public void Collide(MovingObject a, ImmobileObject b, Vector2[] linePoints)
{
Vector2[] aVertices = a.GetAllVertices();
for (int i = 0; i < aVertices.Length; i++)
{
aVertices[i] += a.Position;
}
Vector2[] bVertices = b.GetAllVertices();
for (int i = 0; i < bVertices.Length; i++)
{
bVertices[i] += b.Position;
}
Vector2 closestOnB = ClosestPointToLine(a.Center + a.Position, linePoints[2], linePoints[3]);
Vector2 closestOnA = GetClosestPoint(closestOnB, aVertices);
a.Position -= closestOnA - closestOnB;
Vector2 bVector = linePoints[3] - linePoints[2];
bVector.Normalize();
bVector *= a.Velocity.Length();
a.Velocity = ClosestPointToLine(a.Velocity, -bVector, bVector);
Vector2 normalizedVelocity = new Vector2(a.Velocity.X, a.Velocity.Y);
normalizedVelocity.Normalize();
if (a.Velocity.LengthSquared() > b.Friction * b.Friction)
{
a.Velocity -= normalizedVelocity * b.Friction;
}
else
{
a.Velocity.X = 0;
a.Velocity.Y = 0;
}
}
public Vector2[][] GetCollision(MovingObject a, ImmobileObject b)
{
List <Vector2[]> collisions = new List <Vector2[]>();
Vector2 lastVertexA = a.GetVertex(a.VertexCount - 1) + a.Position;
for (int i = 0; i < a.VertexCount; i++)
{
Vector2 vertexA = a.GetVertex(i) + a.Position;
Vector2 lastVertexB = b.GetVertex(b.VertexCount - 1) + b.Position;
for (int j = 0; j < b.VertexCount; j++)
{
Vector2 vertexB = b.GetVertex(j) + b.Position;
if (CheckLineIntersection(lastVertexA, vertexA, lastVertexB, vertexB))
{
collisions.Add(new Vector2[] {
lastVertexA,
vertexA,
lastVertexB,
vertexB
});
}
lastVertexB = vertexB;
}
lastVertexA = vertexA;
}
return(collisions.ToArray());
}
public bool CheckCollision(MovingObject a)
{
for (int i = 0; i < ImmobileObjects.Count; i++)
{
ImmobileObject obj = ImmobileObjects[i];
if (GetCollision(a, obj).Length > 0)
{
return(true);
}
}
return(false);
}
public void Update()
{
foreach (MovingObject obj in MovingObjects)
{
obj.Velocity += Gravity;
obj.Update();
}
for (int i = 0; i < MovingObjects.Count; i++)
{
MovingObject obj = MovingObjects[i];
obj.TouchingSurface = false;
for (int j = 0; j < ImmobileObjects.Count; j++)
{
ImmobileObject targetObj = ImmobileObjects[j];
Vector2[][] allLinePoints = GetCollision(obj, targetObj);
Vector2[] closest = null;
float? closestDist = null;
foreach (Vector2[] linePoints in allLinePoints)
{
float dist = (ClosestPointToLine(obj.Center + obj.Position, linePoints[2], linePoints[3]) - (obj.Center + obj.Position)).LengthSquared();
if (closest == null || dist < closestDist)
{
closest = linePoints;
closestDist = dist;
}
}
if (closest != null)
{
Collide(obj, targetObj, closest);
obj.TouchingSurface = true;
}
}
if (!obj.TouchingSurface)
{
Vector2 normalizedVelocity = new Vector2(obj.Velocity.X, obj.Velocity.Y);
normalizedVelocity.Normalize();
if (obj.Velocity.LengthSquared() > AirFriction.LengthSquared())
{
obj.Velocity -= normalizedVelocity * AirFriction;
}
else
{
obj.Velocity.X = 0;
obj.Velocity.Y = 0;
}
}
}
for (int i = 0; i < GameObjectLinks.Count; i++)
{
GameObjectLink link = GameObjectLinks[i];
link.Update();
}
}