void
p2tr_cdt_validate_edges (P2trCDT *self)
{
P2trHashSetIter iter;
P2trEdge *e;
p2tr_hash_set_iter_init (&iter, self->mesh->edges);
while (p2tr_hash_set_iter_next (&iter, (gpointer*)&e))
{
if (! e->constrained && e->tri == NULL)
p2tr_exception_geometric ("Found a non constrained edge without a triangle");
if (e->tri != NULL)
{
gboolean found = FALSE;
gint i = 0;
for (i = 0; i < 3; i++)
if (e->tri->edges[i] == e)
{
found = TRUE;
break;
}
if (! found)
p2tr_exception_geometric ("An edge has a triangle to which it does not belong!");
}
}
}
/**
* Insert a point so that is splits an existing edge. This function
* assumes that the point is on the edge itself and between its
* end-points.
* If the edge being split is constrained, then the function returns a
* list containing both parts resulted from the splitting. In that case,
* THE RETURNED EDGES MUST BE UNREFERENCED!
*/
GList*
p2tr_cdt_split_edge (P2trCDT *self,
P2trEdge *e,
P2trPoint *C)
{
/* W
* /|\
* / | \
* / | \ E.Mirror.Tri: YXW
* X*---*---*Y E: X->Y
* \ |C / E.Tri: XYV
* \ | /
* \|/
* V
*/
P2trPoint *X = P2TR_EDGE_START (e), *Y = e->end;
P2trPoint *V = (e->tri != NULL) ? p2tr_triangle_get_opposite_point(e->tri, e) : NULL;
P2trPoint *W = (e->mirror->tri != NULL) ? p2tr_triangle_get_opposite_point (e->mirror->tri, e->mirror) : NULL;
gboolean constrained = e->constrained;
P2trEdge *XC, *CY;
GList *new_tris = NULL, *fan = NULL, *new_edges = NULL;
p2tr_edge_remove (e);
XC = p2tr_mesh_new_edge (self->mesh, X, C, constrained);
CY = p2tr_mesh_new_edge (self->mesh, C, Y, constrained);
fan = p2tr_utils_new_reversed_pointer_list (4, W, X, V, Y);
new_tris = p2tr_cdt_triangulate_fan (self, C, fan);
g_list_free (fan);
/* Now make this a CDT again
* The new triangles will be unreffed by the flip_fix function, which
* is good since we receive them with an extra reference!
*/
p2tr_cdt_flip_fix (self, new_tris);
g_list_free (new_tris);
if (constrained)
{
/* If this was a subsegment, then both parts of the subsegment
* should exist */
if (p2tr_edge_is_removed (XC) || p2tr_edge_is_removed (CY))
p2tr_exception_geometric ("Subsegments gone!");
else
{
new_edges = g_list_prepend (new_edges, CY);
new_edges = g_list_prepend (new_edges, XC);
}
}
else
{
p2tr_edge_unref (XC);
p2tr_edge_unref (CY);
}
p2tr_cdt_on_new_point (self, C);
return new_edges;
}
void
p2tr_cdt_validate_cdt (P2trCDT *self)
{
P2trHashSetIter iter;
P2trTriangle *tri;
p2tr_hash_set_iter_init (&iter, self->mesh->triangles);
while (p2tr_hash_set_iter_next (&iter, (gpointer*)&tri))
if (! p2tr_cdt_has_empty_circum_circle(self, tri))
p2tr_exception_geometric ("Not a CDT!");
}
P2trPoint*
p2tr_cdt_insert_point (P2trCDT *self,
const P2trVector2 *pc,
P2trTriangle *point_location_guess)
{
P2trTriangle *tri;
P2trPoint *pt;
gboolean inserted = FALSE;
gint i;
P2TR_CDT_VALIDATE_UNUSED (self);
if (point_location_guess == NULL)
tri = p2tr_mesh_find_point (self->mesh, pc);
else
tri = p2tr_mesh_find_point_local (self->mesh, pc, point_location_guess);
if (tri == NULL)
p2tr_exception_geometric ("Tried to add point outside of domain!");
pt = p2tr_mesh_new_point (self->mesh, pc);
/* If the point falls on a line, we should split the line */
for (i = 0; i < 3; i++)
{
P2trEdge *edge = tri->edges[i];
if (p2tr_math_orient2d (& P2TR_EDGE_START(edge)->c,
&edge->end->c, pc) == P2TR_ORIENTATION_LINEAR)
{
GList *parts = p2tr_cdt_split_edge (self, edge, pt), *eIter;
for (eIter = parts; eIter != NULL; eIter = eIter->next)
p2tr_edge_unref ((P2trEdge*)eIter->data);
g_list_free(parts);
inserted = TRUE;
break;
}
}
if (! inserted)
/* If we reached this line, then the point is inside the triangle */
p2tr_cdt_insert_point_into_triangle (self, pt, tri);
/* We no longer need the triangle */
p2tr_triangle_unref (tri);
P2TR_CDT_VALIDATE_UNUSED (self);
return pt;
}
P2trPoint*
p2tr_cdt_insert_point (P2trCDT *self,
const P2trVector2 *pc,
P2trTriangle *point_location_guess)
{
P2trTriangle *tri;
P2trPoint *pt;
gboolean inserted = FALSE;
gint i;
if (point_location_guess == NULL)
tri = p2tr_mesh_find_point (self->mesh, pc);
else
tri = p2tr_mesh_find_point_local (self->mesh, pc, point_location_guess);
if (tri == NULL)
p2tr_exception_geometric ("Tried to add point outside of domain!");
pt = p2tr_mesh_new_point (self->mesh, pc);
/* If the point falls on a line, we should split the line */
for (i = 0; i < 3; i++)
{
P2trEdge *edge = tri->edges[i];
if (p2tr_math_orient2d (& P2TR_EDGE_START(edge)->c,
&edge->end->c, pc) == P2TR_ORIENTATION_LINEAR)
{
p2tr_cdt_split_edge (self, edge, pt);
inserted = TRUE;
break;
}
}
if (! inserted)
/* If we reached this line, then the point is inside the triangle */
p2tr_cdt_insert_point_into_triangle (self, pt, tri);
p2tr_cdt_on_new_point (self, pt);
return pt;
}
