public bool CanMergePolygons()
{
// The two polygon partners can be merged if the two vectors on each point where they would merge don't create a concave polygon
// Concave testing is done through a cross product and assumes CCW winding of the polyon points
// Can merge point P of the Major/CCW partner?
{
// A = CWW[P - 1]
// B = CWW[P]
// C = CW[P + 1]
var A = this.MajorPartner.PrevPoint(this.MajorPartner_pIndex);
var B = this.MajorPartner.Points[this.MajorPartner_pIndex];
var C = this.MinorPartner.NextPoint(this.MinorPartner_pIndex);
float cross = GeoMath.Cross(A, B, C);
if (cross > 0)
{
return(false);
}
}
// Can merge point Q of Major/CCW partner?
{
// A = CWW[Q + 1]
// B = CWW[Q]
// C = CW[Q-1]
var A = this.MajorPartner.NextPoint(this.MajorPartner_qIndex);
var B = this.MajorPartner.Points[this.MajorPartner_qIndex];
var C = this.MinorPartner.PrevPoint(this.MinorPartner_qIndex);
float cross = GeoMath.Cross(A, B, C);
if (cross < 0)
{
return(false);
}
}
return(true);
}