public static void half_diff_coords_to_std_coords(double _ThetaHalf, double _PhiHalf, double _ThetaDiff, double _PhiDiff,
out double _ThetaIn, out double _PhiIn, out double _ThetaOut, out double _PhiOut)
{
double SinTheta_half = Math.Sin(_ThetaHalf);
Half.Set(Math.Cos(_PhiHalf) * SinTheta_half, Math.Sin(_PhiHalf) * SinTheta_half, Math.Cos(_ThetaHalf));
// Build the 2 vectors representing the frame in which we can use the diff angles
Vector3 OrthoX;
Half.Cross(ref Normal, out OrthoX);
if (OrthoX.LengthSq() < 1e-6)
{
OrthoX.Set(1, 0, 0);
}
else
{
OrthoX.Normalize();
}
Vector3 OrthoY;
Half.Cross(ref OrthoX, out OrthoY);
// Rotate using diff angles to retrieve incoming direction
Half.Rotate(ref OrthoX, -_ThetaDiff, out Temp);
Temp.Rotate(ref Half, _PhiDiff, out In);
// We can get the outgoing vector either by rotating the incoming vector half a circle
// Temp.Rotate( ref Half, _PhiDiff + Math.PI, out Out );
// ...or by mirroring in "Half tangent space"
double MirrorX = -In.Dot(ref OrthoX);
double MirrorY = -In.Dot(ref OrthoY);
double z = In.Dot(ref Half);
Out.Set(
MirrorX * OrthoX.x + MirrorY * OrthoY.x + z * Half.x,
MirrorX * OrthoX.y + MirrorY * OrthoY.y + z * Half.y,
MirrorX * OrthoX.z + MirrorY * OrthoY.z + z * Half.z
);
// CHECK
// Vector3 CheckHalf = new Vector3() { x = In.x+Out.x, y = In.y+Out.y, z = In.z+Out.z };
// CheckHalf.Normalize(); // Is this Half ???
// CHECK
// Finally, we can retrieve the angles we came here to look for...
_ThetaIn = Math.Acos(In.z);
_PhiIn = Math.Atan2(In.y, In.x);
_ThetaOut = Math.Acos(Out.z);
_PhiOut = Math.Atan2(Out.y, Out.x);
}
public static void half_diff_coords_to_std_coords(double _ThetaHalf, double _PhiHalf, double _ThetaDiff, double _PhiDiff,
ref Vector3 _In, ref Vector3 _Out)
{
double SinTheta_half = Math.Sin(_ThetaHalf);
Half.Set(Math.Cos(_PhiHalf) * SinTheta_half, Math.Sin(_PhiHalf) * SinTheta_half, Math.Cos(_ThetaHalf));
// Build the 2 vectors representing the frame in which we can use the diff angles
Vector3 OrthoX;
Half.Cross(ref Normal, out OrthoX);
if (OrthoX.LengthSq() < 1e-6)
{
OrthoX.Set(1, 0, 0);
}
else
{
OrthoX.Normalize();
}
Vector3 OrthoY;
Half.Cross(ref OrthoX, out OrthoY);
// Rotate using diff angles to retrieve incoming direction
Half.Rotate(ref OrthoX, -_ThetaDiff, out Temp);
Temp.Rotate(ref Half, _PhiDiff, out _In);
// ...or by mirroring in "Half tangent space"
double MirrorX = -_In.Dot(ref OrthoX);
double MirrorY = -_In.Dot(ref OrthoY);
double z = _In.Dot(ref Half);
_Out.Set(
MirrorX * OrthoX.x + MirrorY * OrthoY.x + z * Half.x,
MirrorX * OrthoX.y + MirrorY * OrthoY.y + z * Half.y,
MirrorX * OrthoX.z + MirrorY * OrthoY.z + z * Half.z
);
// if ( _In.z < -0.5 || _Out.z < -0.5 )
// throw new Exception( "RHA MAIS MERDE!" );
}