/// <summary>
/// Reset the collision flags of this gameObject to only None
/// </summary>
protected CollisionFlags2D ResetCollisionFlags(CollisionFlags2D collisions)
{
collisions |= CollisionFlags2D.None;
collisions &= ~CollisionFlags2D.Back;
collisions &= ~CollisionFlags2D.Top;
collisions &= ~CollisionFlags2D.Bottom;
collisions &= ~CollisionFlags2D.Front;
return(collisions);
}
private void Awake()
{
characterTransform = GetComponent <Transform>();
characterBody = GetComponent <Rigidbody2D>();
characterBody.isKinematic = true;
contactFilter.SetLayerMask(Physics2D.GetLayerCollisionMask(gameObject.layer));
contactFilter.useLayerMask = true;
hitList = new List <RaycastHit2D>(16);
collisionFlags = CollisionFlags2D.None;
characterUpDirection = Vector2.up;
}
/**
* // Useful just before teleporting the controller, for example.
* public void ResetSlopes()
* {
* switchCeiling = switchGround = false;
* ground = upGround = downGround = null;
* ceiling = upCeiling = downCeiling = null;
* groundTriggers.Clear();
* groundTriggers.TrimExcess();
* ceilingTriggers.Clear();
* ceilingTriggers.TrimExcess();
* }
* /**/
#endregion
#region Monobehaviour
void Awake()
{
collisionFlags = new CollisionFlags2D();
if (!self)
{
self = GetComponent <Transform>();
}
if (!box)
{
box = GetComponent <BoxCollider2D>();
}
//stepSize = 0.1f;
//groundTriggers = new List<SlopeZone>();
//ceilingTriggers = new List<SlopeZone>();
}
/// <summary>
/// Move character while being contrained by collisions
/// </summary>
/// <param name="deltaPosition"></param>
public void Move(Vector2 deltaPosition)
{
//---------------------------------------------------------------------------------------------------------
// Reset the collision flags before invoking the movement method. If the user needs the flags from the
// previous call they should be used before invoking this method. At this point the character will
// move and recieve new flags.
//---------------------------------------------------------------------------------------------------------
collisionFlags = ResetCollisionFlags(collisionFlags);
//---------------------------------------------------------------------------------------------------------
// We first get our up direction and calculate the dot product with respect to the deltaposition direction.
// We also calculate the total distance to travel this frame.
//---------------------------------------------------------------------------------------------------------
Vector2 upDirection = characterUpDirection;
//---------------------------------------------------------------------------------------------------------
// Initial cast. Here we use the full movement vector before splitting into side/up movement. If no
// collisions are found we can early exit the method.
//---------------------------------------------------------------------------------------------------------
if (!MoveInitial(characterBody, deltaPosition, contactFilter, hitList, contactOffset))
{
return;
}
//---------------------------------------------------------------------------------------------------------
// We decompose our movement into a normal and tangent vector with respect to the characters up direction.
// The normal vector points in the direction of the up direction while the tangent Vector points
// in the perpendicular direction to the normal with respect to the deltaposition. Remember that the
// character up direction must be normalized and non zero.
//---------------------------------------------------------------------------------------------------------
Vector2 vertVector = upDirection * Vector2.Dot(upDirection, deltaPosition);
Vector2 sideVector = deltaPosition - vertVector;
//---------------------------------------------------------------------------------------------------------
// Run the horizontal and vertical move methods. Note that we do the horizontal movement first. This
// is by design. Changing the order of these calls requires a full remake of the controller.
//---------------------------------------------------------------------------------------------------------
collisionFlags |= MoveHorizontal(characterTransform, characterBody, sideVector, upDirection, contactFilter, hitList,
contactOffset, positionIterations, collisionFlags, slopeLimit, slideOnGround, slideOnCeilings, forceSlide);
collisionFlags |= MoveVertical(characterTransform, characterBody, vertVector, upDirection, contactFilter, hitList,
contactOffset, positionIterations, collisionFlags, slopeLimit, slideOnGround, slideOnCeilings, forceSlide);
}
/// <summary>
/// Contains casting and movement logic for the vertical movement of the character. This is a secondary movement meaning
/// i only handles simple logic like moving down or up if not on the ground.
