paulxstretch/deps/juce/modules/juce_opengl/geometry/juce_Quaternion.h

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/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2020 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
By using JUCE, you agree to the terms of both the JUCE 6 End-User License
Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
End User License Agreement: www.juce.com/juce-6-licence
Privacy Policy: www.juce.com/juce-privacy-policy
Or: You may also use this code under the terms of the GPL v3 (see
www.gnu.org/licenses).
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
namespace juce
{
//==============================================================================
/**
Holds a quaternion (a 3D vector and a scalar value).
@tags{OpenGL}
*/
template <typename Type>
class Quaternion
{
public:
Quaternion() noexcept : scalar() {}
Quaternion (const Quaternion& other) noexcept : vector (other.vector), scalar (other.scalar) {}
Quaternion (Vector3D<Type> vectorPart, Type scalarPart) noexcept : vector (vectorPart), scalar (scalarPart) {}
Quaternion (Type x, Type y, Type z, Type w) noexcept : vector (x, y, z), scalar (w) {}
/** Creates a quaternion from an angle and an axis. */
static Quaternion fromAngle (Type angle, Vector3D<Type> axis) noexcept
{
return Quaternion (axis.normalised() * std::sin (angle / (Type) 2), std::cos (angle / (Type) 2));
}
Quaternion& operator= (Quaternion other) noexcept
{
vector = other.vector;
scalar = other.scalar;
return *this;
}
Quaternion& operator*= (Quaternion other) noexcept
{
const Type oldScalar (scalar);
scalar = (scalar * other.scalar) - (vector * other.vector);
vector = (other.vector * oldScalar) + (vector * other.scalar) + (vector ^ other.vector);
return *this;
}
Type length() const noexcept { return std::sqrt (normal()); }
Type normal() const noexcept { return scalar * scalar + vector.lengthSquared(); }
Quaternion normalised() const noexcept
{
const Type len (length());
jassert (len > 0);
return Quaternion (vector / len, scalar / len);
}
/** Returns the matrix that will perform the rotation specified by this quaternion. */
Matrix3D<Type> getRotationMatrix() const noexcept
{
const Type norm (normal());
const Type s (norm > 0 ? ((Type) 2) / norm : 0);
const Type xs (s * vector.x), ys (s * vector.y), zs (s * vector.z);
const Type wx (xs * scalar), wy (ys * scalar), wz (zs * scalar);
const Type xx (xs * vector.x), xy (ys * vector.x), xz (zs * vector.x);
const Type yy (ys * vector.y), yz (zs * vector.y), zz (zs * vector.z);
return Matrix3D<Type> (((Type) 1) - (yy + zz), xy - wz, xz + wy, 0,
xy + wz, ((Type) 1) - (xx+ zz), yz - wx, 0,
xz - wy, yz + wx, ((Type) 1) - (xx + yy), 0,
0, 0, 0, (Type) 1);
}
/** The vector part of the quaternion. */
Vector3D<Type> vector;
/** The scalar part of the quaternion. */
Type scalar;
};
} // namespace juce