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- /*
- *
- * Mathematics Subpackage (VrMath)
- *
- *
- * Author: Samuel R. Buss, [email protected].
- * Web page: http://math.ucsd.edu/~sbuss/MathCG
- *
- *
- This software is provided 'as-is', without any express or implied warranty.
- In no event will the authors be held liable for any damages arising from the use of this software.
- Permission is granted to anyone to use this software for any purpose,
- including commercial applications, and to alter it and redistribute it freely,
- subject to the following restrictions:
- 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
- 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
- 3. This notice may not be removed or altered from any source distribution.
- *
- *
- */
- #include "LinearR2.h"
- #include <assert.h>
- // ******************************************************
- // * VectorR2 class - math library functions *
- // * * * * * * * * * * * * * * * * * * * * * * * * * * **
- const VectorR2 VectorR2::Zero(0.0, 0.0);
- const VectorR2 VectorR2::UnitX( 1.0, 0.0);
- const VectorR2 VectorR2::UnitY( 0.0, 1.0);
- const VectorR2 VectorR2::NegUnitX(-1.0, 0.0);
- const VectorR2 VectorR2::NegUnitY( 0.0,-1.0);
- const Matrix2x2 Matrix2x2::Identity(1.0, 0.0, 0.0, 1.0);
- // ******************************************************
- // * Matrix2x2 class - math library functions *
- // * * * * * * * * * * * * * * * * * * * * * * * * * * **
- // ******************************************************
- // * LinearMapR2 class - math library functions *
- // * * * * * * * * * * * * * * * * * * * * * * * * * * **
- LinearMapR2 LinearMapR2::Inverse() const // Returns inverse
- {
- register double detInv = 1.0/(m11*m22 - m12*m21) ;
- return( LinearMapR2( m22*detInv, -m21*detInv, -m12*detInv, m11*detInv ) );
- }
- LinearMapR2& LinearMapR2::Invert() // Converts into inverse.
- {
- register double detInv = 1.0/(m11*m22 - m12*m21) ;
- double temp;
- temp = m11*detInv;
- m11= m22*detInv;
- m22=temp;
- m12 = -m12*detInv;
- m21 = -m22*detInv;
- return ( *this );
- }
- VectorR2 LinearMapR2::Solve(const VectorR2& u) const // Returns solution
- {
- // Just uses Inverse() for now.
- return ( Inverse()*u );
- }
- // ******************************************************
- // * RotationMapR2 class - math library functions *
- // * * * * * * * * * * * * * * * * * * * * * * * * * * **
- // ***************************************************************
- // * 2-space vector and matrix utilities *
- // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- // ***************************************************************
- // Stream Output Routines *
- // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- ostream& operator<< ( ostream& os, const VectorR2& u )
- {
- return (os << "<" << u.x << "," << u.y << ">");
- }
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