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commands.c
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1993-05-22
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514 lines
/* commands.c */
/* $Id: commands.c,v 3.7 1993/01/15 14:00:28 espie Exp espie $
* $Log: commands.c,v $
* Revision 3.7 1993/01/15 14:00:28 espie
* Added bg/fg test.
*
* Revision 3.6 1992/11/27 10:29:00 espie
* General cleanup
*
* Revision 3.5 1992/11/24 10:51:19 espie
* More precise vibrato table.
*
* Revision 3.4 1992/11/23 10:12:23 espie
* *** empty log message ***
*
* Revision 3.3 1992/11/22 17:20:01 espie
* Simplified delay_pattern.
*
* Revision 3.2 1992/11/20 14:53:32 espie
* Added finetune.
*
* Revision 3.1 1992/11/19 20:44:47 espie
* Protracker commands.
*
* Revision 3.0 1992/11/18 16:08:05 espie
* New release.
*
* Revision 2.12 1992/11/13 13:24:24 espie
* Added some extended commands: E12AB, and some.
* now use set_volume in audio.c. All the device-dependent operation
* is there.
* Defensive programming: check the range of each note
* for arpeggio setup.
* Structured part of the code, especially replay ``automaton''
* and setting up of effects.
*
* Revision 1.9 1991/11/17 17:09:53 espie
* Added missing prototypes.
* Dynamic oversample and frequency.
* Added arpeggio.
* Fixed up vibrato depth.
* Added vibslide and portaslide.
* Added command 9.
*/
#include <stdio.h>
#include "defs.h"
#include "extern.h"
#include "channel.h"
#include "song.h"
LOCAL char *id = "$Id: commands.c,v 3.7 1993/01/15 14:00:28 espie Exp espie $";
/* sine table for the vibrato effect */
int vibrato_table[64] =
{
0,50,100,149,196,241,284,325,362,396,426,452,473,490,502,510,512,
510,502,490,473,452,426,396,362,325,284,241,196,149,100,50,0,-49,
-99,-148,-195,-240,-283,-324,-361,-395,-425,-451,-472,-489,-501,
-509,-511,-509,-501,-489,-472,-451,-425,-395,-361,-324,-283,-240,
-195,-148,-99,-49
};
/***
*
*
* setting up effects/doing effects.
* The set_xxx gets called while parsing the effect,
* the do_xxx gets called each tick, and update the
* sound parameters while playing it.
*
*
***/
void do_nothing(ch)
struct channel *ch;
{
}
void set_nothing(a, ch)
struct automaton *a;
struct channel *ch;
{
}
/* slide pitch (up or down) */
void do_slide(ch)
struct channel *ch;
{
ch->pitch += ch->slide;
ch->pitch = MIN(ch->pitch, MAX_PITCH);
ch->pitch = MAX(ch->pitch, MIN_PITCH);
set_current_pitch(ch, ch->pitch);
}
void set_upslide(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_slide;
if (a->para)
ch->slide = a->para;
}
void set_downslide(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_slide;
if (a->para)
ch->slide = -a->para;
}
/* modulating the pitch with vibrato */
void do_vibrato(ch)
struct channel *ch;
{
int offset;
/* this is no longer a literal transcription of the pt
* code. I have rescaled the vibrato table.
*/
ch->viboffset += ch->vibrate;
ch->viboffset &= 63;
/* please don't use logical shift on signed values */
offset = (vibrato_table[ch->viboffset] * ch->vibdepth)/256;
/* temporary update of only the step value,
* note that we do not change the saved pitch.
*/
set_current_pitch(ch, ch->pitch + offset);
}
void set_vibrato(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_vibrato;
if (a->para)
{
ch->vibrate = HI(a->para);
ch->vibdepth = LOW(a->para);
}
}
/* arpeggio looks a bit like chords: we alternate between two
* or three notes very fast.
* Issue: we are able to re-generate real chords. Would that be
* better ? To try.
