Files
OpenRA/OpenRA.Game/Traits/Target.cs
2013-08-12 21:34:18 +12:00

131 lines
3.4 KiB
C#

#region Copyright & License Information
/*
* Copyright 2007-2011 The OpenRA Developers (see AUTHORS)
* This file is part of OpenRA, which is free software. It is made
* available to you under the terms of the GNU General Public License
* as published by the Free Software Foundation. For more information,
* see COPYING.
*/
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
namespace OpenRA.Traits
{
public enum TargetType { Invalid, Actor, Terrain, FrozenActor }
public struct Target
{
public static readonly Target[] None = {};
public static readonly Target Invalid = new Target { type = TargetType.Invalid };
TargetType type;
Actor actor;
FrozenActor frozen;
WPos pos;
int generation;
public static Target FromPos(WPos p) { return new Target { pos = p, type = TargetType.Terrain }; }
public static Target FromCell(CPos c) { return new Target { pos = c.CenterPosition, type = TargetType.Terrain }; }
public static Target FromOrder(Order o)
{
return o.TargetActor != null
? Target.FromActor(o.TargetActor)
: Target.FromCell(o.TargetLocation);
}
public static Target FromActor(Actor a)
{
return new Target
{
actor = a,
type = a != null ? TargetType.Actor : TargetType.Invalid,
generation = a.Generation,
};
}
public static Target FromFrozenActor(FrozenActor a) { return new Target { frozen = a, type = TargetType.FrozenActor }; }
public bool IsValid { get { return Type != TargetType.Invalid; } }
public Actor Actor { get { return actor; } }
public FrozenActor FrozenActor { get { return frozen; } }
public TargetType Type
{
get
{
if (type == TargetType.Actor)
{
// Actor is no longer in the world
if (!actor.IsInWorld || actor.IsDead())
return TargetType.Invalid;
// Actor generation has changed (teleported or captured)
if (actor.Generation != generation)
return TargetType.Invalid;
}
return type;
}
}
// Representative position - see Positions for the full set of targetable positions.
public WPos CenterPosition
{
get
{
switch (Type)
{
case TargetType.Actor:
return actor.CenterPosition;
case TargetType.FrozenActor:
return frozen.CenterPosition;
case TargetType.Terrain:
return pos;
default:
case TargetType.Invalid:
throw new InvalidOperationException("Attempting to query the position of an invalid Target");
}
}
}
// Positions available to target for range checks
static readonly WPos[] NoPositions = {};
public IEnumerable<WPos> Positions
{
get
{
switch (Type)
{
case TargetType.Actor:
var targetable = actor.TraitOrDefault<ITargetable>();
if (targetable == null)
return new [] { actor.CenterPosition };
var positions = targetable.TargetablePositions(actor);
return positions.Any() ? positions : new [] { actor.CenterPosition };
case TargetType.FrozenActor:
return new [] { frozen.CenterPosition };
case TargetType.Terrain:
return new [] { pos };
default:
case TargetType.Invalid:
return NoPositions;
}
}
}
public bool IsInRange(WPos origin, WRange range)
{
if (Type == TargetType.Invalid)
return false;
// Target ranges are calculated in 2D, so ignore height differences
var rangeSquared = range.Range*range.Range;
return Positions.Any(t => (t - origin).HorizontalLengthSquared <= rangeSquared);
}
}
}