bool PointInPolyline(
const ON_3dPoint& P,
const ON_Polyline pline,
double tol
)
{
if (!pline.IsClosed(tol)) { /* no inside to speak of */
return false;
}
/* First we need to find a point that's in the plane and outside the polyline */
ON_BoundingBox bbox;
PolylineBBox(pline, &bbox);
ON_3dPoint adder;
int i;
for (i = 0; i < pline.Count(); i++) {
adder = P - pline[i];
if (!VNEAR_ZERO(adder, tol)) {
break;
}
}
ON_3dPoint DistantPoint = P;
int multiplier = 2;
do {
DistantPoint += adder*multiplier;
multiplier = multiplier*multiplier;
} while (bbox.IsPointIn(DistantPoint, false));
bool inside = false;
int rv;
ON_3dPoint result[2];
for (i = 0; i < pline.Count() - 1; i++) {
rv = SegmentSegmentIntersect(P, DistantPoint, pline[i], pline[i + 1], result, tol);
if (rv == 1) {
inside = !inside;
} else if (rv == 2) {
bu_exit(-1, "This is very unlikely bug in PointInPolyline which needs to be fixed\n");
}
}
return inside;
}
int TriIntersections::Faces(
ON_ClassArray<ON_3dPoint[3]> UNUSED(faces)
)
{
if (intersections.Count() == 0) {
return 0;
}
/* first we get an array of all the segments we can use to make
* our faces.
*/
ON_SimpleArray<ON_Line> segments; /*the segments we have to make faces */
ON_SimpleArray<bool> flippable; /* whether or not the segment has direction */
ON_SimpleArray<bool> segexternal; /* whether or not the segment is from the edge */
for (int i = 0; i < intersections.Count(); i++) {
segments.Append(intersections[i]);
segments.Append(intersections[i]);
flippable.Append(false);
flippable.Append(false);
segexternal.Append(false);
segexternal.Append(false);
}
for (int i = 0; i < 3; i++) {
if (edges[i].Count() == 2) { /* the edge was never intersected */
segments.Append(ON_Line(edges[i][0], edges[i][0]));
flippable.Append(true);
segexternal.Append(true);
} else {
for (int j = 0; j < (edges[i].Count() - 1); j++) {
if (dir[i][j] == dir[i][j + 1]) {
/* this indicates an error in the intersection data */
return -1;
} else if (dir[i][j] == 0 || dir[i][j+1] == 1) {
segments.Append(ON_Line(edges[i][j], edges[i][j+1]));
flippable.Append(false);
segexternal.Append(true);
} else {
segments.Append(ON_Line(edges[i][j+1], edges[i][j]));
flippable.Append(false);
segexternal.Append(true);
}
}
}
}
/* Now that the segments are all set up it's time to make them
* into faces.
*/
ON_ClassArray<ON_Polyline> outlines;
ON_SimpleArray<bool> line_external; /* stores whether each polyline is internal */
ON_Polyline outline;
while (segments.Count() != 0) {
outline.Append(segments[0].from);
outline.Append(segments[0].to);
segments.Remove(0);
int i = 0;
bool ext = false; /* keeps track of the ternality of the path we're assembling */
while (!outline.IsClosed(tol)) {
if (i >= segments.Count()) {
return -1;
} else if (VNEAR_EQUAL(segments[i].from, outline[outline.Count() - 1], tol)) {
outline.Append(segments[i].to);
} else if (VNEAR_EQUAL(segments[i].to, outline[0], tol)) {
outline.Insert(0, segments[i].from);
} else if (VNEAR_EQUAL(segments[i].from, outline[0], tol) && flippable[i]) {
outline.Insert(0, segments[i].to);
} else if (VNEAR_EQUAL(segments[i].to, outline[outline.Count() - 1], tol) && flippable[i]) {
outline.Append(segments[i].from);
} else {
i++;
continue;
}
/* only executed when we append edge i */
segments.Remove(i);
flippable.Remove(i);
ext &= segexternal[i];
segexternal.Remove(i);
i = 0;
}
outlines.Append(outline);
line_external.Append(ext);
}
/* XXX - now we need to setup the ternality tree for the paths */
return 0;
}