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.

Defines

#define RpD   ((2 * M_PI) / 360.)
#define D2R(d)   (double)(d * RpD)
#define R2D(d)   (double)(d / RpD)

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.

(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.


Define Documentation

#define D2R (  )     (double)(d * RpD)

Definition at line 18 of file rotate.c.

Referenced by G_rotate_around_point().

#define R2D (  )     (double)(d / RpD)

Definition at line 19 of file rotate.c.

#define RpD   ((2 * M_PI) / 360.)

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.

Referenced by 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 62 of file rotate.c.

References G_rotate_around_point().


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