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From: bl@infovax.UUCP (Bj|rn Larsson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: pccurses v1.3 mvwin() problem
Message-ID: <307@infovax.UUCP>
Date: 11 Nov 89 23:38:26 GMT
References: <16679@dartvax.Dartmouth.EDU> <306@infovax.UUCP>
Reply-To: bl@infovax.UUCP (Bj|rn Larsson)
Organization: Infovox AB, SOLNA, Sweden
Lines: 175

In article <306@infovax.UUCP> bl@infovax.UUCP I write:
>In article <16679@dartvax.Dartmouth.EDU> pete@othello.dartmouth.edu (Pete Schmitt) writes:
>	<stuff deleted>
>Below is a modified version of the example, which works with pccurses.

Forget that! Just after posting I realized my example more or less emu-
lates overwrite(), not overlay(). Please no flames... instead I rewrote
the overlay/overwrite module to make it behave like Pete (and others)
wants. The revised version is for a (possibly) upcoming version 1.4.
I have not checked that it compiles, links and works correctly with the
1.3 package (I tested it with a 1.4a temporary version) but it should.
If there are any problems, they should not be worse than compiler
warnings. Just rebuild the pccurses libraries with the below overlay.c
module replacing the 1.3 version:

/****************************************************************/
/* Overlay() and overwrite() functions of the PCcurses package	*/
/*								*/
/****************************************************************/
/* This version of curses is based on ncurses, a curses version	*/
/* originally written by Pavel Curtis at Cornell University.	*/
/* I have made substantial changes to make it run on IBM PC's,	*/
/* and therefore consider myself free to make it public domain.	*/
/*		Bjorn Larsson (...mcvax!enea!infovax!bl)	*/
/****************************************************************/
/* 1.4b: Overlaying window will not line up with over-		*/
/*	 layed window's origin, but at it's 'own' origin	*/
/*	 relative to the overlayed's origin:		891111	*/
/* 1.4a: Portability improvements:			890408	*/
/* 1.3:	 MSC -W3, Turbo'C' -w -w-pro checks:		881005	*/
/* 1.2:	 Max limits off by 1. Fixed thanks to S. Creps:	881002	*/
/* 1.0:	 Release:					870515	*/
/****************************************************************/

#include <curses.h>
#include <curspriv.h>

char _curses_overlay_rcsid[] = "@(#)overlay.c    v.1.4b - 891111";

/****************************************************************/
/* Overlay() overwrites 'win1' upon 'win2', with 'win1' appea-	*/
/* ring in 'win2' at it own origin relative to 'win2's origin.	*/
/* This is a departure, but a desirable one, from the initial	*/
/* definition of this function. Overlay is transparent; blanks	*/
/* from 'win1' are not copied to 'win2'.			*/
/****************************************************************/

void overlay(win1, win2)
  WINDOW	*win1, *win2;
  {
  int		*minchng;
  int		*maxchng;
  int		*w1ptr;
  int		*w2ptr;
  int		 attrs;
  int		 col;
  int		 line;
  int		 last_line;
  int		 last_col;

  last_col = min(win1->_maxx + win1->_begx, win2->_maxx) - 1;
  last_line = min(win1->_maxy + win1->_begy, win2->_maxy) - 1;
  attrs = win2->_attrs & ATR_MSK;
  minchng = win2->_minchng + win1->_begy;
  maxchng = win2->_maxchng + win1->_begy;

  for(line = win1->_begy;  line <= last_line;  line++)
    {
    register short   fc, lc;

    w1ptr = win1->_line[line - win1->_begy];
    w2ptr = win2->_line[line] + win1->_begx;
    fc = _NO_CHANGE;

    for(col = win1->_begx;  col <= last_col;  col++)
      {
      if ((*w1ptr & CHR_MSK) != ' ')
	{
	*w2ptr = (*w1ptr & CHR_MSK) | attrs;
	if (fc == _NO_CHANGE)
	  fc = col;
	lc = col;
	} /* if */
      w1ptr++;
      w2ptr++;
      } /* for */

    if (*minchng == _NO_CHANGE)
      {
      *minchng = fc;
      *maxchng = lc;
      } /* if */
    else
      if (fc != _NO_CHANGE)
	{
	if (fc < *minchng)
	  *minchng = fc;
	if (lc > *maxchng)
	  *maxchng = lc;
	} /* else if */
    minchng++;
    maxchng++;
    } /* for */
  } /* overlay */

/****************************************************************/
/* Overwrite() overwrites 'win1' upon 'win2', with 'win1' ap-	*/
/* pearing in 'win2' at it own origin relative to 'win2's ori-	*/
/* gin. This is a departure, but a desirable one, from the	*/
/* initial definition of this function. Overwrite is non-trans-	*/
/* parent; blanks from 'win1' are copied to 'win2'.		*/
/****************************************************************/

void	overwrite(win1, win2)
  WINDOW	*win1, *win2;
  {
  int		*minchng;
  int		*maxchng;
  int		*w1ptr;
  int		*w2ptr;
  int		 attrs;
  int		 col;
  int		 line;
  int		 last_line;
  int		 last_col;

  last_col = min(win1->_maxx + win1->_begx, win2->_maxx) - 1;
  last_line = min(win1->_maxy + win1->_begy, win2->_maxy) - 1;
  attrs = win2->_attrs & ATR_MSK;
  minchng = win2->_minchng + win1->_begy;
  maxchng = win2->_maxchng + win1->_begy;

  for(line = win1->_begy;  line <= last_line;  line++)
    {
    register short   fc, lc;

    w1ptr = win1->_line[line - win1->_begy];
    w2ptr = win2->_line[line] + win1->_begx;
    fc = _NO_CHANGE;

    for(col = win1->_begx;  col <= last_col;  col++)
      {
      if ((*w1ptr & CHR_MSK) != (*w2ptr & CHR_MSK))
	{
	*w2ptr = (*w1ptr & CHR_MSK) | attrs;
	if (fc == _NO_CHANGE)
	  fc = col;
	lc = col;
	} /* if */
      w1ptr++;
      w2ptr++;
      } /* for */

    if (*minchng == _NO_CHANGE)
      {
      *minchng = fc;
      *maxchng = lc;
      } /* if */
    else
      if (fc != _NO_CHANGE)
	{
	if (fc < *minchng)
	  *minchng = fc;
	if (lc > *maxchng)
	  *maxchng = lc;
	} /* else if */
    minchng++;
    maxchng++;
    } /* for */
  } /* overwrite */
-- 
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