/// <summary>
/// 判断两条线段是否相交
/// 现在有线段AB和线段CB
//用线段AB的方向和C，D两点分别做差乘比较。如果C,D在同侧则return跳出
//用线段CD的方向和A，B两点分别做差乘比较。如果A,B在同侧则return跳出
//最终返回相交
/// </summary>
/// <param name="a"></param>
/// <param name="b"></param>
/// <param name="c"></param>
/// <param name="d"></param>
/// <returns></returns>
static bool IsTwoSegmentIntersection(Vector2L a2d, Vector2L b2d, Vector2L c2d, Vector2L d2d)
{
Vector3L a = new Vector3L(a2d.x, 0, a2d.y);
Vector3L b = new Vector3L(b2d.x, 0, b2d.y);
Vector3L c = new Vector3L(c2d.x, 0, c2d.y);
Vector3L d = new Vector3L(d2d.x, 0, d2d.y);
var crossA = FixPointMath.Sign(Vector3L.Cross(d - c, a - c).y);
var crossB = FixPointMath.Sign(Vector3L.Cross(d - c, b - c).y);
if (FixPointMath.Approximately(crossA, crossB))
{
return(false);
}
var crossC = FixPointMath.Sign(Vector3L.Cross(b - a, c - a).y);
var crossD = FixPointMath.Sign(Vector3L.Cross(b - a, d - a).y);
if (FixPointMath.Approximately(crossC, crossD))
{
return(false);
}
return(true);
}
public static FloatL MoveTowards(FloatL current, FloatL target, FloatL maxDelta)
{
if (FixPointMath.Abs(target - current) <= maxDelta)
{
return(target);
}
return(current + FixPointMath.Sign(target - current) * maxDelta);
}
