hondacrx
120 lines
4.1 KiB
C#
120 lines
4.1 KiB
C#
/*
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* Copyright (C) 2012-2020 CypherCore <http://github.com/CypherCore>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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using System;
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using System.Numerics;
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namespace Framework.GameMath
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{
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class CollisionDetection
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{
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public static float collisionTimeForMovingPointFixedAABox(Vector3 origin, Vector3 dir, AxisAlignedBox box, ref Vector3 location, out bool Inside)
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{
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Vector3 normal = Vector3.Zero;
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if (collisionLocationForMovingPointFixedAABox(origin, dir, box, ref location, out Inside, ref normal))
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{
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return Vector3.Distance(location, origin);
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}
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else
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{
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return float.PositiveInfinity;
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}
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}
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public static bool collisionLocationForMovingPointFixedAABox(Vector3 origin, Vector3 dir, AxisAlignedBox box, ref Vector3 location, out bool Inside, ref Vector3 normal)
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{
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Inside = true;
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Vector3 MinB = box.Lo;
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Vector3 MaxB = box.Hi;
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Vector3 MaxT = new(-1.0f, -1.0f, -1.0f);
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// Find candidate planes.
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for (int i = 0; i < 3; ++i)
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{
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if (origin.GetAt(i) < MinB.GetAt(i))
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{
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location.SetAt(MinB.GetAt(i), i);
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Inside = false;
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// Calculate T distances to candidate planes
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if ((uint)dir.GetAt(i) != 0)
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{
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MaxT.SetAt((MinB.GetAt(i) - origin.GetAt(i)) / dir.GetAt(i), i);
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}
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}
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else if (origin.GetAt(i) > MaxB.GetAt(i))
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{
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location.SetAt(MaxB.GetAt(i), i);
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Inside = false;
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// Calculate T distances to candidate planes
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if ((uint)dir.GetAt(i) != 0)
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{
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MaxT.SetAt((MaxB.GetAt(i) - origin.GetAt(i)) / dir.GetAt(i), i);
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}
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}
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}
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if (Inside)
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{
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// Ray origin inside bounding box
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location = origin;
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return false;
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}
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// Get largest of the maxT's for final choice of intersection
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int WhichPlane = 0;
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if (MaxT.Y > MaxT.GetAt(WhichPlane))
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{
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WhichPlane = 1;
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}
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if (MaxT.Z > MaxT.GetAt(WhichPlane))
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{
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WhichPlane = 2;
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}
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// Check final candidate actually inside box
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if (Convert.ToBoolean((uint)MaxT.GetAt(WhichPlane) & 0x80000000))
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{
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// Miss the box
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return false;
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}
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for (int i = 0; i < 3; ++i)
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{
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if (i != WhichPlane)
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{
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location.SetAt(origin.GetAt(i) + MaxT.GetAt(WhichPlane) * dir.GetAt(i), i);
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if ((location.GetAt(i) < MinB.GetAt(i)) ||
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(location.GetAt(i) > MaxB.GetAt(i)))
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{
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// On this plane we're outside the box extents, so
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// we miss the box
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return false;
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}
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}
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}
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// Choose the normal to be the plane normal facing into the ray
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normal = Vector3.Zero;
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normal.SetAt((float)((dir.GetAt(WhichPlane) > 0) ? -1.0 : 1.0), WhichPlane);
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return true;
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}
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}
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}
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