public virtual void Collided(PhysicsObject collider, Edge collidingEdge, Vector2 projectionVector, float deltaTime)
{
}
private void CheckCollisions(PhysicsObject physicsObject, float deltaTime)
{
// Check collision with all objects within our cells
Bag <PhysicsObject> collidedObjects = new Bag <PhysicsObject>();
physicsObject.ContainingCells.ForEach((cell) =>
{
Bag <PhysicsObject> possibleColliders = _grid[cell.Column, cell.Row];
possibleColliders.ForEachWith((collider) =>
{
/// IMPLEMENT BETTER MOUDLAR VERSION TO FIGURE OUT IF OBJECTS SHOULD COLLIDE. MAYBE SOMETHING LIKE BITWISE COLLISION GROUPS ETC...
if (physicsObject is CharacterObject && collider is CharacterObject)
{
return;
}
#region Depricated collision filters
/// IMPLEMENT A BETTER MODULAR VERSION TO FIGURE OUT COLLISIONS. MAYBE USE BITWISE COLLISION GROUPS ETC...
/*if (physicsObject.Owner != null && physicsObject.Owner.Type == Actor.ActorType.Spirit)
* {
* // Spirits don't collide with objects
* if (curCollider.Owner != null && curCollider.Owner.Type == Actor.ActorType.Object)
* continue;
* }
* if (curCollider.Owner != null && curCollider.Owner.Type == Actor.ActorType.Spirit)
* {
* // Spirits don't collide with objects
* if (physicsObject.Owner != null && physicsObject.Owner.Type == Actor.ActorType.Object)
* continue;
* }*/
#endregion
// Don't collide with ourselfs.
if (collider == physicsObject)
{
return;
}
// Has this object already been checked
if (collider.IsCollisionChecked)
{
return;
}
#region Collide with AABB shape
// Coarse collision.
AABB A = physicsObject.BoundingBox;
AABB B = collider.BoundingBox;
float xDist = Math.Abs(A.Position.X - B.Position.X);
float yDist = Math.Abs(A.Position.Y - B.Position.Y);
// Project half widths.
float xProj = A.XHalfWidth.X + B.XHalfWidth.X;
float yProj = A.YHalfWidth.Y + B.YHalfWidth.Y;
// Early exit.
if (xProj < xDist)
{
return;
}
if (yProj < yDist)
{
return;
}
#endregion
// If we should test AABB only we are done now.
if (physicsObject.TestAABBOnly && collider.TestAABBOnly)
{
#region Test AABB only
// Calculate projection vector.
Vector2 projectionVector;
Vector2 diff = B.Position - A.Position;
float xDiff = ((xProj - xDist) * 1.0f) + ConvertUnits.ToSimUnits(1);
float yDiff = ((yProj - yDist) * 1.0f) + ConvertUnits.ToSimUnits(1);
if (xDiff < yDiff)
{
projectionVector = new Vector2(xDiff * Math.Sign(diff.X), 0);
}
else
{
projectionVector = new Vector2(0, yDiff * Math.Sign(diff.Y));
}
// Are we dealing with sensors
if (!physicsObject.IsSensor && !collider.IsSensor)
{
// Get colliding edge (O(4))
Edge collidingEdge = null;
if (collider.CollisionShape.Type == Shape.ShapeType.SH_POLYGON)
{
var poly = collider.CollisionShape as Polygon;
var projDir = Vector2.Normalize(projectionVector);
for (int i = 0; i < poly.Edges.Length; i++)
{
var edge = poly.Edges[i];
if (Vector2.Dot(projDir, edge.Normal) > 0.9f)
{
collidingEdge = edge;
}
}
}
physicsObject.Collided(collider, collidingEdge, projectionVector, deltaTime);
}
if (physicsObject.OnCollision != null)
{
physicsObject.OnCollision(physicsObject, collider, projectionVector);
}
if (collider.OnCollision != null)
{
collider.OnCollision(collider, physicsObject, Vector2.Zero);
}
collider.IsCollisionChecked = true;
collidedObjects.Add(collider);
#endregion
}
else
{
#region Test Polygon
if (physicsObject.CollisionShape.Type == Shape.ShapeType.SH_POLYGON &&
collider.CollisionShape.Type == Shape.ShapeType.SH_POLYGON)
{
if (CollidePolyPoly(physicsObject.CollisionShape as Polygon, collider.CollisionShape as Polygon, deltaTime))
{
collidedObjects.Add(collider); // Flag object as checked and add to collided list.
}
}
#endregion
}
}, (collider) => { return(collider.IsActive); });
});
// Uncheck collision flags for next object
collidedObjects.ForEach((collider) => { collider.IsCollisionChecked = false; });
}
public Shape(PhysicsObject owner)
{
Owner = owner;
}
private bool CheckLineCollisions(int col, int row, Line line, RayCastCallback callback, bool isFirst, bool isLast, bool ignoreSensor, bool ignoreProjectile)
{
Bag <PhysicsObject> possibleColliders = _grid[col, row];
Vector2 collisionPoint = line.P2;
Vector2 collisionNormal = Vector2.Zero;
PhysicsObject collidingObject = null;
float distance = float.PositiveInfinity;
if (possibleColliders == null)
{
return(false);
}
/// I actually don't now why I put this in - it may causes bugs in future but for the moment it seems to work when commented.
