private void Subdivide(District district, int depth,
int borderLeft, int borderTop,
int borderRight, int borderBottom, Random rand)
{
int width = district.Width - borderLeft - borderRight;
int height = district.Height - borderTop - borderBottom;
if (BlockGenerator.WillAnyFit(width, height)) {
BlockGenerator gen = BlockGenerator.GetRandom(width, height, rand);
if (depth > 3 && rand.Next(width * height) == 0) {
district.SetBlock(gen.Generate(district, borderLeft, borderTop,
borderRight, borderBottom, rand));
return;
}
}
int nextBorder = depth < 4 ? 3 : depth < 6 ? 2 : 1;
int minHorz = 0;
double fitHorz = 0.0;
int minVert = 0;
double fitVert = 0.0;
while ((minHorz + nextBorder) * 2 + borderTop + borderBottom <= district.Height &&
(fitHorz = BlockGenerator.FitnessScore(district.Width - borderLeft - borderRight, minHorz)) == 0.0)
++minHorz;
while ((minVert + nextBorder) * 2 + borderLeft + borderRight <= district.Width &&
(fitVert = BlockGenerator.FitnessScore(minVert, district.Height - borderTop - borderBottom)) == 0.0)
++minVert;
bool horz = fitHorz > 0.0 && (fitVert == 0.0 || fitHorz > fitVert ||
(fitHorz == fitVert && rand.NextDouble() > 0.5));
if (horz) {
int min = borderTop + nextBorder + minHorz;
int max = district.Height - borderBottom - minHorz - nextBorder;
int mid = (min + max) / 2;
district.Split(true, rand.Next((min + mid) / 2, (mid + max) / 2));
Subdivide(district.ChildA, depth + 1, borderLeft, borderTop, borderRight, nextBorder, rand);
Subdivide(district.ChildB, depth + 1, borderLeft, nextBorder, borderRight, borderBottom, rand);
} else if (fitVert > 0.0) {
int min = minVert + borderLeft + nextBorder;
int max = district.Width - borderRight - minVert - nextBorder;
int mid = (min + max) / 2;
district.Split(false, rand.Next((min + mid) / 2, (mid + max) / 2));
Subdivide(district.ChildA, depth + 1, borderLeft, borderTop, nextBorder, borderBottom, rand);
Subdivide(district.ChildB, depth + 1, nextBorder, borderTop, borderRight, borderBottom, rand);
} else {
BlockGenerator gen = BlockGenerator.GetRandom(width, height, rand);
district.SetBlock(gen.Generate(district, borderLeft, borderTop,
borderRight, borderBottom, rand));
}
}