int clip_line(struct liang_barsky_clip_window *c,
float *x1, float *y1, float *x2, float *y2)
{
float dx, dy, tE, tL;
dx = *x2 - *x1;
dy = *y2 - *y1;
if (is_zero(dx) && is_zero(dy) && point_inside(c, *x1, *y1))
return 1;
tE = 0;
tL = 1;
if (clipT(c->x1 - *x1, dx, &tE, &tL) &&
clipT( *x1 - c->x2, -dx, &tE, &tL) &&
clipT(c->y1 - *y1, dy, &tE, &tL) &&
clipT( *y1 - c->y2, -dy, &tE, &tL)) {
if (tL < 1) {
*x2 = ((float) *x1 + tL * dx);
*y2 = ((float) *y1 + tL * dy);
}
if (tE > 0) {
*x1 += tE * dx;
*y1 += tE * dy;
}
return 1;
}
return 0;
}
/* does this sphere contain the point? */
int SPHERE_Contains_Point (void *dummy, SPHERE *sph, double *point)
{
return point_inside (sph->cur_center, sph->cur_radius, point);
}
/* return sphere containing a spatial point */
SPHERE* SPHERE_Containing_Point (SPHERE *sph, double *point)
{
if (point_inside (sph->cur_center, sph->cur_radius, point)) return sph;
else return NULL;
}
static int quadtree_insert_node(quadtree *q, quadtree_node *qn, void *data,
size_t size, double x, double y) {
if (!qn) {
return QUADTREE_ERROR;
}
if (!quadtree_node_has_children(qn) && llist_is_empty(qn->points)) {
quadtree_data *qd = quadtree_data_create(data, size, x, y);
if (!qd) {
return QUADTREE_ERROR;
}
llist_add_to_back(qn->points, qd, sizeof(quadtree_data));
free(qd);
++q->size;
return QUADTREE_OK;
} else {
quadtree_data *d = llist_first(qn->points);
if (d && quadtree_data_same_location(d, x, y)) { // Same point
quadtree_data *qd = quadtree_data_create(data, size, x, y);
if (!qd) {
return QUADTREE_ERROR;
}
llist_add_to_back(qn->points, qd, sizeof(quadtree_data));
free(qd);
return QUADTREE_OK;
} else {
quadtree_data *e = llist_first(qn->points);
// Split node
double minX = qn->bounds.x;
double minY = qn->bounds.y;
double midX = qn->bounds.x + qn->bounds.w / 2;
double midY = qn->bounds.y + qn->bounds.h / 2;
double maxX = qn->bounds.x + qn->bounds.w;
double maxY = qn->bounds.y + qn->bounds.h;
double xDim[4][2] = {
{ midX, maxX - midX },
{ minX, midX - minX },
{ minX, midX - minX },
{ midX, maxX - midX }
};
double yDim[4][2] = {
{ midY, maxY - midY },
{ midY, maxY - midY },
{ minY, midY - minY },
{ minY, midY - minY }
};
quadtree_data *d = llist_first(qn->points);
int ret = QUADTREE_ERROR;
for (int i = 0; i < 4; i++) {
if (point_inside(xDim[i][0], yDim[i][0], xDim[i][1], yDim[i][1], x, y)
|| (d && point_inside(xDim[i][0], yDim[i][0], xDim[i][1], yDim[i][1],
d->x, d->y))) {
if (!qn->children[i]) {
qn->children[i] = quadtree_node_create();
}
quadtree_node_set_bounds(qn->children[i], xDim[i][0], yDim[i][0],
xDim[i][1], yDim[i][1]);
if (point_inside(xDim[i][0], yDim[i][0], xDim[i][1], yDim[i][1], x,
y)) {
quadtree_insert_node(q, qn->children[i], data, size, x, y);
ret = QUADTREE_OK;
} else if (point_inside(xDim[i][0], yDim[i][0], xDim[i][1],
yDim[i][1], d->x, d->y)) {
// Move contained points into child node
qn->children[i]->points = qn->points;
qn->points = NULL;
ret = QUADTREE_OK;
}
}
}
return ret;
}
}
// Shouldn't happen
return QUADTREE_ERROR;
}
/* clip3d:
* A fixed point version of clip3d_f. Works suprisingly well.
