irrlicht/include/quaternion.h

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// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#ifndef __IRR_QUATERNION_H_INCLUDED__
#define __IRR_QUATERNION_H_INCLUDED__
#include "irrTypes.h"
#include "irrMath.h"
#include "matrix4.h"
#include "vector3d.h"
// NOTE: You *only* need this when updating an application from Irrlicht before 1.8 to Irrlicht 1.8 or later.
// Between Irrlicht 1.7 and Irrlicht 1.8 the quaternion-matrix conversions changed.
// Before the fix they had mixed left- and right-handed rotations.
// To test if your code was affected by the change enable IRR_TEST_BROKEN_QUATERNION_USE and try to compile your application.
// This defines removes those functions so you get compile errors anywhere you use them in your code.
// For every line with a compile-errors you have to change the corresponding lines like that:
// - When you pass the matrix to the quaternion constructor then replace the matrix by the transposed matrix.
// - For uses of getMatrix() you have to use quaternion::getMatrix_transposed instead.
// #define IRR_TEST_BROKEN_QUATERNION_USE
namespace irr
{
namespace core
{
//! Quaternion class for representing rotations.
/** It provides cheap combinations and avoids gimbal locks.
Also useful for interpolations. */
class quaternion
{
public:
//! Default Constructor
quaternion() : X(0.0f), Y(0.0f), Z(0.0f), W(1.0f) {}
//! Constructor
quaternion(f32 x, f32 y, f32 z, f32 w) : X(x), Y(y), Z(z), W(w) { }
//! Constructor which converts Euler angles (radians) to a quaternion
quaternion(f32 x, f32 y, f32 z);
//! Constructor which converts Euler angles (radians) to a quaternion
quaternion(const vector3df& vec);
#ifndef IRR_TEST_BROKEN_QUATERNION_USE
//! Constructor which converts a matrix to a quaternion
quaternion(const matrix4& mat);
#endif
//! Equality operator
bool operator==(const quaternion& other) const;
//! inequality operator
bool operator!=(const quaternion& other) const;
#ifndef IRR_TEST_BROKEN_QUATERNION_USE
//! Matrix assignment operator
inline quaternion& operator=(const matrix4& other);
#endif
//! Add operator
quaternion operator+(const quaternion& other) const;
//! Multiplication operator
//! Be careful, unfortunately the operator order here is opposite of that in CMatrix4::operator*
quaternion operator*(const quaternion& other) const;
//! Multiplication operator with scalar
quaternion operator*(f32 s) const;
//! Multiplication operator with scalar
quaternion& operator*=(f32 s);
//! Multiplication operator
vector3df operator*(const vector3df& v) const;
//! Multiplication operator
quaternion& operator*=(const quaternion& other);
//! Calculates the dot product
inline f32 dotProduct(const quaternion& other) const;
//! Sets new quaternion
inline quaternion& set(f32 x, f32 y, f32 z, f32 w);
//! Sets new quaternion based on Euler angles (radians)
inline quaternion& set(f32 x, f32 y, f32 z);
//! Sets new quaternion based on Euler angles (radians)
inline quaternion& set(const core::vector3df& vec);
//! Sets new quaternion from other quaternion
inline quaternion& set(const core::quaternion& quat);
//! returns if this quaternion equals the other one, taking floating point rounding errors into account
inline bool equals(const quaternion& other,
const f32 tolerance = ROUNDING_ERROR_f32 ) const;
//! Normalizes the quaternion
inline quaternion& normalize();
#ifndef IRR_TEST_BROKEN_QUATERNION_USE
//! Creates a matrix from this quaternion
matrix4 getMatrix() const;
#endif
//! Faster method to create a rotation matrix, you should normalize the quaternion before!
void getMatrixFast(matrix4 &dest) const;
//! Creates a matrix from this quaternion
void getMatrix( matrix4 &dest, const core::vector3df &translation=core::vector3df() ) const;
/*!
