[bpt/emacs.git] / src / cm.c

/* Cursor motion subroutines for GNU Emacs.
   Copyright (C) 1985, 1995, 2001-2012  Free Software Foundation, Inc.
    based primarily on public domain code written by Chris Torek

This file is part of GNU Emacs.

GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */


#include <config.h>
#include <stdio.h>
#include <setjmp.h>

#include "lisp.h"
#include "frame.h"
#include "cm.h"
#include "termhooks.h"
#include "termchar.h"
#include "tparam.h"

#define	BIG	9999		/* 9999 good on VAXen.  For 16 bit machines
				   use about 2000.... */

int cost;		/* sums up costs */

/* ARGSUSED */
int
evalcost (int c)
{
  cost++;
  return c;
}

/* The terminal to use for low-level output. */
struct tty_display_info *current_tty;

int
cmputc (int c)
{
  if (current_tty->termscript)
    putc (c & 0177, current_tty->termscript);
  putc (c & 0177, current_tty->output);
  return c;
}

/* NEXT TWO ARE DONE WITH MACROS */
#if 0
/*
 * Assume the cursor is at row row, column col.  Normally used only after
 * clearing the screen, when the cursor is at (0, 0), but what the heck,
 * let's let the guy put it anywhere.
 */

static
at (tty, row, col) {
  curY (tty) = row;
  curX (tty)  = col;
}

/*
 * Add n columns to the current cursor position.
 */

static
addcol (tty, n) {
  curX (tty) += n;

    /*
     * If cursor hit edge of screen, what happened?
     * N.B.: DO NOT!! write past edge of screen.  If you do, you
     * deserve what you get.  Furthermore, on terminals with
     * autowrap (but not magicwrap), don't write in the last column
     * of the last line.
     */

  if (curX (tty) == tty->Wcm->cm_cols) {
	/*
	 * Well, if magicwrap, still there, past the edge of the
	 * screen (!).  If autowrap, on the col 0 of the next line.
	 * Otherwise on last column.
	 */

	if (tty->Wcm->cm_magicwrap)
	    ;			/* "limbo" */
	else if (tty->Wcm->cm_autowrap) {
          curX (tty) = 0;
          curY (tty) ++;		/* Beware end of screen! */
	}
	else
          curX (tty)--;
    }
}
#endif

/*
 * Terminals with magicwrap (xn) don't all behave identically.
 * The VT100 leaves the cursor in the last column but will wrap before
 * printing the next character.  I hear that the Concept terminal does
 * the wrap immediately but ignores the next newline it sees.  And some
 * terminals just have buggy firmware, and think that the cursor is still
 * in limbo if we use direct cursor addressing from the phantom column.
 * The only guaranteed safe thing to do is to emit a CRLF immediately
 * after we reach the last column; this takes us to a known state.
 */
void
cmcheckmagic (struct tty_display_info *tty)
{
  if (curX (tty) == FrameCols (tty))
    {
      if (!MagicWrap (tty) || curY (tty) >= FrameRows (tty) - 1)
	emacs_abort ();
      if (tty->termscript)
	putc ('\r', tty->termscript);
      putc ('\r', tty->output);
      if (tty->termscript)
	putc ('\n', tty->termscript);
      putc ('\n', tty->output);
      curX (tty) = 0;
      curY (tty)++;
    }
}


/*
 * (Re)Initialize the cost factors, given the output speed of the terminal
 * in the variable ospeed.  (Note: this holds B300, B9600, etc -- ie stuff
 * out of <sgtty.h>.)
 */

void
cmcostinit (struct tty_display_info *tty)
{
    char *p;

#define	COST(x,e)	(x ? (cost = 0, tputs (x, 1, e), cost) : BIG)
#define CMCOST(x,e)	((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e)))

    tty->Wcm->cc_up =	 COST (tty->Wcm->cm_up, evalcost);
    tty->Wcm->cc_down =	 COST (tty->Wcm->cm_down, evalcost);
    tty->Wcm->cc_left =	 COST (tty->Wcm->cm_left, evalcost);
    tty->Wcm->cc_right = COST (tty->Wcm->cm_right, evalcost);
    tty->Wcm->cc_home =	 COST (tty->Wcm->cm_home, evalcost);
    tty->Wcm->cc_cr =	 COST (tty->Wcm->cm_cr, evalcost);
    tty->Wcm->cc_ll =	 COST (tty->Wcm->cm_ll, evalcost);
    tty->Wcm->cc_tab =	 tty->Wcm->cm_tabwidth ? COST (tty->Wcm->cm_tab, evalcost) : BIG;

