1fa24a09c7
This is based on Voxware 3.5, and corresponds to Amancio's `guspnp21'. Bug reports to Amancio, please!
139 lines
3.3 KiB
C
139 lines
3.3 KiB
C
/*
|
|
* gus_vol.c - Compute volume for GUS.
|
|
*
|
|
* Greg Lee 1993.
|
|
*/
|
|
#include <i386/isa/sound/sound_config.h>
|
|
|
|
#ifdef CONFIG_GUS
|
|
#include <i386/isa/sound/gus_linearvol.h>
|
|
|
|
#define GUS_VOLUME gus_wave_volume
|
|
|
|
|
|
extern int gus_wave_volume;
|
|
unsigned short gus_adagio_vol(int vel, int mainv, int xpn, int voicev);
|
|
unsigned short gus_linear_vol(int vol, int mainvol);
|
|
|
|
/*
|
|
* Calculate gus volume from note velocity, main volume, expression, and
|
|
* intrinsic patch volume given in patch library. Expression is multiplied
|
|
* in, so it emphasizes differences in note velocity, while main volume is
|
|
* added in -- I don't know whether this is right, but it seems reasonable to
|
|
* me. (In the previous stage, main volume controller messages were changed
|
|
* to expression controller messages, if they were found to be used for
|
|
* dynamic volume adjustments, so here, main volume can be assumed to be
|
|
* constant throughout a song.)
|
|
*
|
|
* Intrinsic patch volume is added in, but if over 64 is also multiplied in, so
|
|
* we can give a big boost to very weak voices like nylon guitar and the
|
|
* basses. The normal value is 64. Strings are assigned lower values.
|
|
*/
|
|
unsigned short
|
|
gus_adagio_vol(int vel, int mainv, int xpn, int voicev)
|
|
{
|
|
int i, m, n, x;
|
|
|
|
/*
|
|
* A voice volume of 64 is considered neutral, so adjust the main
|
|
* volume if something other than this neutral value was assigned in
|
|
* the patch library.
|
|
*/
|
|
x = 256 + 6 * (voicev - 64);
|
|
|
|
/*
|
|
* Boost expression by voice volume above neutral.
|
|
*/
|
|
if (voicev > 65)
|
|
xpn += voicev - 64;
|
|
xpn += (voicev - 64) / 2;
|
|
|
|
/*
|
|
* Combine multiplicative and level components.
|
|
*/
|
|
x = vel * xpn * 6 + (voicev / 4) * x;
|
|
|
|
#ifdef GUS_VOLUME
|
|
/*
|
|
* Further adjustment by installation-specific master volume control
|
|
* (default 60).
|
|
*/
|
|
x = (x * GUS_VOLUME * GUS_VOLUME) / 10000;
|
|
#endif
|
|
|
|
#ifdef GUS_USE_CHN_MAIN_VOLUME
|
|
/*
|
|
* Experimental support for the channel main volume
|
|
*/
|
|
|
|
mainv = (mainv / 2) + 64; /* Scale to 64 to 127 */
|
|
x = (x * mainv * mainv) / 16384;
|
|
#endif
|
|
|
|
if (x < 2)
|
|
return (0);
|
|
else if (x >= 65535)
|
|
return ((15 << 8) | 255);
|
|
|
|
/*
|
|
* Convert to gus's logarithmic form with 4 bit exponent i and 8 bit
|
|
* mantissa m.
|
|
*/
|
|
n = x;
|
|
i = 7;
|
|
if (n < 128) {
|
|
while (i > 0 && n < (1 << i))
|
|
i--;
|
|
} else
|
|
while (n > 255) {
|
|
n >>= 1;
|
|
i++;
|
|
}
|
|
/*
|
|
* Mantissa is part of linear volume not expressed in exponent.
|
|
* (This is not quite like real logs -- I wonder if it's right.)
|
|
*/
|
|
m = x - (1 << i);
|
|
|
|
/*
|
|
* Adjust mantissa to 8 bits.
|
|
*/
|
|
if (m > 0) {
|
|
if (i > 8)
|
|
m >>= i - 8;
|
|
else if (i < 8)
|
|
m <<= 8 - i;
|
|
}
|
|
return ((i << 8) + m);
|
|
}
|
|
|
|
/*
|
|
* Volume-values are interpreted as linear values. Volume is based on the
|
|
* value supplied with SEQ_START_NOTE(), channel main volume (if compiled in)
|
|
* and the volume set by the mixer-device (default 60%).
|
|
*/
|
|
|
|
unsigned short
|
|
gus_linear_vol(int vol, int mainvol)
|
|
{
|
|
int mixer_mainvol;
|
|
|
|
RANGE (vol, 0, 127) ;
|
|
|
|
#ifdef GUS_VOLUME
|
|
mixer_mainvol = GUS_VOLUME;
|
|
#else
|
|
mixer_mainvol = 100;
|
|
#endif
|
|
|
|
#ifdef GUS_USE_CHN_MAIN_VOLUME
|
|
RANGE (mainvol, 0, 127);
|
|
#else
|
|
mainvol = 127;
|
|
#endif
|
|
|
|
return gus_linearvol[(((vol * mainvol) / 127) * mixer_mainvol) / 100];
|
|
}
|
|
|
|
#endif
|