func (s *Sim) potential(unit *unit, x, y float64) float64 {
// Distance to end
//max := 300.0
//dist := (&geo.Vec{x,y}).Distance(&unit.end)
//potEnd := dist/max
potEnd := 1.0
pos := &geo.Vec{x, y}
if unit.path != nil {
for e := unit.path.Front(); e.Next() != nil; e = e.Next() {
pt0 := e.Value.(*geo.Vec)
pt1 := e.Next().Value.(*geo.Vec)
av := geo.OrthogonalVector(pt0, pt1.Sub(pt0), &geo.Vec{x, y})
if av != nil {
potEnd = math.Min(av.Len()/10.0, 1)
} else {
if l := pt0.Sub(pos).Len(); l <= 10 {
potEnd = math.Min(l/10.0, potEnd)
} else if l := pt1.Sub(pos).Len(); l <= 10 {
potEnd = math.Min(l/10.0, potEnd)
}
}
}
}
// other units
MIN := 5.0
MAX := 10.0
potDist := 0.0
for _, oUnit := range s.units {
if oUnit.id != unit.id {
dist := oUnit.pos.Distance(&geo.Vec{x, y})
potDist += 1 - math2.MinMax(1, (dist-MIN)/(MAX-MIN), 0)
}
}
potDist = math2.MinMax(1, potDist, 0)
// trail
potTrail := 0.0
elms := unit.trail.Elements()
for _, elm := range elms {
if elm != nil {
trailPos := elm.(geo.Vec)
dist := trailPos.Distance(&geo.Vec{x, y})
potTrail += 1.0 - math2.MinMax(1, dist/float64(1), 0)
}
}
potTrail = math2.MinMax(1, potTrail, 0)
if unit.id == 0 && potDist > 0 {
//fmt.Println(potDist)
}
pot := 0.5*potEnd + 0*potDist + 0.25*potTrail
xd := int(x)
yd := int(y)
if xd >= 0 && xd < 300 && yd >= 0 && yd < 300 {
if s.static[xd][yd] == 1 {
pot = 1
}
}
return pot
}
func (s *Sim) Update() {
speed := 20.0 / float64(time.Second) // -> 10 units per second
lastUpdate := time.Now()
time.Sleep(1 * time.Nanosecond)
for {
dTime := time.Since(lastUpdate)
start := time.Now()
// Update the units
for _, unit := range s.units {
if unit.pos == unit.end {
// TODO when to finish?
continue
}
min, radMin := 1.0, 0.0
for i := 0; i < 16; i++ {
// TODO We can cache all these static directions
rad := math.Pi * 2 * float64(i) / 16.0
dy := math.Sin(rad)
dx := math.Cos(rad)
pot := s.potential(unit, unit.pos.X+dx, unit.pos.Y+dy)
if pot < min {
min = pot
radMin = rad
}
}
d := speed * float64(dTime)
unit.pos.X += math.Cos(radMin) * d
unit.pos.Y += math.Sin(radMin) * d
// Add position to trail if more than 0.25 units away
if last := unit.trail.Front(); last != nil {
lastPos := last.(geo.Vec)
if lastPos.Distance(&unit.pos) >= 0.25 {
unit.trail.AddToFront(unit.pos)
}
} else {
unit.trail.AddToFront(unit.pos)
}
// if the unit already walks at the next path piece, forget the current front one
if unit.path.Len() > 2 {
pt1 := unit.path.Front().Next().Value.(*geo.Vec)
pt2 := unit.path.Front().Next().Next().Value.(*geo.Vec)
if geo.OrthogonalVector(pt1, pt2.Sub(pt1), &unit.pos) != nil {
unit.path.Remove(unit.path.Front())
}
}
}
// Important: update BEFORE the render
lastUpdate = time.Now()
fps := 1 / (float64(time.Since(start)) / float64(time.Second))
_ = fps
//fmt.Printf("%.f \t\n", fps)
//fmt.Println(fps, s.units[0].pos)
//s.ui.fpsLabel.SetLabel(fmt.Sprintf("%f", fps))
time.Sleep(1 * time.Millisecond)
}
}