public void OnNewContact(IntPtr windowHandle, Multitouch.Contracts.IContact contact)
{
Window window = GetWindow(windowHandle);
if (window != null)
{
window.Contacts.Add(new WindowContact(contact));
Body body;
if (windowToBody.TryGetValue(window, out body))
{
NativeMethods.POINT point = new NativeMethods.POINT((int)contact.X, (int)contact.Y);
Vector2D contactPoint = point.ToVector2D();
if (body.Shape.CanGetIntersection)
{
Vector2D temp = body.Matrices.ToBody * contactPoint;
IntersectionInfo intersectionInfo;
if (body.Shape.TryGetIntersection(temp, out intersectionInfo))
{
FixedHingeJoint joint = new FixedHingeJoint(body, contactPoint, new Lifespan());
engine.AddJoint(joint);
contactJoints[contact.Id] = joint;
}
}
}
}
}
public void OnContactRemoved(IntPtr windowHandle, Multitouch.Contracts.IContact contact)
{
Window window = GetWindow(windowHandle);
if (window != null)
{
WindowContact winContact;
if (window.Contacts.TryGetValue(contact.Id, out winContact))
{
winContact.Update(contact);
}
window.Contacts.Remove(contact.Id);
FixedHingeJoint joint;
if (contactJoints.TryGetValue(contact.Id, out joint))
{
joint.Lifetime.IsExpired = true;
contactJoints.Remove(contact.Id);
}
}
}
public void OnContactMoved(IntPtr windowHandle, Multitouch.Contracts.IContact contact)
{
var w = (from win in windowToBody.Keys
where win.Contacts.Contains(contact.Id)
select win).SingleOrDefault();
WindowContact winContact = null;
if (w != null)
{
if (w.Contacts.TryGetValue(contact.Id, out winContact))
{
winContact.Update(contact);
}
}
Window window = GetWindow(windowHandle);
if (window != null)
{
FixedHingeJoint joint;
if (contactJoints.TryGetValue(contact.Id, out joint))
{
joint.Anchor = new Vector2D(contact.X, contact.Y);
// scale
Body body = joint.Bodies.First();
WindowContacts contacts = window.Contacts;
double previousDistance = 0;
double currentDistance = 0;
int divisor = 0;
RECT windowRect = window.Rectangle;
System.Windows.Point center = new System.Windows.Point(windowRect.Width / 2.0, windowRect.Height / 2.0);
WindowContact[] contactsArray = contacts.ToArray();
for (int i = 0; i < contactsArray.Length; i++)
{
for (int j = i + 1; j < contactsArray.Length; j++)
{
Vector vector = NativeMethods.ScreenToClient(window, contactsArray[j].Position.ToPoint()).ToPoint() -
NativeMethods.ScreenToClient(window, contactsArray[i].Position.ToPoint()).ToPoint();
currentDistance += vector.Length;
center += vector;
Vector previousVector = NativeMethods.ScreenToClient(window, contactsArray[j].PreviousPosition.ToPoint()).ToPoint() -
NativeMethods.ScreenToClient(window, contactsArray[i].PreviousPosition.ToPoint()).ToPoint();
previousDistance += previousVector.Length;
divisor++;
}
}
if (divisor == 0)
{
divisor = 1;
}
previousDistance /= divisor;
currentDistance /= divisor;
center.X /= divisor;
center.Y /= divisor;
double delta = currentDistance / previousDistance;
if (double.IsNaN(delta))
{
delta = 1;
}
window.Scale *= delta;
window.ScaleCenter = center;
body.Transformation *= Matrix2x3.FromScale(new Vector2D(delta, delta));
}
}
else if (w != null && winContact != null)
{
w.Contacts.Remove(contact.Id);
}
}
