setFromRotationMatrix method
Implementation
Quaternion setFromRotationMatrix(m) {
// http://www.euclideanspace.com/maths/geometry/rotations/conversions/matrixToQuaternion/index.htm
// assumes the upper 3x3 of m is a pure rotation matrix (i.e, unscaled)
final te = m.elements;
double m11 = te[0];
double m12 = te[4];
double m13 = te[8];
double m21 = te[1];
double m22 = te[5];
double m23 = te[9];
double m31 = te[2];
double m32 = te[6];
double m33 = te[10];
double trace = m11 + m22 + m33;
if (trace > 0) {
var s = 0.5 / Math.sqrt(trace + 1.0);
_w = 0.25 / s;
_x = (m32 - m23) * s;
_y = (m13 - m31) * s;
_z = (m21 - m12) * s;
} else if (m11 > m22 && m11 > m33) {
var s = 2.0 * Math.sqrt(1.0 + m11 - m22 - m33);
_w = (m32 - m23) / s;
_x = 0.25 * s;
_y = (m12 + m21) / s;
_z = (m13 + m31) / s;
} else if (m22 > m33) {
var s = 2.0 * Math.sqrt(1.0 + m22 - m11 - m33);
_w = (m13 - m31) / s;
_x = (m12 + m21) / s;
_y = 0.25 * s;
_z = (m23 + m32) / s;
} else {
var s = 2.0 * Math.sqrt(1.0 + m33 - m11 - m22);
_w = (m21 - m12) / s;
_x = (m13 + m31) / s;
_y = (m23 + m32) / s;
_z = 0.25 * s;
}
onChangeCallback();
return this;
}