Category : C Source Code
Archive   : PCURSE14.ZIP
Filename : OVERLAY.C

/****************************************************************/
/* 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 ([email protected]) */
/****************************************************************/
/* 1.4: Overlaying window will not line up with over- */
/* layed window's origin, but at it's 'own' origin */
/* relative to the overlayed's origin. Use of short */
/* wherever possible. Portability improvements: 900114 */
/* 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
#include

char _curses_overlay_rcsid[] = "@(#)overlay.c v.1.4 - 900114";

/****************************************************************/
/* 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;
{
short *minchng;
short *maxchng;
short *w1ptr;
short *w2ptr;
short attrs;
short col;
short line;
short last_line;
short 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;
{
short *minchng;
short *maxchng;
short *w1ptr;
short *w2ptr;
short attrs;
short col;
short line;
short last_line;
short 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 */