    /*
     * These last three are actually minimum costs.  When (if) they are
     * candidates for the least-cost motion, the real cost is computed.
     * (Note that "0" is the assumed to generate the minimum cost.
     * While this is not necessarily true, I have yet to see a terminal
     * for which is not; all the terminals that have variable-cost
     * cursor motion seem to take straight numeric values.  --ACT)
     */

    tty->Wcm->cc_abs =  CMCOST (tty->Wcm->cm_abs, evalcost);
    tty->Wcm->cc_habs = CMCOST (tty->Wcm->cm_habs, evalcost);
    tty->Wcm->cc_vabs = CMCOST (tty->Wcm->cm_vabs, evalcost);

#undef CMCOST
#undef COST
}

/*
 * Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using
 * up and down, and left and right, motions, and tabs.  If doit is set
 * actually perform the motion.
 */

static int
calccost (struct tty_display_info *tty,
          int srcy, int srcx, int dsty, int dstx, int doit)
{
    register int    deltay,
                    deltax,
                    c,
                    totalcost;
    int     ntabs,
            n2tabs,
            tabx,
            tab2x,
            tabcost;
    register const char *p;

    /* If have just wrapped on a terminal with xn,
       don't believe the cursor position: give up here
       and force use of absolute positioning.  */

    if (curX (tty) == tty->Wcm->cm_cols)
      goto fail;

    totalcost = 0;
    if ((deltay = dsty - srcy) == 0)
	goto x;
    if (deltay < 0)
	p = tty->Wcm->cm_up, c = tty->Wcm->cc_up, deltay = -deltay;
    else
	p = tty->Wcm->cm_down, c = tty->Wcm->cc_down;
    if (c == BIG) {		/* caint get thar from here */
	if (doit)
	    printf ("OOPS");
	return c;
    }
    totalcost = c * deltay;
    if (doit)
      do
          emacs_tputs (tty, p, 1, cmputc);
      while (0 < --deltay);
x:
    if ((deltax = dstx - srcx) == 0)
	goto done;
    if (deltax < 0) {
	p = tty->Wcm->cm_left, c = tty->Wcm->cc_left, deltax = -deltax;
	goto dodelta;		/* skip all the tab junk */
    }
    /* Tabs (the toughie) */
    if (tty->Wcm->cc_tab >= BIG || !tty->Wcm->cm_usetabs)
	goto olddelta;		/* forget it! */

    /*
     * ntabs is # tabs towards but not past dstx; n2tabs is one more
     * (ie past dstx), but this is only valid if that is not past the
     * right edge of the screen.  We can check that at the same time
     * as we figure out where we would be if we use the tabs (which
     * we will put into tabx (for ntabs) and tab2x (for n2tabs)).
     */

    ntabs = (deltax + srcx % tty->Wcm->cm_tabwidth) / tty->Wcm->cm_tabwidth;
    n2tabs = ntabs + 1;
    tabx = (srcx / tty->Wcm->cm_tabwidth + ntabs) * tty->Wcm->cm_tabwidth;
    tab2x = tabx + tty->Wcm->cm_tabwidth;

    if (tab2x >= tty->Wcm->cm_cols)	/* too far (past edge) */
	n2tabs = 0;

    /*
     * Now set tabcost to the cost for using ntabs, and c to the cost
     * for using n2tabs, then pick the minimum.
     */

		   /* cost for ntabs           +    cost for right motion */
    tabcost = ntabs ? ntabs * tty->Wcm->cc_tab + (dstx - tabx) * tty->Wcm->cc_right
		    : BIG;

		   /* cost for n2tabs          +    cost for left motion */
    c = n2tabs  ?    n2tabs * tty->Wcm->cc_tab + (tab2x - dstx) * tty->Wcm->cc_left
		: BIG;

    if (c < tabcost)		/* then cheaper to overshoot & back up */
	ntabs = n2tabs, tabcost = c, tabx = tab2x;

    if (tabcost >= BIG)		/* caint use tabs */
	goto newdelta;

    /*
     * See if tabcost is less than just moving right
     */

    if (tabcost < (deltax * tty->Wcm->cc_right)) {
	totalcost += tabcost;	/* use the tabs */
	if (doit)
	    while (--ntabs >= 0)
              emacs_tputs (tty, tty->Wcm->cm_tab, 1, cmputc);
	srcx = tabx;
    }

