/* FluidSynth - A Software Synthesizer * * Copyright (C) 2003 Peter Hanappe and others. * * 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 2.1 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, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA */ #ifndef _FLUID_LFO_H #define _FLUID_LFO_H #include "fluid_sys.h" typedef struct _fluid_lfo_t fluid_lfo_t; struct _fluid_lfo_t { fluid_real_t val; /* the current value of the LFO */ unsigned int delay; /* the delay of the lfo in samples */ fluid_real_t increment; /* the lfo frequency is converted to a per-buffer increment */ }; static FLUID_INLINE void fluid_lfo_reset(fluid_lfo_t *lfo) { lfo->val = 0.0f; } // These two cannot be inlined since they're used by event_dispatch DECLARE_FLUID_RVOICE_FUNCTION(fluid_lfo_set_incr); DECLARE_FLUID_RVOICE_FUNCTION(fluid_lfo_set_delay); static FLUID_INLINE fluid_real_t fluid_lfo_get_val(fluid_lfo_t *lfo) { return lfo->val; } static FLUID_INLINE void fluid_lfo_calc(fluid_lfo_t *lfo, unsigned int cur_delay) { if(cur_delay < lfo->delay) { return; } lfo->val += lfo->increment; if(lfo->val > (fluid_real_t) 1.0) { lfo->increment = -lfo->increment; lfo->val = (fluid_real_t) 2.0 - lfo->val; } else if(lfo->val < (fluid_real_t) -1.0) { lfo->increment = -lfo->increment; lfo->val = (fluid_real_t) -2.0 - lfo->val; } } #endif