Creates a matrix from this quaternion
Rotate about a center point
shortcut for
core::quaternion q;
q.rotationFromTo ( vin[i].Normal, forward );
q.getMatrixCenter ( lookat, center, newPos );
core::matrix4 m2;
m2.setInverseTranslation ( center );
lookat *= m2;
core::matrix4 m3;
m2.setTranslation ( newPos );
lookat *= m3;
*/
void getMatrixCenter( matrix4 &dest, const core::vector3df &center, const core::vector3df &translation ) const;
//! Creates a matrix from this quaternion
inline void getMatrix_transposed( matrix4 &dest ) const;
//! Inverts this quaternion
quaternion& makeInverse();
//! Set this quaternion to the linear interpolation between two quaternions
/** NOTE: lerp result is *not* a normalized quaternion. In most cases
you will want to use lerpN instead as most other quaternion functions expect
to work with a normalized quaternion.
\param q1 First quaternion to be interpolated.
\param q2 Second quaternion to be interpolated.
\param time Progress of interpolation. For time=0 the result is
q1, for time=1 the result is q2. Otherwise interpolation
between q1 and q2. Result is not normalized.
*/
quaternion& lerp(quaternion q1, quaternion q2, f32 time);
//! Set this quaternion to the linear interpolation between two quaternions and normalize the result
/**
\param q1 First quaternion to be interpolated.
\param q2 Second quaternion to be interpolated.
\param time Progress of interpolation. For time=0 the result is
q1, for time=1 the result is q2. Otherwise interpolation
between q1 and q2. Result is normalized.
*/
quaternion& lerpN(quaternion q1, quaternion q2, f32 time);
//! Set this quaternion to the result of the spherical interpolation between two quaternions
/** \param q1 First quaternion to be interpolated.
\param q2 Second quaternion to be interpolated.
\param time Progress of interpolation. For time=0 the result is
q1, for time=1 the result is q2. Otherwise interpolation
between q1 and q2.
\param threshold To avoid inaccuracies at the end (time=1) the
interpolation switches to linear interpolation at some point.
This value defines how much of the remaining interpolation will
be calculated with lerp. Everything from 1-threshold up will be
linear interpolation.
*/
quaternion& slerp(quaternion q1, quaternion q2,
f32 time, f32 threshold=.05f);
//! Set this quaternion to represent a rotation from angle and axis.
/** Axis must be unit length.
The quaternion representing the rotation is
q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k).
\param angle Rotation Angle in radians.
\param axis Rotation axis. */
quaternion& fromAngleAxis (f32 angle, const vector3df& axis);
//! Fills an angle (radians) around an axis (unit vector)
void toAngleAxis (f32 &angle, core::vector3df& axis) const;
//! Output this quaternion to an Euler angle (radians)
void toEuler(vector3df& euler) const;
//! Set quaternion to identity
quaternion& makeIdentity();
//! Set quaternion to represent a rotation from one vector to another.
quaternion& rotationFromTo(const vector3df& from, const vector3df& to);
//! Quaternion elements.