*/
int clip3d(int type, fixed min_z, fixed max_z, int vc, AL_CONST V3D *vtx[], V3D *vout[], V3D *vtmp[], int out[])
{
int i, j, vo, vt, flags;
fixed t;
V3D *v3;
AL_CONST V3D *v1, *v2, **vin;
static int flag_table[] = {
INT_NONE, /* flat */
INT_3COLP, /* gcol */
INT_3COL, /* grgb */
INT_UV, /* atex */
INT_UV, /* ptex */
INT_UV, /* atex mask */
INT_UV, /* ptex mask */
INT_UV + INT_1COL, /* atex lit */
INT_UV + INT_1COL, /* ptex lit */
INT_UV + INT_1COL, /* atex mask lit */
INT_UV + INT_1COL, /* ptex mask lit */
INT_UV, /* atex trans */
INT_UV, /* ptex trans */
INT_UV, /* atex mask trans */
INT_UV /* ptex mask trans */
};
type &= ~POLYTYPE_ZBUF;
flags = flag_table[type];
if (max_z > min_z) {
vt = 0;
for (i=0; i<vc; i++)
out[i] = (vtx[i]->z > max_z);
for (i=0, j=vc-1; i<vc; j=i, i++) {
v1 = vtx[j];
v2 = vtx[i];
v3 = vtmp[vt];
if ((out[j] & out[i]) != 0)
continue;
if ((out[j] | out[i]) == 0) {
point_inside(vt);
continue;
}
t = fixdiv(max_z - v1->z, v2->z - v1->z);
point_interp(vt);
v3 = vtmp[vt];
if (out[j])
point_inside(vt);
}
vin = (AL_CONST V3D**)vtmp;
}
else {
vt = vc;
vin = vtx;
}
vo = 0;
for (i=0; i<vt; i++)
out[i] = (vin[i]->z < min_z);
for (i=0, j=vt-1; i<vt; j=i, i++) {
v1 = vin[j];
v2 = vin[i];
v3 = vout[vo];
if ((out[j] & out[i]) != 0)
continue;
if ((out[j] | out[i]) == 0) {
point_inside(vo);
continue;
}
t = fixdiv(min_z - v1->z, v2->z - v1->z);
point_interp(vo);
v3 = vout[vo];
if (out[j])
point_inside(vo);
}
vt = 0;
for (i=0; i<vo; i++)
out[i] = (vout[i]->x < -vout[i]->z);
for (i=0, j=vo-1; i<vo; j=i, i++) {
v1 = vout[j];
v2 = vout[i];
v3 = vtmp[vt];
if ((out[j] & out[i]) != 0)
continue;
if ((out[j] | out[i]) == 0) {
point_inside(vt);
continue;
}
t = fixdiv(-v1->z - v1->x, v2->x - v1->x + v2->z - v1->z);
point_interp(vt);
v3 = vtmp[vt];
if (out[j])
point_inside(vt);
}
vo = 0;
for (i=0; i<vt; i++)
out[i] = (vtmp[i]->x > vtmp[i]->z);
for (i=0, j=vt-1; i<vt; j=i, i++) {
v1 = vtmp[j];
v2 = vtmp[i];
v3 = vout[vo];
if ((out[j] & out[i]) != 0)
continue;
if ((out[j] | out[i]) == 0) {
point_inside(vo);
continue;
}
t = fixdiv(v1->z - v1->x, v2->x - v1->x - v2->z + v1->z);
point_interp(vo);
v3 = vout[vo];
if (out[j])
point_inside(vo);
}
vt = 0;
for (i=0; i<vo; i++)
out[i] = (vout[i]->y < -vout[i]->z);
for (i=0, j=vo-1; i<vo; j=i, i++) {
v1 = vout[j];
v2 = vout[i];
v3 = vtmp[vt];
if ((out[j] & out[i]) != 0)
continue;
if ((out[j] | out[i]) == 0) {
point_inside(vt);
continue;
}
t = fixdiv(-v1->z - v1->y, v2->y - v1->y + v2->z - v1->z);
point_interp(vt);
v3 = vtmp[vt];
if (out[j])
point_inside(vt);
}
vo = 0;
for (i=0; i<vt; i++)
out[i] = (vtmp[i]->y > vtmp[i]->z);
for (i=0, j=vt-1; i<vt; j=i, i++) {
v1 = vtmp[j];
v2 = vtmp[i];
v3 = vout[vo];
if ((out[j] & out[i]) != 0)
continue;
if ((out[j] | out[i]) == 0) {
point_inside(vo);
continue;
}
