1 /*=========================================================================
3 Program: Visualization Toolkit
4 Module: $RCSfile: vtkMath.h,v $
6 Date: $Date: 2002/02/01 06:30:41 $
7 Version: $Revision: 1.1.1.1 $
10 Copyright (c) 1993-1998 Ken Martin, Will Schroeder, Bill Lorensen.
12 This software is copyrighted by Ken Martin, Will Schroeder and Bill Lorensen.
13 The following terms apply to all files associated with the software unless
14 explicitly disclaimed in individual files. This copyright specifically does
15 not apply to the related textbook "The Visualization Toolkit" ISBN
16 013199837-4 published by Prentice Hall which is covered by its own copyright.
18 The authors hereby grant permission to use, copy, and distribute this
19 software and its documentation for any purpose, provided that existing
20 copyright notices are retained in all copies and that this notice is included
21 verbatim in any distributions. Additionally, the authors grant permission to
22 modify this software and its documentation for any purpose, provided that
23 such modifications are not distributed without the explicit consent of the
24 authors and that existing copyright notices are retained in all copies. Some
25 of the algorithms implemented by this software are patented, observe all
26 applicable patent law.
28 IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY FOR
29 DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
30 OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY DERIVATIVES THEREOF,
31 EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, INCLUDING,
34 BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
35 PARTICULAR PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN
36 "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
37 MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
40 =========================================================================*/
41 // .NAME vtkMath - performs common math operations
42 // .SECTION Description
43 // vtkMath is provides methods to perform common math operations. These
44 // include providing constants such as Pi; conversion from degrees to
45 // radians; vector operations such as dot and cross products and vector
46 // norm; matrix determinant for 2x2 and 3x3 matrices; and random
53 #include "vtkWin32Header.h"
55 class VTK_EXPORT vtkMath
59 static vtkMath *New() {return new vtkMath;};
60 virtual const char *GetClassName() {return "vtkMath";};
61 virtual void Delete(); //delete a vtk object.
64 // avoid dll boundary problems
65 void* operator new( size_t tSize, const char *, int);
66 void* operator new( size_t tSize );
67 void operator delete( void* p );
71 static float Pi() {return 3.14159265358979;};
72 static float DegreesToRadians() {return 0.017453292;};
74 // some common methods
75 static float Dot(float x[3], float y[3]);
76 static double Dot(double x[3], double y[3]);
77 static void Cross(float x[3], float y[3], float z[3]);
78 static float Norm(float x[3]);
79 static float Normalize(float x[3]);
80 static float Distance2BetweenPoints(float x[3], float y[3]);
82 // special methods for 2D operations
83 static float Dot2D(float x[3], float y[3]);
84 static double Dot2D(double x[3], double y[3]);
85 static float Norm2D(float x[3]);
86 static float Normalize2D(float x[3]);
89 static float Determinant2x2(float c1[2], float c2[2]);
90 static double Determinant2x2(double a, double b, double c, double d);
91 static float Determinant3x3(float c1[3], float c2[3], float c3[3]);
92 static double Determinant3x3(double a1, double a2, double a3,
93 double b1, double b2, double b3,
94 double c1, double c2, double c3);
95 static int SolveLinearSystem(double **A, double *x, int size);
96 static int InvertMatrix(double **A, double **AI, int size);
97 static int LUFactorLinearSystem(double **A, int *index, int size);
98 static void LUSolveLinearSystem(double **A, int *index, double *x, int size);
99 static double EstimateMatrixCondition(double **A, int size);
101 // Random number generation
102 static void RandomSeed(long s);
103 static float Random();
104 static float Random(float min, float max);
106 // Eigenvalue/vector extraction for 3x3 matrices
107 static int Jacobi(float **a, float *d, float **v);
109 // Roots of polinomial equations
111 static double* SolveCubic( double c0, double c1, double c2, double c3 );
112 static double* SolveQuadratic( double c0, double c1, double c2 );
114 static void SolveCubic( double c0, double c1, double c2, double c3,
115 double *r1, double *r2, double *r3, int *num_roots );
116 static void SolveQuadratic( double c0, double c1, double c2,
117 double *r1, double *r2, int *num_roots );
124 // Dot product of two 3-vectors (float version).
