/**
* gts_edge_swap:
* @e: a #GtsEdge.
* @s: a #GtsSurface.
*
* Performs an "edge swap" on the two triangles sharing @e and
* belonging to @s.
*/
void gts_edge_swap (GtsEdge * e, GtsSurface * s)
{
GtsTriangle * t1 = NULL, * t2 = NULL, * t;
GtsFace * f;
GSList * i;
GtsVertex * v1, * v2, * v3, * v4, * v5, * v6;
GtsEdge * e1, * e2, * e3, * e4;
GtsSegment * v3v6;
g_return_if_fail (e != NULL);
g_return_if_fail (s != NULL);
i = e->triangles;
while (i) {
if (GTS_IS_FACE (i->data) && gts_face_has_parent_surface (i->data, s)) {
if (!t1)
t1 = i->data;
else if (!t2)
t2 = i->data;
else
g_return_if_fail (gts_edge_face_number (e, s) == 2);
}
i = i->next;
}
g_assert (t1 && t2);
gts_triangle_vertices_edges (t1, e, &v1, &v2, &v3, &e, &e1, &e2);
gts_triangle_vertices_edges (t2, e, &v4, &v5, &v6, &e, &e3, &e4);
g_assert (v2 == v4 && v1 == v5);
v3v6 = gts_vertices_are_connected (v3, v6);
if (!GTS_IS_EDGE (v3v6))
v3v6 = GTS_SEGMENT (gts_edge_new (s->edge_class, v3, v6));
f = gts_face_new (s->face_class, e1, GTS_EDGE (v3v6), e4);
if ((t = gts_triangle_is_duplicate (GTS_TRIANGLE (f))) &&
GTS_IS_FACE (t)) {
gts_object_destroy (GTS_OBJECT (f));
f = GTS_FACE (t);
}
gts_surface_add_face (s, f);
f = gts_face_new (s->face_class, GTS_EDGE (v3v6), e2, e3);
if ((t = gts_triangle_is_duplicate (GTS_TRIANGLE (f))) &&
GTS_IS_FACE (t)) {
gts_object_destroy (GTS_OBJECT (f));
f = GTS_FACE (t);
}
gts_surface_add_face (s, f);
gts_surface_remove_face (s, GTS_FACE (t1));
gts_surface_remove_face (s, GTS_FACE (t2));
}
static PyObject*
triangles(PygtsVertex *self, PyObject *args)
{
GSList *triangles, *t;
PygtsTriangle *triangle;
guint i,N;
PyObject *tuple;
SELF_CHECK
triangles = gts_vertex_triangles(PYGTS_VERTEX_AS_GTS_VERTEX(self),NULL);
N = g_slist_length(triangles);
/* Create the tuple */
if( (tuple=PyTuple_New(N)) == NULL) {
PyErr_SetString(PyExc_MemoryError,"could not create tuple");
return NULL;
}
/* Put PygtsVertex objects into the tuple */
t = triangles;
for(i=0;i<N;i++) {
if( (triangle = pygts_triangle_new(GTS_TRIANGLE(t->data))) == NULL ) {
Py_DECREF(tuple);
return NULL;
}
PyTuple_SET_ITEM(tuple, i, (PyObject*)triangle);
t = g_slist_next(t);
}
return tuple;
}
static gboolean triangle_obtuse (GtsVertex * v, GtsFace * f)
{
GtsEdge * e = gts_triangle_edge_opposite (GTS_TRIANGLE (f), v);
return (angle_obtuse (v, f) ||
angle_obtuse (GTS_SEGMENT (e)->v1, f) ||
angle_obtuse (GTS_SEGMENT (e)->v2, f));
}
static GtsSurface * happrox_list (GSList * points,
gboolean keep_enclosing,
gboolean closed,
CostFunc cost_func,
gpointer cost_data,
GtsStopFunc stop_func,
gpointer stop_data)
{
GtsSurface * s = gts_surface_new (gts_surface_class (),
GTS_FACE_CLASS (list_face_class ()),
gts_edge_class (),
gts_vertex_class ());
GtsTriangle * t;
GtsVertex * w1, * w2, * w3;
GtsListFace * f;
/* creates enclosing triangle */
