public bool IsInBorders(Collidable c)
{
int x = ((int)c.GetPosition().X / ZoneWidth) + 1;
int y = ((int)c.GetPosition().Y / ZoneHeight) + 1;
if (x >= 0 && x < GRID_WIDTH && y >= 0 && y < GRID_HEIGHT)
return true;
else
return false;
}
//returns a list of all of the zones a collidable object intersects
public List<Coordinate> GetAllZones(Collidable c)
{
List<Coordinate> retList = new List<Coordinate>();
Coordinate pos = GetPrimaryZone(c);
retList.Add(pos);
Vector2 p = c.GetPosition();
int radius = c.GetHitRadius();
bool up, down, left, right;
up = down = left = right = false;
if (p.X % ZoneWidth <= radius)
{
retList.Add(new Coordinate(pos.X - 1, pos.Y));
left = true;
}
else if ((p.X % ZoneWidth) + radius >= ZoneWidth)
{
retList.Add(new Coordinate(pos.X + 1, pos.Y));
right = true;
}
//Check overlap on vertical zones
if (p.Y % ZoneHeight <= radius)
{
retList.Add(new Coordinate(pos.X, pos.Y - 1));
up = true;
}
else if((p.Y % ZoneHeight) + radius >= ZoneHeight)
{
retList.Add(new Coordinate(pos.X, pos.Y + 1));
down = true;
}
//Checking corner overlaps
if (left)
{
if (up)
retList.Add(new Coordinate(pos.X - 1, pos.Y - 1));
else if (down)
retList.Add(new Coordinate(pos.X - 1, pos.Y + 1));
}
else if (right)
{
if (up)
retList.Add(new Coordinate(pos.X + 1, pos.Y - 1));
else if (down)
retList.Add(new Coordinate(pos.X + 1, pos.Y + 1));
}
return retList;
}
//given a collidable returns the primary zone it resides in
public Coordinate GetPrimaryZone(Collidable c)
{
int row = ((int)c.GetPosition().X / ZoneWidth) + 1;
int column = ((int)c.GetPosition().Y / ZoneHeight) + 1;
return new Coordinate(row, column);
}
//checks if two Collidables collide
public bool DoesCollide(Collidable a, Collidable b)
{
int radius = a.GetHitRadius() + b.GetHitRadius();
int dX = (int)b.GetPosition().X - (int)a.GetPosition().X;
int dY = (int)b.GetPosition().Y - (int)a.GetPosition().Y;
if (radius * radius < dX * dX + dY * dY)
return false;
else
return true;
}
