initial commit, 4.5 stable

thirdparty/jolt_physics/Jolt/Physics/Collision/CollideSoftBodyVerticesVsTriangles.h

@@ -0,0 +1,90 @@
+// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
+// SPDX-FileCopyrightText: 2024 Jorrit Rouwe
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include <Jolt/Physics/Collision/CollideSoftBodyVertexIterator.h>
+#include <Jolt/Geometry/ClosestPoint.h>
+
+JPH_NAMESPACE_BEGIN
+
+/// Collision detection helper that collides soft body vertices vs triangles
+class JPH_EXPORT CollideSoftBodyVerticesVsTriangles
+{
+public:
+						CollideSoftBodyVerticesVsTriangles(Mat44Arg inCenterOfMassTransform, Vec3Arg inScale) :
+		mTransform(inCenterOfMassTransform * Mat44::sScale(inScale)),
+		mInvTransform(mTransform.Inversed()),
+		mNormalSign(ScaleHelpers::IsInsideOut(inScale)? -1.0f : 1.0f)
+	{
+	}
+
+	JPH_INLINE void		StartVertex(const CollideSoftBodyVertexIterator &inVertex)
+	{
+		mLocalPosition = mInvTransform * inVertex.GetPosition();
+		mClosestDistanceSq = FLT_MAX;
+	}
+
+	JPH_INLINE void		ProcessTriangle(Vec3Arg inV0, Vec3Arg inV1, Vec3Arg inV2)
+	{
+		// Get the closest point from the vertex to the triangle
+		uint32 set;
+		Vec3 closest_point = ClosestPoint::GetClosestPointOnTriangle(inV0 - mLocalPosition, inV1 - mLocalPosition, inV2 - mLocalPosition, set);
+		float dist_sq = closest_point.LengthSq();
+		if (dist_sq < mClosestDistanceSq)
+		{
+			mV0 = inV0;
+			mV1 = inV1;
+			mV2 = inV2;
+			mClosestPoint = closest_point;
+			mClosestDistanceSq = dist_sq;
+			mSet = set;
+		}
+	}
+
+	JPH_INLINE void		FinishVertex(const CollideSoftBodyVertexIterator &ioVertex, int inCollidingShapeIndex) const
+	{
+		if (mClosestDistanceSq < FLT_MAX)
+		{
+			// Convert triangle to world space
+			Vec3 v0 = mTransform * mV0;
+			Vec3 v1 = mTransform * mV1;
+			Vec3 v2 = mTransform * mV2;
+			Vec3 triangle_normal = mNormalSign * (v1 - v0).Cross(v2 - v0).NormalizedOr(Vec3::sAxisY());
+
+			if (mSet == 0b111)
+			{
+				// Closest is interior to the triangle, use plane as collision plane but don't allow more than 0.1 m penetration
+				// because otherwise a triangle half a level a way will have a huge penetration if it is back facing
+				float penetration = min(triangle_normal.Dot(v0 - ioVertex.GetPosition()), 0.1f);
+				if (ioVertex.UpdatePenetration(penetration))
+					ioVertex.SetCollision(Plane::sFromPointAndNormal(v0, triangle_normal), inCollidingShapeIndex);
+			}
+			else
+			{
+				// Closest point is on an edge or vertex, use closest point as collision plane
+				Vec3 closest_point = mTransform * (mLocalPosition + mClosestPoint);
+				Vec3 normal = ioVertex.GetPosition() - closest_point;
+				if (normal.Dot(triangle_normal) > 0.0f) // Ignore back facing edges
+				{
+					float normal_length = normal.Length();
+					float penetration = -normal_length;
+					if (ioVertex.UpdatePenetration(penetration))
+						ioVertex.SetCollision(Plane::sFromPointAndNormal(closest_point, normal_length > 0.0f? normal / normal_length : triangle_normal), inCollidingShapeIndex);
+				}
+			}
+		}
+	}
+
+	Mat44				mTransform;
+	Mat44				mInvTransform;
+	Vec3				mLocalPosition;
+	Vec3				mV0, mV1, mV2;
+	Vec3				mClosestPoint;
+	float				mNormalSign;
+	float				mClosestDistanceSq;
+	uint32				mSet;
+};
+
+JPH_NAMESPACE_END