/// </summary>
/// <param name="body"></param>
/// <param name="direction"></param>
/// <param name="filter"></param>
/// <param name="results"></param>
/// <param name="skinWidth"></param>
/// <param name="maxIterations"></param>
protected CollisionFlags2D MoveVertical(Transform transform, Rigidbody2D body, Vector2 direction, Vector2 upDirection, ContactFilter2D filter,
List <RaycastHit2D> results, float skinWidth, int maxIterations, CollisionFlags2D flags, float maxAngle, bool slideGround, bool slideCeilings, bool forceSlideCharacter)
{
//---------------------------------------------------------------------------------------------------------
// Start up code before iteration
//---------------------------------------------------------------------------------------------------------
Vector2 currentPosition = body.position;
Vector2 currentDirection = direction;
Vector2 targetPosition = currentPosition + currentDirection;
int i = 0;
while (i < maxIterations)
{
//---------------------------------------------------------------------------------------------------------
// Cast in the horizontal direction
//---------------------------------------------------------------------------------------------------------
float distance = currentDirection.magnitude;
int hits = body.Cast(currentDirection, filter, results, distance + skinWidth);
//---------------------------------------------------------------------------------------------------------
// Nothing hit, move straight to target position
//---------------------------------------------------------------------------------------------------------
if (hits <= 0)
{
currentPosition = targetPosition;
break;
}
//---------------------------------------------------------------------------------------------------------
// Vertical collision detection
// We first sort the list of hits and get the closest one. Then we update our the character controllers
// position if the movement is larger than the skin width.
//---------------------------------------------------------------------------------------------------------
results.Sort((x, y) => y.distance.CompareTo(x.distance));
RaycastHit2D hit = results[0];
currentPosition = hit.distance > skinWidth ? currentPosition + currentDirection.normalized * (hit.distance - skinWidth) : currentPosition;
//---------------------------------------------------------------------------------------------------------
// We decide if we hit ceiling or ground
//---------------------------------------------------------------------------------------------------------
float normalDotUp = Vector2.Dot(hit.normal, upDirection);
Vector2 verticalDirection = Vector2.Dot(hit.normal, upDirection) >= 0 ? upDirection : -upDirection;
float angle = Vector2.Angle(verticalDirection, hit.normal);
//---------------------------------------------------------------------------------------------------------
// Here we decide if we should apply collision responses on the given geometry during the vertical
// collision call. We first find out if the character hits the ground or ceiling, then we
// calculate the collision flags accordingly. In the end we apply collision responses.
//---------------------------------------------------------------------------------------------------------
bool applyCollisionResponse = false;
if (normalDotUp >= 0)
{
if (angle > maxAngle && slideGround && forceSlideCharacter)
{
applyCollisionResponse = true;
}
else
{
flags |= CollisionFlags2D.Bottom;
}
}
else
{
if (angle > maxAngle && slideCeilings)
{
applyCollisionResponse = true;
flags |= CollisionFlags2D.Top;
}
}
targetPosition = applyCollisionResponse ? CollisionResponse(currentPosition, targetPosition, hit.normal, 0, 0) : currentPosition;
//---------------------------------------------------------------------------------------------------------
// Calculate new target position and Move the body to current position
//---------------------------------------------------------------------------------------------------------
currentDirection = targetPosition - currentPosition;
body.position = currentPosition;
//---------------------------------------------------------------------------------------------------------
// Exit the method if we reached our destination. This prevents the loop from iterating all the way
// to maxIterations each time, saving computation time.
//---------------------------------------------------------------------------------------------------------
if (currentDirection.sqrMagnitude < Mathf.Epsilon * Mathf.Epsilon)
{
break;
}
i++;
}
//---------------------------------------------------------------------------------------------------------
// Final position update
//---------------------------------------------------------------------------------------------------------
body.position = currentPosition;
return(flags);
}
/// <summary>
/// Contains the primary logic for the horizontal casting and movement of the character controller. This is a dominant
/// movement method, meaning the vertical movement is adjusted according to the horizontal movement. This method
/// moves the character up/down slopes, checks the slope limit and does slope clamping. Also does ground
/// checks in each iteration.
