//---------------------------------------------------------------------------
// setupParentToLocal
//
// Setup the matrix to perform a parent -> local transformation, given
// the position and orientation of the local reference frame within the
// parent reference frame.
//
// A very common use of this will be to construct a world -> object matrix.
// To perform this transformation, we would normally FIRST transform
// from world to inertial space, and then rotate from inertial space into
// object space. However, out 4x3 matrix always translates last. So
// we think about creating two matrices T and R, and then concatonating
// M = TR.
//
// We allow the orientation to be specified using either euler angles,
// or a RotationMatrix
public void setupParentToLocal(Vector3 pos, EulerAngles orient)
{
// Create a rotation matrix.
RotationMatrix orientMatrix = new RotationMatrix();
orientMatrix.setup(orient);
// Setup the 4x3 matrix.
setupParentToLocal(pos, orientMatrix);
}
//---------------------------------------------------------------------------
// RotationMatrix::setup
//
// Setup the matrix with the specified orientation
//
// See 10.6.1
public void setup(EulerAngles orientation)
{
// Fetch sine and cosine of angles
float sh,ch, sp,cp, sb,cb;
MathUtil.sinCos(out sh, out ch, orientation.Heading);
MathUtil.sinCos(out sp, out cp, orientation.Pitch);
MathUtil.sinCos(out sb, out cb, orientation.Bank);
// Fill in the matrix elements
m11 = ch * cb + sh * sp * sb;
m12 = -ch * sb + sh * sp * cb;
m13 = sh * cp;
m21 = sb * cp;
m22 = cb * cp;
m23 = -sp;
m31 = -sh * cb + ch * sp * sb;
m32 = sb * sh + ch * sp * cb;
m33 = ch * cp;
}
//---------------------------------------------------------------------------
// setupLocalToParent
//
// Setup the matrix to perform a local -> parent transformation, given
// the position and orientation of the local reference frame within the
// parent reference frame.
//
// A very common use of this will be to construct a object -> world matrix.
// As an example, the transformation in this case is straightforward. We
// first rotate from object space into inertial space, then we translate
// into world space.
//
// We allow the orientation to be specified using either euler angles,
// or a RotationMatrix
public void setupLocalToParent(Vector3 pos, EulerAngles orient)
{
// Create a rotation matrix.
RotationMatrix orientMatrix = new RotationMatrix();
orientMatrix.setup(orient);
// Setup the 4x3 matrix. Note: if we were really concerned with
// speed, we could create the matrix directly into these variables,
// without using the temporary RotationMatrix object. This would
// save us a function call and a few copy operations.
setupLocalToParent(pos, orientMatrix);
}
//---------------------------------------------------------------------------
// EulerAngles::setToRotateObjectToInertial
//
// Setup the quaternion to perform an object->inertial rotation, given the
// orientation in Euler angle format
//
// See 10.6.5 for more information.
public void setToRotateObjectToInertial(EulerAngles orientation)
{
// Compute sine and cosine of the half angles
float sp, sb, sh;
float cp, cb, ch;
MathUtil.sinCos(out sp, out cp, orientation.Pitch * 0.5f);
MathUtil.sinCos(out sb, out cb, orientation.Bank * 0.5f);
MathUtil.sinCos(out sh, out ch, orientation.Heading * 0.5f);
// Compute values
w = ch*cp*cb + sh*sp*sb;
x = ch*sp*cb + sh*cp*sb;
y = -ch*sp*sb + sh*cp*cb;
z = -sh*sp*cb + ch*cp*sb;
}