f32 X; // vectorial (imaginary) part
f32 Y;
f32 Z;
f32 W; // real part
};
// Constructor which converts Euler angles to a quaternion
inline quaternion::quaternion(f32 x, f32 y, f32 z)
{
set(x,y,z);
}
// Constructor which converts Euler angles to a quaternion
inline quaternion::quaternion(const vector3df& vec)
{
set(vec.X,vec.Y,vec.Z);
}
#ifndef IRR_TEST_BROKEN_QUATERNION_USE
// Constructor which converts a matrix to a quaternion
inline quaternion::quaternion(const matrix4& mat)
{
(*this) = mat;
}
#endif
// equal operator
inline bool quaternion::operator==(const quaternion& other) const
{
return ((X == other.X) &&
(Y == other.Y) &&
(Z == other.Z) &&
(W == other.W));
}
// inequality operator
inline bool quaternion::operator!=(const quaternion& other) const
{
return !(*this == other);
}
#ifndef IRR_TEST_BROKEN_QUATERNION_USE
// matrix assignment operator
inline quaternion& quaternion::operator=(const matrix4& m)
{
const f32 diag = m[0] + m[5] + m[10] + 1;
if( diag > 0.0f )
{
const f32 scale = sqrtf(diag) * 2.0f; // get scale from diagonal
// TODO: speed this up
X = (m[6] - m[9]) / scale;
Y = (m[8] - m[2]) / scale;
Z = (m[1] - m[4]) / scale;
W = 0.25f * scale;
}
else
{
if (m[0]>m[5] && m[0]>m[10])
{
// 1st element of diag is greatest value
// find scale according to 1st element, and double it
const f32 scale = sqrtf(1.0f + m[0] - m[5] - m[10]) * 2.0f;
// TODO: speed this up
X = 0.25f * scale;
Y = (m[4] + m[1]) / scale;
Z = (m[2] + m[8]) / scale;
W = (m[6] - m[9]) / scale;
}
else if (m[5]>m[10])
{
// 2nd element of diag is greatest value
// find scale according to 2nd element, and double it
const f32 scale = sqrtf(1.0f + m[5] - m[0] - m[10]) * 2.0f;
// TODO: speed this up
X = (m[4] + m[1]) / scale;
Y = 0.25f * scale;
Z = (m[9] + m[6]) / scale;
W = (m[8] - m[2]) / scale;
}
else
{
// 3rd element of diag is greatest value
// find scale according to 3rd element, and double it
const f32 scale = sqrtf(1.0f + m[10] - m[0] - m[5]) * 2.0f;
// TODO: speed this up
X = (m[8] + m[2]) / scale;
Y = (m[9] + m[6]) / scale;
Z = 0.25f * scale;
W = (m[1] - m[4]) / scale;
}
}
return normalize();
}
#endif
// multiplication operator
inline quaternion quaternion::operator*(const quaternion& other) const
{
quaternion tmp;
tmp.W = (other.W * W) - (other.X * X) - (other.Y * Y) - (other.Z * Z);
tmp.X = (other.W * X) + (other.X * W) + (other.Y * Z) - (other.Z * Y);
tmp.Y = (other.W * Y) + (other.Y * W) + (other.Z * X) - (other.X * Z);
tmp.Z = (other.W * Z) + (other.Z * W) + (other.X * Y) - (other.Y * X);
return tmp;
}
// multiplication operator
inline quaternion quaternion::operator*(f32 s) const
{
return quaternion(s*X, s*Y, s*Z, s*W);
}
// multiplication operator
inline quaternion& quaternion::operator*=(f32 s)
{
X*=s;
Y*=s;
Z*=s;
W*=s;
return *this;
}
// multiplication operator
inline quaternion& quaternion::operator*=(const quaternion& other)
{
return (*this = other * (*this));
}
// add operator
inline quaternion quaternion::operator+(const quaternion& b) const
{
return quaternion(X+b.X, Y+b.Y, Z+b.Z, W+b.W);
}
#ifndef IRR_TEST_BROKEN_QUATERNION_USE
// Creates a matrix from this quaternion
inline matrix4 quaternion::getMatrix() const
{
core::matrix4 m;
getMatrix(m);
return m;
}
#endif
//! Faster method to create a rotation matrix, you should normalize the quaternion before!
inline void quaternion::getMatrixFast( matrix4 &dest) const
{
// TODO:
// gpu quaternion skinning => fast Bones transform chain O_O YEAH!
// http://www.mrelusive.com/publications/papers/SIMD-From-Quaternion-to-Matrix-and-Back.pdf
dest[0] = 1.0f - 2.0f*Y*Y - 2.0f*Z*Z;
dest[1] = 2.0f*X*Y + 2.0f*Z*W;
dest[2] = 2.0f*X*Z - 2.0f*Y*W;
dest[3] = 0.0f;
dest[4] = 2.0f*X*Y - 2.0f*Z*W;
dest[5] = 1.0f - 2.0f*X*X - 2.0f*Z*Z;
dest[6] = 2.0f*Z*Y + 2.0f*X*W;
dest[7] = 0.0f;
dest[8] = 2.0f*X*Z + 2.0f*Y*W;
dest[9] = 2.0f*Z*Y - 2.0f*X*W;
dest[10] = 1.0f - 2.0f*X*X - 2.0f*Y*Y;
dest[11] = 0.0f;
dest[12] = 0.f;
dest[13] = 0.f;
dest[14] = 0.f;
dest[15] = 1.f;
dest.setDefinitelyIdentityMatrix(false);
}
/*!