t = gts_triangle_enclosing (gts_triangle_class (), points, 10.);
gts_triangle_vertices (t, &w1, &w2, &w3);
GTS_POINT (w1)->z = GTS_POINT (w2)->z = GTS_POINT (w3)->z =
keep_enclosing ? -10. : -1e30;
f = GTS_LIST_FACE (gts_face_new (s->face_class, t->e1, t->e2, t->e3));
gts_surface_add_face (s, GTS_FACE (f));
f->points = points;
/* refine surface */
surface_hf_refine (s, cost_func, cost_data, stop_func, stop_data);
/* destroy unused vertices */
gts_surface_foreach_face (s, (GtsFunc) destroy_unused, NULL);
/* destroy enclosing triangle */
if (!keep_enclosing) {
gts_allow_floating_vertices = TRUE;
gts_object_destroy (GTS_OBJECT (w1));
gts_object_destroy (GTS_OBJECT (w2));
gts_object_destroy (GTS_OBJECT (w3));
gts_allow_floating_vertices = FALSE;
}
else if (closed) {
GSList * l = gts_surface_boundary (s);
GtsFace * f;
g_assert (g_slist_length (l) == 3);
f = gts_face_new (s->face_class, l->data, l->next->data, l->next->next->data);
gts_surface_add_face (s, f);
if (!gts_face_is_compatible (f, s))
gts_triangle_revert (GTS_TRIANGLE (f));
g_slist_free (l);
gts_object_destroy (GTS_OBJECT (t));
}
else
gts_object_destroy (GTS_OBJECT (t));
return s;
}
static gboolean angle_obtuse (GtsVertex * v, GtsFace * f)
{
GtsEdge * e = gts_triangle_edge_opposite (GTS_TRIANGLE (f), v);
GtsVector vec1, vec2;
gts_vector_init (vec1, GTS_POINT (v), GTS_POINT (GTS_SEGMENT (e)->v1));
gts_vector_init (vec2, GTS_POINT (v), GTS_POINT (GTS_SEGMENT (e)->v2));
return (gts_vector_scalar (vec1, vec2) < 0.0);
}
/**
* gts_triangle_new:
* @klass: a #GtsTriangleClass.
* @e1: a #GtsEdge.
* @e2: another #GtsEdge touching @e1.
* @e3: another #GtsEdge touching both @e1 and @e2.
*
* Returns: a new #GtsTriangle having @e1, @e2 and @e3 as edges.
*/
GtsTriangle * gts_triangle_new (GtsTriangleClass * klass,
GtsEdge * e1,
GtsEdge * e2,
GtsEdge * e3)
{
GtsTriangle * t;
t = GTS_TRIANGLE (gts_object_new (GTS_OBJECT_CLASS (klass)));
gts_triangle_set (t, e1, e2, e3);
return t;
}
static void mark_as_hole (GtsFace * f, GtsSurface * s)
{
GtsEdge * e1, * e2, * e3;
if (GTS_OBJECT (f)->reserved == f)
return;
GTS_OBJECT (f)->reserved = f;
e1 = GTS_TRIANGLE (f)->e1;
e2 = GTS_TRIANGLE (f)->e2;
e3 = GTS_TRIANGLE (f)->e3;
if (!GTS_IS_CONSTRAINT (e1)) {
GSList * i = e1->triangles;
while (i) {
GtsFace * f1 = i->data;
if (f1 != f && GTS_IS_FACE (f1) && gts_face_has_parent_surface (f1, s))
mark_as_hole (f1, s);
i = i->next;
}
}
if (!GTS_IS_CONSTRAINT (e2)) {
GSList * i = e2->triangles;
while (i) {
GtsFace * f1 = i->data;
if (f1 != f && GTS_IS_FACE (f1) && gts_face_has_parent_surface (f1, s))
mark_as_hole (f1, s);
i = i->next;
}
}
if (!GTS_IS_CONSTRAINT (e3)) {
GSList * i = e3->triangles;
while (i) {
GtsFace * f1 = i->data;
if (f1 != f && GTS_IS_FACE (f1) && gts_face_has_parent_surface (f1, s))
mark_as_hole (f1, s);
i = i->next;
}
}
}
