public bool Equals(Quaternion rhs, Real tolerance)
{
Real fCos = Dot(rhs);
Real angle = (Real)Utility.ACos(fCos);
return(Utility.Abs(angle) <= tolerance);
}
/// <summary>
///
/// </summary>
/// <param name="time"></param>
/// <param name="quatA"></param>
/// <param name="quatB"></param>
/// <param name="useShortestPath"></param>
/// <returns></returns>
public static Quaternion Slerp(Real time, Quaternion quatA, Quaternion quatB, bool useShortestPath)
{
Real cos = quatA.Dot(quatB);
Real angle = (Real)Utility.ACos(cos);
if (Utility.Abs(angle) < EPSILON)
{
return(quatA);
}
Real sin = Utility.Sin(angle);
Real inverseSin = 1.0f / sin;
Real coeff0 = Utility.Sin((1.0f - time) * angle) * inverseSin;
Real coeff1 = Utility.Sin(time * angle) * inverseSin;
Quaternion result;
if (cos < 0.0f && useShortestPath)
{
coeff0 = -coeff0;
// taking the complement requires renormalisation
Quaternion t = coeff0 * quatA + coeff1 * quatB;
t.Normalize();
result = t;
}
else
{
result = (coeff0 * quatA + coeff1 * quatB);
}
return(result);
}
/// <summary>
/// Calculates the logarithm of a Quaternion.
/// </summary>
/// <returns></returns>
public Quaternion Log()
{
// BLACKBOX: Learn this
// If q = cos(A)+sin(A)*(x*i+y*j+z*k) where (x,y,z) is unit length, then
// log(q) = A*(x*i+y*j+z*k). If sin(A) is near zero, use log(q) =
// sin(A)*(x*i+y*j+z*k) since sin(A)/A has limit 1.
// start off with a zero quat
Quaternion result = Quaternion.Zero;
if (Utility.Abs(w) < 1.0f)
{
Real angle = (Real)Utility.ACos(w);
Real sin = Utility.Sin(angle);
if (Utility.Abs(sin) >= EPSILON)
{
Real coeff = angle / sin;
result.x = coeff * x;
result.y = coeff * y;
result.z = coeff * z;
}
else
{
result.x = x;
result.y = y;
result.z = z;
}
}
return(result);
}
public bool Equals(Quaternion rhs, float tolerance)
{
float fCos = Dot(rhs);
float angle = (float)Utility.ACos(fCos);
return(Utility.Abs(angle) <= tolerance);
}
/// <summary>
///
/// </summary>
/// <param name="angle"></param>
/// <param name="axis"></param>
/// <returns></returns>
public void ToAngleAxis(ref Real angle, ref Vector3 axis)
{
// The quaternion representing the rotation is
// q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k)
Real sqrLength = x * x + y * y + z * z;
if (sqrLength > 0.0f)
{
angle = 2.0f * (Real)Utility.ACos(w);
Real invLength = Utility.InvSqrt(sqrLength);
axis.X = x * invLength;
axis.Y = y * invLength;
axis.Z = z * invLength;
}
else
{
angle = 0.0f;
axis.X = 1.0f;
axis.Y = 0.0f;
axis.Z = 0.0f;
}
}
/// <summary>
///
/// </summary>
/// <param name="angle"></param>
/// <param name="axis"></param>
/// <returns></returns>
public void ToAngleAxis(ref Real angle, ref Vector3 axis)
{
// The quaternion representing the rotation is
// q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k)
var sqrLength = this.x * this.x + this.y * this.y + this.z * this.z;
if (sqrLength > 0.0f)
{
angle = 2.0f * (Real)Utility.ACos(this.w);
var invLength = Utility.InvSqrt(sqrLength);
axis.x = this.x * invLength;
axis.y = this.y * invLength;
axis.z = this.z * invLength;
}
else
{
angle = 0.0f;
axis.x = 1.0f;
axis.y = 0.0f;
axis.z = 0.0f;
}
}
/// <summary>
///
/// </summary>
/// <param name="angle"></param>
/// <param name="axis"></param>
/// <returns></returns>
public void ToAngleAxis(ref float angle, ref Vector3 axis)
{
// The quaternion representing the rotation is