Creates a matrix from this quaternion
*/
inline void quaternion::getMatrix(matrix4 &dest,
const core::vector3df &center) const
{
// ok creating a copy may be slower, but at least avoid internal
// state chance (also because otherwise we cannot keep this method "const").
quaternion q( *this);
q.normalize();
f32 X = q.X;
f32 Y = q.Y;
f32 Z = q.Z;
f32 W = q.W;
dest[0] = 1.0f - 2.0f*Y*Y - 2.0f*Z*Z;
dest[1] = 2.0f*X*Y + 2.0f*Z*W;
dest[2] = 2.0f*X*Z - 2.0f*Y*W;
dest[3] = 0.0f;
dest[4] = 2.0f*X*Y - 2.0f*Z*W;
dest[5] = 1.0f - 2.0f*X*X - 2.0f*Z*Z;
dest[6] = 2.0f*Z*Y + 2.0f*X*W;
dest[7] = 0.0f;
dest[8] = 2.0f*X*Z + 2.0f*Y*W;
dest[9] = 2.0f*Z*Y - 2.0f*X*W;
dest[10] = 1.0f - 2.0f*X*X - 2.0f*Y*Y;
dest[11] = 0.0f;
dest[12] = center.X;
dest[13] = center.Y;
dest[14] = center.Z;
dest[15] = 1.f;
dest.setDefinitelyIdentityMatrix ( false );
}
/*!
Creates a matrix from this quaternion
Rotate about a center point
shortcut for
core::quaternion q;
q.rotationFromTo(vin[i].Normal, forward);
q.getMatrix(lookat, center);
core::matrix4 m2;
m2.setInverseTranslation(center);
lookat *= m2;
*/
inline void quaternion::getMatrixCenter(matrix4 &dest,
const core::vector3df &center,
const core::vector3df &translation) const
{
quaternion q(*this);
q.normalize();
f32 X = q.X;
f32 Y = q.Y;
f32 Z = q.Z;
f32 W = q.W;
dest[0] = 1.0f - 2.0f*Y*Y - 2.0f*Z*Z;
dest[1] = 2.0f*X*Y + 2.0f*Z*W;
dest[2] = 2.0f*X*Z - 2.0f*Y*W;
dest[3] = 0.0f;
dest[4] = 2.0f*X*Y - 2.0f*Z*W;
dest[5] = 1.0f - 2.0f*X*X - 2.0f*Z*Z;
dest[6] = 2.0f*Z*Y + 2.0f*X*W;
dest[7] = 0.0f;
dest[8] = 2.0f*X*Z + 2.0f*Y*W;
dest[9] = 2.0f*Z*Y - 2.0f*X*W;
dest[10] = 1.0f - 2.0f*X*X - 2.0f*Y*Y;
dest[11] = 0.0f;
dest.setRotationCenter ( center, translation );
}
// Creates a matrix from this quaternion
inline void quaternion::getMatrix_transposed(matrix4 &dest) const
{
quaternion q(*this);
q.normalize();
f32 X = q.X;
f32 Y = q.Y;
f32 Z = q.Z;
f32 W = q.W;
dest[0] = 1.0f - 2.0f*Y*Y - 2.0f*Z*Z;
dest[4] = 2.0f*X*Y + 2.0f*Z*W;
dest[8] = 2.0f*X*Z - 2.0f*Y*W;
dest[12] = 0.0f;
dest[1] = 2.0f*X*Y - 2.0f*Z*W;
dest[5] = 1.0f - 2.0f*X*X - 2.0f*Z*Z;
dest[9] = 2.0f*Z*Y + 2.0f*X*W;
dest[13] = 0.0f;
dest[2] = 2.0f*X*Z + 2.0f*Y*W;
dest[6] = 2.0f*Z*Y - 2.0f*X*W;
dest[10] = 1.0f - 2.0f*X*X - 2.0f*Y*Y;
dest[14] = 0.0f;
dest[3] = 0.f;
dest[7] = 0.f;
dest[11] = 0.f;
dest[15] = 1.f;
dest.setDefinitelyIdentityMatrix(false);
}
// Inverts this quaternion
inline quaternion& quaternion::makeInverse()
{
X = -X; Y = -Y; Z = -Z;
return *this;
}
// sets new quaternion
inline quaternion& quaternion::set(f32 x, f32 y, f32 z, f32 w)
{
X = x;
Y = y;
Z = z;
W = w;
return *this;
}
// sets new quaternion based on Euler angles
inline quaternion& quaternion::set(f32 x, f32 y, f32 z)
{
f64 angle;
angle = x * 0.5;
const f64 sr = sin(angle);
const f64 cr = cos(angle);
