func (c *Creature) FOV(a *area.Area) (cs map[coord.Coord]struct{}) {
radius := c.Sight
cs = make(map[coord.Coord]struct{})
for x := c.X() - radius; x <= c.X()+radius; x++ {
for y := c.Y() - radius; y <= c.Y()+radius; y++ {
// Distance between creature x and y coordinates and sight radius.
dx := float64(x - c.X())
dy := float64(y - c.Y())
// Distance between creature and sight radius.
dist := math.Sqrt(math.Pow(dx, 2) + math.Pow(dy, 2))
// Discriminate coordinates which are outside of the circle.
if dist > float64(radius) {
continue
}
// Ignore hero.
for _, p := range get_line(c.X(), c.Y(), x, y)[1:] {
if !a.ExistsXY(p.X, p.Y) {
break
}
cs[p] = struct{}{}
// Terrain that breaks line of sight.
if !a.IsXYPathable(p.X, p.Y) {
break
}
}
}
}
return cs
}
