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livetrax/libs/fluidsynth/src/fluid_lfo.h

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/* FluidSynth - A Software Synthesizer
*
* Copyright (C) 2003 Peter Hanappe and others.
*
* This library is free software; you can redistribute it and/or
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* 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
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* Lesser General Public License for more details.
*
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* 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
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#include "fluid_sys.h"
typedef struct _fluid_lfo_t fluid_lfo_t;
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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 */
};
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static FLUID_INLINE void
fluid_lfo_reset(fluid_lfo_t *lfo)
{
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lfo->val = 0.0f;
}
// These two cannot be inlined since they're used by event_dispatch
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DECLARE_FLUID_RVOICE_FUNCTION(fluid_lfo_set_incr);
DECLARE_FLUID_RVOICE_FUNCTION(fluid_lfo_set_delay);
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static FLUID_INLINE fluid_real_t
fluid_lfo_get_val(fluid_lfo_t *lfo)
{
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return lfo->val;
}
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static FLUID_INLINE void
fluid_lfo_calc(fluid_lfo_t *lfo, unsigned int cur_delay)
{
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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