Lucas
06f6a4881c
- Define Pi to avoid running into too many feature test macros - Define _DEFAULT_SOURCE if not in OpenBSD - Add a play target that works in Linux
46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
/*
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* arngment - random music generator
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*
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* Written in 2020 by Lucas
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*
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* To the extent possible under law, the author(s) have dedicated all
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* copyright and related and neighboring rights to this software to the
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* public domain worldwide. This software is distributed without any
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* warranty.
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*
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* You should have received a copy of the CC0 Public Domain Dedication
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* along with this software. If not, see
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* <http://creativecommons.org/publicdomain/zero/1.0/>.
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*/
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#include <math.h>
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/*
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* Apparently, it's too hard for OSes to expose M_PI in a portable way.
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* Definition taken from
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* $OpenBSD: math.h,v 1.36 2018/03/10 20:52:58 kettenis Exp $
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*/
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#define JUST_PI ((double)3.14159265358979323846)
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#define CLAMP(x, a, b) ((x) < (a) ? (a) : (x) > (b) ? (b) : (x))
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double
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synth_distortion(double gain, double x)
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{
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double xg = CLAMP(x * gain, -1.0, 1.0);
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return (x + xg) / 2.0;
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}
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double
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synth_sinewave(double t, double a)
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{
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return sin(2.0 * JUST_PI * t * a);
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}
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double
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synth_trianglewave(double t, double a)
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{
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double x = t * a;
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return 2.0 * fabs(2.0 * (x - floor(0.5 + x))) - 1.0;
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}
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