/// <summary>
/// See IMapper.
/// </summary>
/// <param name="images"></param>
/// <returns></returns>
public override S Mapping(IEnumerable <IImageInfo> images, IMapperStats mapperStats)
{
int candidateSpriteFails = 0;
int candidateSpritesGenerated = 0;
int canvasRectangleAddAttempts = 0;
int canvasNbrCellsGenerated = 0;
// Sort the images by height descending
IOrderedEnumerable <IImageInfo> imageInfosHighestFirst =
images.OrderByDescending(p => p.Height);
int totalAreaAllImages =
(from a in imageInfosHighestFirst select a.Width * a.Height).Sum();
int widthWidestImage =
(from a in imageInfosHighestFirst select a.Width).Max();
int heightHighestImage = imageInfosHighestFirst.First().Height;
S bestSprite = null;
int canvasMaxWidth = Canvas.UnlimitedSize;
int canvasMaxHeight = heightHighestImage;
while (canvasMaxWidth >= widthWidestImage)
{
CanvasStats canvasStats = new CanvasStats();
int lowestFreeHeightDeficitTallestRightFlushedImage;
S spriteInfo =
MappingRestrictedBox(imageInfosHighestFirst, canvasMaxWidth, canvasMaxHeight, canvasStats, out lowestFreeHeightDeficitTallestRightFlushedImage);
canvasRectangleAddAttempts += canvasStats.RectangleAddAttempts;
canvasNbrCellsGenerated += canvasStats.NbrCellsGenerated;
if (spriteInfo == null)
{
// Failure - Couldn't generate a SpriteInfo with the given maximum canvas dimensions
candidateSpriteFails++;
// Try again with a greater max height. Add enough height so that
// you don't get the same rectangle placement as this time.
if (canvasStats.LowestFreeHeightDeficit == Int32.MaxValue)
{
canvasMaxHeight++;
}
else
{
canvasMaxHeight += canvasStats.LowestFreeHeightDeficit;
}
}
else
{
// Success - Managed to generate a SpriteInfo with the given maximum canvas dimensions
candidateSpritesGenerated++;
// Find out if the new SpriteInfo is better than the current best one
if ((bestSprite == null) || (bestSprite.Area > spriteInfo.Area))
{
bestSprite = spriteInfo;
float bestEfficiency = (float)totalAreaAllImages / spriteInfo.Area;
if (bestEfficiency >= CutoffEfficiency)
{
break;
}
}
if (candidateSpritesGenerated >= MaxNbrCandidateSprites)
{
break;
}
// Try again with a reduce maximum canvas width, to see if we can squeeze out a smaller sprite
// Note that in this algorithm, the maximum canvas width is never increased, so a new sprite
// always has the same or a lower width than an older sprite.
canvasMaxWidth = bestSprite.Width - 1;
// Now that we've decreased the width of the canvas to 1 pixel less than the width
// taken by the images on the canvas, we know for sure that the images whose
// right borders are most to the right will have to move up.
//
// To make sure that the next try is not automatically a failure, increase the height of the
// canvas sufficiently for the tallest right flushed image to be placed. Note that when
// images are placed sorted by highest first, it will be the tallest right flushed image
// that will fail to be placed if we don't increase the height of the canvas sufficiently.
if (lowestFreeHeightDeficitTallestRightFlushedImage == Int32.MaxValue)
{
canvasMaxHeight++;
}
else
{
canvasMaxHeight += lowestFreeHeightDeficitTallestRightFlushedImage;
}
}
// ---------------------
// Adjust max canvas width and height to cut out sprites that we'll never accept
int bestSpriteArea = bestSprite.Area;
bool candidateBiggerThanBestSprite;
bool candidateSmallerThanCombinedImages;
while (
(canvasMaxWidth >= widthWidestImage) &&
(!CandidateCanvasFeasable(
canvasMaxWidth, canvasMaxHeight, bestSpriteArea, totalAreaAllImages,
out candidateBiggerThanBestSprite, out candidateSmallerThanCombinedImages)))
{
if (candidateBiggerThanBestSprite)
{
canvasMaxWidth--;
}
if (candidateSmallerThanCombinedImages)
{
canvasMaxHeight++;
}
}
}
if (mapperStats != null)
{
mapperStats.CandidateSpriteFails = candidateSpriteFails;
mapperStats.CandidateSpritesGenerated = candidateSpritesGenerated;
mapperStats.CanvasNbrCellsGenerated = canvasNbrCellsGenerated;
mapperStats.CanvasRectangleAddAttempts = canvasRectangleAddAttempts;
}
return(bestSprite);
}
/// <summary> /// See IMapping /// </summary> /// <param name="images"></param> /// <returns></returns> public abstract S Mapping(IEnumerable <IImageInfo> images, IMapperStats mapperStats);
