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1 | //Copyright (c) 2008-2016 Emil Dotchevski and Reverge Studios, Inc. |
2 | ||
3 | //Distributed under the Boost Software License, Version 1.0. (See accompanying | |
4 | //file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
5 | ||
6 | #ifndef UUID_3DCF6B90AE0E11DE9A315BE555D89593 | |
7 | #define UUID_3DCF6B90AE0E11DE9A315BE555D89593 | |
8 | ||
9 | #include <boost/qvm/inline.hpp> | |
10 | #include <boost/qvm/mat_traits_array.hpp> | |
11 | #include <boost/qvm/static_assert.hpp> | |
12 | ||
13 | namespace | |
14 | boost | |
15 | { | |
16 | namespace | |
17 | qvm | |
18 | { | |
19 | namespace | |
20 | qvm_detail | |
21 | { | |
22 | template <int N> | |
23 | struct | |
24 | det_size | |
25 | { | |
26 | }; | |
27 | ||
28 | template <class M> | |
29 | BOOST_QVM_INLINE_TRIVIAL | |
30 | typename mat_traits<M>::scalar_type | |
31 | determinant_impl_( M const & a, det_size<2> ) | |
32 | { | |
33 | return | |
34 | mat_traits<M>::template read_element<0,0>(a) * mat_traits<M>::template read_element<1,1>(a) - | |
35 | mat_traits<M>::template read_element<1,0>(a) * mat_traits<M>::template read_element<0,1>(a); | |
36 | } | |
37 | ||
38 | template <class M,int N> | |
39 | BOOST_QVM_INLINE_RECURSION | |
40 | typename mat_traits<M>::scalar_type | |
41 | determinant_impl_( M const & a, det_size<N> ) | |
42 | { | |
43 | typedef typename mat_traits<M>::scalar_type T; | |
44 | T m[N-1][N-1]; | |
45 | T det=T(0); | |
46 | for( int j1=0; j1!=N; ++j1 ) | |
47 | { | |
48 | for( int i=1; i!=N; ++i ) | |
49 | { | |
50 | int j2 = 0; | |
51 | for( int j=0; j!=N; ++j ) | |
52 | { | |
53 | if( j==j1 ) | |
54 | continue; | |
55 | m[i-1][j2] = mat_traits<M>::read_element_idx(i,j,a); | |
56 | ++j2; | |
57 | } | |
58 | } | |
59 | T d=determinant_impl_(m,det_size<N-1>()); | |
60 | if( j1&1 ) | |
61 | d=-d; | |
62 | det += mat_traits<M>::read_element_idx(0,j1,a) * d; | |
63 | } | |
64 | return det; | |
65 | } | |
66 | ||
67 | template <class M> | |
68 | BOOST_QVM_INLINE_TRIVIAL | |
69 | typename mat_traits<M>::scalar_type | |
70 | determinant_impl( M const & a ) | |
71 | { | |
72 | BOOST_QVM_STATIC_ASSERT(mat_traits<M>::rows==mat_traits<M>::cols); | |
73 | return determinant_impl_(a,det_size<mat_traits<M>::rows>()); | |
74 | } | |
75 | } | |
76 | } | |
77 | } | |
78 | ||
79 | #endif |