OBJECT *add_stars()
{
VERTEX *v;
if (!(stars = alloc_object())) return 0;
for (int i=0; i<32; i++)
{
if (!(v = alloc_vertex())) return 0;
v->x = -1.0 + 2.0 * ((float)rand() / 32767.0);
v->y = -1.0 + 2.0 * ((float)rand() / 32767.0);
v->z = -1.0 + 2.0 * ((float)rand() / 32767.0);
v->next = stars->vertex_list;
stars->vertex_list = v;
}
return stars;
}
/*-
* Add a tile described by vtype to the side of vertex. This must be
* allowed by the rules -- we do not check it here. New vertices are
* allocated as necessary. The fringe and the forced vertex pool are updated.
* The new tile is drawn on the display.
*
* One thing we do check here is whether the new tile causes an untiled
* area to become enclosed by the tiling. If this would happen, the tile
* is not added. The return value is true iff a tile was added.
*/
static int
add_tile(ModeInfo * mi,
fringe_node_c * vertex, unsigned side, vertex_type_c vtype)
{
tiling_c *tp = &tilings[MI_SCREEN(mi)];
fringe_node_c
*left = (fringe_node_c *) NULL,
*right = (fringe_node_c *) NULL,
*far = (fringe_node_c *) NULL,
*node;
unsigned fc = fringe_changes(mi, vertex, side, vtype, &right, &far, &left);
vertex_type_c
ltype = VT_LEFT(vtype),
rtype = VT_RIGHT(vtype),
ftype = VT_FAR(vtype);
/* By our conventions vertex->next lies to the left of vertex and
vertex->prev to the right. */
/* This should never occur. */
if (fc & FC_BAG) {
tp->done = True;
if (MI_IS_VERBOSE(mi)) {
(void) fprintf(stderr, "Weirdness in add_tile()\n");
(void) fprintf(stderr, "fc = %d, FC_BAG = %d\n", fc, FC_BAG);
}
}
if (side == S_LEFT) {
if (right == NULL)
if ((right = alloc_vertex(mi, vertex_dir(mi, vertex, S_LEFT) -
vtype_angle(vtype), vertex, tp)) == NULL)
return False;
if (far == NULL)
if ((far = alloc_vertex(mi, vertex_dir(mi, left, S_RIGHT) +
vtype_angle(ltype), left, tp)) == NULL)
return False;
} else {
if (left == NULL)
if ((left = alloc_vertex(mi, vertex_dir(mi, vertex, S_RIGHT) +
vtype_angle(vtype), vertex, tp)) == NULL)
return False;
if (far == NULL)
if ((far = alloc_vertex(mi, vertex_dir(mi, right, S_LEFT) -
vtype_angle(rtype), right, tp)) == NULL)
return False;
}
/* Having allocated the new vertices, but before joining them with
the rest of the fringe, check if vertices with same coordinates
already exist. If any such are found, give up. */
node = tp->fringe.nodes;
do {
if (((fc & FC_NEW_LEFT) && fived_equal(node->fived, left->fived))
|| ((fc & FC_NEW_RIGHT) && fived_equal(node->fived, right->fived))
|| ((fc & FC_NEW_FAR) && fived_equal(node->fived, far->fived))) {
/* Better luck next time. */
if (fc & FC_NEW_LEFT)
delete_vertex(mi, left, tp);
if (fc & FC_NEW_RIGHT)
delete_vertex(mi, right, tp);
if (fc & FC_NEW_FAR)
delete_vertex(mi, far, tp);
return False;
}
node = node->next;
} while (node != tp->fringe.nodes);
/* Rechain. */
if (!(fc & FC_CUT_THIS)) {
if (side == S_LEFT) {
vertex->next = right;
right->prev = vertex;
} else {
vertex->prev = left;
left->next = vertex;
}
}
if (!(fc & FC_CUT_FAR)) {
if (!(fc & FC_CUT_LEFT)) {
far->next = left;
left->prev = far;
}
if (!(fc & FC_CUT_RIGHT)) {
far->prev = right;
right->next = far;
}
}
draw_tile(vertex, right, far, left, vtype, mi);
/* Delete vertices that are no longer on the fringe. Check the others. */
if (fc & FC_CUT_THIS) {
tp->fringe.nodes = far;
delete_vertex(mi, vertex, tp);
} else {
add_vtype(vertex, side, vtype);
check_vertex(mi, vertex, tp);
tp->fringe.nodes = vertex;
}
if (fc & FC_CUT_FAR)
delete_vertex(mi, far, tp);
else {
add_vtype(far, fc & FC_CUT_RIGHT ? S_LEFT : S_RIGHT, ftype);
check_vertex(mi, far, tp);
}
if (fc & FC_CUT_LEFT)
delete_vertex(mi, left, tp);
else {
add_vtype(left, fc & FC_CUT_FAR ? S_LEFT : S_RIGHT, ltype);
check_vertex(mi, left, tp);
}
if (fc & FC_CUT_RIGHT)
delete_vertex(mi, right, tp);
else {
add_vtype(right, fc & FC_CUT_FAR ? S_RIGHT : S_LEFT, rtype);
check_vertex(mi, right, tp);
}
return True;
}
MxVertexID MxBlockModel::add_vertex(double x, double y, double z)
{
MxVertexID id = alloc_vertex(x,y,z);
init_vertex(id);
return id;
}
