443be63167
Found via `codespell -i 3 -w --skip="./thirdparty,./share/locale,./fonts" -I ../musescore-whitelist.txt` Whitelist: ``` clas nd ot pres strack tage te ```
238 lines
6.5 KiB
C++
238 lines
6.5 KiB
C++
/* 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 Library 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
|
|
* Library General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Library General Public
|
|
* License along with this library; if not, write to the Free
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
* 02111-1307, USA
|
|
*/
|
|
|
|
#include "conv.h"
|
|
|
|
namespace FluidS {
|
|
|
|
/* conversion tables */
|
|
static float fluid_cb2amp_tab[FLUID_CB_AMP_SIZE];
|
|
static float fluid_atten2amp_tab[FLUID_ATTEN_AMP_SIZE];
|
|
static float fluid_concave_tab[128];
|
|
static float fluid_convex_tab[128];
|
|
static float fluid_pan_tab[FLUID_PAN_SIZE];
|
|
|
|
/*
|
|
* void fluid_synth_init
|
|
*
|
|
* Does all the initialization for this module.
|
|
*/
|
|
void fluid_conversion_config()
|
|
{
|
|
/* centibels to amplitude conversion
|
|
* Note: SF2.01 section 8.1.3: Initial attenuation range is
|
|
* between 0 and 144 dB. Therefore a negative attenuation is
|
|
* not allowed.
|
|
*/
|
|
for (int i = 0; i < FLUID_CB_AMP_SIZE; i++)
|
|
fluid_cb2amp_tab[i] = (float) pow(10.0, (double) i / -200.0);
|
|
|
|
/* NOTE: EMU8k and EMU10k devices don't conform to the SoundFont
|
|
* specification in regards to volume attenuation. The below calculation
|
|
* is an approx. equation for generating a table equivalent to the
|
|
* cb_to_amp_table[] in tables.c of the TiMidity++ source, which I'm told
|
|
* was generated from device testing. By the spec this should be centibels.
|
|
*/
|
|
for (int i = 0; i < FLUID_ATTEN_AMP_SIZE; i++)
|
|
fluid_atten2amp_tab[i] = (float) pow(10.0, (double) i / FLUID_ATTEN_POWER_FACTOR);
|
|
|
|
/* initialize the conversion tables (see fluid_mod.c
|
|
fluid_mod_get_value cases 4 and 8) */
|
|
|
|
/* concave unipolar positive transform curve */
|
|
fluid_concave_tab[0] = 0.0;
|
|
fluid_concave_tab[127] = 1.0;
|
|
|
|
/* convex unipolar positive transform curve */
|
|
fluid_convex_tab[0] = 0;
|
|
fluid_convex_tab[127] = 1.0;
|
|
|
|
/* There seems to be an error in the specs. The equations are
|
|
implemented according to the pictures on SF2.01 page 73. */
|
|
|
|
for (int i = 1; i < 127; i++) {
|
|
double x = -20.0 / 96.0 * log((i * i) / (127.0 * 127.0)) / log(10.0);
|
|
fluid_convex_tab[i] = (float) (1.0 - x);
|
|
fluid_concave_tab[127 - i] = (float) x;
|
|
}
|
|
|
|
/* initialize the pan conversion table */
|
|
double x = M_PI / 2.0 / (FLUID_PAN_SIZE - 1.0);
|
|
for (int i = 0; i < FLUID_PAN_SIZE; i++)
|
|
fluid_pan_tab[i] = (float) sin(i * x);
|
|
}
|
|
|
|
/*
|
|
* fluid_cb2amp
|
|
*
|
|
* in: a value between 0 and 960, 0 is no attenuation
|
|
* out: a value between 1 and 0
|
|
*/
|
|
float fluid_cb2amp(float cb)
|
|
{
|
|
/*
|
|
* cb: an attenuation in 'centibels' (1/10 dB)
|
|
* SF2.01 page 49 # 48 limits it to 144 dB.
|
|
* 96 dB is reasonable for 16 bit systems, 144 would make sense for 24 bit.
|
|
*/
|
|
|
|
/* minimum attenuation: 0 dB */
|
|
if (cb < 0)
|
|
return 1.0;
|
|
if (cb >= FLUID_CB_AMP_SIZE)
|
|
return 0.0;
|
|
return fluid_cb2amp_tab[(int) cb];
|
|
}
|
|
|
|
/*
|
|
* fluid_atten2amp
|
|
*
|
|
* in: a value between 0 and 1440, 0 is no attenuation
|
|
* out: a value between 1 and 0
|
|
*
|
|
* Note: Volume attenuation is supposed to be centibels but EMU8k/10k don't
|
|
* follow this. That's the reason for separate fluid_cb2amp and fluid_atten2amp.
