/*! \brief Finds the Ray intersection parameter.
* \param aabb Aligned box
* \param vorigin A vec3f with the origin of the ray
* \param vdir A vec3f with the direction of the ray
*/
public bool CollideRay(ref IndexedVector3 vorigin, ref IndexedVector3 vdir)
{
IndexedVector3 extents, center;
GetCenterExtend(out center, out extents);
float Dx = vorigin.X - center.X;
if (BoxCollision.BT_GREATER(Dx, extents.X) && Dx * vdir.X >= 0.0f)
{
return(false);
}
float Dy = vorigin.Y - center.Y;
if (BoxCollision.BT_GREATER(Dy, extents.Y) && Dy * vdir.Y >= 0.0f)
{
return(false);
}
float Dz = vorigin.Z - center.Z;
if (BoxCollision.BT_GREATER(Dz, extents.Z) && Dz * vdir.Z >= 0.0f)
{
return(false);
}
float f = vdir.Y * Dz - vdir.Z * Dy;
if (Math.Abs(f) > extents.Y * Math.Abs(vdir.Z) + extents.Z * Math.Abs(vdir.Y))
{
return(false);
}
f = vdir.Z * Dx - vdir.X * Dz;
if (Math.Abs(f) > extents.X * Math.Abs(vdir.Z) + extents.Z * Math.Abs(vdir.X))
{
return(false);
}
f = vdir.X * Dy - vdir.Y * Dx;
if (Math.Abs(f) > extents.X * Math.Abs(vdir.Y) + extents.Y * Math.Abs(vdir.X))
{
return(false);
}
return(true);
}
//! transcache is the transformation cache from box to this AABB
public bool OverlappingTransCache(ref AABB box, ref BT_BOX_BOX_TRANSFORM_CACHE transcache, bool fulltest)
{
//Taken from OPCODE
IndexedVector3 ea, eb; //extends
IndexedVector3 ca, cb; //extends
GetCenterExtend(out ca, out ea);
box.GetCenterExtend(out cb, out eb);
IndexedVector3 T = new IndexedVector3(0, 0, 0);
float t, t2;
int i;
// Class I : A's basis vectors
for (i = 0; i < 3; i++)
{
T[i] = transcache.m_R1to0[i].Dot(ref cb) + transcache.m_T1to0[i] - ca[i];
t = transcache.m_AR[i].Dot(ref eb) + ea[i];
if (BoxCollision.BT_GREATER(T[i], t))
{
return(false);
}
}
// Class II : B's basis vectors
for (i = 0; i < 3; i++)
{
t = Mat3DotCol(ref transcache.m_R1to0, ref T, i);
t2 = Mat3DotCol(ref transcache.m_AR, ref ea, i) + eb[i];
if (BoxCollision.BT_GREATER(t, t2))
{
return(false);
}
}
// Class III : 9 cross products
if (fulltest)
{
// check to see if these need to be restored back or are read-only
float[,] m_R1to0 = MathUtil.BasisMatrixToFloatArray(ref transcache.m_R1to0);
float[,] m_AR = MathUtil.BasisMatrixToFloatArray(ref transcache.m_AR);
int j, m, n, o, p, q, r;
for (i = 0; i < 3; i++)
{
m = (i + 1) % 3;
n = (i + 2) % 3;
o = i == 0 ? 1 : 0;
p = i == 2 ? 1 : 2;
for (j = 0; j < 3; j++)
{
q = j == 2 ? 1 : 2;
r = j == 0 ? 1 : 0;
t = T[n] * m_R1to0[m, j] - T[m] * m_R1to0[n, j];
t2 = ea[o] * m_AR[p, j] + ea[p] * m_AR[o, j] +
eb[r] * m_AR[i, q] + eb[q] * m_AR[i, r];
if (BoxCollision.BT_GREATER(t, t2))
{
return(false);
}
}
}
}
return(true);
}
