//deadEdge: first dead Edge to star
//dir: direction where the wall will go on
//wallDir: direction of the wall, left or right of the dir???
func checkForDeadWall(surface engine.Surface, deadEdge engine.Point, dir int8, wallDir int8) (bool, engine.Point) {
possDead := deadEdge
for {
possDead = possDead.Add(engine.Direction(dir).Point())
if !surface.In(possDead) {
return false, possDead
}
possField := surface[possDead.Y][possDead.X]
possWallPos := possDead.Add(engine.Direction(wallDir).Point())
if !surface.In(possWallPos) {
return false, possDead
}
possWall := surface[possWallPos.Y][possWallPos.X]
if possField.Wall || possField.Point || !possWall.Wall {
return false, possDead
} else {
dead, _ := DeadCorner(surface, possDead)
if dead {
return true, possDead
}
}
}
log.E(-1, "checkForDeadWall: end of For loop")
return false, possDead
}
// check, if given point is a dead corner
func DeadCorner(surface engine.Surface, point engine.Point) (found bool, x int8) {
var p engine.Point
hit := false
x = 0
found = false
if surface[point.Y][point.X].Point {
return
}
// check clockwise, if there is a wall or not.
// If there is a wall two times together, corner is dead
for i := 0; i < 5; i++ {
x = int8(i % 4)
p = point.Add(engine.Direction(x).Point())
if !surface.In(p) || surface[p.Y][p.X].Wall {
if hit {
found = true
return
} else {
hit = true
}
} else {
hit = false
}
}
return
}
func MarkDeadFields(surface *engine.Surface) {
for y := 0; y < len(*surface); y++ {
for x := 0; x < len((*surface)[y]); x++ {
thisPoint := engine.NewPoint(x, y)
// walls can't be dead fields
if !surface.In(thisPoint) || (*surface)[y][x].Wall {
continue
}
dead, dir1 := DeadCorner(*surface, thisPoint)
if dead {
(*surface)[y][x].Dead = true
dir1 = (dir1 + 2) % 4 //dir1, dir2 are the directions of a possible dead wall
dir2 := (dir1 - 1) % 4
deadWall, p := checkForDeadWall(*surface, thisPoint, dir1, (dir2+2)%4)
if deadWall {
markDeadWall(surface, thisPoint, p)
}
deadWall, p = checkForDeadWall(*surface, thisPoint, dir2, (dir1+2)%4)
if deadWall {
markDeadWall(surface, thisPoint, p)
}
}
}
}
}
