ref: 14bec174f551f6441157ffda61263d9fb89b64a7
dir: /src/tremolo.c/
/* * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation; either version 2 of the License, or (at * your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser * General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library. If not, write to the Free Software Foundation, * Fifth Floor, 51 Franklin Street, Boston, MA 02111-1301, USA. */ /* Effect: tremolo (c) 2007 robs@users.sourceforge.net */ #include "synth.h" static int getopts(eff_t effp, int n, char * * argv) { double speed, depth = 40; char dummy; /* To check for extraneous chars. */ char offset[100]; char * synth_args[] = {"sine", "fmod", 0, 0}; if (n < 1 || n > 2 || sscanf(argv[0], "%lf %c", &speed, &dummy) != 1 || speed < 0 || (n > 1 && sscanf(argv[1], "%lf %c", &depth, &dummy) != 1) || depth <= 0 || depth > 100) { st_fail(effp->h->usage); return ST_EOF; } synth_args[2] = argv[0]; sprintf(offset, "%g", 100 - depth / 2); synth_args[3] = offset; return st_synth_getopts(effp, array_length(synth_args), synth_args); } st_effect_t const * st_tremolo_effect_fn(void) { static st_effect_t driver = { "tremolo", "Usage: tremolo speed_Hz [depth_percent];", ST_EFF_MCHAN, getopts, st_synth_start, st_synth_flow, 0, 0, 0, }; return &driver; }