125 inline float vtkMath::Dot(float x[3], float y[3])
127 return (x[0]*y[0] + x[1]*y[1] + x[2]*y[2]);
131 // Dot product of two 3-vectors (double-precision version).
132 inline double vtkMath::Dot(double x[3], double y[3])
134 return (x[0]*y[0] + x[1]*y[1] + x[2]*y[2]);
138 // Dot product of two 2-vectors. The third (z) component is ignored.
139 inline float vtkMath::Dot2D(float x[3], float y[3])
141 return (x[0]*y[0] + x[1]*y[1]);
145 // Dot product of two 2-vectors. The third (z) component is ignored. (Double-precision
147 inline double vtkMath::Dot2D(double x[3], double y[3])
149 return (x[0]*y[0] + x[1]*y[1]);
153 // Compute the norm of 3-vector.
154 inline float vtkMath::Norm(float x[3])
156 return sqrt(x[0]*x[0] + x[1]*x[1] + x[2]*x[2]);
160 // Compute the norm of a 2-vector. Ignores z-component.
161 inline float vtkMath::Norm2D(float x[3])
163 return sqrt(x[0]*x[0] + x[1]*x[1]);
167 // Normalize (in place) a 3-vector. Returns norm of vector.
168 inline float vtkMath::Normalize(float x[3])
171 if ( (den = vtkMath::Norm(x)) != 0.0 ) for (int i=0; i < 3; i++) x[i] /= den;
176 // Normalize (in place) a 2-vector. Returns norm of vector. Ignores z-component.
177 inline float vtkMath::Normalize2D(float x[3])
180 if ( (den = vtkMath::Norm2D(x)) != 0.0 ) for (int i=0; i < 2; i++) x[i] /= den;
185 // Compute determinant of 2x2 matrix. Two columns of matrix are input.
186 inline float vtkMath::Determinant2x2(float c1[2], float c2[2])
188 return (c1[0]*c2[1] - c2[0]*c1[1]);
192 // Calculate the determinant of a 2x2 matrix: | a b |
194 inline double vtkMath::Determinant2x2(double a, double b, double c, double d)
196 return (a * d - b * c);
200 // Compute determinant of 3x3 matrix. Three columns of matrix are input.
201 inline float vtkMath::Determinant3x3(float c1[3], float c2[3], float c3[3])
203 return c1[0]*c2[1]*c3[2] + c2[0]*c3[1]*c1[2] + c3[0]*c1[1]*c2[2] -
204 c1[0]*c3[1]*c2[2] - c2[0]*c1[1]*c3[2] - c3[0]*c2[1]*c1[2];
208 // Calculate the determinent of a 3x3 matrix in the form:
212 inline double vtkMath::Determinant3x3(double a1, double a2, double a3,
213 double b1, double b2, double b3,
214 double c1, double c2, double c3)
216 return ( a1 * vtkMath::Determinant2x2( b2, b3, c2, c3 )
217 - b1 * vtkMath::Determinant2x2( a2, a3, c2, c3 )
218 + c1 * vtkMath::Determinant2x2( a2, a3, b2, b3 ) );
222 // Compute distance squared between two points.
223 inline float vtkMath::Distance2BetweenPoints(float x[3], float y[3])
225 return ((x[0]-y[0])*(x[0]-y[0]) + (x[1]-y[1])*(x[1]-y[1]) +
226 (x[2]-y[2])*(x[2]-y[2]));
230 // Generate random number between (min,max).
231 inline float vtkMath::Random(float min, float max)
233 return (min + vtkMath::Random()*(max-min));