    /*
     * Now might as well just recompute the delta.
     */

newdelta:
    if ((deltax = dstx - srcx) == 0)
	goto done;
olddelta:
    if (deltax > 0)
	p = tty->Wcm->cm_right, c = tty->Wcm->cc_right;
    else
	p = tty->Wcm->cm_left, c = tty->Wcm->cc_left, deltax = -deltax;

dodelta:
    if (c == BIG) {		/* caint get thar from here */
fail:
	if (doit)
	    printf ("OOPS");
	return BIG;
    }
    totalcost += c * deltax;
    if (doit)
      do
          emacs_tputs (tty, p, 1, cmputc);
      while (0 < --deltax);
done:
    return totalcost;
}

#if 0
void
losecursor (void)
{
  curY = -1;
}
#endif

#define	USEREL	0
#define	USEHOME	1
#define	USELL	2
#define	USECR	3

void
cmgoto (struct tty_display_info *tty, int row, int col)
{
    int     homecost,
            crcost,
            llcost,
            relcost,
            directcost;
    int     use IF_LINT (= 0);
    char *p;
    const char *dcm;

  /* First the degenerate case */
    if (row == curY (tty) && col == curX (tty)) /* already there */
    return;

    if (curY (tty) >= 0 && curX (tty) >= 0)
    {
      /* We may have quick ways to go to the upper-left, bottom-left,
       * start-of-line, or start-of-next-line.  Or it might be best to
       * start where we are.  Examine the options, and pick the cheapest.
       */

      relcost = calccost (tty, curY (tty), curX (tty), row, col, 0);
      use = USEREL;
      if ((homecost = tty->Wcm->cc_home) < BIG)
          homecost += calccost (tty, 0, 0, row, col, 0);
      if (homecost < relcost)
          relcost = homecost, use = USEHOME;
      if ((llcost = tty->Wcm->cc_ll) < BIG)
          llcost += calccost (tty, tty->Wcm->cm_rows - 1, 0, row, col, 0);
      if (llcost < relcost)
          relcost = llcost, use = USELL;
      if ((crcost = tty->Wcm->cc_cr) < BIG) {
	  if (tty->Wcm->cm_autolf)
            if (curY (tty) + 1 >= tty->Wcm->cm_rows)
                crcost = BIG;
	      else
                crcost += calccost (tty, curY (tty) + 1, 0, row, col, 0);
	  else
            crcost += calccost (tty, curY (tty), 0, row, col, 0);
      }
      if (crcost < relcost)
	  relcost = crcost, use = USECR;
      directcost = tty->Wcm->cc_abs, dcm = tty->Wcm->cm_abs;
      if (row == curY (tty) && tty->Wcm->cc_habs < BIG)
	  directcost = tty->Wcm->cc_habs, dcm = tty->Wcm->cm_habs;
      else if (col == curX (tty) && tty->Wcm->cc_vabs < BIG)
	  directcost = tty->Wcm->cc_vabs, dcm = tty->Wcm->cm_vabs;
    }
  else
    {
      directcost = 0, relcost = 100000;
      dcm = tty->Wcm->cm_abs;
    }

  /*
   * In the following comparison, the = in <= is because when the costs
   * are the same, it looks nicer (I think) to move directly there.
   */
  if (directcost <= relcost)
    {
      /* compute REAL direct cost */
      cost = 0;
      p = (dcm == tty->Wcm->cm_habs
           ? tgoto (dcm, row, col)
           : tgoto (dcm, col, row));
      emacs_tputs (tty, p, 1, evalcost);
      if (cost <= relcost)
	{	/* really is cheaper */
	  emacs_tputs (tty, p, 1, cmputc);
	  curY (tty) = row, curX (tty) = col;
	  return;
	}
    }

  switch (use)
    {
    case USEHOME:
      emacs_tputs (tty, tty->Wcm->cm_home, 1, cmputc);
      curY (tty) = 0, curX (tty) = 0;
      break;

    case USELL:
      emacs_tputs (tty, tty->Wcm->cm_ll, 1, cmputc);
      curY (tty) = tty->Wcm->cm_rows - 1, curX (tty) = 0;
      break;

    case USECR:
      emacs_tputs (tty, tty->Wcm->cm_cr, 1, cmputc);
      if (tty->Wcm->cm_autolf)
	curY (tty)++;
      curX (tty) = 0;
      break;
    }

