private List<TextureInfo> LayoutAtlas(List<TextureInfo> _Textures, Atlas _Atlas)
{
List<Node> freeList = new List<Node>();
List<TextureInfo> textures = new List<TextureInfo>();
_Atlas.Nodes = new List<Node>();
textures = _Textures.ToList();
Node root = new Node();
root.Bounds.Size = new Size(_Atlas.Width, _Atlas.Height);
root.SplitType = SplitType.Horizontal;
freeList.Add(root);
while (freeList.Count > 0 && textures.Count > 0)
{
Node node = freeList[0];
freeList.RemoveAt(0);
TextureInfo bestFit = FindBestFitForNode(node, textures);
if (bestFit != null)
{
if (node.SplitType == SplitType.Horizontal)
{
HorizontalSplit(node, bestFit.Width, bestFit.Height, freeList);
}
else
{
VerticalSplit(node, bestFit.Width, bestFit.Height, freeList);
}
node.Texture = bestFit;
node.Bounds.Width = bestFit.Width;
node.Bounds.Height = bestFit.Height;
textures.Remove(bestFit);
}
_Atlas.Nodes.Add(node);
}
return textures;
}
private void VerticalSplit(Node _ToSplit, int _Width, int _Height, List<Node> _List)
{
Node n1 = new Node();
n1.Bounds.X = _ToSplit.Bounds.X + _Width + Padding;
n1.Bounds.Y = _ToSplit.Bounds.Y;
n1.Bounds.Width = _ToSplit.Bounds.Width - _Width - Padding;
n1.Bounds.Height = _ToSplit.Bounds.Height;
n1.SplitType = SplitType.Vertical;
Node n2 = new Node();
n2.Bounds.X = _ToSplit.Bounds.X;
n2.Bounds.Y = _ToSplit.Bounds.Y + _Height + Padding;
n2.Bounds.Width = _Width;
n2.Bounds.Height = _ToSplit.Bounds.Height - _Height - Padding;
n2.SplitType = SplitType.Horizontal;
if (n1.Bounds.Width > 0 && n1.Bounds.Height > 0)
_List.Add(n1);
if (n2.Bounds.Width > 0 && n2.Bounds.Height > 0)
_List.Add(n2);
}
private TextureInfo FindBestFitForNode(Node _Node, List<TextureInfo> _Textures)
{
TextureInfo bestFit = null;
float nodeArea = _Node.Bounds.Width * _Node.Bounds.Height;
float maxCriteria = 0.0f;
foreach (TextureInfo ti in _Textures)
{
switch (FitHeuristic)
{
// Max of Width and Height ratios
case BestFitHeuristic.MaxOneAxis:
if (ti.Width <= _Node.Bounds.Width && ti.Height <= _Node.Bounds.Height)
{
float wRatio = (float)ti.Width / (float)_Node.Bounds.Width;
float hRatio = (float)ti.Height / (float)_Node.Bounds.Height;
float ratio = wRatio > hRatio ? wRatio : hRatio;
if (ratio > maxCriteria)
{
maxCriteria = ratio;
bestFit = ti;
}
}
break;
// Maximize Area coverage
case BestFitHeuristic.Area:
if (ti.Width <= _Node.Bounds.Width && ti.Height <= _Node.Bounds.Height)
{
float textureArea = ti.Width * ti.Height;
float coverage = textureArea / nodeArea;
if (coverage > maxCriteria)
{
maxCriteria = coverage;
bestFit = ti;
}
}
break;
}
}
return bestFit;
}