static void edge_mark_as_hole (GtsEdge * e, GtsSurface * s)
{
GSList * i = e->triangles;
while (i) {
GtsFace * f = i->data;
if (GTS_IS_FACE (f) &&
gts_face_has_parent_surface (f, s) &&
triangle_is_hole (GTS_TRIANGLE (f)))
mark_as_hole (f, s);
i = i->next;
}
}
static gdouble interpolated_value (GtsSurface * s, FttVector * p)
{
GtsPoint q;
GtsFace * t;
q.x = p->x; q.y = p->y;
t = gts_point_locate (&q, s, NULL);
if (t == NULL) {
g_warning ("cannot locate point (%g,%g)", p->x, p->y);
return 0.;
}
gts_triangle_interpolate_height (GTS_TRIANGLE (t), &q);
return q.z;
}
static gdouble region_area (GtsVertex * v, GtsFace * f)
{
/* cf. Section 3.3 of [Meyer et al 2002] */
if (gts_triangle_area (GTS_TRIANGLE (f)) == 0.0) return (0.0);
if (triangle_obtuse (v, f)) {
if (angle_obtuse (v, f))
return (gts_triangle_area (GTS_TRIANGLE (f))/2.0);
else
return (gts_triangle_area (GTS_TRIANGLE (f))/4.0);
} else {
GtsEdge * e = gts_triangle_edge_opposite (GTS_TRIANGLE (f), v);
return ((cotan (GTS_SEGMENT (e)->v1, v, GTS_SEGMENT (e)->v2)*
gts_point_distance2 (GTS_POINT (v),
GTS_POINT (GTS_SEGMENT (e)->v2)) +
cotan (GTS_SEGMENT (e)->v2, v, GTS_SEGMENT (e)->v1)*
gts_point_distance2 (GTS_POINT (v),
GTS_POINT (GTS_SEGMENT (e)->v1)))
/8.0);
}
}
static void triangle_destroy (GtsObject * object)
{
GtsTriangle * triangle = GTS_TRIANGLE (object);
GtsEdge * e1 = triangle->e1;
GtsEdge * e2 = triangle->e2;
GtsEdge * e3 = triangle->e3;
e1->triangles = g_slist_remove (e1->triangles, triangle);
if (!GTS_OBJECT_DESTROYED (e1) &&
!gts_allow_floating_edges && e1->triangles == NULL)
gts_object_destroy (GTS_OBJECT (e1));
e2->triangles = g_slist_remove (e2->triangles, triangle);
if (!GTS_OBJECT_DESTROYED (e2) &&
!gts_allow_floating_edges && e2->triangles == NULL)
gts_object_destroy (GTS_OBJECT (e2));
e3->triangles = g_slist_remove (e3->triangles, triangle);
if (!GTS_OBJECT_DESTROYED (e3) &&
!gts_allow_floating_edges && e3->triangles == NULL)
gts_object_destroy (GTS_OBJECT (e3));
(* GTS_OBJECT_CLASS (gts_triangle_class ())->parent_class->destroy) (object);
}
static void list_face_cost_init (ListFace * f)
{
triangle_plane (GTS_TRIANGLE (f), f->p);
}
static gboolean face_is_marked (GtsObject * o)
{
if (o->reserved == o || gts_triangle_is_duplicate (GTS_TRIANGLE (o)))
return TRUE;
return FALSE;
}
static void gts_constraint_split (GtsConstraint * c,
GtsSurface * s,
GtsFifo * fifo)
{
GSList * i;
GtsVertex * v1, * v2;
GtsEdge * e;
g_return_if_fail (c != NULL);
g_return_if_fail (s != NULL);
v1 = GTS_SEGMENT (c)->v1;
v2 = GTS_SEGMENT (c)->v2;
e = GTS_EDGE (c);
i = e->triangles;
while (i) {
GtsFace * f = i->data;
if (GTS_IS_FACE (f) && gts_face_has_parent_surface (f, s)) {
GtsVertex * v = gts_triangle_vertex_opposite (GTS_TRIANGLE (f), e);
if (gts_point_orientation (GTS_POINT (v1),
GTS_POINT (v2),
GTS_POINT (v)) == 0.) {
