private void LayoutChildren(GameObject parent, List <CityLayout> children, Vector2 size)
{
// Algorithm 3.1 in https://wettel.github.io/download/Wettel10b-PhDThesis.pdf
// TODO: Generalize this function to play in Layout Base Class
KDNode ptree = new KDNode(0, 0, size.x, size.y);
Vector2 covrec = Vector2.zero;
float totalArea = 0f;
//order children by size
children = children.OrderByDescending(s => s.LayoutSize.x * s.LayoutSize.z).ToList();
foreach (CityLayout c in children)
{
List <KDNode> pNodes = ptree.AvailableNodes(c);
Dictionary <KDNode, float> preservers = new Dictionary <KDNode, float>();
Dictionary <KDNode, float> expanders = new Dictionary <KDNode, float>();
KDNode targetNode;
KDNode fitNode;
// Check if each available node with preserve or expand current coverage
foreach (var pNode in pNodes)
{
// Check if node preserves or expands coverage area
if (pNode.X + c.LayoutSize.x <= covrec.x && pNode.Y + c.LayoutSize.z <= covrec.y) // Adding element to this node preserves coverage so find waste
{
// Waste is coverage area minus total occupied area plus new element area
float waste = covrec.x * covrec.y - (totalArea + (c.LayoutSize.x * c.LayoutSize.y));
preservers[pNode] = waste;
}
else // Adding element to this node expands coverage so find new ratio
{
// new ratio is new coverage area -> longer/short
float newX = pNode.X + c.LayoutSize.x > covrec.x ? pNode.X + c.LayoutSize.x : covrec.x;
float newY = pNode.Y + c.LayoutSize.z > covrec.y ? pNode.Y + c.LayoutSize.z : covrec.y;
expanders[pNode] = newX > newY ? newX / newY : newY / newX;
}
}
// Find Node to assign to our target node
if (preservers.Count > 0) // If we have preservers use the node with the smallest waste
{
targetNode = preservers.OrderBy(s => s.Value).First().Key;
}
else // Otherwise using the aspect ratio closest to a square (or 1)
{
targetNode = expanders.OrderBy(s => Mathf.Abs(s.Value - 1)).First().Key;
}
// If target is a perfect fit do nothing otherwise split node to get a perfect fit
if (targetNode.IsPerfectFit(c))
{
fitNode = targetNode;
}
else
{
fitNode = targetNode.Split(c);
}
// Update coverage based on added fitnode (but only if it expands either dimension
covrec.x = fitNode.X + fitNode.Width > covrec.x ? fitNode.X + fitNode.Width : covrec.x;
covrec.y = fitNode.Y + fitNode.Height > covrec.y ? fitNode.Y + fitNode.Height : covrec.y;
//Place child on Parent (Unity uses center anchoring but KDtree using top left anchoring)
float xPos = -ptree.Width / 2 + fitNode.Width / 2 + fitNode.X;
float yPos = parent.transform.position.x - parent.transform.localScale.y / 2 + c.LayoutSize.y / 2;
float zPos = ptree.Height / 2 - fitNode.Height / 2 - fitNode.Y;
c.Position = new Vector3(xPos, yPos, zPos);
//update total area of added elements
totalArea += fitNode.Area;
}
//Calc Scale of Parent Package
parent.transform.localScale = new Vector3
{
// TODO: Make decision on Class Size scaling
x = covrec.x > parent.transform.localScale.x ? covrec.x : parent.transform.localScale.x,
y = parent.transform.localScale.y,
z = covrec.y > parent.transform.localScale.z ? covrec.y : parent.transform.localScale.z
//x = Mathf.Clamp(covrec.x, minWidth, maxWidth),
//y = parent.transform.localScale.y,
//z = Mathf.Clamp(covrec.y, minWidth, maxWidth)
};
//Move Children back scaled package and attach as children game objects
foreach (CityLayout c in children)
{
float xDiff = (ptree.Width - covrec.x) / 2;
float zDiff = (ptree.Height - covrec.y) / 2;
Vector3 pos = c.GameObj.transform.localPosition;
pos.x += xDiff;
pos.z -= zDiff;
c.GameObj.transform.localPosition = pos;
c.GameObj.transform.parent = parent.transform;
}
}