/*
TiMidity -- Experimental MIDI to WAVE converter
Copyright (C) 1995 Tuukka Toivonen <toivonen@clinet.fi>
This program is free software; you can redistribute it and/or modify
it under the terms of the Perl Artistic License, available in COPYING.
mix.c */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "SDL.h"
#include "timidity.h"
#include "options.h"
#include "instrum.h"
#include "playmidi.h"
#include "output.h"
#include "tables.h"
#include "resample.h"
#include "mix.h"
/* Returns 1 if envelope runs out */
int recompute_envelope(MidiSong *song, int v)
{
int stage;
stage = song->voice[v].envelope_stage;
if (stage>5)
{
/* Envelope ran out. */
song->voice[v].status = VOICE_FREE;
return 1;
}
if (song->voice[v].sample->modes & MODES_ENVELOPE)
{
if (song->voice[v].status==VOICE_ON || song->voice[v].status==VOICE_SUSTAINED)
{
if (stage>2)
{
/* Freeze envelope until note turns off. Trumpets want this. */
song->voice[v].envelope_increment=0;
return 0;
}
}
}
song->voice[v].envelope_stage=stage+1;
if (song->voice[v].envelope_volume==song->voice[v].sample->envelope_offset[stage] ||
(stage > 2 && song->voice[v].envelope_volume <
song->voice[v].sample->envelope_offset[stage]))
return recompute_envelope(song, v);
song->voice[v].envelope_target = song->voice[v].sample->envelope_offset[stage];
song->voice[v].envelope_increment = song->voice[v].sample->envelope_rate[stage];
if (song->voice[v].envelope_target < song->voice[v].envelope_volume)
song->voice[v].envelope_increment = -song->voice[v].envelope_increment;
return 0;
}
void apply_envelope_to_amp(MidiSong *song, int v)
{
float lamp = song->voice[v].left_amp, ramp;
Sint32 la,ra;
if (song->voice[v].panned == PANNED_MYSTERY)
{
ramp = song->voice[v].right_amp;
if (song->voice[v].tremolo_phase_increment)
{
lamp *= song->voice[v].tremolo_volume;
ramp *= song->voice[v].tremolo_volume;
}
if (song->voice[v].sample->modes & MODES_ENVELOPE)
{
lamp *= (float)vol_table[song->voice[v].envelope_volume>>23];
ramp *= (float)vol_table[song->voice[v].envelope_volume>>23];
}
la = (Sint32)FSCALE(lamp,AMP_BITS);
if (la>MAX_AMP_VALUE)
la=MAX_AMP_VALUE;
ra = (Sint32)FSCALE(ramp,AMP_BITS);
if (ra>MAX_AMP_VALUE)
ra=MAX_AMP_VALUE;
song->voice[v].left_mix = la;
song->voice[v].right_mix = ra;
}
else
{
if (song->voice[v].tremolo_phase_increment)
lamp *= song->voice[v].tremolo_volume;
if (song->voice[v].sample->modes & MODES_ENVELOPE)
lamp *= (float)vol_table[song->voice[v].envelope_volume>>23];
la = (Sint32)FSCALE(lamp,AMP_BITS);
if (la>MAX_AMP_VALUE)
la=MAX_AMP_VALUE;
song->voice[v].left_mix = la;
}
}
static int update_envelope(MidiSong *song, int v)
{
song->voice[v].envelope_volume += song->voice[v].envelope_increment;
/* Why is there no ^^ operator?? */
if (((song->voice[v].envelope_increment < 0) &&
(song->voice[v].envelope_volume <= song->voice[v].envelope_target)) ||
((song->voice[v].envelope_increment > 0) &&
(song->voice[v].envelope_volume >= song->voice[v].envelope_target)))
{
song->voice[v].envelope_volume = song->voice[v].envelope_target;
if (recompute_envelope(song, v))
return 1;
}
return 0;
}
static void update_tremolo(MidiSong *song, int v)
{
Sint32 depth = song->voice[v].sample->tremolo_depth << 7;
if (song->voice[v].tremolo_sweep)
{
/* Update sweep position */