GSList * j = e->triangles;
GtsFace * f1 = NULL;
GtsEdge * e1, * e2;
/* replaces edges with constraints */
gts_triangle_vertices_edges (GTS_TRIANGLE (f), e,
&v1, &v2, &v, &e, &e1, &e2);
if (!GTS_IS_CONSTRAINT (e1)) {
GtsEdge * ne1 =
gts_edge_new (GTS_EDGE_CLASS (GTS_OBJECT (c)->klass), v2, v);
gts_edge_replace (e1, ne1);
gts_object_destroy (GTS_OBJECT (e1));
e1 = ne1;
if (fifo) gts_fifo_push (fifo, e1);
}
if (!GTS_IS_CONSTRAINT (e2)) {
GtsEdge * ne2 =
gts_edge_new (GTS_EDGE_CLASS (GTS_OBJECT (c)->klass), v, v1);
gts_edge_replace (e2, ne2);
gts_object_destroy (GTS_OBJECT (e2));
e2 = ne2;
if (fifo) gts_fifo_push (fifo, e2);
}
/* look for face opposite */
while (j && !f1) {
if (GTS_IS_FACE (j->data) &&
gts_face_has_parent_surface (j->data, s))
f1 = j->data;
j = j->next;
}
if (f1) { /* c is not a boundary of s */
GtsEdge * e3, * e4, * e5;
GtsVertex * v3;
gts_triangle_vertices_edges (GTS_TRIANGLE (f1), e,
&v1, &v2, &v3, &e, &e3, &e4);
e5 = gts_edge_new (s->edge_class, v, v3);
gts_surface_add_face (s, gts_face_new (s->face_class, e5, e2, e3));
gts_surface_add_face (s, gts_face_new (s->face_class, e5, e4, e1));
gts_object_destroy (GTS_OBJECT (f1));
}
gts_object_destroy (GTS_OBJECT (f));
return;
}
}
i = i->next;
}
}
/**
* gts_vertex_principal_directions:
* @v: a #GtsVertex.
* @s: a #GtsSurface.
* @Kh: mean curvature normal (a #GtsVector).
* @Kg: Gaussian curvature (a gdouble).
* @e1: first principal curvature direction (direction of largest curvature).
* @e2: second principal curvature direction.
*
* Computes the principal curvature directions at a point given @Kh
* and @Kg, the mean curvature normal and Gaussian curvatures at that
* point, computed with gts_vertex_mean_curvature_normal() and
* gts_vertex_gaussian_curvature(), respectively.
*
* Note that this computation is very approximate and tends to be
* unstable. Smoothing of the surface or the principal directions may
* be necessary to achieve reasonable results.
*/
void gts_vertex_principal_directions (GtsVertex * v, GtsSurface * s,
GtsVector Kh, gdouble Kg,
GtsVector e1, GtsVector e2)
{
GtsVector N;
gdouble normKh;
GSList * i, * j;
GtsVector basis1, basis2, d, eig;
gdouble ve2, vdotN;
gdouble aterm_da, bterm_da, cterm_da, const_da;
gdouble aterm_db, bterm_db, cterm_db, const_db;
gdouble a, b, c;
gdouble K1, K2;
gdouble *weights, *kappas, *d1s, *d2s;
gint edge_count;
gdouble err_e1, err_e2;
int e;
/* compute unit normal */
normKh = sqrt (gts_vector_scalar (Kh, Kh));
if (normKh > 0.0) {
N[0] = Kh[0] / normKh;
N[1] = Kh[1] / normKh;
N[2] = Kh[2] / normKh;
} else {
/* This vertex is a point of zero mean curvature (flat or saddle
* point). Compute a normal by averaging the adjacent triangles
*/
N[0] = N[1] = N[2] = 0.0;
i = gts_vertex_faces (v, s, NULL);
while (i) {
gdouble x, y, z;
gts_triangle_normal (GTS_TRIANGLE ((GtsFace *) i->data),
