private static bool SegmentSegmentCollinear(Vector2 leftA, Vector2 leftB, float sqrLeftLength, Vector2 rightA, Vector2 rightB,
out IntersectionSegmentSegment2 intersection)
{
Vector2 leftDirection = leftB - leftA;
float rightAProjection = Vector2.Dot(leftDirection, rightA - leftB);
if (Mathf.Abs(rightAProjection) < Geometry.Epsilon)
{
// LB == RA
// LA------LB
// RA------RB
intersection = IntersectionSegmentSegment2.Point(leftB);
return(true);
}
if (rightAProjection < 0)
{
// LB > RA
// LA------LB
// RARB
// RA--RB
// RA------RB
Vector2 pointB;
float rightBProjection = Vector2.Dot(leftDirection, rightB - leftA);
if (rightBProjection > sqrLeftLength)
{
pointB = leftB;
}
else
{
pointB = rightB;
}
intersection = IntersectionSegmentSegment2.Segment(rightA, pointB);
return(true);
}
// LB < RA
// LA------LB
// RA------RB
intersection = IntersectionSegmentSegment2.None();
return(false);
}
private static bool SegmentSegmentCollinear(Vector2 leftA, Vector2 leftB, Vector2 rightA, Vector2 rightB,
out IntersectionSegmentSegment2 intersection)
{
Vector2 leftDirection = leftB - leftA;
float projectionRA = Vector2.Dot(leftDirection, leftB - rightA);
if (Mathf.Abs(projectionRA) < Geometry.Epsilon)
{
// LB == RA
// LA------LB
// RA------RB
intersection = IntersectionSegmentSegment2.Point(leftB);
return(true);
}
if (projectionRA > 0)
{
// LB > RA
// LA------LB
// RARB
// RA--RB
// RA------RB
Vector2 pointB;
float projectionRB = Vector2.Dot(leftDirection, rightB - leftA);
if (projectionRB > leftDirection.sqrMagnitude)
{
pointB = leftB;
}
else
{
pointB = rightB;
}
intersection = IntersectionSegmentSegment2.Segment(rightA, pointB);
return(true);
}
// LB < RA
// LA------LB
// RA------RB
intersection = IntersectionSegmentSegment2.None();
return(false);
}
