1 /*******************************************************************************
2 
3 "A Collection of Useful C++ Classes for Digital Signal Processing"
4  By Vinnie Falco
5 
6 Official project location:
7 https://github.com/vinniefalco/DSPFilters
8 
9 See Documentation.cpp for contact information, notes, and bibliography.
10 
11 --------------------------------------------------------------------------------
12 
13 License: MIT License (http://www.opensource.org/licenses/mit-license.php)
14 Copyright (c) 2009 by Vinnie Falco
15 
16 Permission is hereby granted, free of charge, to any person obtaining a copy
17 of this software and associated documentation files (the "Software"), to deal
18 in the Software without restriction, including without limitation the rights
19 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
20 copies of the Software, and to permit persons to whom the Software is
21 furnished to do so, subject to the following conditions:
22 
23 The above copyright notice and this permission notice shall be included in
24 all copies or substantial portions of the Software.
25 
26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
29 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
30 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
31 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
32 THE SOFTWARE.
33 
34 *******************************************************************************/
35 
36 #ifndef DSPFILTERS_TYPES_H
37 #define DSPFILTERS_TYPES_H
38 
39 #include "DspFilters/Common.h"
40 #include "DspFilters/MathSupplement.h"
41 
42 namespace Dsp {
43 
44 // A conjugate or real pair
45 struct ComplexPair : complex_pair_t
46 {
ComplexPairComplexPair47   ComplexPair ()
48   {
49   }
50 
ComplexPairComplexPair51   explicit ComplexPair (const complex_t& c1)
52     : complex_pair_t (c1, 0.)
53   {
54     assert (isReal());
55   }
56 
ComplexPairComplexPair57   ComplexPair (const complex_t& c1,
58                const complex_t& c2)
59     : complex_pair_t (c1, c2)
60   {
61   }
62 
isConjugateComplexPair63   bool isConjugate () const
64   {
65     return second == std::conj (first);
66   }
67 
isRealComplexPair68   bool isReal () const
69   {
70     return first.imag() == 0 && second.imag() == 0;
71   }
72 
73   // Returns true if this is either a conjugate pair,
74   // or a pair of reals where neither is zero.
isMatchedPairComplexPair75   bool isMatchedPair () const
76   {
77     if (first.imag() != 0)
78       return second == std::conj (first);
79     else
80       return second.imag () == 0 &&
81              second.real () != 0 &&
82              first.real () != 0;
83   }
84 
is_nanComplexPair85   bool is_nan () const
86   {
87     return Dsp::is_nan (first) || Dsp::is_nan (second);
88   }
89 };
90 
91 // A pair of pole/zeros. This fits in a biquad (but is missing the gain)
92 struct PoleZeroPair
93 {
94   ComplexPair poles;
95   ComplexPair zeros;
96 
PoleZeroPairPoleZeroPair97   PoleZeroPair () { }
98 
99   // single pole/zero
PoleZeroPairPoleZeroPair100   PoleZeroPair (const complex_t& p, const complex_t& z)
101     : poles (p), zeros (z)
102   {
103   }
104 
105   // pole/zero pair
PoleZeroPairPoleZeroPair106   PoleZeroPair (const complex_t& p1, const complex_t& z1,
107                 const complex_t& p2, const complex_t& z2)
108     : poles (p1, p2)
109     , zeros (z1, z2)
110   {
111   }
112 
isSinglePolePoleZeroPair113   bool isSinglePole () const
114   {
115     return poles.second == 0. && zeros.second == 0.;
116   }
117 
is_nanPoleZeroPair118   bool is_nan () const
119   {
120     return poles.is_nan() || zeros.is_nan();
121   }
122 };
123 
124 // Identifies the general class of filter
125 enum Kind
126 {
127   kindLowPass,
128   kindHighPass,
129   kindBandPass,
130   kindBandStop,
131   kindLowShelf,
132   kindHighShelf,
133   kindBandShelf,
134   kindOther
135 };
136 
137 }
138 
139 #endif
140