/*
** Copyright (C) 1993 Forte.  All rights reserved
** Written late one night 6/27/93.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <conio.h>
#include <dos.h>
#include "midi.h"
#include "totsr.h"
#include "ultramid.h"

extern int control_break;

/* interrupt clock stuff */
static void interrupt (*orig_clock)(void) = 0L;
static void interrupt clock(void);

static unsigned long clock_interval = 8334L; /* microseconds */
#define CLOCK_DIVISOR 9944U
#define ORIG_CLOCK_DIVISOR 0U

/* the timer interrupt is on vector 0x08 */
#define TIMER 0x08

void (far *um_hook)(void) = 0L;

int	um_data_out( int byte )
{
	if (um_hook) {
	    _AX = TSR_MIDI_OUT;
	    _CX = byte;
	    (*um_hook)();
        }
	return(0);
}

void	um_pitch_bend( int channel, int msb, int lsb )
{
	um_data_out( (pitch_wheel+channel) );
	um_data_out( msb );
	um_data_out( lsb );
}

void	um_program( int channel, int prog )
{
	um_data_out( (program_chng+channel) );
	um_data_out( prog );
}

void	um_chanpressure( int channel, int pitch, int pressure )
{
	um_data_out( (channel_aftertouch+channel) );
	um_data_out( pitch );
	um_data_out( pressure );
}

void	um_pressure( int channel, int pitch, int pressure )
{
	um_data_out( (poly_aftertouch+channel) );
	um_data_out( pitch );
	um_data_out( pressure );
}

void	um_parameter( int channel, int control, int value )
{
	um_data_out( (control_change+channel) );
	um_data_out( control );
	um_data_out( value );
}

int	um_note_on( int channel, int note, int velocity )
{
	int error;

	error = um_data_out( (note_on+channel) );
	error += um_data_out( note );
	error += um_data_out( velocity );
	return(error);
}

void	um_note_off( int channel, int note, int velocity )
{
	um_data_out( (note_off+channel) );
	um_data_out( note );
	um_data_out( velocity );
}

int	reset_um( )
{
	int i;

	_AX = TSR_ALL_NOTES_OFF;
	if (um_hook) (*um_hook)();
	for (i=0; i < 16; i++) {
	    um_parameter(i, 0x78, 0); /* all sounds off */
	    um_parameter(i, 0x79, 0); /* reset all controllers */
	    um_parameter(i, 100, 0); /* RPN MSB 0 */
	    um_parameter(i, 101, 0); /* RPN LSB 0 */
	    um_parameter(i, 6, 2); /* Pitch Bend Sensitivity MSB */
	    um_parameter(i, 38, 0); /* Pitch Bend Sensitivity LSB */
	}
	return(1);
}

static unsigned long us_timer = 0L;
static unsigned long timer = 0L;
static unsigned long tempo = 4800L;

static void interrupt clock()
{
	short t;

	us_timer += clock_interval;
	if (us_timer > tempo) {
		t = us_timer / tempo;
		us_timer -= (t * tempo);
		timer += t;
	}
	if (orig_clock) (*orig_clock)();
}

void um_set_tempo(us, divisor)
unsigned long us;
short divisor;
{
	/*
	** the tempo and divisor values are described in the Standard Midi
	** File specification 1.0
	*/
	int smpte_format, smpte_resolution;

	if (divisor > 0) {
		tempo = us / divisor;
	} else {
		smpte_format = (-divisor >> 8) & 0x7f;
		smpte_resolution = divisor & 0x7f;
		tempo = 1000000 / (smpte_format * smpte_resolution);
	}
	if (tempo <= 0) tempo = 1;
}

void um_reset_tick_counter()
{
	timer = 0L;
	us_timer = 0L;
}

int um_wait_for ( unsigned long some_time )
{
	if (kbhit() || control_break) return(1);
	while (some_time > timer) if (kbhit() || control_break) return(1);
	return(0);
}

#pragma warn -par
int	um_init_hardware(struct MIDILIB *ml)
{
	int vector, i;
	char far *stamp;
	struct track *track;
	unsigned long length;

	for (vector=0x78; vector <= 0x7f; vector++) {
	    um_hook = (void (far *)())getvect(vector);
	    stamp = (char far *)MK_FP( FP_SEG(um_hook), 0x103 );
	    if (strncmp(stamp, "ULTRAMID", 8) == 0) break;
	}
	if (vector <= 0x7f) {
	    midi_message("UltraMID is now loading instrument patches");
	    if (um_hook) {
		_AX = TSR_APP_START;
		(*um_hook)();
	    }
	    reset_um();
	    if (um_hook) {
		for (track=ml->Mp_tracks; track; track = track->next_track) {
		    _ES = FP_SEG(track->data);
		    asm push es
		    _DI = FP_OFF(track->data);
		    asm push di
		    length = track->length;
		    asm mov bx, word ptr length+2
		    asm mov dx, word ptr length
		    asm pop di
		    asm pop es
		    _AX = TSR_LOAD_MIDI_PATCHES;
		    (*um_hook)();
		}
		_AX = TSR_START_SEQUENCE;
		(*um_hook)();
	    }
        } else {
	    um_hook = 0L;
	    midi_error("Couldn't find UltraMID");
	    return(1);
	}
	return(0);
}
#pragma warn .par

void	um_cleanup( void )
{
	reset_um();
	if (um_hook) {
	    _AX = TSR_APP_END;
	    (*um_hook)();
	}
}

void	um_init_timers(void)
{
	orig_clock = getvect(TIMER);
	setvect(TIMER, clock);
	outportb(0x43, 0x36);
	outportb(0x40, CLOCK_DIVISOR & 0xff);
	outportb(0x40, (CLOCK_DIVISOR & 0xff00) >> 8);
}

void	um_cleanup_timers(void)
{
	outportb(0x43, 0x36);
	outportb(0x40, ORIG_CLOCK_DIVISOR & 0xff);
	outportb(0x40, (ORIG_CLOCK_DIVISOR & 0xff00) >> 8);
	if (orig_clock) setvect(TIMER, orig_clock);
}