public static void Barycentric(Vector a, Vector b, Vector c, Vector p, out float u, out float v, out float w)
{
Vector v0 = b - a, v1 = c - a, v2 = p - a;
float d00 = (float)JMath.Dot(v0, v0);
float d01 = (float)JMath.Dot(v0, v1);
float d11 = (float)JMath.Dot(v1, v1);
float d20 = (float)JMath.Dot(v2, v0);
float d21 = (float)JMath.Dot(v2, v1);
float denom = d00 * d11 - d01 * d01;
v = (d11 * d20 - d01 * d21) / denom;
w = (d00 * d21 - d01 * d20) / denom;
u = 1 - v - w;
}
public static bool SegmentTest(Vector a, Vector b, Vector c, Vector d)
{
double triaa = JMath.SignedTriangleArea(a, b, d);
double triab = JMath.SignedTriangleArea(a, b, c);
if (triaa * triab < 0.0)
{
double triac = JMath.SignedTriangleArea(c, d, a);
double triad = triac + triab - triaa;
if (triac * triad < 0.0)
{
return(true);
}
}
return(false);
}
public static bool SegmentTest(Vector a, Vector b, Vector c, Vector d, out Vector i)
{
double triaa = JMath.SignedTriangleArea(a, b, d);
double triab = JMath.SignedTriangleArea(a, b, c);
if (triaa * triab < 0.0)
{
double triac = JMath.SignedTriangleArea(c, d, a);
double triad = triac + triab - triaa;
if (triac * triad < 0.0)
{
double t = triac / (triac - triad);
i = a + (b - a) * t;
return(true);
}
}
i = null;
return(false);
}
public static Vector ClosestPointOnSegment(Vector vA, Vector vB, Vector vPoint)
{
Vector VectorA = vPoint - vA;
Vector diff = vB - vA;
float d = (float)diff.Length;
Vector VectorB = diff.Normalize();
float t = (float)JMath.Dot(VectorB, VectorA);
if (t <= 0)
{
return(vA);
}
if (t >= d)
{
return(vB);
}
Vector res = vA + VectorB * t;
return(res);
}
public static double AngleDeg(Vector va, Vector vb)
{
return(JMath.AngleRad(va, vb) / Math.PI * 180.0);
}
/*
* a*b=|a|*|b|*cos angle
* cos angle=a*b/(|a|*|b|)
* angle = arccos (a*b/(|a|*|b|))
*/
public static double AngleRad(Vector va, Vector vb)
{
return(Math.Acos(JMath.Dot(va, vb) / (va.Length + vb.Length)));
}