angle = y * 0.5;
const f64 sp = sin(angle);
const f64 cp = cos(angle);
angle = z * 0.5;
const f64 sy = sin(angle);
const f64 cy = cos(angle);
const f64 cpcy = cp * cy;
const f64 spcy = sp * cy;
const f64 cpsy = cp * sy;
const f64 spsy = sp * sy;
X = (f32)(sr * cpcy - cr * spsy);
Y = (f32)(cr * spcy + sr * cpsy);
Z = (f32)(cr * cpsy - sr * spcy);
W = (f32)(cr * cpcy + sr * spsy);
return normalize();
}
// sets new quaternion based on Euler angles
inline quaternion& quaternion::set(const core::vector3df& vec)
{
return set( vec.X, vec.Y, vec.Z);
}
// sets new quaternion based on other quaternion
inline quaternion& quaternion::set(const core::quaternion& quat)
{
return (*this=quat);
}
//! returns if this quaternion equals the other one, taking floating point rounding errors into account
inline bool quaternion::equals(const quaternion& other, const f32 tolerance) const
{
return core::equals( X, other.X, tolerance) &&
core::equals( Y, other.Y, tolerance) &&
core::equals( Z, other.Z, tolerance) &&
core::equals( W, other.W, tolerance);
}
// normalizes the quaternion
inline quaternion& quaternion::normalize()
{
// removed conditional branch since it may slow down and anyway the condition was
// false even after normalization in some cases.
return (*this *= (f32)reciprocal_squareroot ( (f64)(X*X + Y*Y + Z*Z + W*W) ));
}
// Set this quaternion to the result of the linear interpolation between two quaternions
inline quaternion& quaternion::lerp( quaternion q1, quaternion q2, f32 time)
{
const f32 scale = 1.0f - time;
return (*this = (q1*scale) + (q2*time));
}
// Set this quaternion to the result of the linear interpolation between two quaternions and normalize the result
inline quaternion& quaternion::lerpN( quaternion q1, quaternion q2, f32 time)
{
const f32 scale = 1.0f - time;
return (*this = ((q1*scale) + (q2*time)).normalize() );
}
// set this quaternion to the result of the interpolation between two quaternions
inline quaternion& quaternion::slerp( quaternion q1, quaternion q2, f32 time, f32 threshold)
{
f32 angle = q1.dotProduct(q2);
// make sure we use the short rotation
if (angle < 0.0f)
{
q1 *= -1.0f;
angle *= -1.0f;
}
if (angle <= (1-threshold)) // spherical interpolation
{
const f32 theta = acosf(angle);
const f32 invsintheta = reciprocal(sinf(theta));
const f32 scale = sinf(theta * (1.0f-time)) * invsintheta;
const f32 invscale = sinf(theta * time) * invsintheta;
return (*this = (q1*scale) + (q2*invscale));
}
else // linear interpolation
return lerpN(q1,q2,time);
}
// calculates the dot product
inline f32 quaternion::dotProduct(const quaternion& q2) const
{
return (X * q2.X) + (Y * q2.Y) + (Z * q2.Z) + (W * q2.W);
}
//! axis must be unit length, angle in radians
inline quaternion& quaternion::fromAngleAxis(f32 angle, const vector3df& axis)
