OGSF library - loading and manipulating surfaces. More...

#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/ogsf.h>

Include dependency graph for gs_util.c:

Functions
double	GS_geodistance (double from, double to, const char *units)
	Calculate distance between 2 coordinates. More...

float	GS_distance (float from, float to)
	Calculate distance. More...

float	GS_P2distance (float from, float to)
	Calculate distance in plane. More...

void	GS_v3eq (float v1, float v2)
	Copy vector values. More...

void	GS_v3add (float v1, float v2)
	Sum vectors. More...

void	GS_v3sub (float v1, float v2)
	Subtract vectors. More...

void	GS_v3mult (float *v1, float k)
	Multiple vectors. More...

int	GS_v3norm (float *v1)
	Change v1 so that it is a unit vector (2D) More...

int	GS_v2norm (float *v1)
	Change v1 so that it is a unit vector (3D) More...

int	GS_dv3norm (double *dv1)
	Changes v1 so that it is a unit vector. More...

int	GS_v3normalize (float v1, float v2)
	Change v2 so that v1v2 is a unit vector. More...

int	GS_v3dir (float v1, float v2, float *v3)
	Get a normalized direction from v1 to v2, store in v3. More...

void	GS_v2dir (float v1, float v2, float *v3)
	Get a normalized direction from v1 to v2, store in v3 (2D) More...

void	GS_v3cross (float v1, float v2, float *v3)
	Get the cross product v3 = v1 cross v2. More...

void	GS_v3mag (float v1, float mag)
	Magnitude of vector. More...

int	GS_coordpair_repeats (float p1, float p2, int nhist)
	ADD. More...

Detailed Description

OGSF library - loading and manipulating surfaces.

GRASS OpenGL gsurf OGSF Library

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

Author: Bill Brown USACERL, GMSL/University of Illinois; Doxygenized by Martin Landa <landa.martin gmail.com> (May 2008)

Definition in file gs_util.c.

Function Documentation

◆ GS_coordpair_repeats()

int GS_coordpair_repeats	(	float *	p1,
		float *	p2,
		int	nhist
	)

ADD.

Initialize by calling with a number nhist to represent number of previous entries to check, then call with zero as nhist

Parameters

p1	first point
p2	second point
nhist	?

Returns: -1 on error; -2; 1; 9

Definition at line 440 of file gs_util.c.

References NULL.

◆ GS_distance()

float GS_distance	(	float *	from,
		float *	to
	)

Calculate distance.

Parameters

from	'from' point (X,Y,Z)
to	'to' point (X,Y,Z)

Returns: distance

Definition at line 141 of file gs_util.c.

References X, x, Y, and Z.

Referenced by GS_look_here(), gs_setlos_enterdata(), gsd_zup_twist(), and gv_line_length().

◆ GS_dv3norm()

int GS_dv3norm ( double * dv1 )

Changes v1 so that it is a unit vector.

Parameters

dv1 vector

Returns: 0 if magnitude of dv1 is zero; 1 if magnitude of dv1 > 0

Definition at line 295 of file gs_util.c.

References X, Y, and Z.

◆ GS_geodistance()

double GS_geodistance	(	double *	from,
		double *	to,
		const char *	units
	)

Calculate distance between 2 coordinates.

Units is one of:

"meters",
"miles",
"kilometers",
"feet",
"yards",
"nmiles" (nautical miles),
"rods",
"inches",
"centimeters",
"millimeters",
"micron",
"nanometers",
"cubits",
"hands",
"furlongs",
"chains"

Default is meters.

Parameters

from	starting point
to	ending point
units	map units

Returns: distance between two geographic coordinates in current projection

Definition at line 55 of file gs_util.c.

References Gs_distance().

◆ GS_P2distance()

float GS_P2distance	(	float *	from,
		float *	to
	)

Calculate distance in plane.

Parameters

from	'from' point (X,Y)
to	'to' point (X,Y)

Returns: distance

Definition at line 160 of file gs_util.c.

References X, x, and Y.

Referenced by gv_line_length(), and seg_intersect_vregion().

◆ GS_v2dir()

void GS_v2dir	(	float *	v1,
		float *	v2,
		float *	v3
	)

Get a normalized direction from v1 to v2, store in v3 (2D)

Parameters

	v1	first vector
	v2	second vector
[out]	v3	output vector

Returns: 0 if magnitude of dx is zero; 1 if magnitude of dx > 0

Definition at line 382 of file gs_util.c.

