate_around_point()

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 30 of file rotate.c.

References D2R.

Referenced by G_rotate_around_point_int(), and stroke_chain().

◆ G_rotate_around_point_int()

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 57 of file rotate.c.

References G_rotate_around_point(), and x.

Macros

Functions