&x, &y, &z);
N[0] += x;
N[1] += y;
N[2] += z;
i = i->next;
}
g_return_if_fail (gts_vector_norm (N) > 0.0);
gts_vector_normalize (N);
}
/* construct a basis from N: */
/* set basis1 to any component not the largest of N */
basis1[0] = basis1[1] = basis1[2] = 0.0;
if (fabs (N[0]) > fabs (N[1]))
basis1[1] = 1.0;
else
basis1[0] = 1.0;
/* make basis2 orthogonal to N */
gts_vector_cross (basis2, N, basis1);
gts_vector_normalize (basis2);
/* make basis1 orthogonal to N and basis2 */
gts_vector_cross (basis1, N, basis2);
gts_vector_normalize (basis1);
aterm_da = bterm_da = cterm_da = const_da = 0.0;
aterm_db = bterm_db = cterm_db = const_db = 0.0;
weights = g_malloc (sizeof (gdouble)*g_slist_length (v->segments));
kappas = g_malloc (sizeof (gdouble)*g_slist_length (v->segments));
d1s = g_malloc (sizeof (gdouble)*g_slist_length (v->segments));
d2s = g_malloc (sizeof (gdouble)*g_slist_length (v->segments));
edge_count = 0;
i = v->segments;
while (i) {
GtsEdge * e;
GtsFace * f1, * f2;
gdouble weight, kappa, d1, d2;
GtsVector vec_edge;
if (! GTS_IS_EDGE (i->data)) {
i = i->next;
continue;
}
e = i->data;
/* since this vertex passed the tests in
* gts_vertex_mean_curvature_normal(), this should be true. */
g_assert (gts_edge_face_number (e, s) == 2);
/* identify the two triangles bordering e in s */
f1 = f2 = NULL;
j = e->triangles;
while (j) {
if ((! GTS_IS_FACE (j->data)) ||
(! gts_face_has_parent_surface (GTS_FACE (j->data), s))) {
j = j->next;
continue;
}
if (f1 == NULL)
f1 = GTS_FACE (j->data);
else {
f2 = GTS_FACE (j->data);
break;
}
j = j->next;
}
g_assert (f2 != NULL);
/* We are solving for the values of the curvature tensor
* B = [ a b ; b c ].
* The computations here are from section 5 of [Meyer et al 2002].
*
* The first step is to calculate the linear equations governing
* the values of (a,b,c). These can be computed by setting the
* derivatives of the error E to zero (section 5.3).
*
* Since a + c = norm(Kh), we only compute the linear equations
* for dE/da and dE/db. (NB: [Meyer et al 2002] has the
* equation a + b = norm(Kh), but I'm almost positive this is
* incorrect.)
*
* Note that the w_ij (defined in section 5.2) are all scaled by
* (1/8*A_mixed). We drop this uniform scale factor because the
* solution of the linear equations doesn't rely on it.
*
* The terms of the linear equations are xterm_dy with x in
* {a,b,c} and y in {a,b}. There are also const_dy terms that are
* the constant factors in the equations.
*/
/* find the vector from v along edge e */
gts_vector_init (vec_edge, GTS_POINT (v),
GTS_POINT ((GTS_SEGMENT (e)->v1 == v) ?
GTS_SEGMENT (e)->v2 : GTS_SEGMENT (e)->v1));
ve2 = gts_vector_scalar (vec_edge, vec_edge);
vdotN = gts_vector_scalar (vec_edge, N);
/* section 5.2 - There is a typo in the computation of kappa. The
* edges should be x_j-x_i.