|
|
*/
|
|
float fluid_atten2amp(float atten)
|
|
{
|
|
if (atten < 0)
|
|
return 1.0;
|
|
else if (atten >= FLUID_ATTEN_AMP_SIZE)
|
|
return 0.0;
|
|
else
|
|
return fluid_atten2amp_tab[(int) atten];
|
|
}
|
|
|
|
/*
|
|
* fluid_tc2sec_delay
|
|
*/
|
|
float fluid_tc2sec_delay(float tc)
|
|
{
|
|
/* SF2.01 section 8.1.2 items 21, 23, 25, 33
|
|
* SF2.01 section 8.1.3 items 21, 23, 25, 33
|
|
*
|
|
* The most negative number indicates a delay of 0. Range is limited
|
|
* from -12000 to 5000
|
|
*/
|
|
if (tc <= -32768.0f)
|
|
return (float) 0.0f;
|
|
if (tc < -12000.)
|
|
tc = (float) -12000.0f;
|
|
if (tc > 5000.0f)
|
|
tc = (float) 5000.0f;
|
|
return (float) pow(2.0, (double) tc / 1200.0);
|
|
}
|
|
|
|
/*
|
|
* fluid_tc2sec_attack
|
|
*/
|
|
float fluid_tc2sec_attack(float tc)
|
|
{
|
|
/* SF2.01 section 8.1.2 items 26, 34
|
|
* SF2.01 section 8.1.3 items 26, 34
|
|
* The most negative number indicates a delay of 0
|
|
* Range is limited from -12000 to 8000 */
|
|
if (tc<=-32768.)
|
|
return (float) 0.0;
|
|
if (tc<-12000.)
|
|
tc=(float) -12000.0;
|
|
if (tc>8000.)
|
|
tc=(float) 8000.0;
|
|
return (float) pow(2.0, (double) tc / 1200.0);
|
|
}
|
|
|
|
/*
|
|
* fluid_tc2sec
|
|
*/
|
|
float fluid_tc2sec(float tc)
|
|
{
|
|
/* No range checking here! */
|
|
return (float) pow(2.0, (double) tc / 1200.0);
|
|
}
|
|
|
|
/*
|
|
* fluid_tc2sec_release
|
|
*/
|
|
float fluid_tc2sec_release(float tc)
|
|
{
|
|
/* SF2.01 section 8.1.2 items 30, 38
|
|
* SF2.01 section 8.1.3 items 30, 38
|
|
* No 'most negative number' rule here!
|
|
* Range is limited from -12000 to 8000
|
|
*/
|
|
if (tc<=-32768.)
|
|
return (float) 0.0;
|
|
if (tc<-12000.)
|
|
tc=(float) -12000.0;
|
|
if (tc>8000.)
|
|
tc=(float) 8000.0;
|
|
return (float) pow(2.0, (double) tc / 1200.0);
|
|
}
|
|
|
|
/*
|
|
* fluid_act2hz
|
|
*
|
|
* Convert from absolute cents to Hertz
|
|
*/
|
|
float fluid_act2hz(float c)
|
|
{
|
|
return (float) (8.176 * pow(2.0, (double) c / 1200.0));
|
|
}
|
|
|
|
/*
|
|
* fluid_pan
|
|
*/
|
|
float fluid_pan(float c, int left)
|
|
{
|
|
if (left)
|
|
c = -c;
|
|
if (c < -500)
|
|
return (float) 0.0;
|
|
else if (c > 500)
|
|
return (float) 1.0;
|
|
else
|
|
return fluid_pan_tab[(int) (c + 500)];
|
|
}
|
|
|
|
/*
|
|
* fluid_concave
|
|
*/
|
|
float fluid_concave(float val)
|
|
{
|
|
if (val < 0)
|
|
return 0;
|
|
else if (val > 127)
|
|
return 1;
|
|
return fluid_concave_tab[(int) val];
|
|
}
|
|
|
|
/*
|
|
* fluid_convex
|
|
*/
|
|
float fluid_convex(float val)
|
|
{
|
|
if (val < 0)
|
|
return 0;
|
|
else if (val > 127)
|
|
return 1;
|
|
return fluid_convex_tab[(int) val];
|
|
}
|
|
}
|
|
|