private void MouseLeftButtonDown(Vector2 position)
{
Vect mousePosition = MouseToSpace(position);
// give the mouse click a little radius to make it easier to click small shapes.
double radius = 5.0;
PointQueryInfo info = space.PointQueryNearest(mousePosition, radius, GrabbableFilter);
if (info == null)
{
return;
}
Shape shape = info.Shape;
Body body = shape.Body;
double mass = body.Mass;
if (double.IsInfinity(mass))
{
return;
}
// Use the closest point on the surface if the click is outside of the shape.
Vect nearest = info.Distance > 0.0 ? info.Point : mousePosition;
cursorJoint = new PivotJoint(cursorBody, body, Vect.Zero, body.WorldToLocal(nearest));
cursorJoint.MaxForce = 5000.0;
cursorJoint.ErrorBias = Math.Pow(1.0 - 0.15, 60.0);
space.AddConstraint(cursorJoint);
demo[currentDemo].OnMouseLeftButtonDown(chipmunkDemoMouse);
}
public void PointQueryTest()
{
var body = new Body(1, 1.66);
var shape = new Box(body, 2, 2, 0);
PointQueryInfo point = shape.PointQuery(new Vect(3, 4));
Assert.AreEqual(-5, point.Distance, "#1");
Assert.AreEqual(new Vect(0, 0), point.Point, "#2");
Assert.AreSame(shape, point.Shape, "#3");
Assert.AreEqual(-0.6, point.Gradient.X, 0.00000000001, "#4");
Assert.AreEqual(-0.8, point.Gradient.Y, 0.00000000001, "#5");
}
public override void OnMouseRightButtonDown(Vect chipmunkDemoMouse)
{
PointQueryInfo info = space.PointQueryNearest(chipmunkDemoMouse, 0.0, ChipmunkDemoGame.GrabbableFilter);
if (info == null || info.Shape == null)
{
return;
}
Body body = info.Shape.Body;
if (body.Type == BodyType.Static)
{
body.Type = BodyType.Dynamic;
body.Mass = pentagonMass;
body.Moment = pentagonMoment;
}
else
{
body.Type = BodyType.Static;
}
}
private void SliceQuery(Shape shape, Vect point, Vect normal, double alpha, SliceContext context)
{
Vect a = context.A;
Vect b = context.B;
// Check that the slice was complete by checking that the endpoints aren't in the sliced shape.
PointQueryInfo infoA = shape.PointQuery(a);
if (infoA == null || infoA.Distance <= 0.0)
{
return;
}
PointQueryInfo infoB = shape.PointQuery(b);
if (infoB == null || infoB.Distance <= 0.0)
{
return;
}
// Can't modify the space during a query.
// Must make a post-step callback to do the actual slicing.
space.AddPostStepCallback(SliceShapePostStep, shape, context);
}
