public int FindIntersection(LineSegment line2, ref Vector3 intersection)
{
if (Start.x == End.x)
{
if (line2.Start.x == line2.End.x)
{
return(-1);
}
intersection.x = Start.x;
intersection.y = line2.CalcY(intersection.x);
if ((intersection.y >= Start.y) && (intersection.y <= End.y))
{
return(1);
}
return(-1);
}
return(mLine.FindIntersection(line2, ref intersection));
}
public int FindIntersection(Edge e2, ref Vector3 intersection)
{
LineSegment line2 = e2.Line;
if (Line.Start.x == Line.End.x)
{
if (line2.Start.x == line2.End.x)
{
return(-1);
}
intersection.x = Line.Start.x;
intersection.y = line2.CalcY(intersection.x);
if ((intersection.y < Line.Start.y) || (intersection.y > Line.End.y))
{
return(-1);
}
if ((intersection.y == Line.Start.y) || (intersection.y == Line.End.y))
{
return(0);
}
return(1);
}
return(Line.FindIntersection(line2, ref intersection));
}
public override int Compare(Edge e1, Edge e2)
{
if (e1 == e2)
{
return(0);
}
LineSegment s1 = e1.Line;
LineSegment s2 = e2.Line;
Vector3 v1 = s1.End - s1.Start;
Vector3 v2 = s2.End - s2.Start;
float y1 = s1.CalcY(CurrentX);
float y2 = s2.CalcY(CurrentX);
Vector3 sweep = new Vector3(0, -1, 0);
float dx;
v1.Normalize();
v2.Normalize();
//
// Check for vertical lines
//
if (y1 == float.MaxValue)
{
if (y2 == float.MaxValue)
{
dx = s1.Start.x - s2.Start.x;
// both vertical, sort on X
if (Math.Abs(dx) > LineSegment.EPSILON)
{
return((dx > 0) ? 1 : -1);
}
return(e1.Tri.ID - e2.Tri.ID);
}
//
// first edge is vertical, not the second
// choose vertical direction based on
// the slope of the other line
// if Y increases with X, treat the vertical
// line as being above. Otherwise point it
// down and treat as below.
//
dx = s1.Start.x - CurrentX;
if (Math.Abs(dx) < LineSegment.EPSILON)
{
y1 = y2; // they intersect at CurrentX
}
}
//
// second edge is vertical, not the first
// choose vertical direction based on
// the slope of the other line
// if Y increases with X, treat the vertical
// line as being above. Otherwise point it
// down and treat as below.
//
else if (y2 == float.MaxValue)
{
dx = s2.Start.x - CurrentX;
if (Math.Abs(dx) < LineSegment.EPSILON)
{
y2 = y1; // they intersect at CurrentX
}
}
//
// Compare Y values at the current X
//
float dy = y1 - y2;
if (Math.Abs(dy) > LineSegment.EPSILON)
{
return((dy > 0) ? 1 : -1);
}
//
// sort based on angle around common point
//
float a1 = Vector3.Dot(sweep, v1);
float a2 = Vector3.Dot(sweep, v2);
float t = a2 - a1;
if (Math.Abs(t) > LineSegment.EPSILON)
{
return((t > 0) ? 1 : -1);
}
return(e1.Tri.ID - e2.Tri.ID);
}