// q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k)
float sqrLength = x * x + y * y + z * z;
if (sqrLength > 0.0f)
{
angle = 2.0f * (float)Utility.ACos(w);
float invLength = Utility.InvSqrt(sqrLength);
axis.x = x * invLength;
axis.y = y * invLength;
axis.z = z * invLength;
}
else
{
angle = 0.0f;
axis.x = 1.0f;
axis.y = 0.0f;
axis.z = 0.0f;
}
}
internal unsafe void UpdateGeometry()
{
if (!this.IsCreated)
{
return;
}
// 95% of camera far clip distance
float TODO_Radius = this.SkyX.Camera.FarClipDistance * 0.95f;
_vertices[0].X = 0;
_vertices[0].Z = 0;
_vertices[0].Y = TODO_Radius;
_vertices[0].NX = 0;
_vertices[0].NZ = 0;
_vertices[0].NY = 1;
_vertices[0].U = 4;
_vertices[0].V = 4;
_vertices[0].Opacity = 1;
float angleStep = (Utility.PI / 2.0f) / (this.Circles - 1.0f);
float r, uvr, c, s, sc;
int x, y;
for (y = 0; y < this.Circles - 1; y++)
{
r = Utility.Cos(Utility.PI / 2.0f - angleStep * (y + 1.0f));
uvr = (y + 1.0f) / (this.Circles - 1.0f);
for (x = 0; x < this.Steps; x++)
{
c = Utility.Cos(Utility.TWO_PI * x / (float)this.Steps) * r;
s = Utility.Sin(Utility.TWO_PI * x / (float)this.Steps) * r;
sc = Utility.Sin(Utility.ACos(r));
_vertices[1 + y * this.Steps + x].X = c * TODO_Radius;
_vertices[1 + y * this.Steps + x].Z = s * TODO_Radius;
_vertices[1 + y * this.Steps + x].Y = sc * TODO_Radius;
_vertices[1 + y * this.Steps + x].NX = c;
_vertices[1 + y * this.Steps + x].NZ = s;
_vertices[1 + y * this.Steps + x].NY = sc;
_vertices[1 + y * this.Steps + x].U = (1.0f + c * uvr / r) * 4.0f;
_vertices[1 + y * this.Steps + x].V = (1.0f + s * uvr / r) * 4.0f;
_vertices[1 + y * this.Steps + x].Opacity = 1;
}
}
r = Utility.Cos(angleStep);
uvr = (this.Circles + 1.0f) / (this.Circles - 1.0f);
for (x = 0; x < this.Steps; x++)
{
c = Utility.Cos(Utility.TWO_PI * x / (float)this.Steps) * r;
s = Utility.Sin(Utility.TWO_PI * x / (float)this.Steps) * r;
_vertices[1 + (this.Circles - 1) * this.Steps + x].X = _vertices[1 + (this.Circles - 2) * this.Steps + x].X;
_vertices[1 + (this.Circles - 1) * this.Steps + x].Z = _vertices[1 + (this.Circles - 2) * this.Steps + x].Z;
_vertices[1 + (this.Circles - 1) * this.Steps + x].Y = _vertices[1 + (this.Circles - 2) * this.Steps + x].Y - TODO_Radius * this.SkydomeFadingPercent;
_vertices[1 + (this.Circles - 1) * this.Steps + x].NX = _vertices[1 + (this.Circles - 2) * this.Steps + x].NX;
_vertices[1 + (this.Circles - 1) * this.Steps + x].NZ = _vertices[1 + (this.Circles - 2) * this.Steps + x].NZ;
_vertices[1 + (this.Circles - 1) * this.Steps + x].NY = _vertices[1 + (this.Circles - 2) * this.Steps + x].NY;
_vertices[1 + (this.Circles - 1) * this.Steps + x].U = (1.0f + c * uvr / 4) * 4.0f;
_vertices[1 + (this.Circles - 1) * this.Steps + x].V = (1.0f + s * uvr / 4) * 4.0f;
_vertices[1 + (this.Circles - 1) * this.Steps + x].Opacity = this.SmoothSkydomeFading ? 0 : 1;
}
// Update data
fixed(PosUVVertex *addr = &_vertices[0])
{
_vertexBuffer.WriteData(0, _vertexBuffer.SizeInBytes, addr, true);
}
// Update bounds
AxisAlignedBox meshBounds = new AxisAlignedBox(new Vector3(-TODO_Radius, 0, -TODO_Radius),
new Vector3(TODO_Radius, TODO_Radius, TODO_Radius));
//_mesh.BoundingBox = meshBounds;
_mesh._setBounds(meshBounds);
_sceneNode.NeedUpdate();
//for (int i = 0; i < _vertices.Length; i++)
// LogVertices(_vertices[i]);
}