*/
void do_arpeggio(ch)
struct channel *ch;
{
if (++ch->arpindex >= MAX_ARP)
ch->arpindex =0;
set_current_pitch(ch, ch->arp[ch->arpindex]);
}
void set_arpeggio(a, ch)
struct automaton *a;
struct channel *ch;
{
/* normal play is arpeggio with 0/0 */
if (!a->para)
return;
/* arpeggio can be installed relative to the
* previous note, so we have to check that there
* actually is a current(previous) note
*/
if (ch->note == NO_NOTE)
{
fprintf(stderr,
"No note present for arpeggio");
error = FAULT;
}
else
{
int note;
ch->arp[0] = pitch_table[ch->note][ch->finetune];
note = ch->note + HI(a->para);
if (note < NUMBER_NOTES)
ch->arp[1] = pitch_table[note][ch->finetune];
else
{
fprintf(stderr,
"Arpeggio note out of range");
error = FAULT;
}
note = ch->note + LOW(a->para);
if (note < NUMBER_NOTES)
ch->arp[2] = pitch_table[note][ch->finetune];
else
{
fprintf(stderr,
"Arpeggio note out of range");
error = FAULT;
}
ch->arpindex = 0;
ch->adjust = do_arpeggio;
}
}
/* volume slide. Mostly used to simulate waveform control.
* (attack/decay/sustain).
*/
void do_slidevol(ch)
struct channel *ch;
{
ch->volume += ch->volumerate;
set_current_volume(ch, ch->volume);
}
/* note that volumeslide does not have a ``take default''
* behavior. If para is 0, this is truly a 0 volumeslide.
* Issue: is the test really necessary ? Can't we do
* a HI(para) - LOW(para). Answer: protracker does not.
*/
void parse_slidevol(ch, para)
struct channel *ch;
int para;
{
if (LOW(para))
ch->volumerate = -LOW(para);
else
ch->volumerate = HI(para);
}
void set_slidevol(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_slidevol;
parse_slidevol(ch, a->para);
}
/* extended command: retrig note at a fast pace
*/
void do_retrig(ch)
struct channel *ch;
{
if (--ch->current <= 0)
{
reset_note(ch, ch->note, ch->pitch);
ch->current = ch->retrig;
}
}
/* extended command: start note after a small
* delay
*/
void do_latestart(ch)
struct channel *ch;
{
if (--ch->current <= 0)
{
reset_note(ch, ch->note, ch->pitch);
ch->adjust = do_nothing;
}
}
/* extended command: cut note after some time.
* Note we only kill the volume.
*/
void do_cut(ch)
struct channel *ch;
{
if (ch->retrig)
{
if (--ch->retrig == 0)
set_current_volume(ch, 0);
}
}
void set_extended(a, ch)
struct automaton *a;
struct channel *ch;
{
switch(HI(a->para))
{
case 0:
break;
case 1:
ch->pitch += LOW(a->para);
ch->pitch = MIN(ch->pitch, MAX_PITCH);
ch->pitch = MAX(ch->pitch, MIN_PITCH);
set_current_pitch(ch, ch->pitch);
break;
case 2:
ch->pitch -= LOW(a->para);
ch->pitch = MIN(ch->pitch, MAX_PITCH);
ch->pitch = MAX(ch->pitch, MIN_PITCH);
set_current_pitch(ch, ch->pitch);
break;
case 5:
ch->finetune = LOW(a->para);
break;
case 6:
/* Note: the current implementation of protracker
* does not allow for a jump from pattern to pattern,
* but it looks like a logical extension to the current
* format.
