1 /*
2 This file is part of LilyPond, the GNU music typesetter.
3
4 Copyright (C) 1997--2020 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 using std::string;
26 using std::vector;
27
28 double
log_2(double x)29 log_2 (double x)
30 {
31 return log (x) / log (2.0);
32 }
33
34 Real
directed_round(Real f,Direction d)35 directed_round (Real f, Direction d)
36 {
37 if (d < 0)
38 return floor (f);
39 else
40 return ceil (f);
41 }
42
43 /*
44 0 at threshold, 1 at 0, with 1/x falloff.
45 */
46 Real
peak_around(Real epsilon,Real threshold,Real x)47 peak_around (Real epsilon, Real threshold, Real x)
48 {
49 if (x < 0)
50 return 1.0;
51 return std::max (- epsilon * (x - threshold) / ((x + epsilon) * threshold), 0.0);
52 }
53
54 /*
55 0 at 0, 1 at standard_x, and increasing thereafter.
56 */
57 Real
convex_amplifier(Real standard_x,Real increase_factor,Real x)58 convex_amplifier (Real standard_x, Real increase_factor, Real x)
59 {
60 return (exp (increase_factor * x / standard_x) - 1.0) / (exp (increase_factor) - 1.0);
61 }
62
63 string
camel_case_to_lisp_identifier(const string & in)64 camel_case_to_lisp_identifier (const string &in)
65 {
66 vector<char> out;
67
68 /* don't add '-' before first character */
69 out.push_back (char (tolower (in[0])));
70
71 for (size_t inpos = 1; inpos < in.size (); inpos++)
72 {
73 if (isupper (in[inpos]))
74 out.push_back ('-');
75 out.push_back ( char (tolower (in[inpos])));
76 }
77
78 string result (&out[0], out.size ());
79 replace_all (&result, '_', '-');
80
81 return result;
82 }
83