func messages(w http.ResponseWriter, r *http.Request) {
c, err := upgrader.Upgrade(w, r, nil)
if err != nil {
log.Print("upgrade:", err)
return
}
defer c.Close()
// i := 5
rect := Rect{ID: 1, X: 10, Y: 0, Height: 50, Width: 50}
go func() {
for {
_, message, err := c.ReadMessage()
if err != nil {
log.Println("read:", err)
break
}
log.Printf("recv: %s", message)
msg := string(message)
if msg == KeyRight {
rect.XVector = physics.AddVectors(rect.XVector, physics.Vector(20))
} else if msg == KeyLeft {
rect.XVector = physics.AddVectors(rect.XVector, physics.Vector(-20.0))
}
if msg == KeyUp {
rect.YVector = physics.AddVectors(rect.YVector, physics.Vector(20))
} else if msg == KeyDown {
rect.YVector = physics.AddVectors(rect.YVector, physics.Vector(-20))
}
}
}()
for {
rect.Tick()
if err := c.WriteJSON(rect); err != nil {
log.Println("write:", err)
break
}
rect.XVector = Friction(rect.XVector)
rect.YVector = Friction(rect.YVector)
// i += 5
// if rect.X > 50 {
// i = -5
// } else if rect.X == 0 {
// i = 5
// }
// rect.X += i
// rect.Y += i
// log.Println(rect)
time.Sleep(15 * time.Millisecond)
// time.Sleep(1 * time.Second)
}
}
func Friction(v physics.Vector) physics.Vector {
if v.Magnitude() < 1 {
return physics.Vector(0.0)
}
if v.Direction() == physics.PositiveDirection {
return physics.AddVectors(v, physics.Vector(-1.0))
}
return physics.AddVectors(v, physics.Vector(1.0))
}