  (void) calccost (tty, curY (tty), curX (tty), row, col, 1);
  curY (tty) = row, curX (tty) = col;
}

/* Clear out all terminal info.
   Used before copying into it the info on the actual terminal.
 */

void
Wcm_clear (struct tty_display_info *tty)
{
  memset (tty->Wcm, 0, sizeof (struct cm));
  UP = 0;
  BC = 0;
}

/*
 * Initialized stuff
 * Return 0 if can do CM.
 * Return -1 if cannot.
 * Return -2 if size not specified.
 */

int
Wcm_init (struct tty_display_info *tty)
{
#if 0
  if (tty->Wcm->cm_abs && !tty->Wcm->cm_ds)
    return 0;
#endif
  if (tty->Wcm->cm_abs)
    return 0;
  /* Require up and left, and, if no absolute, down and right */
  if (!tty->Wcm->cm_up || !tty->Wcm->cm_left)
    return - 1;
  if (!tty->Wcm->cm_abs && (!tty->Wcm->cm_down || !tty->Wcm->cm_right))
    return - 1;
  /* Check that we know the size of the screen.... */
  if (tty->Wcm->cm_rows <= 0 || tty->Wcm->cm_cols <= 0)
    return - 2;
  return 0;
}
Commit	Line	Data
d427b66a	1	/* Cursor motion subroutines for GNU Emacs.
acaf905b	2	Copyright (C) 1985, 1995, 2001-2012 Free Software Foundation, Inc.
d427b66a JB	3	based primarily on public domain code written by Chris Torek
	4
	5	This file is part of GNU Emacs.
	6
9ec0b715	7	GNU Emacs is free software: you can redistribute it and/or modify
d427b66a	8	it under the terms of the GNU General Public License as published by
9ec0b715 GM	9	the Free Software Foundation, either version 3 of the License, or
9ec0b715 GM	10	(at your option) any later version.
d427b66a JB	11
	12	GNU Emacs is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
9ec0b715	18	along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
d427b66a JB	19
d427b66a JB	20
18160b98	21	#include <config.h>
d427b66a	22	#include <stdio.h>
d7306fe6	23	#include <setjmp.h>
28d440ab	24
28d440ab KL	25	#include "lisp.h"
28d440ab KL	26	#include "frame.h"
d427b66a JB	27	#include "cm.h"
d427b66a JB	28	#include "termhooks.h"
28d440ab	29	#include "termchar.h"
af8a867c	30	#include "tparam.h"
bb10ca93	31
d427b66a JB	32	#define BIG 9999 /* 9999 good on VAXen. For 16 bit machines
	33	use about 2000.... */
	34
d427b66a JB	35	int cost; /* sums up costs */
	36
	37	/* ARGSUSED */
dfcf069d	38	int
d3da34e0	39	evalcost (int c)
d427b66a JB	40	{
d427b66a JB	41	cost++;
97f11a9d	42	return c;
d427b66a JB	43	}
d427b66a JB	44
28d440ab	45	/* The terminal to use for low-level output. */
28d7d09f	46	struct tty_display_info *current_tty;
28d440ab	47
dfcf069d	48	int
d3da34e0	49	cmputc (int c)
d427b66a	50	{
0b0d3e0b KL	51	if (current_tty->termscript)
	52	putc (c & 0177, current_tty->termscript);
	53	putc (c & 0177, current_tty->output);
97f11a9d	54	return c;
d427b66a JB	55	}
	56
	57	/* NEXT TWO ARE DONE WITH MACROS */
	58	#if 0
	59	/*
	60	* Assume the cursor is at row row, column col. Normally used only after
	61	* clearing the screen, when the cursor is at (0, 0), but what the heck,
	62	* let's let the guy put it anywhere.
	63	*/
	64
	65	static
fca177d4 KL	66	at (tty, row, col) {
	67	curY (tty) = row;
	68	curX (tty) = col;
d427b66a JB	69	}
	70
	71	/*
	72	* Add n columns to the current cursor position.
	73	*/
	74
	75	static
fca177d4 KL	76	addcol (tty, n) {
fca177d4 KL	77	curX (tty) += n;
d427b66a JB	78
	79	/*
