/// <summary>
/// calculates collisions between the ball and a paddle, and finds the paddle surface that was hit
/// </summary>
/// <param name="paddle">the paddle that is being hit</param>
/// <param name="newPosition">the position the ball has</param>
/// <param name="newVelocity">the velocity the ball is trying to move with</param>
/// <returns>the position, length and surface of the collision</returns>
public CollisionReturn CollidesWithPaddle(Paddle paddle, Vector newPosition, Vector newVelocity)
{
Ray[] Vectors = new Ray[4]; // vector rays of moving ball
Vectors[TopEdge] = new Ray(newPosition, newVelocity);
Vectors[RightEdge] = new Ray(Vector.Add(newPosition, new Vector(Size.X, 0)), newVelocity);
Vectors[BottomEdge] = new Ray(Vector.Add(newPosition, new Vector(0, Size.Y)), newVelocity);
Vectors[LeftEdge] = new Ray(Vector.Add(newPosition, new Vector(Size.X, Size.Y)), newVelocity);
CollisionReturn collisionReturn = new CollisionReturn(false);
foreach (Ray ray in Vectors)
{
int edgeID = 0;
foreach (Ray edge in paddle.Edges)
{
RaycastReturn raycastReturn = Ray.Raycast(ray, edge);
if (raycastReturn.Intersects)
{
if (collisionReturn.Intersects)
{
if (raycastReturn.length < collisionReturn.length)
{
collisionReturn = new CollisionReturn(raycastReturn);
collisionReturn.Edge = edgeID;
}
}
else
{
collisionReturn = new CollisionReturn(raycastReturn);
collisionReturn.Edge = edgeID;
}
}
edgeID++;
}
}
return collisionReturn;
}
/// <summary>
/// calculates collisions between the ball and a block, and finds the block surface tha was hit
/// </summary>
/// <param name="block">the block being hit</param>
/// <param name="newPosition">the position the ball has</param>
/// <param name="newVelocity">the velocity the ball is trying to move with</param>
/// <param name="collidedRays">a list of rayIDs which have already collided with a surface</param>
/// <returns>the position, length and surface of the collision</returns>
public CollisionReturn CollidesWithBlock(Block block, Vector newPosition, Vector newVelocity, List<int> collidedRays)
{
// vector rays of moving ball
Ray[] Vectors = new Ray[4];
Vectors[TopEdge] = new Ray(newPosition, newVelocity);
Vectors[RightEdge] = new Ray(Vector.Add(newPosition, new Vector(Size.X, 0)), newVelocity);
Vectors[BottomEdge] = new Ray(Vector.Add(newPosition, new Vector(0, Size.Y)), newVelocity);
Vectors[LeftEdge] = new Ray(Vector.Add(newPosition, new Vector(Size.X, Size.Y)), newVelocity);
CollisionReturn collisionReturn = new CollisionReturn(false);
int rayID = 0;
foreach (Ray ray in Vectors)
{
int edgeID = 0;
if (!collidedRays.Contains(rayID)) // if the ray being used hasn't already collided with a box
{
// check every edge of the block
foreach (Ray edge in block.Edges)
{
RaycastReturn raycastReturn = Ray.Raycast(ray, edge); // see if the ray meets the edge
if (raycastReturn.Intersects)
{
// if there has already been a collision, check for a shorter one
if (collisionReturn.Intersects)
{
if (raycastReturn.length < collisionReturn.length) // if the ball velocity ray hits this edge before any other ray hits an edge
{
collisionReturn = new CollisionReturn(raycastReturn);
collisionReturn.Edge = edgeID;
collisionReturn.Ray = rayID;
}
}
// haven't had a ray collision yet, so use this collision by default
else
{
collisionReturn = new CollisionReturn(raycastReturn);
collisionReturn.Edge = edgeID;
collisionReturn.Ray = rayID;
}
}
edgeID++; // check next edge
}
}
rayID++; // check next ray
}
return collisionReturn; // return results
}