Vertices

Name

Vertices -- vertex object and related functions.

Synopsis


#include <gts.h>


#define     GTS_VERTEX_CLASS                (klass)
#define     GTS_VERTEX                      (obj)
#define     GTS_IS_VERTEX                   (obj)
struct      GtsVertexClass;
struct      GtsVertex;

GtsVertexClass* gts_vertex_class            (void);
GtsVertex*  gts_vertex_new                  (GtsVertexClass *klass,
                                             gdouble x,
                                             gdouble y,
                                             gdouble z);
gboolean    gts_vertex_is_unattached        (GtsVertex *v);
gboolean    gts_vertex_is_boundary          (GtsVertex *v,
                                             GtsSurface *surface);
guint       gts_vertex_is_contact           (GtsVertex *v,
                                             gboolean sever);
GtsSegment* gts_vertices_are_connected      (GtsVertex *v1,
                                             GtsVertex *v2);
void        gts_vertex_replace              (GtsVertex *v,
                                             GtsVertex *with);
GSList*     gts_vertex_neighbors            (GtsVertex *v,
                                             GSList *list,
                                             GtsSurface *surface);
GSList*     gts_vertex_triangles            (GtsVertex *v,
                                             GSList *list);
GSList*     gts_vertex_faces                (GtsVertex *v,
                                             GtsSurface *surface,
                                             GSList *list);
GSList*     gts_vertex_fan_oriented         (GtsVertex *v,
                                             GtsSurface *surface);
gboolean    gts_vertex_encroaches_edge      (GtsVertex *v,
                                             GtsEdge *e);
GSList*     gts_vertices_from_segments      (GSList *segments);
GList*      gts_vertices_merge              (GList *vertices,
                                             gdouble epsilon);

Description

Vertices are points used as endpoints of GtsSegment. They are derived from GtsPoint.

Details

GTS_VERTEX_CLASS()

#define     GTS_VERTEX_CLASS(klass)

Casts klass to GtsVertexClass.

klass :

a descendant of GtsVertexClass.


GTS_VERTEX()

#define     GTS_VERTEX(obj)

Casts obj to GtsVertex.

obj :

a descendant of GtsVertex.


GTS_IS_VERTEX()

#define     GTS_IS_VERTEX(obj)

Evaluates to TRUE if obj is a descendant of GtsVertex, FALSE otherwise.

obj :

a pointer to test.


struct GtsVertexClass

struct GtsVertexClass {

  GtsPointClass parent_class;

  void        (* intersection_attributes) (GtsVertex *, 
					   GtsObject *, 
					   GtsObject *);
};

The vertex class. No virtual functions are associated.


struct GtsVertex

struct GtsVertex {

  GtsPoint p;
  
  GSList * segments;
};

The vertex object.

GtsPoint p

The parent object.

GSList *segments

Contains all the GtsSegment using this vertex as one of their endpoints.


gts_vertex_class ()

GtsVertexClass* gts_vertex_class            (void);

Returns :

the GtsVertexClass.


gts_vertex_new ()

GtsVertex*  gts_vertex_new                  (GtsVertexClass *klass,
                                             gdouble x,
                                             gdouble y,
                                             gdouble z);

klass :

a GtsVertexClass.

x :

the x-coordinate of the vertex to create.

y :

the y-coordinate of the vertex to create.

z :

the y-coordinate of the vertex to create.

Returns :

a new GtsVertex with x, y and z as coordinates.


gts_vertex_is_unattached ()

gboolean    gts_vertex_is_unattached        (GtsVertex *v);

v :

a GtsVertex.

Returns :

TRUE if v is not the endpoint of any GtsSegment, FALSE otherwise.


gts_vertex_is_boundary ()

gboolean    gts_vertex_is_boundary          (GtsVertex *v,
                                             GtsSurface *surface);

v :

a GtsVertex.

surface :

a GtsSurface or NULL.

Returns :

TRUE if v is used by a GtsEdge boundary of surface as determined by gts_edge_is_boundary(), FALSE otherwise.


gts_vertex_is_contact ()

guint       gts_vertex_is_contact           (GtsVertex *v,
                                             gboolean sever);

v :

a GtsVertex.

sever :

if TRUE and if v is a contact vertex between two or more sets of connected triangles replaces it with as many vertices, clones of v.

Returns :

the number of sets of connected triangles sharing v as a contact vertex.


gts_vertices_are_connected ()

GtsSegment* gts_vertices_are_connected      (GtsVertex *v1,
                                             GtsVertex *v2);

v1 :

a GtsVertex.

v2 :

another GtsVertex.

Returns :

if v1 and v2 are the vertices of the same GtsSegment this segment else NULL.


gts_vertex_replace ()

void        gts_vertex_replace              (GtsVertex *v,
                                             GtsVertex *with);

Replaces vertex v with vertex with. v and with must be different. All the GtsSegment which have v has one of their vertices are updated. The segments list of vertex v is freed and v->segments is set to NULL.

v :

a GtsVertex.

with :

another GtsVertex.


gts_vertex_neighbors ()

GSList*     gts_vertex_neighbors            (GtsVertex *v,
                                             GSList *list,
                                             GtsSurface *surface);

Adds to list all the GtsVertex connected to v by a GtsSegment and not already in list. If surface is not NULL only the vertices connected to v by an edge belonging to surface are considered.

v :

a GtsVertex.

list :

a list of GtsVertex.

surface :

a GtsSurface or NULL.

Returns :

the new list of unique GtsVertex.


gts_vertex_triangles ()

GSList*     gts_vertex_triangles            (GtsVertex *v,
                                             GSList *list);

Adds all the GtsTriangle which share v as a vertex and do not already belong to list.

v :

a GtsVertex.

list :

a list of GtsTriangle.

Returns :

the new list of unique GtsTriangle which share v as a vertex.


gts_vertex_faces ()

GSList*     gts_vertex_faces                (GtsVertex *v,
                                             GtsSurface *surface,
                                             GSList *list);

Adds all the GtsFace belonging to surface (if not NULL) which share v as a vertex and do not already belong to list.

v :

a GtsVertex.

surface :

a GtsSurface or NULL.

list :

a list of GtsFace.

Returns :

the new list of unique GtsFace belonging to surface which share v as a vertex.


gts_vertex_fan_oriented ()

GSList*     gts_vertex_fan_oriented         (GtsVertex *v,
                                             GtsSurface *surface);

v :

a GtsVertex.

surface :

a GtsSurface.

Returns :

a list of GtsEdge describing in counterclockwise order the boundary of the fan of summit v, the faces of the fan belonging to surface.


gts_vertex_encroaches_edge ()

gboolean    gts_vertex_encroaches_edge      (GtsVertex *v,
                                             GtsEdge *e);

v :

a GtsVertex.

e :

a GtsEdge.

Returns :

TRUE if v is strictly contained in the diametral circle of e, FALSE otherwise.


gts_vertices_from_segments ()

GSList*     gts_vertices_from_segments      (GSList *segments);

segments :

a list of GtsSegment.

Returns :

a list of GtsVertex, vertices of a GtsSegment in segments. Each element in the list is unique (no duplicates).


gts_vertices_merge ()

GList*      gts_vertices_merge              (GList *vertices,
                                             gdouble epsilon);

For each vertex v in vertices look if there are any vertex of vertices contained in a box centered on v of size 2*epsilon. If there are, replace them with v (using gts_vertex_replace()), destroy them and remove them from list. This is done efficiently using Kd-Trees.

vertices :

a list of GtsVertex.

epsilon :

half the size of the bounding box to consider for each vertex.

Returns :

the updated list of vertices.