59 lines
2.1 KiB
C++
59 lines
2.1 KiB
C++
// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
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// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
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// SPDX-License-Identifier: MIT
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#pragma once
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#include <Jolt/ObjectStream/SerializableObject.h>
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JPH_NAMESPACE_BEGIN
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class StreamIn;
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class StreamOut;
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/// Describes the mass and inertia properties of a body. Used during body construction only.
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class JPH_EXPORT MassProperties
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{
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JPH_DECLARE_SERIALIZABLE_NON_VIRTUAL(JPH_EXPORT, MassProperties)
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public:
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/// Using eigendecomposition, decompose the inertia tensor into a diagonal matrix D and a right-handed rotation matrix R so that the inertia tensor is \f$R \: D \: R^{-1}\f$.
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/// @see https://en.wikipedia.org/wiki/Moment_of_inertia section 'Principal axes'
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/// @param outRotation The rotation matrix R
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/// @param outDiagonal The diagonal of the diagonal matrix D
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/// @return True if successful, false if failed
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bool DecomposePrincipalMomentsOfInertia(Mat44 &outRotation, Vec3 &outDiagonal) const;
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/// Set the mass and inertia of a box with edge size inBoxSize and density inDensity
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void SetMassAndInertiaOfSolidBox(Vec3Arg inBoxSize, float inDensity);
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/// Set the mass and scale the inertia tensor to match the mass
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void ScaleToMass(float inMass);
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/// Calculates the size of the solid box that has an inertia tensor diagonal inInertiaDiagonal
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static Vec3 sGetEquivalentSolidBoxSize(float inMass, Vec3Arg inInertiaDiagonal);
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/// Rotate the inertia by 3x3 matrix inRotation
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void Rotate(Mat44Arg inRotation);
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/// Translate the inertia by a vector inTranslation
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void Translate(Vec3Arg inTranslation);
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/// Scale the mass and inertia by inScale, note that elements can be < 0 to flip the shape
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void Scale(Vec3Arg inScale);
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/// Saves the state of this object in binary form to inStream.
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void SaveBinaryState(StreamOut &inStream) const;
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/// Restore the state of this object from inStream.
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void RestoreBinaryState(StreamIn &inStream);
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/// Mass of the shape (kg)
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float mMass = 0.0f;
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/// Inertia tensor of the shape (kg m^2)
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Mat44 mInertia = Mat44::sZero();
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};
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JPH_NAMESPACE_END
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