song->voice[v].tremolo_sweep_position += song->voice[v].tremolo_sweep;
if (song->voice[v].tremolo_sweep_position >= (1 << SWEEP_SHIFT))
song->voice[v].tremolo_sweep=0; /* Swept to max amplitude */
else
{
/* Need to adjust depth */
depth *= song->voice[v].tremolo_sweep_position;
depth >>= SWEEP_SHIFT;
}
}
song->voice[v].tremolo_phase += song->voice[v].tremolo_phase_increment;
/* if (song->voice[v].tremolo_phase >= (SINE_CYCLE_LENGTH<<RATE_SHIFT))
song->voice[v].tremolo_phase -= SINE_CYCLE_LENGTH<<RATE_SHIFT; */
song->voice[v].tremolo_volume = (float)
(1.0 - FSCALENEG((sine(song->voice[v].tremolo_phase >> RATE_SHIFT) + 1.0)
* depth * TREMOLO_AMPLITUDE_TUNING,
17));
/* I'm not sure about the +1.0 there -- it makes tremoloed voices'
volumes on average the lower the higher the tremolo amplitude. */
}
/* Returns 1 if the note died */
static int update_signal(MidiSong *song, int v)
{
if (song->voice[v].envelope_increment && update_envelope(song, v))
return 1;
if (song->voice[v].tremolo_phase_increment)
update_tremolo(song, v);
apply_envelope_to_amp(song, v);
return 0;
}
#define MIXATION(a) *lp++ += (a)*s;
static void mix_mystery_signal(MidiSong *song, sample_t *sp, Sint32 *lp, int v,
int count)
{
Voice *vp = song->voice + v;
final_volume_t
left=vp->left_mix,
right=vp->right_mix;
int cc;
sample_t s;
if (!(cc = vp->control_counter))
{
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
right = vp->right_mix;
}
while (count)
if (cc < count)
{
count -= cc;
while (cc--)
{
s = *sp++;
MIXATION(left);
MIXATION(right);
}
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
right = vp->right_mix;
}
else
{
vp->control_counter = cc - count;
while (count--)
{
s = *sp++;
MIXATION(left);
MIXATION(right);
}
return;
}
}
static void mix_center_signal(MidiSong *song, sample_t *sp, Sint32 *lp, int v,
int count)
{
Voice *vp = song->voice + v;
final_volume_t
left=vp->left_mix;
int cc;
sample_t s;
if (!(cc = vp->control_counter))
{
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
}
while (count)
if (cc < count)
{
count -= cc;
while (cc--)
{
s = *sp++;
MIXATION(left);
MIXATION(left);
}
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
}
else
{
vp->control_counter = cc - count;
while (count--)
{
s = *sp++;
MIXATION(left);
MIXATION(left);
}
return;
}
}
static void mix_single_signal(MidiSong *song, sample_t *sp, Sint32 *lp, int v,
int count)
{
Voice *vp = song->voice + v;
final_volume_t
left=vp->left_mix;
int cc;
sample_t s;
if (!(cc = vp->control_counter))
{
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
}
while (count)
if (cc < count)
{
count -= cc;
while (cc--)
{
s = *sp++;
MIXATION(left);
lp++;
}
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
}
else
{
vp->control_counter = cc - count;
while (count--)
{
s = *sp++;
MIXATION(left);
lp++;
}
return;
}
}
static void mix_mono_signal(MidiSong *song, sample_t *sp, Sint32 *lp, int v,
int count)
{
Voice *vp = song->voice + v;
final_volume_t
left=vp->left_mix;
int cc;
sample_t s;
if (!(cc = vp->control_counter))
{
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
}
while (count)
if (cc < count)
{
count -= cc;
while (cc--)
{
s = *sp++;
MIXATION(left);
}
cc = song->control_ratio;
if (update_signal(song, v))
return; /* Envelope ran out */
left = vp->left_mix;
}
else
{
vp->control_counter = cc - count;
