зеркало из https://github.com/mozilla/pjs.git
111 строки
3.3 KiB
C
111 строки
3.3 KiB
C
/* Libart_LGPL - library of basic graphic primitives
|
|
* Copyright (C) 1998-2000 Raph Levien
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Library General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library 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
|
|
* Library General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Library General Public
|
|
* License along with this library; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include "art_misc.h"
|
|
#include "art_uta.h"
|
|
#include "art_uta_ops.h"
|
|
|
|
#ifndef MIN
|
|
#define MIN(a,b) ((a) < (b) ? (a) : (b))
|
|
#endif
|
|
|
|
#ifndef MAX
|
|
#define MAX(a,b) ((a) > (b) ? (a) : (b))
|
|
#endif
|
|
|
|
/**
|
|
* art_uta_union: Compute union of two uta's.
|
|
* @uta1: One uta.
|
|
* @uta2: The other uta.
|
|
*
|
|
* Computes the union of @uta1 and @uta2. The union is approximate,
|
|
* but coverage is guaranteed over all pixels included in either of
|
|
* the arguments, ie more pixels may be covered than the "exact"
|
|
* union.
|
|
*
|
|
* Note: this routine is used in the Gnome Canvas to accumulate the
|
|
* region that needs to be repainted. However, since it copies over
|
|
* the entire uta (which might be largish) even when the update may be
|
|
* small, it can be a performance bottleneck. There are two approaches
|
|
* to this problem, both of which are probably worthwhile. First, the
|
|
* generated uta's should always be limited to the visible window,
|
|
* thus guaranteeing that uta's never become large. Second, there
|
|
* should be a new, destructive union operation that only touches a
|
|
* small part of the uta when the update is small.
|
|
*
|
|
* Return value: The new union uta.
|
|
**/
|
|
ArtUta *
|
|
art_uta_union (ArtUta *uta1, ArtUta *uta2)
|
|
{
|
|
ArtUta *uta;
|
|
int x0, y0, x1, y1;
|
|
int x, y;
|
|
int ix, ix1, ix2;
|
|
ArtUtaBbox bb, bb1, bb2;
|
|
|
|
x0 = MIN(uta1->x0, uta2->x0);
|
|
y0 = MIN(uta1->y0, uta2->y0);
|
|
x1 = MAX(uta1->x0 + uta1->width, uta2->x0 + uta2->width);
|
|
y1 = MAX(uta1->y0 + uta1->height, uta2->y0 + uta2->height);
|
|
uta = art_uta_new (x0, y0, x1, y1);
|
|
|
|
/* could move the first two if/else statements out of the loop */
|
|
ix = 0;
|
|
for (y = y0; y < y1; y++)
|
|
{
|
|
ix1 = (y - uta1->y0) * uta1->width + x0 - uta1->x0;
|
|
ix2 = (y - uta2->y0) * uta2->width + x0 - uta2->x0;
|
|
for (x = x0; x < x1; x++)
|
|
{
|
|
if (x < uta1->x0 || y < uta1->y0 ||
|
|
x >= uta1->x0 + uta1->width || y >= uta1->y0 + uta1->height)
|
|
bb1 = 0;
|
|
else
|
|
bb1 = uta1->utiles[ix1];
|
|
|
|
if (x < uta2->x0 || y < uta2->y0 ||
|
|
x >= uta2->x0 + uta2->width || y >= uta2->y0 + uta2->height)
|
|
bb2 = 0;
|
|
else
|
|
bb2 = uta2->utiles[ix2];
|
|
|
|
if (bb1 == 0)
|
|
bb = bb2;
|
|
else if (bb2 == 0)
|
|
bb = bb1;
|
|
else
|
|
bb = ART_UTA_BBOX_CONS(MIN(ART_UTA_BBOX_X0(bb1),
|
|
ART_UTA_BBOX_X0(bb2)),
|
|
MIN(ART_UTA_BBOX_Y0(bb1),
|
|
ART_UTA_BBOX_Y0(bb2)),
|
|
MAX(ART_UTA_BBOX_X1(bb1),
|
|
ART_UTA_BBOX_X1(bb2)),
|
|
MAX(ART_UTA_BBOX_Y1(bb1),
|
|
ART_UTA_BBOX_Y1(bb2)));
|
|
uta->utiles[ix] = bb;
|
|
ix++;
|
|
ix1++;
|
|
ix2++;
|
|
}
|
|
}
|
|
return uta;
|
|
}
|