/*if (possibleColliders.Count > 0)
* {
* // Cut out segment within the current cell.
* //
*
* // Create a sensor within the cell to collide with
* float xCell = (col + 0.5f) * _cellSize + Origin.X;
* float yCell = (row + 0.5f) * _cellSize + Origin.Y;
*
* var cellCollider = new Sensor(this, new Vector2(xCell, yCell), new Vector2(_cellSize, _cellSize));
*
* var newStart = Vector2.Zero;
* var newEnd = Vector2.Zero;
* var newNorm = Vector2.Zero;
* var mirrorLine = new Line(line.P2, line.P1);
*
* if (!CollideLinePoly(line, (Polygon)cellCollider.CollisionShape, out newStart, out newNorm))
* {
* newStart = line.P1;
* }
* if (!CollideLinePoly(mirrorLine, (Polygon)cellCollider.CollisionShape, out newEnd, out newNorm))
* {
* newEnd = line.P2;
* }
*
* line = new Line(newStart, newEnd);
*
* cellCollider.Dispense(); // Remove from world
* }*/
// Test each object to collide with line.
possibleColliders.ForEachWith((collider) =>
{
if (ignoreSensor)
{
if (collider.IsSensor)
{
return;
}
}
if (ignoreProjectile)
{
if (collider.IsProjectile)
{
return;
}
}
if (collider.CollisionShape.Type == Shape.ShapeType.SH_POLYGON)
{
var poly = collider.CollisionShape as Polygon;
if (isFirst)
{
if (CollidePointPoly(line.P1, poly))
{
return;
}
}
Vector2 curCollisionPoint, curCollisionNormal;
if (CollideLinePoly(line, poly, out curCollisionPoint, out curCollisionNormal))
{
// Check for closest point
float curDistance = (curCollisionPoint - line.P1).Length();
if (curDistance < distance)
{
distance = curDistance;
collidingObject = collider;
collisionPoint = curCollisionPoint;
collisionNormal = curCollisionNormal;
}
}
}
}, (collider) => { return(collider.IsActive); });
if (collidingObject != null)
{
callback(collidingObject, collisionPoint, collisionNormal);
_drawPoints.Add(collisionPoint);
return(true);
}
return(false);
}
public override void Collided(PhysicsObject collider, Edge collidingEdge, Vector2 projectionVector, float deltaTime)
{
if (!IsActive)
{
return;
}
if (IsEthereal || collider.IsEthereal)
{
return;
}
_projectionVector = projectionVector;
// After collision project out of colliding surface.
Position -= projectionVector;
if (projectionVector.Length() == 0.0f) // Return when no projection.
{
return;
}
// Split reflection velocity into friction and bounce vector.
var surfaceNorm = Vector2.Normalize(projectionVector);
var surfaceDir = new Vector2(surfaceNorm.Y, -surfaceNorm.X);
_surfaceNormal = surfaceNorm;
// Get collision point
//
// Distance to line
Vector2 p1 = collidingEdge.P1;
Vector2 p2 = collidingEdge.P2;
float normalLength = (float)Math.Sqrt((p2.X - p1.X) * (p2.X - p1.X) + (p2.Y - p1.Y) * (p2.Y - p1.Y));
float dist = Math.Abs((Position.X - p1.X) * (p2.Y - p1.Y) - (Position.Y - p1.Y) * (p2.X - p1.X)) / normalLength;
Vector2 collisionPoint = Position + surfaceNorm * dist;
if ((p1 - collisionPoint).Length() < 0.3f || (p2 - collisionPoint).Length() < 0.3f)
{
//Position += surfaceDir * 0.09f * Math.Sign(Velocity.X);
}
Vector2 bounce = surfaceNorm * Vector2.Dot(Velocity, surfaceNorm) * Restitution * -1 * 0;
Vector2 friction = surfaceDir * Vector2.Dot(Velocity, surfaceDir) * (1 - Friction);
if (Vector2.Dot(surfaceNorm, Vector2.UnitY) > _maxSlope)
{
MotionState = MotionStates.MS_LANDED;
// Enable character to walk up and down a specific slope at a certain speed
Vector2 velDirection = surfaceDir;
if (Vector2.Dot(velDirection, Velocity) < 0)
{
velDirection = -velDirection;
}
Velocity = velDirection * Velocity.Length() * Friction;
// Move with dynamic object.
if (collider.IsStatic == false)
{
var dynamicObject = collider as DynamicObject;
Position += dynamicObject.Velocity * deltaTime;
}
}
else
{
_bounceVector = bounce;
_frictionVector = friction;
// Add up to reflection vector.
_reflectionVector = bounce + friction;
Velocity = _reflectionVector;
}
// Check if we push colliding object.
float xProj = Math.Abs(Vector2.Dot(surfaceNorm, Vector2.UnitX));
if (xProj > 0.9f && xProj < 1.1f)
{
CharacterState = CharacterPhysicsState.CPS_PUSHING;
}
}