//Mouse down
void ArcBall::click(GLfloat x, GLfloat y, Matrix4fT *stTrans)
{
Point2fT NewPt;
NewPt.T[0] = x;
NewPt.T[1] = y;
//Map the point to the sphere
this->_mapToSphere(&NewPt, &this->StVec);
Matrix4fSetRotationScaleFromMatrix4f(&this->StTransform, stTrans);
}
void ArcBall::dragAccumulate(GLfloat x, GLfloat y, Matrix4fT *transform)
{
Quat4fT tmpQuat;
Matrix3fT tmpRot;
drag(x, y, &tmpQuat);
// Set output to the initial transform
Matrix4fSetRotationScaleFromMatrix4f(transform, &this->StTransform);
// get current rotation matrix
Matrix3fSetRotationFromQuat4f(&tmpRot, &tmpQuat);
// Apply to initial transform
Matrix4fMulRotationFromMatrix3f(transform, &tmpRot);
}
/**
* Performs SVD on this matrix and gets scale and rotation.
* Rotation is placed into rot3, and rot4.
* @param rot3 the rotation factor(Matrix3d). if null, ignored
* @param rot4 the rotation factor(Matrix4) only upper 3x3 elements are changed. if null, ignored
* @return scale factor
*/
inline static GLfloat Matrix4fSVD(const Matrix4fT* NewObj, Matrix3fT* rot3, Matrix4fT* rot4) {
GLfloat s, n;
// this is a simple svd.
// Not complete but fast and reasonable.
// See comment in Matrix3d.
s = sqrtf(
( (NewObj->s.XX * NewObj->s.XX) + (NewObj->s.XY * NewObj->s.XY) + (NewObj->s.XZ * NewObj->s.XZ) +
(NewObj->s.YX * NewObj->s.YX) + (NewObj->s.YY * NewObj->s.YY) + (NewObj->s.YZ * NewObj->s.YZ) +
(NewObj->s.ZX * NewObj->s.ZX) + (NewObj->s.ZY * NewObj->s.ZY) + (NewObj->s.ZZ * NewObj->s.ZZ) ) / 3.0f );
if (rot3) { //if pointer not null
//this->getRotationScale(rot3);
rot3->s.XX = NewObj->s.XX; rot3->s.XY = NewObj->s.XY; rot3->s.XZ = NewObj->s.XZ;
rot3->s.YX = NewObj->s.YX; rot3->s.YY = NewObj->s.YY; rot3->s.YZ = NewObj->s.YZ;
rot3->s.ZX = NewObj->s.ZX; rot3->s.ZY = NewObj->s.ZY; rot3->s.ZZ = NewObj->s.ZZ;
// zero-div may occur.
n = 1.0f / sqrtf( (NewObj->s.XX * NewObj->s.XX) +
(NewObj->s.XY * NewObj->s.XY) +
(NewObj->s.XZ * NewObj->s.XZ) );
rot3->s.XX *= n;
rot3->s.XY *= n;
rot3->s.XZ *= n;
n = 1.0f / sqrtf( (NewObj->s.YX * NewObj->s.YX) +
(NewObj->s.YY * NewObj->s.YY) +
(NewObj->s.YZ * NewObj->s.YZ) );
rot3->s.YX *= n;
rot3->s.YY *= n;
rot3->s.YZ *= n;
n = 1.0f / sqrtf( (NewObj->s.ZX * NewObj->s.ZX) +
(NewObj->s.ZY * NewObj->s.ZY) +
(NewObj->s.ZZ * NewObj->s.ZZ) );
rot3->s.ZX *= n;
rot3->s.ZY *= n;
rot3->s.ZZ *= n;
}
if (rot4) { //if pointer not null
if (rot4 != NewObj) {
Matrix4fSetRotationScaleFromMatrix4f(rot4, NewObj); // private method
}
// zero-div may occur.
n = 1.0f / sqrtf( (NewObj->s.XX * NewObj->s.XX) +
(NewObj->s.XY * NewObj->s.XY) +
(NewObj->s.XZ * NewObj->s.XZ) );
rot4->s.XX *= n;
rot4->s.XY *= n;
rot4->s.XZ *= n;
n = 1.0f / sqrtf( (NewObj->s.YX * NewObj->s.YX) +
(NewObj->s.YY * NewObj->s.YY) +
(NewObj->s.YZ * NewObj->s.YZ) );
rot4->s.YX *= n;
rot4->s.YY *= n;
rot4->s.YZ *= n;
n = 1.0f / sqrtf( (NewObj->s.ZX * NewObj->s.ZX) +
(NewObj->s.ZY * NewObj->s.ZY) +
(NewObj->s.ZZ * NewObj->s.ZZ) );
rot4->s.ZX *= n;
rot4->s.ZY *= n;
rot4->s.ZZ *= n;
}
return s;
}