/// </summary>
/// <param name="body"></param>
/// <param name="direction"></param>
/// <param name="filter"></param>
/// <param name="results"></param>
/// <param name="skinWidth"></param>
/// <param name="maxIterations"></param>
protected CollisionFlags2D MoveHorizontal(Transform transform, Rigidbody2D body, Vector2 direction, Vector2 upDirection, ContactFilter2D filter,
List <RaycastHit2D> results, float skinWidth, int maxIterations, CollisionFlags2D flags, float maxAngle, bool slideGround, bool slideCeilings, bool forceSlideCharacter)
{
//---------------------------------------------------------------------------------------------------------
// Start up code before iteration
//---------------------------------------------------------------------------------------------------------
Vector2 currentPosition = body.position;
Vector2 currentDirection = direction;
Vector2 targetPosition = currentPosition + currentDirection;
int i = 0;
while (i < maxIterations)
{
//---------------------------------------------------------------------------------------------------------
// Cast in the horizontal direction
//---------------------------------------------------------------------------------------------------------
float distance = currentDirection.magnitude;
int hits = body.Cast(currentDirection, filter, results, distance + skinWidth);
//---------------------------------------------------------------------------------------------------------
// Nothing hit, move straight to target position
//---------------------------------------------------------------------------------------------------------
if (hits <= 0)
{
currentPosition = targetPosition;
break;
}
//---------------------------------------------------------------------------------------------------------
// Horizontal collision detection
// We first sort the list of hits and get the closest one. Then we update our the character controllers
// position if the movement is larger than the skin width.
//---------------------------------------------------------------------------------------------------------
results.Sort((x, y) => y.distance.CompareTo(x.distance));
RaycastHit2D hit = results[0];
currentPosition = hit.distance > skinWidth ? currentPosition + currentDirection.normalized * (hit.distance - skinWidth) : currentPosition;
//---------------------------------------------------------------------------------------------------------
// We decide if we hit ceiling or ground
//---------------------------------------------------------------------------------------------------------
float normalDotUp = Vector2.Dot(hit.normal, upDirection);
Vector2 verticalDirection = normalDotUp >= 0 ? upDirection : -upDirection;
float angle = Vector2.Angle(verticalDirection, hit.normal);
//---------------------------------------------------------------------------------------------------------
// Here we decide if we should apply collision responses on the given geometry during the horizontal
// collision call. We first find out if the character hits the ground or ceiling. After this
// we calculate if the character hit with it's back or front and set the collision flags
// accordingly. In the end we apply collision responses
//---------------------------------------------------------------------------------------------------------
bool applyCollisionResponse = false;
if (normalDotUp >= 0)
{
if (angle <= maxAngle && slideGround)
{
applyCollisionResponse = true;
}
}
else
{
if (angle <= maxAngle && slideCeilings)
{
applyCollisionResponse = true;
}
}
if (Vector2.Dot(transform.right, hit.normal) < 0)
{
flags |= CollisionFlags2D.Front;
}
else
{
flags |= CollisionFlags2D.Back;
}
targetPosition = applyCollisionResponse ? CollisionResponse(currentPosition, targetPosition, hit.normal, 0, 0) : currentPosition;
//---------------------------------------------------------------------------------------------------------
// Move body to current position and get ready for the next iteration. If this is the last iteration,
// the values calculated here will not be used.
//---------------------------------------------------------------------------------------------------------
currentDirection = targetPosition - currentPosition;
body.position = currentPosition;
//---------------------------------------------------------------------------------------------------------
// If we already reached our target we can exit the method. Saves us iterations in case we have many
// position updates. If we didn't have this, the method would iterate to the end each time
//---------------------------------------------------------------------------------------------------------
if (currentDirection.sqrMagnitude < Mathf.Epsilon * Mathf.Epsilon)
{
break;
}
i++;
}
//---------------------------------------------------------------------------------------------------------
// Final position update
//---------------------------------------------------------------------------------------------------------
body.position = currentPosition;
return(flags);
}