	80	* If cursor hit edge of screen, what happened?
	81	* N.B.: DO NOT!! write past edge of screen. If you do, you
	82	* deserve what you get. Furthermore, on terminals with
	83	* autowrap (but not magicwrap), don't write in the last column
	84	* of the last line.
	85	*/
	86
fca177d4	87	if (curX (tty) == tty->Wcm->cm_cols) {
d427b66a JB	88	/*
	89	* Well, if magicwrap, still there, past the edge of the
	90	* screen (!). If autowrap, on the col 0 of the next line.
	91	* Otherwise on last column.
	92	*/
	93
fca177d4	94	if (tty->Wcm->cm_magicwrap)
d427b66a	95	; /* "limbo" */
fca177d4 KL	96	else if (tty->Wcm->cm_autowrap) {
	97	curX (tty) = 0;
	98	curY (tty) ++; /* Beware end of screen! */
d427b66a JB	99	}
d427b66a JB	100	else
fca177d4	101	curX (tty)--;
d427b66a JB	102	}
	103	}
	104	#endif
	105
902a3b86 KH	106	/*
	107	* Terminals with magicwrap (xn) don't all behave identically.
	108	* The VT100 leaves the cursor in the last column but will wrap before
	109	* printing the next character. I hear that the Concept terminal does
	110	* the wrap immediately but ignores the next newline it sees. And some
	111	* terminals just have buggy firmware, and think that the cursor is still
	112	* in limbo if we use direct cursor addressing from the phantom column.
	113	* The only guaranteed safe thing to do is to emit a CRLF immediately
	114	* after we reach the last column; this takes us to a known state.
	115	*/
	116	void
28d7d09f	117	cmcheckmagic (struct tty_display_info *tty)
902a3b86	118	{
6548cf00	119	if (curX (tty) == FrameCols (tty))
902a3b86	120	{
6548cf00	121	if (!MagicWrap (tty) \|\| curY (tty) >= FrameRows (tty) - 1)
1088b922	122	emacs_abort ();
0b0d3e0b KL	123	if (tty->termscript)
	124	putc ('\r', tty->termscript);
	125	putc ('\r', tty->output);
	126	if (tty->termscript)
	127	putc ('\n', tty->termscript);
	128	putc ('\n', tty->output);
6548cf00 KL	129	curX (tty) = 0;
6548cf00 KL	130	curY (tty)++;
902a3b86 KH	131	}
	132	}
	133
	134
d427b66a JB	135	/*
	136	* (Re)Initialize the cost factors, given the output speed of the terminal
	137	* in the variable ospeed. (Note: this holds B300, B9600, etc -- ie stuff
	138	* out of <sgtty.h>.)
	139	*/
	140
dfcf069d	141	void
28d7d09f	142	cmcostinit (struct tty_display_info *tty)
d427b66a JB	143	{
	144	char *p;
	145
	146	#define COST(x,e) (x ? (cost = 0, tputs (x, 1, e), cost) : BIG)
	147	#define CMCOST(x,e) ((x == 0) ? BIG : (p = tgoto(x, 0, 0), COST(p ,e)))
	148
6548cf00 KL	149	tty->Wcm->cc_up = COST (tty->Wcm->cm_up, evalcost);
	150	tty->Wcm->cc_down = COST (tty->Wcm->cm_down, evalcost);
	151	tty->Wcm->cc_left = COST (tty->Wcm->cm_left, evalcost);
	152	tty->Wcm->cc_right = COST (tty->Wcm->cm_right, evalcost);
	153	tty->Wcm->cc_home = COST (tty->Wcm->cm_home, evalcost);
	154	tty->Wcm->cc_cr = COST (tty->Wcm->cm_cr, evalcost);
	155	tty->Wcm->cc_ll = COST (tty->Wcm->cm_ll, evalcost);
	156	tty->Wcm->cc_tab = tty->Wcm->cm_tabwidth ? COST (tty->Wcm->cm_tab, evalcost) : BIG;
d427b66a JB	157
	158	/*
	159	* These last three are actually minimum costs. When (if) they are
	160	* candidates for the least-cost motion, the real cost is computed.
	161	* (Note that "0" is the assumed to generate the minimum cost.
	162	* While this is not necessarily true, I have yet to see a terminal
