// Aka Jarvis march
public static List <Vector3D> GiftWrappingXZ(List <Vector3D> positions)
{
// Find leftmost point
int leftMostPoint = 0;
for (int i = 1; i < positions.Count; i++)
{
if (positions[i].x < positions[leftMostPoint].x)
{
leftMostPoint = i;
}
}
int pointOnHull = leftMostPoint;
int endPoint = 0;
List <Vector3D> res = new List <Vector3D>();
do
{
res.Add(positions[pointOnHull]);
endPoint = pointOnHull == 0?1:0;
for (int j = 0; j < positions.Count; j++)
{
if (j != pointOnHull && HMeshMath.LeftOfXZ(positions[pointOnHull], positions[endPoint], positions[j]))
{
endPoint = j;
}
}
pointOnHull = endPoint;
} while (endPoint != leftMostPoint);
return(res);
}
public static List <Vector3D> AklToussaintHeuristicXZ(List <Vector3D> positions)
{
int maxX = 0, maxZ = 0, minX = 0, minZ = 0;
for (int i = 0; i < positions.Count; i++)
{
if (positions[i].x < positions[minX].x)
{
minX = i;
}
if (positions[i].x > positions[maxX].x)
{
maxX = i;
}
if (positions[i].y < positions[minZ].z)
{
minZ = i;
}
if (positions[i].y > positions[maxZ].z)
{
maxZ = i;
}
}
List <int> points = new List <int>();
points.Add(minX);
if (!points.Contains(minZ))
{
points.Add(minZ);
}
if (!points.Contains(maxX))
{
points.Add(maxX);
}
if (!points.Contains(maxZ))
{
points.Add(maxZ);
}
if (points.Count <= 2)
{
return(positions);
}
/*Gizmos.color = Color.green;
* for (int i=0;i<points.Count;i++){
* Gizmos.DrawLine((positions[points[i]]+Vector3D.one*0.01f).ToVector3(), (positions[points[(i+1)%points.Count]]+Vector3D.one*0.01f).ToVector3());
* }*/
List <Vector3D> res = new List <Vector3D>();
for (int i = 0; i < positions.Count; i++)
{
if (points.Contains(i))
{
res.Add(positions[i]);
}
else
{
bool inside = true;
for (int j = 0; j < points.Count && inside; j++)
{
inside = HMeshMath.LeftOfXZ(positions[points[j]], positions[points[(j + 1) % points.Count]], positions[i]);
}
if (!inside)
{
res.Add(positions[i]);
}
}
}
return(res);
}
