Subversion Repositories gelsvn

Rev

Rev 5 | Rev 113 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 bj 1 
#include "ArithSqMat3x3Float.h"
2 
#include "Mat3x3f.h"
3 
 
4 
namespace CGLA {
5 
 
6 
	template<class V, class M>
7 
	M invert(const ArithSqMat3x3Float<V,M>& _a)
8 
	{
9 
		M a(_a[0], _a[1], _a[2]);
10 
		M	b;
11 
		b.identity();
12 
 
45 jab 13 
		unsigned int  i, j, i1;
2 bj 14 
 
15 
		for (j=0; j<3; j++)
16 
			{
17 
				i1 = j;                 // Row with largest pivot candidate
18 
				for (i=j+1; i<3; i++)
19 
					if (fabs(a[i][j]) > fabs(a[i1][j]))
20 
						i1 = i;
21 
 
22 
				// Swap rows i1 and j in a and b to put pivot on diagonal
23 
				V a_tmp = a[i1];
24 
				a[i1] = a[j];
25 
				a[j]  = a_tmp;
26 
 
27 
				V b_tmp = b[i1];
28 
				b[i1] = b[j];
29 
				b[j]  = b_tmp;
30 
 
31 
				// Scale row j to have a unit diagonal
5 jab 32 
				if (a[j][j] == 0.0)
2 bj 33 
					throw(Mat3x3fSingular("Tried to invert Singular matrix"));
34 
 
35 
				b[j] /= a[j][j];
36 
				a[j] /= a[j][j];
37 
 
38 
				// Eliminate off-diagonal elems in col j of a, doing identical ops to b
39 
				for (i=0; i<3; i++)
40 
					if (i!=j)
41 
						{
42 
							b[i] -= a[i][j] * b[j];
43 
							a[i] -= a[i][j] * a[j];
44 
						}
45 
			}
46 
		return b;
47 
	}
48 
 
49 
	template class ArithSqMat3x3Float<Vec3f,Mat3x3f>;
50 
	template Mat3x3f invert(const ArithSqMat3x3Float<Vec3f,Mat3x3f>&);
51 
}