t = fixdiv(v1->z - v1->y, v2->y - v1->y - v2->z + v1->z);
point_interp(vo);
v3 = vout[vo];
if (out[j])
point_inside(vo);
}
if (type == POLYTYPE_FLAT)
vout[0]->c = vtx[0]->c;
return vo;
}
/** for a pair (p, q) of points, add the edge pq if their are visible to each other
*/
void handle(struct Point *p, struct Point *q, struct Map_info *out)
{
/* if it's a point without segments, just report the edge */
if (segment1(q) == NULL && segment2(q) == NULL && before(p, q, p->vis)) {
report(p, q, out);
}
else if (segment1(p) != NULL && q == other1(p)) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment1(q) == segment1(p) && segment2(q) != NULL &&
left_turn(p, q, other2(q))) {
p->vis = segment2(q);
}
else if (segment2(q) == segment1(p) && segment1(q) != NULL &&
left_turn(p, q, other1(q))) {
p->vis = segment1(q);
}
else
p->vis = q->vis;
report(p, q, out);
}
else if (segment2(p) != NULL && q == other2(p)) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment1(q) == segment2(p) && segment2(q) != NULL &&
left_turn(p, q, other2(q))) {
p->vis = segment2(q);
}
else if (segment2(q) == segment2(p) && segment1(q) != NULL &&
left_turn(p, q, other1(q))) {
p->vis = segment1(q);
}
else
p->vis = q->vis;
report(p, q, out);
}
else if (segment1(q) == p->vis && segment1(q) != NULL) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment2(q) != NULL && left_turn(p, q, other2(q)))
p->vis = segment2(q);
else
p->vis = q->vis;
/* check that p and q are not on the same boundary and that the edge pq is inside the boundary */
if (p->cat == -1 || p->cat != q->cat ||
!point_inside(p, (p->x + q->x) * 0.5, (p->y + q->y) * 0.5))
report(p, q, out);
}
else if (segment2(q) == p->vis && segment2(q) != NULL) {
/* we need to check if there is another segment at q so it can be set to the vis */
if (segment1(q) != NULL && left_turn(p, q, other1(q)))
p->vis = segment1(q);
else
p->vis = q->vis;
/* check that p and q are not on the same boundary and that the edge pq is inside the boundary */
if (p->cat == -1 || p->cat != q->cat ||
!point_inside(p, (p->x + q->x) * 0.5, (p->y + q->y) * 0.5))
report(p, q, out);
}
else if (before(p, q, p->vis)) {
/* if q only has one segment, then this is the new vis */
if (segment2(q) == NULL)
p->vis = segment1(q);
else if (segment1(q) == NULL)
p->vis = segment2(q);
/* otherwise take the one with biggest slope */
else if (left_turn(p, q, other1(q)) && !left_turn(p, q, other2(q)))
p->vis = segment1(q);
else if (!left_turn(p, q, other1(q)) && left_turn(p, q, other2(q)))
p->vis = segment2(q);
else if (left_turn(q, other2(q), other1(q)))
p->vis = segment1(q);
else
p->vis = segment2(q);
/* check that p and q are not on the same boundary and that the edge pq is inside the boundary */
if (p->cat == -1 || p->cat != q->cat ||
!point_inside(p, (p->x + q->x) * 0.5, (p->y + q->y) * 0.5))
report(p, q, out);
}
}
