115 lines
2.4 KiB
C++
115 lines
2.4 KiB
C++
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#ifndef GOMEZ_Basis_H
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#define GOMEZ_Basis_H
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/**
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* Taken from:
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* http://www.gamasutra.com/features/19990702/data_structures_01.htm
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* http://www.gamasutra.com/features/19991018/Gomez_1.htm
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*
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* Both by Miguel Gomez
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*/
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#include "matrix.hpp"
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namespace GomezMath {
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// An orthonormal basis with respect to a parent
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//
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class Basis
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{
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public:
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Matrix R;
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public:
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Basis ()
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{
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}
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Basis (const Vector & v0,
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const Vector & v1, const Vector & v2):R (v0, v1, v2)
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{
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}
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Basis (const Matrix & m):R (m)
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{
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}
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const Vector & operator [] (long i) const
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{
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return R.C[i];
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}
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const Vector & x () const
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{
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return R.C[0];
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}
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const Vector & y () const
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{
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return R.C[1];
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}
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const Vector & z () const
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{
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return R.C[2];
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}
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const Matrix & basis () const
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{
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return R;
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}
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void basis (const Vector & v0, const Vector & v1, const Vector & v2)
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{
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this->R[0] = v0;
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this->R[1] = v1;
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this->R[2] = v2;
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}
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// Right-Handed Rotations
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void rotateAboutX (const Scalar & a)
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{
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if (0 != a) //don’t rotate by 0
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{
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Vector b1 = this->y () * cos (a) + this->z () * sin (a);
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Vector b2 = -this->y () * sin (a) + this->z () * cos (a);
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//set basis
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this->R[1] = b1;
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this->R[2] = b2;
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//x is unchanged
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}
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}
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void rotateAboutY (const Scalar & a)
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{
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if (0 != a) //don’t rotate by 0
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{
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Vector b2 = this->z () * cos (a) + this->x () * sin (a); //rotate z
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Vector b0 = -this->z () * sin (a) + this->x () * cos (a); //rotate x
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//set basis
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this->R[2] = b2;
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this->R[0] = b0;
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//y is unchanged
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}
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}
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void rotateAboutZ (const Scalar & a)
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{
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if (0 != a) //don’t rotate by 0
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{
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//don’t over-write basis before calculation is done
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Vector b0 = this->x () * cos (a) + this->y () * sin (a); //rotate x
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Vector b1 = -this->x () * sin (a) + this->y () * cos (a); //rotate y
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//set basis
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this->R[0] = b0;
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this->R[1] = b1;
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//z is unchanged
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}
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}
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//rotate the basis about the unit axis u by theta (radians)
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void rotate (const Scalar & theta, const Vector & u);
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//rotate, length of da is theta, unit direction of da is u
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void rotate (const Vector & da);
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// Transformations
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const Vector transformVectorToLocal (const Vector & v) const
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{
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return Vector (R.C[0].dot (v), R.C[1].dot (v), R.C[2].dot (v));
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}
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const Point transformVectorToParent (const Vector & v) const
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{
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return R.C[0] * v.x + R.C[1] * v.y + R.C[2] * v.z;
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}
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};
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}
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#endif
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