public static bool SegmentTest(JellyVector2 a, JellyVector2 b, JellyVector2 c, JellyVector2 d)
{
float triaa = SignedTriangleArea(a, b, d);
float triab = SignedTriangleArea(a, b, c);
float triac = 0;
float triad = 0;
if (triaa * triab < 0.0)
{
triac = SignedTriangleArea(c, d, a);
triad = triac + triab - triaa;
if (triac * triad < 0.0)
{
return(true);
}
}
if (triaa + triab + triac + triad == 0.0)
{
JellyVector2 ab = b - a;
float abdab = JellyVector2.Dot(ab, ab);
JellyVector2 ac = c - a;
float abdac = JellyVector2.Dot(ab, ac);
JellyVector2 ad = d - a;
float abdad = JellyVector2.Dot(ab, ad);
float min = System.Math.Min(abdac, abdad);
float max = System.Math.Max(abdac, abdad);
return(min < abdab && max > 0);
}
return(false);
}
public static void Barycentric(JellyVector2 a, JellyVector2 b, JellyVector2 c, JellyVector2 p, out float u, out float v, out float w)
{
JellyVector2 v0 = b - a, v1 = c - a, v2 = p - a;
float d00 = JellyVector2.Dot(v0, v0);
float d01 = JellyVector2.Dot(v0, v1);
float d11 = JellyVector2.Dot(v1, v1);
float d20 = JellyVector2.Dot(v2, v0);
float d21 = JellyVector2.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 JellyVector2 ClosestPointOnSegment(JellyVector2 a, JellyVector2 b, JellyVector2 c)
{
JellyVector2 ab = b - a;
float t = JellyVector2.Dot(c - a, ab) / JellyVector2.Dot(ab, ab);
if (t < 0)
{
return(a);
}
if (t > 1)
{
return(b);
}
return(a + ab * t);
}
public static bool SegmentTest(JellyVector2 a, JellyVector2 b, JellyVector2 c, JellyVector2 d, out JellyVector2 i)
{
float triaa = SignedTriangleArea(a, b, d);
float triab = SignedTriangleArea(a, b, c);
float triac = 0;
float triad = 0;
if (triaa * triab < 0.0)
{
triac = SignedTriangleArea(c, d, a);
triad = triac + triab - triaa;
if (triac * triad < 0.0)
{
float t = triac / (triac - triad);
i = a + (b - a) * t;
return(true);
}
}
if (triaa + triab + triac + triad == 0.0)
{
JellyVector2 ab = b - a;
float abdab = JellyVector2.Dot(ab, ab);
JellyVector2 ac = c - a;
float abdac = JellyVector2.Dot(ab, ac);
JellyVector2 ad = d - a;
float abdad = JellyVector2.Dot(ab, ad);
float min = System.Math.Min(abdac, abdad);
float max = System.Math.Max(abdac, abdad);
if (min < abdab && max > 0)
{
i = (a + b + c + d) * 0.25f;
return(true);
}
}
i = JellyVector2.Zero;//it should be null,change in XNA
return(false);
}
