54 lines
1.6 KiB
C#
54 lines
1.6 KiB
C#
using Robust.Shared.Map;
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namespace Content.Server.NPC.Pathfinding;
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public sealed partial class PathfindingSystem
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{
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// TODO: Re-use the existing simplifier. Because the pathfinding API sucks I just copy-pasted for now.
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public static List<TileRef> Simplify(List<TileRef> vertices, float tolerance = 0)
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{
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if (vertices.Count <= 3)
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return vertices;
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var simplified = new List<TileRef>();
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for (var i = 0; i < vertices.Count; i++)
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{
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// No wraparound for negative sooooo
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var prev = vertices[i == 0 ? vertices.Count - 1 : i - 1];
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var current = vertices[i];
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var next = vertices[(i + 1) % vertices.Count];
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// If they collinear, continue
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if (IsCollinear(in prev, in current, in next, tolerance))
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continue;
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simplified.Add(current);
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}
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// Farseer didn't seem to handle straight lines and nuked all points
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if (simplified.Count == 0)
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{
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simplified.Add(vertices[0]);
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simplified.Add(vertices[^1]);
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}
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return simplified;
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}
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private static bool IsCollinear(in TileRef prev, in TileRef current, in TileRef next, float tolerance)
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{
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return FloatInRange(Area(in prev, in current, in next), -tolerance, tolerance);
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}
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private static float Area(in TileRef a, in TileRef b, in TileRef c)
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{
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return a.X * (b.Y - c.Y) + b.X * (c.Y - a.Y) + c.X * (a.Y - b.Y);
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}
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private static bool FloatInRange(float value, float min, float max)
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{
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return (value >= min && value <= max);
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}
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}
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