private void AddCollidableObject(ICutlassCollidable collidableObject)
{
//Want to extend collisions slightly outside visible screen.
BoundingRectangle collisionSpace = BoundingRectangle.Scale(_ViewScreen.VisibleArea, 1.1f, _ViewScreen.VisibleArea.Center);
BoundingRectangle intersection = BoundingRectangle.Intersection(collidableObject.CurrentFrameBoundingRect, collisionSpace);
int minHorizontalGroup = -1,
maxHorizontalGroup = -1,
minVerticalGroup = -1,
maxVerticalGroup = -1;
if (!intersection.IsZero)
{
float groupWidth = collisionSpace.Width / _HorizontalGroups;
float groupHeight = collisionSpace.Height / _VerticalGroups;
minHorizontalGroup = Math.Max(0, (int)((intersection.Left - collisionSpace.Left) / groupWidth));
maxHorizontalGroup = Math.Min(_HorizontalGroups - 1, (int)((intersection.Right - collisionSpace.Left) / groupWidth));
minVerticalGroup = Math.Max(0, (int)((intersection.Top - collisionSpace.Top) / groupHeight));
maxVerticalGroup = Math.Min(_VerticalGroups - 1, (int)((intersection.Bottom - collisionSpace.Top) / groupHeight));
for (int i = minHorizontalGroup; i <= maxHorizontalGroup; i++)
{
for (int j = minVerticalGroup; j <= maxVerticalGroup; j++)
{
if (_CurrentCollidableObjects[i, j] == null)
{
_CurrentCollidableObjects[i, j] = new List <ICutlassCollidable>();
}
_CurrentCollidableObjects[i, j].Add(collidableObject);
}
}
}
}