	163	* for which is not; all the terminals that have variable-cost
	164	* cursor motion seem to take straight numeric values. --ACT)
	165	*/
	166
6548cf00 KL	167	tty->Wcm->cc_abs = CMCOST (tty->Wcm->cm_abs, evalcost);
	168	tty->Wcm->cc_habs = CMCOST (tty->Wcm->cm_habs, evalcost);
	169	tty->Wcm->cc_vabs = CMCOST (tty->Wcm->cm_vabs, evalcost);
d427b66a JB	170
	171	#undef CMCOST
	172	#undef COST
	173	}
	174
	175	/*
	176	* Calculate the cost to move from (srcy, srcx) to (dsty, dstx) using
	177	* up and down, and left and right, motions, and tabs. If doit is set
	178	* actually perform the motion.
	179	*/
	180
dfcf069d	181	static int
28d7d09f KL	182	calccost (struct tty_display_info *tty,
28d7d09f KL	183	int srcy, int srcx, int dsty, int dstx, int doit)
d427b66a JB	184	{
	185	register int deltay,
	186	deltax,
	187	c,
	188	totalcost;
	189	int ntabs,
	190	n2tabs,
	191	tabx,
	192	tab2x,
	193	tabcost;
fbceeba2	194	register const char *p;
d427b66a JB	195
	196	/* If have just wrapped on a terminal with xn,
	197	don't believe the cursor position: give up here
	198	and force use of absolute positioning. */
	199
6548cf00	200	if (curX (tty) == tty->Wcm->cm_cols)
d427b66a JB	201	goto fail;
	202
	203	totalcost = 0;
	204	if ((deltay = dsty - srcy) == 0)
	205	goto x;
	206	if (deltay < 0)
6548cf00	207	p = tty->Wcm->cm_up, c = tty->Wcm->cc_up, deltay = -deltay;
d427b66a	208	else
6548cf00	209	p = tty->Wcm->cm_down, c = tty->Wcm->cc_down;
d427b66a JB	210	if (c == BIG) { /* caint get thar from here */
	211	if (doit)
	212	printf ("OOPS");
	213	return c;
	214	}
	215	totalcost = c * deltay;
	216	if (doit)
12ea59a2	217	do
28d440ab	218	emacs_tputs (tty, p, 1, cmputc);
12ea59a2	219	while (0 < --deltay);
177c0ea7	220	x:
d427b66a JB	221	if ((deltax = dstx - srcx) == 0)
	222	goto done;
	223	if (deltax < 0) {
6548cf00	224	p = tty->Wcm->cm_left, c = tty->Wcm->cc_left, deltax = -deltax;
d427b66a JB	225	goto dodelta; /* skip all the tab junk */
	226	}
	227	/* Tabs (the toughie) */
6548cf00	228	if (tty->Wcm->cc_tab >= BIG \|\| !tty->Wcm->cm_usetabs)
d427b66a JB	229	goto olddelta; /* forget it! */
d427b66a JB	230
177c0ea7	231	/*
d427b66a JB	232	* ntabs is # tabs towards but not past dstx; n2tabs is one more
	233	* (ie past dstx), but this is only valid if that is not past the
	234	* right edge of the screen. We can check that at the same time
	235	* as we figure out where we would be if we use the tabs (which
	236	* we will put into tabx (for ntabs) and tab2x (for n2tabs)).
	237	*/
	238
6548cf00	239	ntabs = (deltax + srcx % tty->Wcm->cm_tabwidth) / tty->Wcm->cm_tabwidth;
d427b66a	240	n2tabs = ntabs + 1;
6548cf00 KL	241	tabx = (srcx / tty->Wcm->cm_tabwidth + ntabs) * tty->Wcm->cm_tabwidth;
6548cf00 KL	242	tab2x = tabx + tty->Wcm->cm_tabwidth;
d427b66a	243
6548cf00	244	if (tab2x >= tty->Wcm->cm_cols) /* too far (past edge) */
d427b66a JB	245	n2tabs = 0;
d427b66a JB	246
177c0ea7	247	/*
d427b66a JB	248	* Now set tabcost to the cost for using ntabs, and c to the cost
	249	* for using n2tabs, then pick the minimum.
	250	*/
	251
c3b4957f	252	/* cost for ntabs + cost for right motion */
6548cf00	253	tabcost = ntabs ? ntabs * tty->Wcm->cc_tab + (dstx - tabx) * tty->Wcm->cc_right
