public void Reverse( out Line2 outLine )
{
outLine.P0 = P1;
outLine.P1 = P0;
}
public Vector2? Intersection( Line2 l )
{
var p = P0;
var r = P1 - P0;
var q = l.P0;
var s = l.P1 - l.P0;
var qp_s = (float) Math.Round( Utils.Cross( q - p, s ), 3 );
var qp_r = (float) Math.Round( Utils.Cross( q - p, r ), 3 );
var r_s = (float) Math.Round( Utils.Cross( r, s ), 3 );
float t = qp_s / r_s;
float u = qp_r / r_s;
if ( r_s == 0 )
{
if ( qp_r == 0 )
{
var t0 = Vector2.Dot( q - p, r ) / Vector2.Dot( r, r );
var t1 = t0 + Vector2.Dot( s, r ) / Vector2.Dot( r, r );
if ( Vector2.Dot( s, r ) >= 0 )
{
if ( t0 <= 1 && t1 >= 0 )
return q;
}
else if ( t1 <= 1 && t0 >= 0 )
{
return q;
}
}
else
{
return null;
}
}
else if ( (0 <= t && t <= 1) && (0 <= u && u <= 1) )
{
return p + t*r;
}
return null;
}
