1 /*
2 This file is part of LilyPond, the GNU music typesetter.
3
4 Copyright (C) 1997--2021 Han-Wen Nienhuys <hanwen@xs4all.nl>
5 Jan Nieuwenhuizen <janneke@gnu.org>
6
7 LilyPond is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
11
12 LilyPond is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "misc.hh"
22 #include "offset.hh"
23 #include "warn.hh"
24
25 #include <vector>
26
27 using std::string;
28 using std::vector;
29
30 double
log_2(double x)31 log_2 (double x)
32 {
33 return log (x) / log (2.0);
34 }
35
36 Real
directed_round(Real f,Direction d)37 directed_round (Real f, Direction d)
38 {
39 if (d < CENTER)
40 return floor (f);
41 else
42 return ceil (f);
43 }
44
45 /*
46 0 at threshold, 1 at 0, with 1/x falloff.
47 */
48 Real
peak_around(Real epsilon,Real threshold,Real x)49 peak_around (Real epsilon, Real threshold, Real x)
50 {
51 if (x < 0)
52 return 1.0;
53 return std::max (- epsilon * (x - threshold) / ((x + epsilon) * threshold), 0.0);
54 }
55
56 /*
57 0 at 0, 1 at standard_x, and increasing thereafter.
58 */
59 Real
convex_amplifier(Real standard_x,Real increase_factor,Real x)60 convex_amplifier (Real standard_x, Real increase_factor, Real x)
61 {
62 return (exp (increase_factor * x / standard_x) - 1.0) / (exp (increase_factor) - 1.0);
63 }
64
65 string
camel_case_to_lisp_identifier(const string & in)66 camel_case_to_lisp_identifier (const string &in)
67 {
68 vector<char> out;
69
70 /* don't add '-' before first character */
71 out.push_back (char (tolower (in[0])));
72
73 for (size_t inpos = 1; inpos < in.size (); inpos++)
74 {
75 if (isupper (in[inpos]))
76 out.push_back ('-');
77 out.push_back ( char (tolower (in[inpos])));
78 }
79
80 string result (&out[0], out.size ());
81 replace_all (&result, '_', '-');
82
83 return result;
84 }
85