*/
kappa = 2.0 * vdotN / ve2;
/* section 5.2 */
/* I don't like performing a minimization where some of the
* weights can be negative (as can be the case if f1 or f2 are
* obtuse). To ensure all-positive weights, we check for
* obtuseness and use values similar to those in region_area(). */
weight = 0.0;
if (! triangle_obtuse(v, f1)) {
weight += ve2 *
cotan (gts_triangle_vertex_opposite (GTS_TRIANGLE (f1), e),
GTS_SEGMENT (e)->v1, GTS_SEGMENT (e)->v2) / 8.0;
} else {
if (angle_obtuse (v, f1)) {
weight += ve2 * gts_triangle_area (GTS_TRIANGLE (f1)) / 4.0;
} else {
weight += ve2 * gts_triangle_area (GTS_TRIANGLE (f1)) / 8.0;
}
}
if (! triangle_obtuse(v, f2)) {
weight += ve2 *
cotan (gts_triangle_vertex_opposite (GTS_TRIANGLE (f2), e),
GTS_SEGMENT (e)->v1, GTS_SEGMENT (e)->v2) / 8.0;
} else {
if (angle_obtuse (v, f2)) {
weight += ve2 * gts_triangle_area (GTS_TRIANGLE (f2)) / 4.0;
} else {
weight += ve2 * gts_triangle_area (GTS_TRIANGLE (f2)) / 8.0;
}
}
/* projection of edge perpendicular to N (section 5.3) */
d[0] = vec_edge[0] - vdotN * N[0];
d[1] = vec_edge[1] - vdotN * N[1];
d[2] = vec_edge[2] - vdotN * N[2];
gts_vector_normalize (d);
/* not explicit in the paper, but necessary. Move d to 2D basis. */
d1 = gts_vector_scalar (d, basis1);
d2 = gts_vector_scalar (d, basis2);
/* store off the curvature, direction of edge, and weights for later use */
weights[edge_count] = weight;
kappas[edge_count] = kappa;
d1s[edge_count] = d1;
d2s[edge_count] = d2;
edge_count++;
/* Finally, update the linear equations */
aterm_da += weight * d1 * d1 * d1 * d1;
bterm_da += weight * d1 * d1 * 2 * d1 * d2;
cterm_da += weight * d1 * d1 * d2 * d2;
const_da += weight * d1 * d1 * (- kappa);
aterm_db += weight * d1 * d2 * d1 * d1;
bterm_db += weight * d1 * d2 * 2 * d1 * d2;
cterm_db += weight * d1 * d2 * d2 * d2;
const_db += weight * d1 * d2 * (- kappa);
i = i->next;
}
/* now use the identity (Section 5.3) a + c = |Kh| = 2 * kappa_h */
aterm_da -= cterm_da;
const_da += cterm_da * normKh;
aterm_db -= cterm_db;
const_db += cterm_db * normKh;
/* check for solvability of the linear system */
if (((aterm_da * bterm_db - aterm_db * bterm_da) != 0.0) &&
((const_da != 0.0) || (const_db != 0.0))) {
linsolve (aterm_da, bterm_da, -const_da,
aterm_db, bterm_db, -const_db,
&a, &b);
c = normKh - a;
eigenvector (a, b, c, eig);
} else {
/* region of v is planar */
eig[0] = 1.0;
eig[1] = 0.0;
}
/* Although the eigenvectors of B are good estimates of the
* principal directions, it seems that which one is attached to
* which curvature direction is a bit arbitrary. This may be a bug
* in my implementation, or just a side-effect of the inaccuracy of
* B due to the discrete nature of the sampling.
