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

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

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

ADD.

Initialize by calling with a number nhist to represent number of previous entrys 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 443 of file GS_util.c.

References G_free(), and NULL.

Referenced by GS_draw_flowline_at_xy().

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, y, and Y.

Referenced by gs_distance_onsurf(), GS_get_selected_point_on_surface(), GS_look_here(), gs_los_intersect1(), gs_setlos_enterdata(), gsd_zup_twist(), gv_line_length(), and Nviz_set_cplane_here().

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 n, X, and Y.

Referenced by gsd_def_cplane().

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().

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, y, and Y.

Referenced by gsd_arrow(), gsd_draw_cplane_fence(), gv_line_length(), and seg_intersect_vregion().

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 385 of file GS_util.c.

References n, X, and Y.

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 n, X, and Y.

Referenced by GS_draw_flowline_at_xy().

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, and Y.

Referenced by GS_moveto(), GS_set_viewdir(), gs_setlos_enterdata(), and gsd_arrow_onsurf().

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 406 of file GS_util.c.

References X, and Y.

Referenced by gsd_arrow_onsurf(), gsd_surf_map_old(), and Gv_load_vect().

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 353 of file GS_util.c.

References n, X, and Y.

Referenced by GS_get_modelposition(), GS_get_viewdir(), GS_look_here(), gs_los_intersect(), gs_los_intersect1(), gs_setlos_enterdata(), gsd_arrow_onsurf(), gsd_get_zup(), and Nviz_set_cplane_here().

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, and Y.

Referenced by gpd_obj(), GS_draw_lighting_model(), GS_draw_lighting_model1(), GS_get_focus(), GS_get_from(), GS_get_from_real(), GS_get_selected_point_on_surface(), GS_get_to(), GS_init_view(), gs_los_intersect(), GS_moveto(), Gs_save_3dview(), GS_set_focus(), GS_set_focus_real(), GS_set_viewdir(), gsd_arrow_onsurf(), gsd_check_focus(), gsd_surf_map_old(), gsd_wall(), gsd_zup_twist(), gsdrape_get_allsegments(), and gsdrape_get_segments().

void GS_v3mag	(	float *	v1,
		float *	mag
	)

Magnitude of vector.

Parameters

	v1	vector
[out]	mag	magnitude value

Definition at line 421 of file GS_util.c.

References X, and Y.

Referenced by gsd_arrow_onsurf(), and gsd_surf_map_old().

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, and Y.

Referenced by GS_look_here(), Gs_save_3dview(), gs_setlos_enterdata(), gsd_arrow_onsurf(), gsd_check_focus(), and Nviz_set_cplane_here().

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 n, X, and Y.

Referenced by GS_set_viewdir(), gsd_3darrow(), gsd_arrow(), gsd_draw_cplane_fence(), and iso_calc_cube().

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 322 of file GS_util.c.

References n, X, and Y.

Referenced by GS_init_view(), GS_moveto(), and gsd_check_focus().

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, and Y.

Referenced by GS_moveto(), and gsd_surf_map_old().

Functions

Detailed Description

Function Documentation