/// Creates a fixture from a shape and attach it to this body.
/// This is a convenience function. Use FixtureDef if you need to set parameters
/// like friction, restitution, user data, or filtering.
/// If the Density is non-zero, this function automatically updates the mass of the body.
/// @param shape the shape to be cloned.
/// @param Density the shape Density (set to zero for static bodies).
/// @warning This function is locked during callbacks.
public Fixture CreateFixture(Shape shape){
FixtureDef def = new FixtureDef();
def.shape = shape.Clone();
def.Density = shape.Density;
def.Filter = shape.Filter;
return CreateFixture(def);
}
/// Initialize the proxy using the given shape. The shape
/// must remain in scope while the proxy is in use.
public void Set(Shape shape, int index){
switch (shape.GetShapeType())
{
case ShapeType.Circle:
{
CircleShape circle = (CircleShape)shape;
m_vertices = new List<Vec2>();
m_vertices.Add(circle.m_p);
m_radius = circle.m_radius;
}
break;
case ShapeType.Polygon:
{
PolygonShape polygon = (PolygonShape)shape;
m_vertices = new List<Vec2>();
m_vertices.AddRange(polygon.m_vertices);
m_radius = polygon.m_radius;
}
break;
case ShapeType.Chain:
{
ChainShape chain = (ChainShape)shape;
Utilities.Assert(0 <= index && index < chain.m_count);
m_buffer[0] = chain.m_vertices[index];
if (index + 1 < chain.m_count)
{
m_buffer[1] = chain.m_vertices[index + 1];
}
else
{
m_buffer[1] = chain.m_vertices[0];
}
m_vertices = new List<Vec2>();
m_vertices.AddRange(m_buffer);
m_radius = chain.m_radius;
}
break;
case ShapeType.Edge:
{
EdgeShape edge = (EdgeShape)shape;
m_vertices = new List<Vec2>();
m_vertices.AddRange(new Vec2[]{edge.m_vertex1, edge.m_vertex2});
m_radius = edge.m_radius;
}
break;
default:
Utilities.Assert(false);
break;
}
}
/// The constructor sets the default fixture definition values.
public FixtureDef()
{
shape = null;
UserData = null;
friction = 0.2f;
restitution = 0.0f;
Density = 0.0f;
IsSensor = false;
Filter = new Filter();
}
/// Determine if two generic shapes overlap.
public static bool TestOverlap(Shape shapeA, int indexA,
Shape shapeB, int indexB,
Transform xfA, Transform xfB){
DistanceInput input = new DistanceInput();
input.proxyA.Set(shapeA, indexA);
input.proxyB.Set(shapeB, indexB);
input.transformA = xfA;
input.transformB = xfB;
input.useRadii = true;
SimplexCache cache = new SimplexCache();
cache.count = 0;
DistanceOutput output;
Utilities.Distance(out output, cache, input);
return output.distance < 10.0f * Single.Epsilon;
}
// We need separation create/destroy functions from the constructor/destructor because
// the destructor cannot access the allocator (no destructor arguments allowed by C++).
internal void Create(Body body, FixtureDef def){
m_userData = def.UserData;
m_friction = def.friction;
m_restitution = def.restitution;
m_body = body;
m_next = null;
m_filter = def.Filter;
m_isSensor = def.IsSensor;
m_shape = def.shape.Clone();
// Reserve proxy space
int childCount = m_shape.GetChildCount();
m_proxies = new List<FixtureProxy>();
m_Density = def.Density;
}
internal Fixture(){
m_userData = null;
m_body = null;
m_next = null;
m_proxies = new List<FixtureProxy>();
m_shape = null;
m_Density = 0.0f;
}