Files
OpenRA/OpenRa.Game/Traits/Activities/ReturnToBase.cs

96 lines
2.5 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace OpenRa.Game.Traits.Activities
{
class ReturnToBase : IActivity
{
public IActivity NextActivity { get; set; }
bool isCanceled;
bool isCalculated;
Actor dest;
float2 w1, w2, w3; /* tangent points to turn circles */
float2 landPoint;
Actor ChooseAirfield(Actor self)
{
var airfield = Game.world.Actors
.Where(a => a.LegacyInfo == Rules.UnitInfo["AFLD"] /* todo: generalize this */
&& a.Owner == self.Owner
&& !Reservable.IsReserved(a))
.FirstOrDefault();
if (airfield == null)
throw new NotImplementedException("nowhere to land; what to do?");
return airfield;
}
void Calculate(Actor self)
{
if (dest == null) dest = ChooseAirfield(self);
var res = dest.traits.GetOrDefault<Reservable>();
if (res != null)
self.traits.Get<Plane>().reservation = res.Reserve(self);
var landPos = dest.CenterLocation;
var unit = self.traits.Get<Unit>();
var speed = .2f * Util.GetEffectiveSpeed(self);
var approachStart = landPos - new float2(unit.Altitude * speed, 0);
var turnRadius = (128f / self.LegacyInfo.ROT) * speed / (float)Math.PI;
/* work out the center points */
var fwd = -float2.FromAngle(unit.Facing / 128f * (float)Math.PI);
var side = new float2(-fwd.Y, fwd.X); /* rotate */
var sideTowardBase = new[] { side, -side }
.OrderBy(a => float2.Dot(a, self.CenterLocation - approachStart))
.First();
var c1 = self.CenterLocation + turnRadius * sideTowardBase;
var c2 = approachStart + new float2(0,
turnRadius * Math.Sign(self.CenterLocation.Y - approachStart.Y)); // above or below start point
/* work out tangent points */
var d = c2 - c1;
var e = (turnRadius / d.Length) * d;
var f = new float2(-e.Y, e.X); /* rotate */
/* todo: support internal tangents, too! */
if (f.X > 0) f = -f;
w1 = c1 + f;
w2 = c2 + f;
w3 = approachStart;
landPoint = landPos;
isCalculated = true;
}
public ReturnToBase(Actor self, Actor dest)
{
this.dest = dest;
}
public IActivity Tick(Actor self)
{
if (isCanceled) return NextActivity;
if (!isCalculated)
Calculate(self);
return Util.SequenceActivities(
new Fly(w1),
new Fly(w2),
new Fly(w3),
new Land(landPoint),
NextActivity);
}
public void Cancel(Actor self) { isCanceled = true; NextActivity = null; }
}
}