func (cg *Gen) fits(oc OffsetChunk) bool {
// If a grid is defined, chunks must set in it.
if cg.grid.X > 0 && num.AbsMod(oc.offset.X, cg.grid.X) != 0 {
return false
}
if cg.grid.Y > 0 && num.AbsMod(oc.offset.Y, cg.grid.Y) != 0 {
return false
}
inside := oc.chunk.InsideBounds()
for pt, cell := range oc.chunk.cells {
if pt.In(inside) {
if _, ok := cg.cells[pt.Add(oc.offset)]; ok {
return false
}
} else {
if existingCell, ok := cg.cells[pt.Add(oc.offset)]; ok {
// Non-peg cells in a chunk can overwrite peg cells in the
// existing map.
overwritingPeg := oc.chunk.isPegCell(existingCell) && !oc.chunk.isPegCell(cell)
if !overwritingPeg && cell != existingCell {
return false
}
}
}
}
return true
}
// HexCirclePoint returns a point along the edge of a radius sized hexagon
// tile "circle" specified by windingIndex. The HexCircumference(radius)
// consecutive clockwise points on the circle are denoted by consecutive
// windingIndex values.
func HexCirclePoint(radius int, windingIndex int) image.Point {
if radius == 0 {
return image.Pt(0, 0)
}
sector := num.AbsMod(windingIndex, HexCircumference(radius)) / radius
offset := num.AbsMod(windingIndex, radius)
return HexDirs[sector].Mul(radius).Add(HexDirs[(sector+2)%6].Mul(offset))
}