d427b66a JB	254	: BIG;
d427b66a JB	255
c3b4957f	256	/* cost for n2tabs + cost for left motion */
6548cf00	257	c = n2tabs ? n2tabs * tty->Wcm->cc_tab + (tab2x - dstx) * tty->Wcm->cc_left
d427b66a JB	258	: BIG;
	259
	260	if (c < tabcost) /* then cheaper to overshoot & back up */
	261	ntabs = n2tabs, tabcost = c, tabx = tab2x;
	262
	263	if (tabcost >= BIG) /* caint use tabs */
	264	goto newdelta;
	265
177c0ea7	266	/*
d427b66a JB	267	* See if tabcost is less than just moving right
	268	*/
	269
6548cf00	270	if (tabcost < (deltax * tty->Wcm->cc_right)) {
d427b66a JB	271	totalcost += tabcost; /* use the tabs */
	272	if (doit)
	273	while (--ntabs >= 0)
6548cf00	274	emacs_tputs (tty, tty->Wcm->cm_tab, 1, cmputc);
d427b66a JB	275	srcx = tabx;
	276	}
	277
177c0ea7	278	/*
d427b66a JB	279	* Now might as well just recompute the delta.
	280	*/
	281
177c0ea7	282	newdelta:
d427b66a JB	283	if ((deltax = dstx - srcx) == 0)
d427b66a JB	284	goto done;
177c0ea7	285	olddelta:
d427b66a	286	if (deltax > 0)
6548cf00	287	p = tty->Wcm->cm_right, c = tty->Wcm->cc_right;
d427b66a	288	else
6548cf00	289	p = tty->Wcm->cm_left, c = tty->Wcm->cc_left, deltax = -deltax;
d427b66a	290
177c0ea7	291	dodelta:
d427b66a JB	292	if (c == BIG) { /* caint get thar from here */
	293	fail:
	294	if (doit)
	295	printf ("OOPS");
	296	return BIG;
	297	}
	298	totalcost += c * deltax;
	299	if (doit)
12ea59a2	300	do
28d440ab	301	emacs_tputs (tty, p, 1, cmputc);
12ea59a2	302	while (0 < --deltax);
177c0ea7	303	done:
d427b66a JB	304	return totalcost;
	305	}
	306
	307	#if 0
268c2c36 AS	308	void
268c2c36 AS	309	losecursor (void)
d427b66a JB	310	{
	311	curY = -1;
	312	}
	313	#endif
	314
	315	#define USEREL 0
	316	#define USEHOME 1
	317	#define USELL 2
	318	#define USECR 3
	319
dfcf069d	320	void
d3da34e0	321	cmgoto (struct tty_display_info *tty, int row, int col)
d427b66a JB	322	{
	323	int homecost,
	324	crcost,
	325	llcost,
	326	relcost,
	327	directcost;
6be7d3da	328	int use IF_LINT (= 0);
fbceeba2 PE	329	char *p;
fbceeba2 PE	330	const char *dcm;
d427b66a JB	331
d427b66a JB	332	/* First the degenerate case */
6548cf00	333	if (row == curY (tty) && col == curX (tty)) /* already there */
d427b66a JB	334	return;
d427b66a JB	335
6548cf00	336	if (curY (tty) >= 0 && curX (tty) >= 0)
d427b66a JB	337	{
	338	/* We may have quick ways to go to the upper-left, bottom-left,
	339	* start-of-line, or start-of-next-line. Or it might be best to
	340	* start where we are. Examine the options, and pick the cheapest.
	341	*/
	342
6548cf00	343	relcost = calccost (tty, curY (tty), curX (tty), row, col, 0);
d427b66a	344	use = USEREL;
6548cf00	345	if ((homecost = tty->Wcm->cc_home) < BIG)
28d440ab	346	homecost += calccost (tty, 0, 0, row, col, 0);
d427b66a	347	if (homecost < relcost)
28d440ab	348	relcost = homecost, use = USEHOME;
6548cf00 KL	349	if ((llcost = tty->Wcm->cc_ll) < BIG)
6548cf00 KL	350	llcost += calccost (tty, tty->Wcm->cm_rows - 1, 0, row, col, 0);
d427b66a	351	if (llcost < relcost)
28d440ab	352	relcost = llcost, use = USELL;
6548cf00 KL	353	if ((crcost = tty->Wcm->cc_cr) < BIG) {
	354	if (tty->Wcm->cm_autolf)
	355	if (curY (tty) + 1 >= tty->Wcm->cm_rows)
	356	crcost = BIG;
d427b66a	357	else
6548cf00	358	crcost += calccost (tty, curY (tty) + 1, 0, row, col, 0);
