public void XAreaEqualToYAreaAndXLongestDimensionLessThanY()
{
Sprite x = new Sprite("X", new Bitmap(15, 20), 0, false);
Sprite y = new Sprite("Y", new Bitmap(10, 30), 0, false);
SpriteSizeComparer comparer = new SpriteSizeComparer();
int expected = -1;
int actual = comparer.Compare(x, y);
Assert.AreEqual(expected, actual);
}
public void XAreaLessThanYArea()
{
Sprite x = new Sprite("X", new Bitmap(10, 20), 0, false);
Sprite y = new Sprite("Y", new Bitmap(20, 30), 0, false);
SpriteSizeComparer comparer = new SpriteSizeComparer();
int expected = -1;
int actual = comparer.Compare(x, y);
Assert.AreEqual(expected, actual);
}
/// <summary>
/// Uses all images found in the specified source folder to build a compacted sprite sheet.
/// Images used maintain their original orientation, but may be cropped to remove transparency
/// if the <paramref name="cropTransparency"/> parameter is true.
/// </summary>
/// <param name="sourceFolder">Folder containing images to use in the sprite sheet.
/// All images in the folder will be used.</param>
/// <param name="outputName">Name to use for the sprite sheet output image file and XML definition file.</param>
/// <param name="cropTransparency">True if transparent pixels should be removed when determining
/// the source area of the image, or false if not.</param>
public void BuildSheet(string sourceFolder, string outputName, bool cropTransparency, bool roundUpPower2Size)
{
if (!Directory.Exists(sourceFolder))
{
throw new ArgumentException(string.Format("Source folder '{0}' does not exist", sourceFolder), "sourceFolder");
}
if (string.IsNullOrWhiteSpace(outputName))
{
throw new ArgumentNullException("outputName");
}
DirectoryInfo dirInfo = new DirectoryInfo(sourceFolder);
FileInfo[] files = dirInfo.GetFiles("*.png");
if ((files == null) || (files.Length == 0))
{
// Not finding image files means nothing can be built, but this should not
// be treated as an exception
return;
}
// Replace spaces in the name with underscores to help with compatibility
// with other tools or across platforms.
outputName = outputName.Replace(' ', '_');
string sheetName = Path.Combine(sourceFolder, outputName + ".png");
string xmlName = Path.Combine(sourceFolder, outputName + ".xml");
if (File.Exists(sheetName))
{
File.Delete(sheetName);
}
if (File.Exists(xmlName))
{
File.Delete(xmlName);
}
// Calculate the total area of all images and find the widest.
// Then create a list of images, sorted from smallest to largest.
int totalArea = 0;
int maxWidth = 0;
List<Sprite> sprites = new List<Sprite>();
foreach (FileInfo file in files)
{
if (file.FullName != sheetName)
{
Bitmap image = new Bitmap(file.FullName);
Sprite sprite = new Sprite(Path.GetFileNameWithoutExtension(file.FullName).Replace(' ', '_'), image, HorizontalPadding, VerticalPadding, cropTransparency);
sprites.Add(sprite);
totalArea += sprite.Width * sprite.Height;
maxWidth = (sprite.Width > maxWidth) ? sprite.Width : maxWidth;
}
}
sprites.Sort(new SpriteSizeComparer());
sprites.Reverse();
// Target width of the output sprite sheet is the larger of either the square root
// of the total area of all images, rounded up, or the width of the widest image.
int targetWidth = Math.Max((int)Math.Ceiling(Math.Sqrt(totalArea)), maxWidth);
if (roundUpPower2Size)
{
targetWidth = MathHelper.LeastPower2GreaterThanX(targetWidth);
}
int remainingWidth = targetWidth;
int nextX = 0;
int nextY = 0;
int maxHeightInRow = 0;
for (int i = 0; i < sprites.Count; ++i)
{
// If the next image being added is wider than the remaining allowed
// width of the current row of images, start a new row
if (remainingWidth - sprites[i].Width <= 0)
{
remainingWidth = targetWidth;
nextX = 0;
nextY += maxHeightInRow;
maxHeightInRow = 0;
}
sprites[i].SheetPosition = new Point(nextX, nextY);
remainingWidth -= sprites[i].Width;
nextX += sprites[i].Width;
if (sprites[i].Height > maxHeightInRow)
{
maxHeightInRow = sprites[i].Height;
}
}
int targetHeight = nextY + maxHeightInRow;
if (roundUpPower2Size)
{
targetHeight = MathHelper.LeastPower2GreaterThanX(targetHeight);
}
Size size = new Size(targetWidth, targetHeight);
WriteOutput(outputName, sheetName, xmlName, size, sprites);
}
