Files
OpenRA/OpenRA.Mods.Common/HitShapes/Polygon.cs
2022-05-28 00:35:10 -05:00

130 lines
4.4 KiB
C#

#region Copyright & License Information
/*
* Copyright 2007-2022 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, either version 3 of
* the License, or (at your option) any later version. For more
* information, see COPYING.
*/
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using OpenRA.Graphics;
using OpenRA.Mods.Common.Graphics;
using OpenRA.Mods.Common.Traits;
using OpenRA.Primitives;
namespace OpenRA.Mods.Common.HitShapes
{
public class PolygonShape : IHitShape
{
public WDist OuterRadius { get; private set; }
[FieldLoader.Require]
public readonly int2[] Points;
[Desc("Defines the top offset relative to the actor's center.")]
public readonly int VerticalTopOffset = 0;
[Desc("Defines the bottom offset relative to the actor's center.")]
public readonly int VerticalBottomOffset = 0;
[Desc("Rotates shape by an angle relative to actor facing. Mostly required for buildings on isometric terrain.",
"Mobile actors do NOT need this!")]
public readonly WAngle LocalYaw = WAngle.Zero;
WVec[] combatOverlayVertsTop;
WVec[] combatOverlayVertsBottom;
int[] squares;
public PolygonShape() { }
public PolygonShape(int2[] points) { Points = points; }
public void Initialize()
{
if (VerticalTopOffset < VerticalBottomOffset)
throw new YamlException("VerticalTopOffset must be equal to or higher than VerticalBottomOffset.");
OuterRadius = new WDist(Points.Max(x => x.Length));
combatOverlayVertsTop = Points.Select(p => new WVec(p.X, p.Y, VerticalTopOffset)).ToArray();
combatOverlayVertsBottom = Points.Select(p => new WVec(p.X, p.Y, VerticalBottomOffset)).ToArray();
squares = new int[Points.Length];
squares[0] = (Points[0] - Points[Points.Length - 1]).LengthSquared;
for (var i = 1; i < Points.Length; i++)
squares[i] = (Points[i] - Points[i - 1]).LengthSquared;
}
static int DistanceSquaredFromLineSegment(int2 c, int2 a, int2 b, int ab2)
{
var ac = c - a;
var ac2 = ac.LengthSquared;
var bc2 = (c - b).LengthSquared;
// c is closest to point a
if (ac2 + ab2 <= bc2)
return ac2;
// c is closest to point b
if (bc2 + ab2 <= ac2)
return bc2;
// c is closest to its unknown orthogonal projection (p) onto the line spanned by b with a as the origin
// Cast to a long for the calculations to avoid overflows
var ab = b - a;
var ap2 = ac.X * ab.X + ac.Y * ab.Y;
var ap = new int2((int)((long)ab.X * ap2 / ab2), (int)((long)ab.Y * ap2 / ab2));
// Length of vector pc squared.
return (ac - ap).LengthSquared;
}
public WDist DistanceFromEdge(in WVec v)
{
var p = new int2(v.X, v.Y);
var z = Math.Abs(v.Z);
if (Points.PolygonContains(p))
return new WDist(z);
var min2 = DistanceSquaredFromLineSegment(p, Points[Points.Length - 1], Points[0], squares[0]);
for (var i = 1; i < Points.Length; i++)
{
var d2 = DistanceSquaredFromLineSegment(p, Points[i - 1], Points[i], squares[i]);
if (d2 < min2)
min2 = d2;
}
return new WDist(Exts.ISqrt(min2 + z * z));
}
public WDist DistanceFromEdge(WPos pos, WPos origin, WRot orientation)
{
orientation += WRot.FromYaw(LocalYaw);
if (pos.Z > origin.Z + VerticalTopOffset)
return DistanceFromEdge((pos - (origin + new WVec(0, 0, VerticalTopOffset))).Rotate(-orientation));
if (pos.Z < origin.Z + VerticalBottomOffset)
return DistanceFromEdge((pos - (origin + new WVec(0, 0, VerticalBottomOffset))).Rotate(-orientation));
return DistanceFromEdge((pos - new WPos(origin.X, origin.Y, pos.Z)).Rotate(-orientation));
}
IEnumerable<IRenderable> IHitShape.RenderDebugOverlay(HitShape hs, WorldRenderer wr, WPos actorPos, WRot orientation)
{
orientation += WRot.FromYaw(LocalYaw);
var vertsTop = combatOverlayVertsTop.Select(v => actorPos + v.Rotate(orientation)).ToArray();
var vertsBottom = combatOverlayVertsBottom.Select(v => actorPos + v.Rotate(orientation)).ToArray();
var shapeColor = hs.IsTraitDisabled ? Color.LightGray : Color.Yellow;
yield return new PolygonAnnotationRenderable(vertsTop, actorPos, 1, shapeColor);
yield return new PolygonAnnotationRenderable(vertsBottom, actorPos, 1, shapeColor);
yield return new CircleAnnotationRenderable(actorPos, OuterRadius, 1, hs.IsTraitDisabled ? Color.Gray : Color.LimeGreen);
}
}
}