d427b66a	359	else
6548cf00	360	crcost += calccost (tty, curY (tty), 0, row, col, 0);
d427b66a JB	361	}
	362	if (crcost < relcost)
	363	relcost = crcost, use = USECR;
6548cf00 KL	364	directcost = tty->Wcm->cc_abs, dcm = tty->Wcm->cm_abs;
	365	if (row == curY (tty) && tty->Wcm->cc_habs < BIG)
	366	directcost = tty->Wcm->cc_habs, dcm = tty->Wcm->cm_habs;
	367	else if (col == curX (tty) && tty->Wcm->cc_vabs < BIG)
	368	directcost = tty->Wcm->cc_vabs, dcm = tty->Wcm->cm_vabs;
d427b66a JB	369	}
	370	else
	371	{
	372	directcost = 0, relcost = 100000;
6548cf00	373	dcm = tty->Wcm->cm_abs;
d427b66a JB	374	}
d427b66a JB	375
177c0ea7	376	/*
d427b66a JB	377	* In the following comparison, the = in <= is because when the costs
	378	* are the same, it looks nicer (I think) to move directly there.
	379	*/
	380	if (directcost <= relcost)
	381	{
	382	/* compute REAL direct cost */
	383	cost = 0;
c3b4957f KL	384	p = (dcm == tty->Wcm->cm_habs
	385	? tgoto (dcm, row, col)
	386	: tgoto (dcm, col, row));
28d440ab	387	emacs_tputs (tty, p, 1, evalcost);
d427b66a JB	388	if (cost <= relcost)
d427b66a JB	389	{ /* really is cheaper */
28d440ab	390	emacs_tputs (tty, p, 1, cmputc);
6548cf00	391	curY (tty) = row, curX (tty) = col;
d427b66a JB	392	return;
	393	}
	394	}
	395
	396	switch (use)
	397	{
177c0ea7	398	case USEHOME:
6548cf00 KL	399	emacs_tputs (tty, tty->Wcm->cm_home, 1, cmputc);
6548cf00 KL	400	curY (tty) = 0, curX (tty) = 0;
d427b66a JB	401	break;
d427b66a JB	402
177c0ea7	403	case USELL:
6548cf00 KL	404	emacs_tputs (tty, tty->Wcm->cm_ll, 1, cmputc);
6548cf00 KL	405	curY (tty) = tty->Wcm->cm_rows - 1, curX (tty) = 0;
d427b66a JB	406	break;
d427b66a JB	407
177c0ea7	408	case USECR:
6548cf00 KL	409	emacs_tputs (tty, tty->Wcm->cm_cr, 1, cmputc);
	410	if (tty->Wcm->cm_autolf)
	411	curY (tty)++;
	412	curX (tty) = 0;
d427b66a JB	413	break;
	414	}
	415
6548cf00 KL	416	(void) calccost (tty, curY (tty), curX (tty), row, col, 1);
6548cf00 KL	417	curY (tty) = row, curX (tty) = col;
d427b66a JB	418	}
	419
	420	/* Clear out all terminal info.
	421	Used before copying into it the info on the actual terminal.
	422	*/
	423
dfcf069d	424	void
28d7d09f	425	Wcm_clear (struct tty_display_info *tty)
d427b66a	426	{
72af86bd	427	memset (tty->Wcm, 0, sizeof (struct cm));
d427b66a JB	428	UP = 0;
	429	BC = 0;
	430	}
	431
	432	/*
	433	* Initialized stuff
	434	* Return 0 if can do CM.
	435	* Return -1 if cannot.
	436	* Return -2 if size not specified.
	437	*/
	438
dfcf069d	439	int
28d7d09f	440	Wcm_init (struct tty_display_info *tty)
d427b66a JB	441	{
d427b66a JB	442	#if 0
6548cf00	443	if (tty->Wcm->cm_abs && !tty->Wcm->cm_ds)
d427b66a JB	444	return 0;
d427b66a JB	445	#endif
6548cf00	446	if (tty->Wcm->cm_abs)
d427b66a JB	447	return 0;
d427b66a JB	448	/* Require up and left, and, if no absolute, down and right */
6548cf00	449	if (!tty->Wcm->cm_up \|\| !tty->Wcm->cm_left)
d427b66a	450	return - 1;
6548cf00	451	if (!tty->Wcm->cm_abs && (!tty->Wcm->cm_down \|\| !tty->Wcm->cm_right))
d427b66a JB	452	return - 1;
d427b66a JB	453	/* Check that we know the size of the screen.... */
6548cf00	454	if (tty->Wcm->cm_rows <= 0 \|\| tty->Wcm->cm_cols <= 0)
d427b66a JB	455	return - 2;
	456	return 0;
	457	}