References X, and Y.

◆ GS_v2norm()

int GS_v2norm ( float * v1 )

Change v1 so that it is a unit vector (3D)

Parameters

[in,out] v1 vector

Returns: 0 if magnitude of v1 is zero; 1 if magnitude of v1 > 0

Definition at line 271 of file gs_util.c.

References X, and Y.

◆ GS_v3add()

void GS_v3add	(	float *	v1,
		float *	v2
	)

Sum vectors.

v1 += v2

Parameters

[in,out]	v1	first vector
	v2	second vector

Definition at line 195 of file gs_util.c.

References X, Y, and Z.

Referenced by gs_setlos_enterdata().

◆ GS_v3cross()

void GS_v3cross	(	float *	v1,
		float *	v2,
		float *	v3
	)

Get the cross product v3 = v1 cross v2.

Parameters

	v1	first vector
	v2	second vector
[out]	v3	output vector

Definition at line 403 of file gs_util.c.

References X, Y, and Z.

◆ GS_v3dir()

int GS_v3dir	(	float *	v1,
		float *	v2,
		float *	v3
	)

Get a normalized direction from v1 to v2, store in v3.

Parameters

	v1	first vector
	v2	second vector
[out]	v3	output vector

Returns: 0 if magnitude of dx is zero; 1 if magnitude of dx > 0

Definition at line 351 of file gs_util.c.

References X, Y, and Z.

Referenced by GS_get_viewdir(), gs_setlos_enterdata(), and gsd_get_zup().

◆ GS_v3eq()

void GS_v3eq	(	float *	v1,
		float *	v2
	)

Copy vector values.

v1 = v2

Parameters

[out]	v1	first vector
	v2	second vector

Definition at line 178 of file gs_util.c.

References X, Y, and Z.

Referenced by gpd_obj(), GS_get_from(), GS_get_from_real(), GS_get_to(), Gs_save_3dview(), gsd_check_focus(), gsd_zup_twist(), and gsdrape_get_allsegments().

◆ GS_v3mag()

void GS_v3mag	(	float *	v1,
		float *	mag
	)

Magnitude of vector.

Parameters

	v1	vector
[out]	mag	magnitude value

Definition at line 418 of file gs_util.c.

References X, Y, and Z.

◆ GS_v3mult()

void GS_v3mult	(	float *	v1,
		float	k
	)

Multiple vectors.

v1 *= k

Parameters

[in,out]	v1	vector
	k	multiplicator

Definition at line 229 of file gs_util.c.

References X, Y, and Z.

Referenced by Gs_save_3dview(), gs_setlos_enterdata(), and gsd_check_focus().

◆ GS_v3norm()

int GS_v3norm ( float * v1 )

Change v1 so that it is a unit vector (2D)

Parameters

[in,out] v1 vector

Returns: 0 if magnitude of v1 is zero; 1 if magnitude of v1 > 0

Definition at line 246 of file gs_util.c.

References X, Y, and Z.

◆ GS_v3normalize()

int GS_v3normalize	(	float *	v1,
		float *	v2
	)

Change v2 so that v1v2 is a unit vector.

Parameters

v1	first vector
v2[in,out]	second vector

Returns: 0 if magnitude of dx is zero; 1 if magnitude of dx > 0

Definition at line 321 of file gs_util.c.

References X, Y, and Z.

Referenced by gsd_check_focus().

◆ GS_v3sub()

void GS_v3sub	(	float *	v1,
		float *	v2
	)

Subtract vectors.

v1 -= v2

Parameters

[in,out]	v1	first vector
	v2	second vector

Definition at line 212 of file gs_util.c.

References X, Y, and Z.

Functions

Detailed Description

Function Documentation

◆ GS_coordpair_repeats()

◆ GS_distance()

◆ GS_dv3norm()

◆ GS_geodistance()

◆ GS_P2distance()

◆ GS_v2dir()

◆ GS_v2norm()

◆ GS_v3add()

◆ GS_v3cross()

◆ GS_v3dir()

◆ GS_v3eq()

◆ GS_v3mag()

◆ GS_v3mult()

◆ GS_v3norm()

◆ GS_v3normalize()

◆ GS_v3sub()