/** Triangulate between two polylines as if they where convex hulls, very similar to D&C merge
* (Gift wrapping idea) from 3D Convex hull theory. Used for a tunnel start **/
public void triangulateTunnelStart(Polyline originPoly, Polyline destinyPoly) //TODO:some times does not triangulate correctly!
//Start from a line between the first one of each polyline, by construction one is generated from the projection of the other=>NO as it has changed(smooth)
{
Vertex a = originPoly.getVertex(0);
Vertex b = destinyPoly.getVertex(0);
int aIndex = 1;
int bIndex = 1;
/*//For getting the starting line, using minimum distance points
* //int j = 0;
* float minDistance = Vector3.Distance (a.getPosition(), b.getPosition());
* for (int j = 0; j < originPoly.getSize (); ++j) {
* for (int i = 0; i < destinyPoly.getSize (); ++i) {
* float auxDistance = Vector3.Distance (originPoly.getVertex(j).getPosition (), destinyPoly.getVertex (i).getPosition ());
* if (auxDistance < minDistance) {
* a = originPoly.getVertex (j);
* b = destinyPoly.getVertex (i);
* minDistance = auxDistance;
* bIndex = i + 1;
* aIndex = j + 1;
* }
* }
* }*/
//Find lowerest tangent
//The lower point of origin will be either the first or last vertex(by construction)
/*if (a.getPosition ().y > originPoly.getVertex (-1).getPosition ().y) {
* a = originPoly.getVertex (-1);
* aIndex = 0;
* }
* int j = 0;
* float minPos = float.MaxValue;
* for (int i = 0; i < destinyPoly.getSize (); ++i) {
* float auxPos = destinyPoly.getVertex (i).getPosition ().y;
* if (auxPos < minPos) {
* b = destinyPoly.getVertex (i);
* minPos = auxPos;
* bIndex = i + 1;
* }
* }*/
const int maxFoll = 5;
int bFoll = 0, aFoll = 0; //To controll not the same sida is always the winner, as it produces artifacts some cases
int bIter = 0, aIter = 0;
bool aWins = false;
while (aIter < originPoly.getSize() && bIter < destinyPoly.getSize())
{
//This line ab will be triangulated with a point c either from one polyliline or the other, depending the one that has
//smallest angle with ab line(A-winner or B-winner).c It's always an adjacent vertex, we can use they are clockwise sorted(lucky!)
Vector3 ab = b.getPosition() - a.getPosition();
//Check the B polylilne candidate
Vertex bWinner = destinyPoly.getVertex(bIndex);
float bAngle = Vector3.Angle(-ab, bWinner.getPosition() - b.getPosition());
//Check the A polylilne candidate
Vertex aWinner = originPoly.getVertex(aIndex);
float aAngle = Vector3.Angle(ab, aWinner.getPosition() - a.getPosition());
//aAngle = Vector3.Distance (aWinner.getPosition (), b.getPosition ());
//bAngle = Vector3.Distance (bWinner.getPosition (), a.getPosition ());
//Check not same polyline accumulates too much wins
if (aFoll > maxFoll)
{
aWins = false;
aFoll = 0;
}
else if (bFoll > maxFoll)
{
aWins = true;
bFoll = 0;
}
else
{
aWins = aAngle < bAngle;
}
//If it's A-winner(from first poly) a=c, if it's from b-Winner b = c
if (aWins) //A wins!
{
addTriangle(a.getIndex(), aWinner.getIndex(), b.getIndex());
a = aWinner;
++aIndex;
++aIter;
++aFoll;
}
else //B wins!
{
addTriangle(a.getIndex(), bWinner.getIndex(), b.getIndex());
b = bWinner;
++bIndex;
++bIter;
++bFoll;
}
} //Repeat until ab we arrive to some of the polylines start, then triangulate with a or b constant(depends on polyline)
if (aIter >= originPoly.getSize())
{
while (bIter < destinyPoly.getSize())
{
Vertex bWinner = destinyPoly.getVertex(bIndex);
addTriangle(a.getIndex(), bWinner.getIndex(), b.getIndex());
b = bWinner;
++bIndex;
++bIter;
}
}
else if (bIter >= destinyPoly.getSize())
{
while (aIter < originPoly.getSize())
{
Vertex aWinner = originPoly.getVertex(aIndex);
addTriangle(a.getIndex(), aWinner.getIndex(), b.getIndex());
a = aWinner;
++aIndex;
++aIter;
}
}
//TODO: check strange artifacts cases,
//may be procuduced by winner decision, maybe smallest angle is not the best choice(or checking worng angle)
}