public static bool IntersectionExists(FixedLine2 a, FixedLine2 b)
{
int sign1 = (a.start.y - (b.slope.Mul(a.start.x)) - b.yIntercept).Sign();
int sign2 = (a.end.y - (b.slope.Mul(a.end.x)) - b.yIntercept).Sign();
return(sign1 != sign2);
}
public static bool LineIntersection(FixedLine2 left, FixedLine2 right, out FixedVector2 intersection)
{
intersection = FixedVector2.NAN;
//check if we have parralel lines (even if we have two overlapping lines)
if ((left.isHorizontal && right.isHorizontal) || ((left.isVertical && right.isVertical)))
{
return(false);
}
if (left.isHorizontal && right.isVertical)
{
horizontal = left;
vertical = right;
}
else if (right.isHorizontal && left.isVertical)
{
horizontal = right;
vertical = left;
}
intersection = new FixedVector2(vertical.start.x, horizontal.start.y);
if ((FixedMath.Min(horizontal.start.x, horizontal.end.x) <= intersection.x) && intersection.x <= FixedMath.Max(horizontal.start.x, horizontal.end.x) &&
(FixedMath.Min(vertical.start.y, vertical.end.y) <= intersection.y) && intersection.y <= FixedMath.Max(vertical.start.y, vertical.end.y))
{
return(true);
}
//check for sloped lines while accounting for vertical lines
return(false);
}
public static bool AAOrthogonalLineIntersection(FixedLine2 horizontal, FixedLine2 vertical, out FixedVector2 intersection)
{
intersection = new FixedVector2(vertical.start.x, horizontal.start.y);
if ((FixedMath.Min(horizontal.start.x, horizontal.end.x) < intersection.x) && intersection.x < FixedMath.Max(horizontal.start.x, horizontal.end.x) &&
(FixedMath.Min(vertical.start.y, vertical.end.y) < intersection.y) && intersection.y < FixedMath.Max(vertical.start.y, vertical.end.y))
{
return(true);
}
//check for sloped lines while accounting for vertical lines
return(false);
}
public static bool LineLineIntersection(FixedLine2 line1, FixedLine2 line2, out FixedVector2 intersection)
{
intersection = new FixedVector2(long.MinValue, long.MinValue);
//standard form of line 1
long a1 = line1.end.y - line1.start.y;
long b1 = line1.start.x - line1.end.x;
long c1 = a1.Mul(line1.start.x) - b1.Mul(line1.start.y);
//standard form of line 2
long a2 = line2.end.y - line2.start.y;
long b2 = line2.start.x - line2.end.x;
long c2 = a2.Mul(line2.start.x) - b2.Mul(line2.start.y);
// float delta = A1*B2 - A2*B1;
// if(delta == 0)
// throw new ArgumentException("Lines are parallel");
//
// float x = (B2*C1 - B1*C2)/delta;
// float y = (A1*C2 - A2*C1)/delta;
long determinant = a1.Mul(b2) - a2.Mul(b1);
//line are parallel
if (determinant.Abs() < FixedMath.Hundredth)
{
return(false);
}
long x = (b2.Mul(c1) - b1.Mul(c2)).Div(determinant);
long y = (a1.Mul(c2) - a2.Mul(c1)).Div(determinant);
intersection = new FixedVector2(x, y);
// UnityEngine.Debug.DrawLine (new FixedVector2 (0, 0).ToVector3 (), intersection.ToVector3 ());
if ((FixedMath.Min(line1.start.x, line1.end.x) < x && x < FixedMath.Max(line1.start.x, line1.end.x)) &&
(FixedMath.Min(line1.start.y, line1.end.y) < y && y < FixedMath.Max(line1.start.y, line1.end.y)))
{
return(true);
}
return(false);
}
public static bool AreParallel(FixedLine2 a, FixedLine2 b)
{
return(a.slope == b.slope);
}