24 lines
1.1 KiB
C#
24 lines
1.1 KiB
C#
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using System;
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using CultMath;
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using static CultMath.math;
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// The one law that turns a wanted heading into a facing command. Ship.Update reads only Ship.Turn; whoever
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// wants the hull to face somewhere (the player's face-the-aim state, an agent state) asks here and writes Turn.
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public static class Steering
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{
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const float Deadband = .01f;
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// Positive is clockwise. Lateral component of the heading with sqrt shaping and a deadband; a heading
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// behind the hull turns at full demand (its lateral component alone would vanish at exactly astern).
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// A zero or non-finite heading holds course.
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public static float Toward(Ship ship, float2 heading)
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{
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if (!float.IsFinite(heading.x) || !float.IsFinite(heading.y) || lengthsq(heading) < 1e-12f) return 0f;
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var dir = normalize(ship.Direction);
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var wanted = normalize(heading);
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var d = dot(wanted, dir.Rotate(ItemRotation.Clockwise));
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if (dot(wanted, dir) < 0f) return d < 0f ? -1f : 1f;
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if (abs(d) < Deadband) return 0f;
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return sqrt(abs(d)) * sign(d);
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}
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}
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