/// <summary>
/// Frees the specified old rectangle.
/// </summary>
/// <param name="oldRectangle">The old rectangle.</param>
public void Free(ref Rectangle oldRectangle)
{
freeRectangles.Add(oldRectangle);
}
/// <summary>
/// Tries to fit a single rectangle with the specified width and height.
/// </summary>
/// <param name="width">Width requested.</param>
/// <param name="height">Height requested</param>
/// <param name="bestRectangle">Fill with the rectangle if it was successfully inserted.</param>
/// <returns><c>true</c> if it was successfully inserted.</returns>
public bool Insert(int width, int height, ref Rectangle bestRectangle)
{
return(Insert(width, height, freeRectangles, ref bestRectangle));
}
private static bool Insert(int width, int height, List <Rectangle> freeRectanglesList, ref Rectangle bestRectangle)
{
// Info on algorithm: http://clb.demon.fi/files/RectangleBinPack.pdf
int bestScore = int.MaxValue;
int freeRectangleIndex = -1;
// Find space for new rectangle
for (int i = 0; i < freeRectanglesList.Count; ++i)
{
var currentFreeRectangle = freeRectanglesList[i];
if (width == currentFreeRectangle.Width && height == currentFreeRectangle.Height)
{
// Perfect fit
bestRectangle.X = currentFreeRectangle.X;
bestRectangle.Y = currentFreeRectangle.Y;
bestRectangle.Width = width;
bestRectangle.Height = height;
freeRectangleIndex = i;
break;
}
if (width <= currentFreeRectangle.Width && height <= currentFreeRectangle.Height)
{
// Can fit inside
// Use "BAF" heuristic (best area fit)
var score = currentFreeRectangle.Width * currentFreeRectangle.Height - width * height;
if (score < bestScore)
{
bestRectangle.X = currentFreeRectangle.X;
bestRectangle.Y = currentFreeRectangle.Y;
bestRectangle.Width = width;
bestRectangle.Height = height;
bestScore = score;
freeRectangleIndex = i;
}
}
}
// No space could be found
if (freeRectangleIndex == -1)
{
return(false);
}
var freeRectangle = freeRectanglesList[freeRectangleIndex];
// Choose an axis to split (trying to minimize the smaller area "MINAS")
int w = freeRectangle.Width - bestRectangle.Width;
int h = freeRectangle.Height - bestRectangle.Height;
var splitHorizontal = (bestRectangle.Width * h > w * bestRectangle.Height);
// Form the two new rectangles.
var bottom = new Rectangle {
X = freeRectangle.X, Y = freeRectangle.Y + bestRectangle.Height, Width = splitHorizontal ? freeRectangle.Width : bestRectangle.Width, Height = h
};
var right = new Rectangle {
X = freeRectangle.X + bestRectangle.Width, Y = freeRectangle.Y, Width = w, Height = splitHorizontal ? bestRectangle.Height : freeRectangle.Height
};
if (bottom.Width > 0 && bottom.Height > 0)
{
freeRectanglesList.Add(bottom);
}
if (right.Width > 0 && right.Height > 0)
{
freeRectanglesList.Add(right);
}
// Remove previously selected freeRectangle
if (freeRectangleIndex != freeRectanglesList.Count - 1)
{
freeRectanglesList[freeRectangleIndex] = freeRectanglesList[freeRectanglesList.Count - 1];
}
freeRectanglesList.RemoveAt(freeRectanglesList.Count - 1);
return(true);
}
