/*
   =============================================================================
	itcpos.c -- text cursor positioning for the instrument display
	Version 12 -- 1989-12-19 -- D.N. Lynx Crowe
   =============================================================================
*/

#include "ram.h"

#define	CW_0	0x0000
#define	CW_F	0xFFFF

static uint16_t itcur[] = {

	CW_0, CW_0, CW_0, CW_0,	/* 0 */
	CW_0, CW_0, CW_0, CW_0,	/* 1 */
	CW_0, CW_0, CW_0, CW_0,	/* 2 */
	CW_0, CW_0, CW_0, CW_0,	/* 3 */
	CW_0, CW_0, CW_0, CW_0,	/* 4 */
	CW_0, CW_0, CW_0, CW_0,	/* 5 */
	CW_0, CW_0, CW_0, CW_0,	/* 6 */
	CW_0, CW_0, CW_0, CW_0,	/* 7 */
	CW_0, CW_0, CW_0, CW_0,	/* 8 */
	CW_0, CW_0, CW_0, CW_0,	/* 9 */
	CW_0, CW_0, CW_0, CW_0,	/* 10 */
	CW_0, CW_0, CW_0, CW_0,	/* 11 */
	CW_F, CW_F, CW_0, CW_0,	/* 12 */
	CW_0, CW_0, CW_0, CW_0,	/* 13 */
	CW_0, CW_0, CW_0, CW_0,	/* 14 */
	CW_0, CW_0, CW_0, CW_0	/* 15 */
};

/*
   =============================================================================
	itcini() -- initialize instrument text cursor
   =============================================================================
*/

void itcini(int16_t color)
{
	if ((v_regs[5] & 0x0180) NE 0x0100)
		vbank(1);

	andcopy(v_cur, itcur, exp_c(color), 64);
}

/*
   =============================================================================
	itcpos() -- position the instrument text cursor at ('row', 'col')
   =============================================================================
*/

void itcpos(int16_t row, int16_t col)
{
	register int16_t yrow, xcol;
	register struct octent *op;

	if (v_regs[5] & 0x0180)		/* point at the control bank */
		vbank(0);

	yrow = row * 14;		/* get cursor display position */
	xcol = col * 8;

	op = &v_obtab[TCURS];		/* point at v_obtab entry */
	setipl(VID_DI);			/* disable Vertical Interval interrupt */
	v_odtab[TCPRI][0] &= ~V_BLA;	/* blank the object */
	objclr(TCPRI);			/* turn off the old location */

	op->objx = xcol;		/* update v_obtab entry */
	op->objy = yrow;
	op->obase = &v_cur[0];
	op->odtw1 = (uint16_t)(0x0400 | (0x03FF & (xcol >> 1)));

	SetPri(TCURS, TCPRI);		/* turn on the new location */

	stcrow = row;			/* update cursor position */
	stccol = col;
}

/*
   =============================================================================
	advicur() -- advance the instrument display text cursor
   =============================================================================
*/

void advicur(void)
{
	register int16_t newcol;

	if (infield(stcrow, stccol, curfet))
		cfetp = infetp;
	else
		return;

	newcol = stccol + 1;

	if (newcol LE cfetp->frcol)
		itcpos(stcrow, newcol);
}

/*
   =============================================================================
	bspicur() -- backspace the instrument display text cursor
   =============================================================================
*/

void bspicur(void)
{
	register int16_t newcol;

	if (infield(stcrow, stccol, curfet))
		cfetp = infetp;
	else
		return;

	newcol = stccol - 1;

	if (newcol GE cfetp->flcol)
		itcpos(stcrow, newcol);
}