// removeWallBetween removes the wall between two neighboring coordinates
func (m *Maze) removeWallBetween(c1, c2 common.Coordinate) {
d1 := c1.GetDir(c2)
r1, _ := m.GetRoom(c1.X, c1.Y)
r1.RmWall(d1)
d2 := c2.GetDir(c1)
r2, _ := m.GetRoom(c2.X, c2.Y)
r2.RmWall(d2)
}
// addWall on both sides
func (m *Maze) addWall(c common.Coordinate, dir int) {
nb := c.Neighbor(dir)
if m.contains(nb) {
r, _ := m.GetRoom(c.X, c.Y)
r.AddWall(dir)
r, _ = m.GetRoom(nb.X, nb.Y)
r.AddWall(common.ReverseDirection[dir])
}
}
// pickNeighbor selects a neighboring unexplored coordinate
func pickNeighbor(coordinate common.Coordinate, explored map[common.Coordinate]Survey) (common.Coordinate, int, bool) {
survey := explored[coordinate]
idxs := rand.Perm(len(allDirections))
for _, idx := range idxs {
dir := allDirections[idx]
if !survey.HasWall(dir) {
neighbor := coordinate.Neighbor(dir)
if _, ok := explored[neighbor]; !ok {
return neighbor, dir, true
}
}
}
return coordinate, 0, false
}
// floodfill starts from some coordinate, and randomly moves(floodfills) neighboring coordinates if unexplored.
// This is used to create deadends.
func (m *Maze) floodfill(c, from common.Coordinate, explored map[common.Coordinate]bool) {
m.sealRoom(c)
m.removeWallBetween(c, from)
explored[c] = true
nbs := c.Neighbors()
idxs := rand.Perm(len(nbs))
for _, idx := range idxs {
nb := nbs[idx]
if m.contains(nb) && !explored[nb] {
m.floodfill(nb, c, explored)
}
}
}