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#ifndef lint
#ifdef sccs
static char sccsid[] = "@(#)rect.c 20.17 93/06/28 Copyr 1984 Sun Micro";
#endif
#endif
/*
* (c) Copyright 1989 Sun Microsystems, Inc. Sun design patents
* pending in the U.S. and foreign countries. See LEGAL NOTICE
* file for terms of the license.
*/
/*
* Overview: Implements the interface described by rect.h which defines
* the rectangle structure
*/
#include <stdio.h>
#include <xview_private/i18n_impl.h>
#include <xview/base.h> /* HUH? xv_error.h also does this */
#include <xview/rect.h>
#include <xview/xv_error.h>
/*
* Rect geometry functions
*/
rect_intersection(r1, r2, r)
register struct rect *r1, *r2, *r;
{
r->r_left = MAX(r1->r_left, r2->r_left);
r->r_top = MAX(r1->r_top, r2->r_top);
r->r_width = MIN(r1->r_left + r1->r_width, r2->r_left + r2->r_width) -
r->r_left;
if (r->r_width < 0)
r->r_width = 0;
r->r_height = MIN(r1->r_top + r1->r_height, r2->r_top + r2->r_height) -
r->r_top;
if (r->r_height < 0)
r->r_height = 0;
return;
}
unsigned
rect_clipvector(r, x1arg, y1arg, x2arg, y2arg)
register struct rect *r;
int *x1arg, *y1arg, *x2arg, *y2arg;
{ /* clip vector 1=>2 to r, return TRUE if
* visible. Cohen-Sutherland algorithm. */
register short x1 = *x1arg, y1 = *y1arg, x2 = *x2arg, y2 = *y2arg;
register char bits1, bits2, bits;
coord t, n, d, p;
unsigned done, accept;
done = FALSE;
do {
bits1 = 0;
if (y1 < r->r_top)
bits1 |= 1;
if (y1 > rect_bottom(r))
bits1 |= 2;
if (x1 > rect_right(r))
bits1 |= 4;
if (x1 < r->r_left)
bits1 |= 8;
bits2 = 0;
if (y2 < r->r_top)
bits2 |= 1;
if (y2 > rect_bottom(r))
bits2 |= 2;
if (x2 > rect_right(r))
bits2 |= 4;
if (x2 < r->r_left)
bits2 |= 8;
accept = ((bits1 | bits2) == 0);
if (accept)
done = TRUE; /* vector all inside clip volume */
else {
accept = ((bits1 & bits2) == 0);
if (!accept)
done = TRUE; /* vec all outside clip vol */
else { /* vector needs clip */
if (bits1 == 0) { /* make sure v1 is outside */
p = x1;
x1 = x2;
x2 = p;
p = y1;
y1 = y2;
y2 = p;
bits = bits1;
bits1 = bits2;
bits2 = bits;
}
if (bits1 & 1) {/* clip above */
n = (r->r_top - y1);
d = (y2 - y1);
t = (x2 - x1);
t *= n;
t /= d;
x1 = x1 + t;
y1 = r->r_top;
} else if (bits1 & 2) { /* clip below */
n = (rect_bottom(r) - y1);
d = (y2 - y1);
t = (x2 - x1);
t *= n;
t /= d;
x1 = x1 + t;
y1 = rect_bottom(r);
} else if (bits1 & 4) { /* clip right */
n = (rect_right(r) - x1);
d = (x2 - x1);
t = (y2 - y1);
t *= n;
t /= d;
y1 = y1 + t;
x1 = rect_right(r);
} else if (bits1 & 8) { /* clip r_left */
n = (r->r_left - x1);
d = (x2 - x1);
t = (y2 - y1);
t *= n;
t /= d;
y1 = y1 + t;
x1 = r->r_left;
}
}
}
} while (!done);
*x1arg = x1;
*y1arg = y1;
*x2arg = x2;
*y2arg = y2;
return (accept);
}
unsigned
rect_order(r1, r2, sortorder)
struct rect *r1, *r2;
int sortorder;
{ /* Return true if r1 & r2 are in the
* specified relationship. */
switch (sortorder) {
case RECTS_TOPTOBOTTOM:
if (r1->r_top <= r2->r_top)
return (TRUE);
break;
case RECTS_BOTTOMTOTOP:
if (rect_bottom(r1) >= rect_bottom(r2))
return (TRUE);
break;
case RECTS_LEFTTORIGHT:
if (r1->r_left <= r2->r_left)
return (TRUE);
break;
case RECTS_RIGHTTOLEFT:
if (rect_right(r1) >= rect_right(r2))
return (TRUE);
break;
case RECTS_UNSORTED:
return (TRUE);
break;
default:
xv_error(NULL,
ERROR_STRING,
XV_MSG("Bad sortorder arg in mostRect"),
0);
break;
}
return (FALSE);
}
struct rect
rect_bounding(r1, r2)
register struct rect *r1, *r2;
{
struct rect r;
if (rect_isnull(r1))
r = *r2;
else if (rect_isnull(r2))
r = *r1;
else {
r.r_left = MIN(r1->r_left, r2->r_left);
r.r_top = MIN(r1->r_top, r2->r_top);
r.r_width = MAX(r1->r_left + r1->r_width, r2->r_left + r2->r_width)
- r.r_left;
r.r_height = MAX(r1->r_top + r1->r_height, r2->r_top + r2->r_height)
- r.r_top;
}
return (r);
}
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