func ExampleGetRouteBetween_point() {
from := &terrain.Position{0, 0}
to := &terrain.Position{0, 0}
route := terrain.GetRouteBetween(from, to)
fmt.Println(route)
// Output: [[0 0]]
}
func ExampleGetRouteBetween_other() {
from := &terrain.Position{-1, 5}
to := &terrain.Position{5, 0}
route := terrain.GetRouteBetween(from, to)
fmt.Println(route)
// Output: [[-1 5] [0 4] [1 3] [2 3] [3 2] [4 1] [5 0]]
}
func ExampleGetRouteBetween_horizontal() {
from := &terrain.Position{-2, 0}
to := &terrain.Position{4, 0}
route := terrain.GetRouteBetween(from, to)
fmt.Println(route)
// Output: [[-2 0] [-1 0] [0 0] [1 0] [2 0] [3 0] [4 0]]
}
func ExampleGetRouteBetween_diagonal() {
from := &terrain.Position{-2, 2}
to := &terrain.Position{2, -2}
route := terrain.GetRouteBetween(from, to)
fmt.Println(route)
// Output: [[-2 2] [-1 1] [0 0] [1 -1] [2 -2]]
}
// Compute an entity's new position.
// Returns an EntityDiff if the entity has changed, nil otherwise.
func (m *Mover) UpdateEntity(ent *entity.Entity, now message.AbsoluteTick) (req *entity.UpdateRequest, collidesWith interface{}) {
// TODO: remove Mover.lastUpdates?
var last message.AbsoluteTick
var ok bool
if last, ok = m.lastUpdates[ent.Id]; !ok {
last = now
}
m.lastUpdates[ent.Id] = now
dt := time.Duration(now-last) * clock.TickDuration // Convert to seconds
if dt == 0 {
return
}
if dt < 0 {
return // TODO: figure out if it's the right thing to do here
}
speed := ent.Speed
pos := ent.Position
nextPos := speed.GetNextPosition(pos, dt)
if nextPos == nil {
return
}
// Check terrain
// TODO: use brensenham algorithm
// See http://tech-algorithm.com/articles/drawing-line-using-bresenham-algorithm/
route := terrain.GetRouteBetween(pos, nextPos)
stoppedAt, collidesWith := checkRoute(route, ent, m.engine.ctx.Terrain, m.engine.ctx.Entity.List())
if stoppedAt != nil {
// The entity has been stopped while moving
nextPos = stoppedAt
}
newEnt := entity.New()
newEnt.Id = ent.Id
newEnt.Position = nextPos
diff := &message.EntityDiff{Position: true}
req = entity.NewUpdateRequest(now, newEnt, diff)
return
}