/// <summary>
/// Called when a manipulation gesture is currently happening
/// </summary>
/// <param name="eventData">The data of the manipulation event</param>
public void OnManipulationUpdated(ManipulationEventData eventData)
{
if (transformationManager.enabled)
{
// compute the difference of the drag gesture in comparison to the last frame
// this way the rotation speed is not accumulating but only depends on the current drag speed
Vector3 delta = lastCummulativeDelta - eventData.CumulativeDelta;
delta *= -1;
switch (handleType)
{
case HandleType.SCALE:
{
// it is also possible to scale without preserving the aspect ratio
// this option is implemented in here but it is currently not used
bool preserveAspectRatio = true;
if (preserveAspectRatio)
{
Vector2 centerProj = Camera.main.WorldToScreenPoint(toManipulate.position);
Vector2 handleProj = Camera.main.WorldToScreenPoint(transform.position);
Vector2 fromCenterToHandle = handleProj - centerProj;
fromCenterToHandle = fromCenterToHandle.normalized;
int drawDirection = Math.Sign(Vector2.Dot(delta, fromCenterToHandle));
// fromCenterToHandle points outwards from the center
// thus:
// if drawDirection < 0: inwards-drag => scale down
// if drawDirection > 0: outwards-drag => scale up
// just get the most dominant 2D-axis to determine the strength of the scale
// float max = Math.Max(Math.Abs(delta.x), Math.Abs(delta.y));
// get the length of the drag vector in order to determine the strength of the operation
float max = delta.magnitude;
// determine scaling factor
float scaleFac = 1.0f + (speed * max * drawDirection);
#if BOUNDING_BOX_DEBUG
// the following are debug lines which can be used to visualize the relevant vectors
// they are only visible in the game view
//Debug.DrawLine(toManipulate.position, toManipulate.position + new Vector3(fromCenterToHandle.x, fromCenterToHandle.y, 0), Color.red);
//Debug.DrawLine(Camera.main.transform.position, Camera.main.transform.position + (delta * 10000), Color.cyan);
#endif
// scale
transformationManager.Scale(scaleFac * Vector3.one);
}
else
{
Vector3 scaleVec = speed * new Vector3(
delta.x * gestureOrientation.x,
delta.y * gestureOrientation.y,
delta.z * gestureOrientation.z);
transformationManager.Scale(scaleVec);
}
break;
}
case HandleType.ROTATE:
{
// it uses the projection of the axis and computes everything in the viewport plane
Vector3 projectedDelta = Vector3.Project(delta, projectionCross);
float rotationAngle = projectedDelta.magnitude * Vector3.Dot(projectedDelta.normalized, projectionCross.normalized) * 360;
#if BOUNDING_BOX_DEBUG
// the following are debug lines which can be used to visualize the relevant vectors
// they are only visible in the game view
//Debug.DrawLine(toManipulate.position, toManipulate.position + currentAxis, Color.red);
//Debug.DrawLine(Camera.main.transform.position, Camera.main.transform.position + currentAxisProjection, Color.magenta);
//Debug.DrawLine(Camera.main.transform.position, Camera.main.transform.position + projectionCross, Color.green);
//Debug.DrawLine(Camera.main.transform.position, Camera.main.transform.position + (projectedDelta * 10000), Color.blue);
//Debug.DrawLine(Camera.main.transform.position, Camera.main.transform.position + (delta * 10000), Color.cyan);
#endif
#if ALTERNATIVE_SOLUTION
// this solution determines the angle at the object between the camera and its offset by the drag vector
// with the aid of the cross product the "sign of the angle" can be determined
// i.e. if the drag direction is pointing to the left or the right of the axis as seen from the camera
Vector3 objToCam = Camera.main.transform.position - toManipulate.position;
Vector3 objToTarget = (Camera.main.transform.position + delta) - toManipulate.position;
float rotationAngle = Vector3.Angle(objToCam, objToTarget);
Vector3 crossProduct = Vector3.Cross(objToCam, objToTarget);
if (Vector3.Dot(crossProduct, currentAxis) < 0)
{
rotationAngle *= -1;
}
#endif
Debug.Log("Rotation by: " + rotationAngle);
// rotate around the given axis by the calculated angle
transformationManager.Rotate(gestureOrientation, speed * rotationAngle);
break;
}
case HandleType.TRANSLATE:
{
transformationManager.Translate(speed * delta);
break;
}
}
// remember the cumulativeDelta in order to calculate the difference to this in the next frame
lastCummulativeDelta = eventData.CumulativeDelta;
}
}
public void TestRotate_NegativeAngle()
{
go.transform.rotation = Quaternion.identity;
transManager.Rotate(Vector3.up, -10);
Assert.IsTrue(go.transform.rotation.eulerAngles.Equals(new Vector3(0, 350, 0)));
}
