private LandblockGroup DoTrySplit()
{
var landblockGroupSplitHelper = new LandblockGroupSplitHelper();
var remainingLandblocks = new List <Landblock>(landblocks);
landblockGroupSplitHelper.Add(remainingLandblocks[remainingLandblocks.Count - 1]);
remainingLandblocks.RemoveAt(remainingLandblocks.Count - 1);
doAnotherPass:
bool needsAnotherPass = false;
for (int i = remainingLandblocks.Count - 1; i >= 0; i--)
{
if (landblockGroupSplitHelper.BoundaryDistance(remainingLandblocks[i]) < LandblockGroupMinSpacing)
{
landblockGroupSplitHelper.Add(remainingLandblocks[i]);
remainingLandblocks.RemoveAt(i);
needsAnotherPass = true;
}
}
if (needsAnotherPass)
{
goto doAnotherPass;
}
// If they're the same size, there's no split possible
if (Count == landblockGroupSplitHelper.Count)
{
return(null);
}
// Split was a success
var newLandblockGroup = new LandblockGroup();
foreach (var landblock in landblockGroupSplitHelper)
{
// Remove the split landblocks. Do this manually, not through the public Remove() function
landblocks.Remove(landblock);
// Add them through the proper .Add() method to the new LandblockGroup
newLandblockGroup.Add(landblock);
}
RecalculateBoundaries();
// This can result in returning groups that overlap this ones boundary.
// However, that isn't a problem for processing them on separate threads.
// In the event a new landblock is added that is within range of both this block and any new block, they will be recombined at that point.
return(newLandblockGroup);
}
/// <summary>
/// This will calculate the distance between the landblock group boarders.<para />
/// -X = Inside the bounds, where -1 is an overlapping outer perimeter<para />
/// 0 = Outside of the bounds but adjacent (touching)<para />
/// +X = Has X landblocks between this and the bounds of the group<para />
/// Distances are measured horizontally and vertically (not diagonally) pictured here: https://math.stackexchange.com/questions/2724537/finding-the-clear-spacing-distance-between-two-rectangles
/// </summary>
public int BoundaryDistance(LandblockGroup landblockGroup)
{
return((int)Math.Max(
Math.Abs(xCenter - landblockGroup.xCenter) - (width + landblockGroup.width) / 2.0,
Math.Abs(yCenter - landblockGroup.yCenter) - (height + landblockGroup.height) / 2.0));
}