/*
   =============================================================================
	ucslice.c -- update score display center slice
	Version 7 -- 1988-09-28 -- D.N. Lynx Crowe
   =============================================================================
*/

#undef	DEBUGGER

#include "debug.h"

#include "stddefs.h"
#include "slice.h"
#include "hwdefs.h"
#include "score.h"
#include "graphdef.h"
#include "vsdd.h"

#include "midas.h"
#include "scdsp.h"
#include "scfns.h"

/* variables defined elsewhere */

extern	uint16_t	*saddr;		/* score object base address */

extern	int16_t		ndisp;		/* current display number */
extern	int16_t		sd;		/* scroll direction flag */
extern	int16_t		soffset;	/* score object scroll offset */

extern	int16_t		gtctab[];	/* group to color table */
extern	int16_t		lintab1[];	/* note top line table - N_SHARP */
extern	int16_t		lintab2[];	/* note top line table - N_FLAT */
extern	int16_t		nbmasks[];	/* pixel mask table for slices */
extern	int16_t		nttab1[];	/* gdsel code transition table - fwd */
extern	int16_t		nttab2[];	/* gdsel code transition table - bak */

extern	uint16_t	pxtbl[][4];	/* pixel mask table - notes */
extern	uint16_t	epxtbl[][16];	/* pixel mask table - events */

extern	struct	gdsel	*gdfsep;	/* gdsel freechain pointer */

extern	struct	gdsel	*gdstbc[];	/* group status list heads */

/* 
*/

/*
   =============================================================================
	ucslice()

	Updates the center slice.

	Note transitions are based on the value of global variable 'sd',
	which is zero for forward, and non-zero for backward scrolling.

	Note colors come from 'gtctab[]'.

	This code must be very fast or the display bogs down the system.
   =============================================================================
*/

void ucslice(void)
{
	register uint16_t *pxptr, *slptr;
	register struct gdsel *gdsep;
	register int32_t lc;
	register uint16_t i, ncolor, mask1, mask2;
	uint16_t *ncptr, *nctabp;
	struct gdsel **gdstp, *gdprv, *gdnxt;
	int16_t *lintab;

	DB_ENTR("ucslice()");

	lc = 128L;
	mask1 = nbmasks[soffset];
	mask2 = ~mask1;

	/* initialize note color, note control, and group control pointers */

	gdstp = gdstbc;				/* group control table */
	nctabp = sd ? nttab2 : nttab1;		/* note transition table */
	ncptr = gtctab;				/* group to color table */

	lintab = (ac_code EQ N_SHARP) ? lintab1 : lintab2;	/* line table */

/* 
*/

	for (i = 0; i < 12; i++) {	/* scan the group control table ... */

		ncolor = mask1 & *ncptr++;	/* get note color mask */
		gdprv = (struct gdsel *)gdstp;	/* setup previous pointer */
		gdsep = *gdstp++;		/* setup current pointer */

		if (gdsep) {	/* ... process each active group ... */

			do {	/* ... for each note played by the group ... */

				if (ndisp EQ 2) {	/* ... if display is up */

					/* setup slice and pixel pointers */

					slptr = saddr + 64L +
						((int32_t)lintab[gdsep->note] << 7);

					pxptr = &pxtbl[gdsep->code][0];

					/* update the slice */

					*slptr = (*slptr & mask2) | (*pxptr++ & ncolor);
					slptr += lc;

					*slptr = (*slptr & mask2) | (*pxptr++ & ncolor);
					slptr += lc;

					*slptr = (*slptr & mask2) | (*pxptr++ & ncolor);

				}

				gdnxt = gdsep->next;	/* set 'next element' pointer */

				/* update and check element code */

				if (0 EQ (gdsep->code = nctabp[gdsep->code])) {

					/* if it's zero, delete the element */

					gdprv->next = gdnxt;
					gdsep->next = gdfsep;
					gdfsep = gdsep;

				} else
					gdprv = gdsep;

				gdsep = gdnxt;	/* set pointer for next pass */

			} while (gdsep);
		}
	}

/* 
*/
	for (; i < NGDSEL; i++) {

		gdprv = (struct gdsel *)gdstp;	/* setup previous pointer */
		gdsep = *gdstp++;		/* setup current pointer */

		if (gdsep) {	/* ... process each active event priority ... */

			do {	/* ... for each event of this priority  ... */

				if (ndisp EQ 2) {	/* ... if display is up */

					/* setup slice and pixel pointers */

					slptr = saddr + 27200L;
					pxptr = &epxtbl[gdsep->code][0];

					/* get event color */

					ncolor = mask1 & gdsep->note;

					/* update the slice */

					if (*pxptr++)  /* 212 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 213 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 214 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 215 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 216 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 217 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;
/* 
*/
					if (*pxptr++)  /* 218 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 219 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 220 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 221 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr++)  /* 222 */
						*slptr = (*slptr & mask2) | ncolor;

					slptr += lc;

					if (*pxptr)    /* 223 */
						*slptr = (*slptr & mask2) | ncolor;
				}

				gdnxt = gdsep->next;	/* set next pointer */
				gdprv->next = gdnxt;	/* delete the element */
				gdsep->next = gdfsep;
				gdfsep = gdsep;
				gdsep  = gdnxt;		/* set pointer for next pass */

			} while (gdsep);
		}
	}

	DB_EXIT("ucslice");
}