while (count--)
{
s = *sp++;
MIXATION(left);
}
return;
}
}
static void mix_mystery(MidiSong *song, sample_t *sp, Sint32 *lp, int v, int count)
{
final_volume_t
left = song->voice[v].left_mix,
right = song->voice[v].right_mix;
sample_t s;
while (count--)
{
s = *sp++;
MIXATION(left);
MIXATION(right);
}
}
static void mix_center(MidiSong *song, sample_t *sp, Sint32 *lp, int v, int count)
{
final_volume_t
left = song->voice[v].left_mix;
sample_t s;
while (count--)
{
s = *sp++;
MIXATION(left);
MIXATION(left);
}
}
static void mix_single(MidiSong *song, sample_t *sp, Sint32 *lp, int v, int count)
{
final_volume_t
left = song->voice[v].left_mix;
sample_t s;
while (count--)
{
s = *sp++;
MIXATION(left);
lp++;
}
}
static void mix_mono(MidiSong *song, sample_t *sp, Sint32 *lp, int v, int count)
{
final_volume_t
left = song->voice[v].left_mix;
sample_t s;
while (count--)
{
s = *sp++;
MIXATION(left);
}
}
/* Ramp a note out in c samples */
static void ramp_out(MidiSong *song, sample_t *sp, Sint32 *lp, int v, Sint32 c)
{
/* should be final_volume_t, but Uint8 gives trouble. */
Sint32 left, right, li, ri;
sample_t s=0; /* silly warning about uninitialized s */
left=song->voice[v].left_mix;
li=-(left/c);
if (!li) li=-1;
/* printf("Ramping out: left=%d, c=%d, li=%d\n", left, c, li); */
if (!(song->encoding & PE_MONO))
{
if (song->voice[v].panned==PANNED_MYSTERY)
{
right=song->voice[v].right_mix;
ri=-(right/c);
while (c--)
{
left += li;
if (left<0)
left=0;
right += ri;
if (right<0)
right=0;
s=*sp++;
MIXATION(left);
MIXATION(right);
}
}
else if (song->voice[v].panned==PANNED_CENTER)
{
while (c--)
{
left += li;
if (left<0)
return;
s=*sp++;
MIXATION(left);
MIXATION(left);
}
}
else if (song->voice[v].panned==PANNED_LEFT)
{
while (c--)
{
left += li;
if (left<0)
return;
s=*sp++;
MIXATION(left);
lp++;
}
}
else if (song->voice[v].panned==PANNED_RIGHT)
{
while (c--)
{
left += li;
if (left<0)
return;
s=*sp++;
lp++;
MIXATION(left);
}
}
}
else
{
/* Mono output. */
while (c--)
{
left += li;
if (left<0)
return;
s=*sp++;
MIXATION(left);
}
}
}
/**************** interface function ******************/
void mix_voice(MidiSong *song, Sint32 *buf, int v, Sint32 c)
{
Voice *vp = song->voice + v;
sample_t *sp;
if (vp->status==VOICE_DIE)
{
if (c>=MAX_DIE_TIME)
c=MAX_DIE_TIME;
sp=resample_voice(song, v, &c);
if(c > 0)
ramp_out(song, sp, buf, v, c);
vp->status=VOICE_FREE;
}
else
{
sp=resample_voice(song, v, &c);
if (song->encoding & PE_MONO)
{
/* Mono output. */
if (vp->envelope_increment || vp->tremolo_phase_increment)
mix_mono_signal(song, sp, buf, v, c);
else
mix_mono(song, sp, buf, v, c);
}
else
{
if (vp->panned == PANNED_MYSTERY)
{
if (vp->envelope_increment || vp->tremolo_phase_increment)
mix_mystery_signal(song, sp, buf, v, c);
else
mix_mystery(song, sp, buf, v, c);
}
else if (vp->panned == PANNED_CENTER)
{
if (vp->envelope_increment || vp->tremolo_phase_increment)
mix_center_signal(song, sp, buf, v, c);
else
mix_center(song, sp, buf, v, c);
}
else
{
/* It's either full left or full right. In either case,
every other sample is 0. Just get the offset right: */
if (vp->panned == PANNED_RIGHT) buf++;
if (vp->envelope_increment || vp->tremolo_phase_increment)
mix_single_signal(song, sp, buf, v, c);
else
mix_single(song, sp, buf, v, c);
}
}
}
}