bool ofxGtsSurface::prepareBoolean(ofxGtsSurface &source) {
if(!loaded || !source.loaded) {
ofLog(OF_LOG_NOTICE, "Gts surface not loaded, could not perform boolean operation");
return false;
}
if(!gts_surface_is_orientable(surface)) {
ofLog(OF_LOG_ERROR, "Gts surface is not an orientable manifold, could not perform boolean operation");
return false;
}
if(gts_surface_is_self_intersecting(surface)) {
ofLog(OF_LOG_ERROR, "Gts surface self-intersects, could not perform boolean operation");
return false;
}
if(!gts_surface_is_orientable(source.surface)) {
ofLog(OF_LOG_ERROR, "Gts surface is not an orientable manifold, could not perform boolean operation");
return false;
}
if(gts_surface_is_self_intersecting(source.surface)) {
ofLog(OF_LOG_ERROR, "Gts surface self-intersects, could not perform boolean operation");
return false;
}
GSList *bboxes = NULL;
gts_surface_foreach_face(surface, (GtsFunc) prepend_triangle_bbox, &bboxes);
/* build bounding box tree for first surface */
tree1 = gts_bb_tree_new(bboxes);
/* free list of bboxes */
g_slist_free (bboxes);
is_open1 = gts_surface_volume(surface) < 0. ? TRUE : FALSE;
/* build bounding boxes for second surface */
bboxes = NULL;
gts_surface_foreach_face(source.surface, (GtsFunc) prepend_triangle_bbox, &bboxes);
/* build bounding box tree for second surface */
tree2 = gts_bb_tree_new(bboxes);
/* free list of bboxes */
g_slist_free (bboxes);
is_open2 = gts_surface_volume (source.surface) < 0. ? TRUE : FALSE;
si = gts_surface_inter_new (gts_surface_inter_class (),
surface, source.surface, tree1, tree2, is_open1, is_open2);
gboolean closed = TRUE;
gts_surface_inter_check(si, &closed);
boolPerformed = true;
if(!closed) {
ofLog(OF_LOG_NOTICE, "Gts surface is not closed, could not perform boolean operation");
return false;
}
return true;
}
/**
* gts_bb_tree_surface:
* @s: a #GtsSurface.
*
* Returns: a new hierarchy of bounding boxes bounding the faces of @s.
*/
GNode * gts_bb_tree_surface (GtsSurface * s)
{
GSList * bboxes = NULL;
GNode * tree;
g_return_val_if_fail (s != NULL, NULL);
gts_surface_foreach_face (s, (GtsFunc) prepend_triangle_bbox, &bboxes);
tree = gts_bb_tree_new (bboxes);
g_slist_free (bboxes);
return tree;
}
/**
* gts_bb_tree_new:
* @bboxes: a list of #GtsBBox.
*
* Builds a new hierarchy of bounding boxes for @bboxes. At each
* level, the GNode->data field contains a #GtsBBox bounding box of
* all the children. The tree is binary and is built by repeatedly
* cutting in two approximately equal halves the bounding boxes at
* each level until a leaf node (i.e. a bounding box given in @bboxes)
* is reached. In order to minimize the depth of the tree, the cutting
* direction is always chosen as perpendicular to the longest
* dimension of the bounding box.
*
* Returns: a new hierarchy of bounding boxes.
*/
GNode * gts_bb_tree_new (GSList * bboxes)
{
GSList * i, * positive = NULL, * negative = NULL;
GNode * node;
GtsBBox * bbox;
guint dir, np = 0, nn = 0;
gdouble * p1, * p2;
gdouble cut;
g_return_val_if_fail (bboxes != NULL, NULL);
if (bboxes->next == NULL) /* leaf node */
return g_node_new (bboxes->data);
bbox = gts_bbox_bboxes (gts_bbox_class (), bboxes);
node = g_node_new (bbox);
if (bbox->x2 - bbox->x1 > bbox->y2 - bbox->y1) {
if (bbox->z2 - bbox->z1 > bbox->x2 - bbox->x1)
dir = 2;
else
dir = 0;
}
else if (bbox->z2 - bbox->z1 > bbox->y2 - bbox->y1)
dir = 2;
else
dir = 1;
p1 = (gdouble *) &bbox->x1;
p2 = (gdouble *) &bbox->x2;
cut = (p1[dir] + p2[dir])/2.;
i = bboxes;
while (i) {
bbox = i->data;
p1 = (gdouble *) &bbox->x1;
p2 = (gdouble *) &bbox->x2;
if ((p1[dir] + p2[dir])/2. > cut) {
positive = g_slist_prepend (positive, bbox);
np++;
}
else {
negative = g_slist_prepend (negative, bbox);
nn++;
}
i = i->next;
}
if (!positive) {
GSList * last = g_slist_nth (negative, (nn - 1)/2);
positive = last->next;
last->next = NULL;
}
else if (!negative) {
GSList * last = g_slist_nth (positive, (np - 1)/2);
negative = last->next;
last->next = NULL;
}
g_node_prepend (node, gts_bb_tree_new (positive));
g_slist_free (positive);
g_node_prepend (node, gts_bb_tree_new (negative));
g_slist_free (negative);
return node;
}
