/* Extended Module Player
 * Copyright (C) 1996-1999 Claudio Matsuoka and Hipolito Carraro Jr
 *
 * This file is part of the Extended Module Player and is distributed
 * under the terms of the GNU General Public License. See doc/COPYING
 * for more information.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "xmpi.h"
#include "player.h"
#include "driver.h"

/* Commands in the volume and waveform sequence table:
 *
 *	Cmd	Vol	Wave	Action
 *
 *	0xff	    END		End sequence
 *	0xfe	    JMP		Jump
 *	0xfd	 -	ARE	End arpeggio definition
 *	0xfc	 -	ARP	Begin arpeggio definition
 *	0xfb	    HLT		Halt
 *	0xfa	JWS	JVS	Jump waveform/volume sequence
 *	0xf9	     -		-
 *	0xf8	     -		-
 *	0xf7	 -	VWF	Set vibrato waveform
 *	0xf6	EST	RES	?/reset pitch
 *	0xf5	EN2	VBS	Looping envelope/set vibrato speed
 *	0xf4	EN1	VBD	One shot envelope/set vibrato depth
 *	0xf3	    CHU		Change volume/pitch up speed
 *	0xf2	    CHD		Change volume/pitch down speed
 *	0xf1	    WAI		Wait
 *	0xf0	    SPD		Set speed
 */

extern uint8 **med_vol_table;
extern uint8 **med_wav_table;

#define VT med_vol_table[xc->ins][xc->med_vp++]
#define WT med_wav_table[xc->ins][xc->med_wp++]
#define VT_SKIP xc->med_vp++
#define WT_SKIP xc->med_wp++


void xmp_med_synth (int chn, struct xmp_channel *xc, int rst)
{
    int b, jws = 0, jvs = 0, loop = 0, jump = 0;

    if (med_vol_table == NULL || med_wav_table == NULL)
	return;

    if (med_vol_table[xc->ins] == NULL || med_wav_table[xc->ins] == NULL)
	return;

    if (rst) {
	xc->med_period = xc->period;
	xc->med_vp = xc->med_vc = xc->med_vw = 0;
	xc->med_wp = xc->med_wc = xc->med_ww = 0;
	xc->med_vs = xxih[xc->ins].vts;
	xc->med_ws = xxih[xc->ins].wts;
    }

    if (xc->med_vs > 0 && xc->med_vc-- == 0) {
	xc->med_vc = xc->med_vs - 1;

	if (xc->med_vw > 0) {
	    xc->med_vw--;
	    goto skip_vol;
	}

	jump = loop = jws = 0;
	switch (b = VT) {
	    while (jump--) {
	    case 0xff:		/* END */
	    case 0xfb:		/* HLT */
		xc->med_vp--;
		break;
	    case 0xfe:		/* JMP */
		if (loop)	/* avoid infinite loop */
		    break;
		xc->med_vp = VT;
		loop = jump = 1;
		break;
	    case 0xfa:		/* JWS */
		jws = VT;
		break;
	    case 0xf5:		/* EN2 */
	    case 0xf4:		/* EN1 */
		VT_SKIP;	/* Not implemented */
		break;
	    case 0xf3:		/* CHU */
		xc->med_vv = VT;
		break;
	    case 0xf2:		/* CHD */
		xc->med_vv = -VT;
		break;
	    case 0xf1:		/* WAI */
		xc->med_vw = VT;
		break;
	    case 0xf0:		/* SPD */
		xc->med_vs = VT;
		break;
	    default:
		if (b >= 0x00 && b <= 0x40)
		    xc->volume = b;
	    }
	}
skip_vol:

	if (xc->med_ww > 0) {
	    xc->med_ww--;
	    goto skip_wav;
	}

	jump = loop = jvs = 0;
	switch (b = WT) {
	    while (jump--) {
	    case 0xff:		/* END */
	    case 0xfb:		/* HLT */
		xc->med_wp--;
		break;
	    case 0xfe:		/* JMP */
		if (loop)	/* avoid infinite loop */
		    break;
		xc->med_wp = WT;
		loop = jump = 1;
		break;
	    case 0xfc:		/* ARP */
		while (WT != 0xfd);
		break;
	    case 0xfa:		/* JVS */
		jws = WT;
		break;
	    case 0xf7:		/* VWF */
		xc->y_type = WT;
		break;
	    case 0xf6:		/* RES */
		xc->period = xc->med_period;
		break;
	    case 0xf5:		/* VBS */
		xc->y_rate = WT;
		break;
	    case 0xf4:		/* VBD */
		xc->y_depth = WT;
		break;
	    case 0xf3:		/* CHU */
		xc->med_wv = -WT;
		break;
	    case 0xf2:		/* CHD */
		xc->med_wv = WT;
		break;
	    case 0xf1:		/* WAI */
		xc->med_ww = WT;
		break;
	    case 0xf0:		/* SPD */
		xc->med_ws = WT;
		break;
	    default:
		if (b < xxih[xc->ins].nsm && xxi[xc->ins][b].sid != xc->smp)
		    xmp_drv_setsmp (chn, xc->smp = xxi[xc->ins][b].sid);
	    }
	}
skip_wav:

	xc->volume += xc->med_vv;
	if (xc->volume < 0)
	    xc->volume = 0;
	if (xc->volume > 64)
	    xc->volume = 64;

	/* xc->period += xc->med_wv; */
    }

    if (jws) {
	xc->med_wp = jws;
	jws = 0;
    }

    if (jvs) {
	xc->med_vp = jvs;
	jvs = 0;
    }
}