{
const f32 fHalfAngle = 0.5f*angle;
const f32 fSin = sinf(fHalfAngle);
W = cosf(fHalfAngle);
X = fSin*axis.X;
Y = fSin*axis.Y;
Z = fSin*axis.Z;
return *this;
}
inline void quaternion::toAngleAxis(f32 &angle, core::vector3df &axis) const
{
const f32 scale = sqrtf(X*X + Y*Y + Z*Z);
if (core::iszero(scale) || W > 1.0f || W < -1.0f)
{
angle = 0.0f;
axis.X = 0.0f;
axis.Y = 1.0f;
axis.Z = 0.0f;
}
else
{
const f32 invscale = reciprocal(scale);
angle = 2.0f * acosf(W);
axis.X = X * invscale;
axis.Y = Y * invscale;
axis.Z = Z * invscale;
}
}
inline void quaternion::toEuler(vector3df& euler) const
{
const f64 sqw = W*W;
const f64 sqx = X*X;
const f64 sqy = Y*Y;
const f64 sqz = Z*Z;
const f64 test = 2.0 * (Y*W - X*Z);
if (core::equals(test, 1.0, 0.000001))
{
// heading = rotation about z-axis
euler.Z = (f32) (-2.0*atan2(X, W));
// bank = rotation about x-axis
euler.X = 0;
// attitude = rotation about y-axis
euler.Y = (f32) (core::PI64/2.0);
}
else if (core::equals(test, -1.0, 0.000001))
{
// heading = rotation about z-axis
euler.Z = (f32) (2.0*atan2(X, W));
// bank = rotation about x-axis
euler.X = 0;
// attitude = rotation about y-axis
euler.Y = (f32) (core::PI64/-2.0);
}
else
{
// heading = rotation about z-axis
euler.Z = (f32) atan2(2.0 * (X*Y +Z*W),(sqx - sqy - sqz + sqw));
// bank = rotation about x-axis
euler.X = (f32) atan2(2.0 * (Y*Z +X*W),(-sqx - sqy + sqz + sqw));
// attitude = rotation about y-axis
euler.Y = (f32) asin( clamp(test, -1.0, 1.0) );
}
}
inline vector3df quaternion::operator* (const vector3df& v) const
{
// nVidia SDK implementation
vector3df uv, uuv;
const vector3df qvec(X, Y, Z);
uv = qvec.crossProduct(v);
uuv = qvec.crossProduct(uv);
uv *= (2.0f * W);
uuv *= 2.0f;
return v + uv + uuv;
}
// set quaternion to identity
inline core::quaternion& quaternion::makeIdentity()
{
W = 1.f;
X = 0.f;
Y = 0.f;
Z = 0.f;
return *this;
}
inline core::quaternion& quaternion::rotationFromTo(const vector3df& from, const vector3df& to)
{
// Based on Stan Melax's article in Game Programming Gems
// Copy, since cannot modify local
vector3df v0 = from;
vector3df v1 = to;
v0.normalize();
v1.normalize();
const f32 d = v0.dotProduct(v1);
if (d >= 1.0f) // If dot == 1, vectors are the same
{
return makeIdentity();
}
else if (d <= -1.0f) // exactly opposite
{
core::vector3df axis(1.0f, 0.f, 0.f);
axis = axis.crossProduct(v0);
if (axis.getLength()==0)
{
axis.set(0.f,1.f,0.f);
axis = axis.crossProduct(v0);
}
// same as fromAngleAxis(core::PI, axis).normalize();
return set(axis.X, axis.Y, axis.Z, 0).normalize();
}
const f32 s = sqrtf( (1+d)*2 ); // optimize inv_sqrt
const f32 invs = 1.f / s;
const vector3df c = v0.crossProduct(v1)*invs;
return set(c.X, c.Y, c.Z, s * 0.5f).normalize();
}
} // end namespace core
} // end namespace irr
#endif