/// <summary>
/// Determines if a ray intersects the polygon, and at what position the ray first intersects the polygon.
/// </summary>
/// <param name="rayLine">The line segment representing the ray.</param>
/// <param name="intersectionPoint">The first intersection of the ray and the polygon. Is NAN if no intersection.</param>
/// <returns>Returns if the polygon was intersected by the ray.</returns>
public bool RayIntersection(LineSegment rayLine, out Vector2 intersectionPoint)
{
intersectionPoint = new Vector2(float.NaN, float.NaN);
//Low-level detection
if (LineSegment.Distance(CenterPoint, rayLine.EndPoints[0]) <= rayLine.Length + MaximumRadius)
{
LineSegment[] sideSegments = SideSegments;
float minDist = 0;
for (int j = 0; j < sideSegments.Length; j++)
{
Vector2 potentialIntersectionPoint = new Vector2();
if (sideSegments[j].IntersectsSegment(rayLine, ref potentialIntersectionPoint))
{
float distanceToRayOrigin = LineSegment.Distance(potentialIntersectionPoint, rayLine.EndPoints[0]);
if (float.IsNaN(intersectionPoint.X) || distanceToRayOrigin < minDist)
{
minDist = distanceToRayOrigin;
intersectionPoint = potentialIntersectionPoint;
}
}
}
}
return(!float.IsNaN(intersectionPoint.X));
}
public PolygonPoint(Vector2 point, Polygon polygon)
{
initialRotation = polygon.TotalRotation;
this.polygon = polygon;
radius = LineSegment.Distance(point, polygon.CenterPoint);
angle = (float)Math.Atan2(point.Y - polygon.CenterPoint.Y, point.X - polygon.CenterPoint.X);
}
/// <summary>
/// Creates a joint that applies forces to both bodies to keep the points at a specified distance.
/// </summary>
/// <param name="elasticity">Elasticity of the joint.</param>
/// <param name="rb1">The first RigidBody.</param>
/// <param name="p1">The point on the first RigidBody.</param>
/// <param name="rb2">The second RigidBody.</param>
/// <param name="p2">The point on the second RigidBody.</param>
/// <param name="stretchLimit"></param>
public ElasticJoint(float elasticity, RigidBody rb1, Vector2 p1, RigidBody rb2, Vector2 p2)
{
targetDistance = LineSegment.Distance(p1, p2);
this.rb1 = rb1;
this.rb2 = rb2;
this.p1 = new PolygonPoint(p1, rb1.CollisionPolygon);
this.p2 = new PolygonPoint(p2, rb2.CollisionPolygon);
this.elasticity = elasticity;
}
private float GetInertia(float mass)
{
//return mass * 150;
//Sum vertices
Vector2[] vertices = CollisionPolygon.Vertices;
float massDivision = mass / vertices.Length;
float inertialSum = 0;
for (int i = 0; i < vertices.Length; i++)
{
inertialSum += massDivision * (float)Math.Pow(LineSegment.Distance(vertices[i], CollisionPolygon.CenterPoint), 2);
}
return(inertialSum / INERTIAL_DIVISOR);
}
public void ControlUpdate(GameTime gameTime, MouseState mouseState, Vector2 scale, Vector2 translation)
{
currentMouseState = mouseState;
//Apply transformations to position
Vector2 relativeMousePosition = new Vector2((mouseState.Position.X + translation.X) * scale.X, (mouseState.Position.Y + translation.Y) * scale.Y);
//Update control
if (currentMouseState.LeftButton == ButtonState.Pressed)
{
if (prevMouseState.LeftButton == ButtonState.Released)
{
//Potentially add joint control
T[] bodies = GetBodies();
for (int i = 0; i < bodies.Length; i++)
{
if (bodies[i].CollisionPolygon.MaximumRadius >= LineSegment.Distance(bodies[i].CollisionPolygon.CenterPoint, relativeMousePosition) && bodies[i].CollisionPolygon.ContainsPoint(relativeMousePosition))
{
//Add joint control
CreateJointControl(relativeMousePosition, bodies[i]);
break;
}
}
}
else
{
//Uphold current joint control (if exists)
if (interactionJoint != null)
{
UpdateJointControl(relativeMousePosition);
}
}
}
else
{
if (prevMouseState.LeftButton == ButtonState.Pressed)
{
//Remove joint control (if exists)
RemoveJointControl();
}
}
Update(gameTime);
prevMouseState = mouseState;
}
public float GetHeight()
{
Line normalLine = new LineSegment(vertices[0], vertices[1]).NormalLine;
return(LineSegment.Distance(normalLine.PointProjection(vertices[0]), normalLine.PointProjection(vertices[2])));
}
public float GetBase()
{
return(LineSegment.Distance(vertices[0], vertices[1]));
}