*/
if (LOW(a->para) == 0)
{
a->loop_pattern_num = a->pattern_num;
a->loop_note_num = a->note_num;
}
else
{
if (a->loop_counter == 0)
a->loop_counter = LOW(a->para);
else
a->loop_counter--;
if (a->loop_counter > 0)
a->do_stuff |= JUMP_PATTERN;
}
break;
case 9:
ch->retrig = LOW(a->para);
ch->current = ch->retrig;
ch->adjust = do_retrig;
break;
case 10:
ch->volume += LOW(a->para);
break;
case 11:
ch->volume -= LOW(a->para);
break;
case 12:
ch->retrig = LOW(a->para);
ch->adjust = do_cut;
break;
case 13:
ch->mode = DO_NOTHING;
ch->current = LOW(a->para);
ch->adjust = do_latestart;
break;
case 14:
a->counter -= (LOW(a->para) + 1) * a->speed;
a->do_stuff |= DELAY_PATTERN;
break;
default:
fprintf(stderr, "Not supported %d-%d\n", HI(a->para), LOW(a->para));
break;
}
}
/* portamento: gets from a given pitch to another.
* We can simplify the routine by cutting it in
* a pitch up and pitch down part while setting up
* the effect.
*/
void do_portamento(ch)
struct channel *ch;
{
if (ch->pitch < ch->pitchgoal)
{
ch->pitch += ch->pitchrate;
ch->pitch = MIN(ch->pitch, ch->pitchgoal);
}
else if (ch->pitch > ch->pitchgoal)
{
ch->pitch -= ch->pitchrate;
ch->pitch = MAX(ch->pitch, ch->pitchgoal);
}
/* if we want to implement funk glissando, we need a change right
* there
*/
set_current_pitch(ch, ch->pitch);
}
/* if para and pitch are 0, this is obviously a continuation
* of the previous portamento.
*/
void set_portamento(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_portamento;
if (a->para)
ch->pitchrate = a->para;
if (a->pitch)
ch->pitchgoal = a->pitch;
}
/*
* combined commands.
*/
void do_portaslide(ch)
struct channel *ch;
{
do_portamento(ch);
do_slidevol(ch);
}
void set_portaslide(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_portaslide;
if (a->pitch)
ch->pitchgoal = a->pitch;
parse_slidevol(ch, a->para);
}
void do_vibratoslide(ch)
struct channel *ch;
{
do_vibrato(ch);
do_slidevol(ch);
}
void set_vibratoslide(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->adjust = do_vibratoslide;
parse_slidevol(ch, a->para);
}
/***
*
* effects that just need a setup part
*
***/
/* IMPORTANT: because of the special nature of
* the player, we can't process each effect independently,
* we have to merge effects from the four channel before
* doing anything about it. For instance, there can be
* several speed change in the same note,
* only the last one takes effect.
*/
void set_speed(a, ch)
struct automaton *a;
struct channel *ch;
{
a->new_speed = a->para;
a->do_stuff |= SET_SPEED;
}
void set_skip(a, ch)
struct automaton *a;
struct channel *ch;
{
/* yep, this is BCD. */
a->new_note = HI(a->para) * 10 + LOW(a->para);
a->do_stuff |= SET_SKIP;
}
void set_fastskip(a, ch)
struct automaton *a;
struct channel *ch;
{
a->new_pattern = a->para;
a->do_stuff |= SET_FASTSKIP;
}
/* immediate effect: starts the sample somewhere
* off the start.
*/
void set_offset(a, ch)
struct automaton *a;
struct channel *ch;
{
ch->pointer = int_to_fix(a->para * 256);
}
/* change the volume of the current channel.
* Is effective until there is a new set_volume,
* slide_volume, or an instrument is reloaded
* explicitly by giving its number. Obviously, if
* you load an instrument and do a set_volume in the
* same note, the set_volume will take precedence.
*/
void set_volume(a, ch)
struct automaton *a;
struct channel *ch;
{
set_current_volume(ch, a->para);
}
/* Initialize the whole effect table */
void init_effects(table)
void (*table[])();
{
table[0] = set_arpeggio;
table[15] = set_speed;
table[13] = set_skip;
table[11] = set_fastskip;
table[12] = set_volume;
table[10] = set_slidevol;
table[9] = set_offset;
table[3] = set_portamento;
table[5] = set_portaslide;
table[2] = set_upslide;
table[1] = set_downslide;
table[4] = set_vibrato;
table[6] = set_vibratoslide;
table[14] = set_extended;
table[7] = set_nothing;
table[8] = set_nothing;
}