public void childIsTranslatedAndThenParentIsRotated()
{
var child = new Transform();
var parent = new Transform();
child.parent = parent;
var translation = new Vector3(1, -1, 0);
child.localTranslation = translation;
parent.rotateLocal(flipUpsideDown);
assertVectorEquals(Vector3.Transform(Vector3.Zero, child.worldMatrix), -translation);
}
public void childRotatesAroundCenterWhenTurningUpsideDown()
{
var child = new Transform();
var parent = new Transform();
child.parent = parent;
var center = new Vector3(1, -1, 0);
child.localTranslation = -center;
parent.localTranslation = center;
parent.rotateLocal(flipUpsideDown);
assertVectorEquals(Vector3.Transform(Vector3.Zero, child.worldMatrix), new Vector3(2, -2, 0));
}
public void rotationHappensBeforeTranslation()
{
var child = new Transform();
var center = new Vector3(1, -1, 0);
child.localTranslation = center;
child.rotateLocal(Quaternion.CreateFromRotationMatrix(flipUpsideDown));
var transformed = Vector3.Transform(center, child.worldMatrix);
assertVectorEquals(transformed, Vector3.Zero);
}
public void childRotatesWhenParentIsRotated()
{
var child = new Transform();
var parent = new Transform();
child.parent = parent;
var rotationMatrix = Matrix.CreateRotationZ(1);
parent.rotateLocal(rotationMatrix);
assertMatrixEquals(child.worldMatrix, rotationMatrix);
}