*
* To overcome this behavior, we'll evaluate which assignment best
* matches the given eigenvectors by comparing the curvature
* estimates computed above and the curvatures calculated from the
* discrete differential operators. */
gts_vertex_principal_curvatures (0.5 * normKh, Kg, &K1, &K2);
err_e1 = err_e2 = 0.0;
/* loop through the values previously saved */
for (e = 0; e < edge_count; e++) {
gdouble weight, kappa, d1, d2;
gdouble temp1, temp2;
gdouble delta;
weight = weights[e];
kappa = kappas[e];
d1 = d1s[e];
d2 = d2s[e];
temp1 = fabs (eig[0] * d1 + eig[1] * d2);
temp1 = temp1 * temp1;
temp2 = fabs (eig[1] * d1 - eig[0] * d2);
temp2 = temp2 * temp2;
/* err_e1 is for K1 associated with e1 */
delta = K1 * temp1 + K2 * temp2 - kappa;
err_e1 += weight * delta * delta;
/* err_e2 is for K1 associated with e2 */
delta = K2 * temp1 + K1 * temp2 - kappa;
err_e2 += weight * delta * delta;
}
g_free (weights);
g_free (kappas);
g_free (d1s);
g_free (d2s);
/* rotate eig by a right angle if that would decrease the error */
if (err_e2 < err_e1) {
gdouble temp = eig[0];
eig[0] = eig[1];
eig[1] = -temp;
}
e1[0] = eig[0] * basis1[0] + eig[1] * basis2[0];
e1[1] = eig[0] * basis1[1] + eig[1] * basis2[1];
e1[2] = eig[0] * basis1[2] + eig[1] * basis2[2];
gts_vector_normalize (e1);
/* make N,e1,e2 a right handed coordinate sytem */
gts_vector_cross (e2, N, e1);
gts_vector_normalize (e2);
}
static PyObject *
new_(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
PyObject *o;
PygtsObject *obj;
guint alloc_gtsobj = TRUE;
PyObject *o1_,*o2_,*o3_;
GtsVertex *v1=NULL, *v2=NULL, *v3=NULL;
GtsEdge *e1=NULL,*e2=NULL,*e3=NULL,*e;
GtsSegment *s1,*s2,*s3;
gboolean flag=FALSE; /* Flag when the args are gts.Point objects */
GtsFace *f;
GtsTriangle *t;
guint N;
/* Parse the args */
if(kwds) {
o = PyDict_GetItemString(kwds,"alloc_gtsobj");
if(o==Py_False) {
alloc_gtsobj = FALSE;
}
if(o!=NULL) {
PyDict_DelItemString(kwds, "alloc_gtsobj");
}
}
if(kwds) {
Py_INCREF(Py_False);
PyDict_SetItemString(kwds,"alloc_gtsobj", Py_False);
}
/* Allocate the gtsobj (if needed) */
if( alloc_gtsobj ) {
/* Parse the args */
if( (N = PyTuple_Size(args)) < 3 ) {
PyErr_SetString(PyExc_TypeError,"expected three Edges or three Vertices");
return NULL;
}
o1_ = PyTuple_GET_ITEM(args,0);
o2_ = PyTuple_GET_ITEM(args,1);
o3_ = PyTuple_GET_ITEM(args,2);
/* Convert to PygtsObjects */
if( pygts_edge_check(o1_) ) {
e1 = PYGTS_EDGE_AS_GTS_EDGE(o1_);
}
else {
if( pygts_vertex_check(o1_) ) {
v1 = PYGTS_VERTEX_AS_GTS_VERTEX(o1_);
flag = TRUE;
}
}
if( pygts_edge_check(o2_) ) {
e2 = PYGTS_EDGE_AS_GTS_EDGE(o2_);
}
else {
if( pygts_vertex_check(o2_) ) {
v2 = PYGTS_VERTEX_AS_GTS_VERTEX(o2_);
flag = TRUE;
}
}
if( pygts_edge_check(o3_) ) {
e3 = PYGTS_EDGE_AS_GTS_EDGE(o3_);
}
else {
if(pygts_vertex_check(o3_)) {
v3 = PYGTS_VERTEX_AS_GTS_VERTEX(o3_);
flag = TRUE;
}
}
/* Check for three edges or three vertices */
if( !((e1!=NULL && e2!=NULL && e3!=NULL) ||
(v1!=NULL && v2!=NULL && v3!=NULL)) ) {
PyErr_SetString(PyExc_TypeError,
"three Edge or three Vertex objects expected");
return NULL;
}
if(flag) {
/* Create gts edges */
if( (e1 = gts_edge_new(gts_edge_class(),v1,v2)) == NULL ) {
PyErr_SetString(PyExc_MemoryError, "could not create Edge");
return NULL;
}
if( (e2 = gts_edge_new(gts_edge_class(),v2,v3)) == NULL ) {
PyErr_SetString(PyExc_MemoryError, "could not create Edge");
gts_object_destroy(GTS_OBJECT(e1));
return NULL;
}
if( (e3 = gts_edge_new(gts_edge_class(),v3,v1)) == NULL ) {
PyErr_SetString(PyExc_MemoryError, "could not create Edge");
gts_object_destroy(GTS_OBJECT(e1));
gts_object_destroy(GTS_OBJECT(e2));
return NULL;
}
/* Check for duplicates */
if( (e = gts_edge_is_duplicate(e1)) != NULL ) {
gts_object_destroy(GTS_OBJECT(e1));
e1 = e;
}
if( (e = gts_edge_is_duplicate(e2)) != NULL ) {
gts_object_destroy(GTS_OBJECT(e2));
e2 = e;
}
if( (e = gts_edge_is_duplicate(e3)) != NULL ) {
gts_object_destroy(GTS_OBJECT(e3));
e3 = e;
}
}
/* Check that edges connect */
s1 = GTS_SEGMENT(e1);
s2 = GTS_SEGMENT(e2);
s3 = GTS_SEGMENT(e3);
if( !((s1->v1==s3->v2 && s1->v2==s2->v1 && s2->v2==s3->v1) ||
(s1->v1==s3->v2 && s1->v2==s2->v2 && s2->v1==s3->v1) ||
(s1->v1==s3->v1 && s1->v2==s2->v1 && s2->v2==s3->v2) ||
(s1->v2==s3->v2 && s1->v1==s2->v1 && s2->v2==s3->v1) ||
(s1->v1==s3->v1 && s1->v2==s2->v2 && s2->v1==s3->v2) ||
(s1->v2==s3->v2 && s1->v1==s2->v2 && s2->v1==s3->v1) ||
(s1->v2==s3->v1 && s1->v1==s2->v1 && s2->v2==s3->v2) ||
(s1->v2==s3->v1 && s1->v1==s2->v2 && s2->v1==s3->v2)) ) {
PyErr_SetString(PyExc_RuntimeError, "Edges in face must connect");
if(!g_hash_table_lookup(obj_table,GTS_OBJECT(e1))) {
gts_object_destroy(GTS_OBJECT(e1));
}
if(!g_hash_table_lookup(obj_table,GTS_OBJECT(e1))) {
gts_object_destroy(GTS_OBJECT(e2));
}
if(!g_hash_table_lookup(obj_table,GTS_OBJECT(e1))) {
gts_object_destroy(GTS_OBJECT(e3));
}
return NULL;
}
/* Create the GtsFace */
if( (f = gts_face_new(gts_face_class(),e1,e2,e3)) == NULL ) {
PyErr_SetString(PyExc_MemoryError, "could not create Face");
if(!g_hash_table_lookup(obj_table,GTS_OBJECT(e1))) {
gts_object_destroy(GTS_OBJECT(e1));
}
if(!g_hash_table_lookup(obj_table,GTS_OBJECT(e1))) {
gts_object_destroy(GTS_OBJECT(e2));
}
if(!g_hash_table_lookup(obj_table,GTS_OBJECT(e1))) {
gts_object_destroy(GTS_OBJECT(e3));
}
return NULL;
}
/* Check for duplicate */
t = gts_triangle_is_duplicate(GTS_TRIANGLE(f));
if( t != NULL ) {
gts_object_destroy(GTS_OBJECT(f));
if(!GTS_IS_FACE(t)) {
PyErr_SetString(PyExc_TypeError, "expected a Face (internal error)");
}
f = GTS_FACE(t);
}
/* If corresponding PyObject found in object table, we are done */
if( (obj=(PygtsObject*)g_hash_table_lookup(obj_table,GTS_OBJECT(f))) != NULL ) {
Py_INCREF(obj);
return (PyObject*)obj;
}
}
/* Chain up */
obj = PYGTS_OBJECT(PygtsTriangleType.tp_new(type,args,kwds));
if( alloc_gtsobj ) {
obj->gtsobj = GTS_OBJECT(f);
/* Create the parent GtsSurface */
if( (obj->gtsobj_parent = parent(GTS_FACE(obj->gtsobj))) == NULL ) {
gts_object_destroy(obj->gtsobj);
obj->gtsobj = NULL;
return NULL;
}
pygts_object_register(PYGTS_OBJECT(obj));
}
return (PyObject*)obj;
}
