812 lines
25 KiB
C
812 lines
25 KiB
C
/*
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* Server-side region objects. Based on the X11 implementation.
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*
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* Copyright 1993, 1994, 1995, 2004 Alexandre Julliard
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* Modifications and additions: Copyright 1998 Huw Davies
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* 1999 Alex Korobka
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Note:
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* This is a simplified version of the code, without all the explanations.
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* Check the equivalent GDI code to make sense of it.
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*/
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/************************************************************************
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Copyright (c) 1987, 1988 X Consortium
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Permission is hereby granted, free of charge, to any person obtaining a copy
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of this software and associated documentation files (the "Software"), to deal
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in the Software without restriction, including without limitation the rights
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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the Software is
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furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
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AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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Except as contained in this notice, the name of the X Consortium shall not be
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used in advertising or otherwise to promote the sale, use or other dealings
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in this Software without prior written authorization from the X Consortium.
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Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts.
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All Rights Reserved
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Permission to use, copy, modify, and distribute this software and its
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documentation for any purpose and without fee is hereby granted,
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provided that the above copyright notice appear in all copies and that
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both that copyright notice and this permission notice appear in
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supporting documentation, and that the name of Digital not be
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used in advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
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ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
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DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
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ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
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WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
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ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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SOFTWARE.
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************************************************************************/
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#include <stdarg.h>
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#include <stdlib.h>
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#include <string.h>
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#include "request.h"
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#include "user.h"
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struct region
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{
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int size;
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int num_rects;
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rectangle_t *rects;
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rectangle_t extents;
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};
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#define RGN_DEFAULT_RECTS 2
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#define EXTENTCHECK(r1, r2) \
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((r1)->right > (r2)->left && \
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(r1)->left < (r2)->right && \
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(r1)->bottom > (r2)->top && \
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(r1)->top < (r2)->bottom)
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typedef int (*overlap_func_t)( struct region *reg, const rectangle_t *r1, const rectangle_t *r1End,
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const rectangle_t *r2, const rectangle_t *r2End, int top, int bottom );
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typedef int (*non_overlap_func_t)( struct region *reg, const rectangle_t *r,
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const rectangle_t *rEnd, int top, int bottom );
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static const rectangle_t empty_rect; /* all-zero rectangle for empty regions */
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/* add a rectangle to a region */
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static inline rectangle_t *add_rect( struct region *reg )
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{
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if (reg->num_rects >= reg->size - 1)
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{
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rectangle_t *new_rect = realloc( reg->rects, 2 * sizeof(rectangle_t) * reg->size );
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if (!new_rect)
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{
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set_error( STATUS_NO_MEMORY );
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return 0;
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}
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reg->rects = new_rect;
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reg->size *= 2;
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}
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return reg->rects + reg->num_rects++;
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}
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/* make sure all the rectangles are valid and that the region is properly y-x-banded */
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static inline int validate_rectangles( const rectangle_t *rects, unsigned int nb_rects )
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{
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const rectangle_t *ptr, *end;
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for (ptr = rects, end = rects + nb_rects; ptr < end; ptr++)
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{
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if (ptr->left >= ptr->right || ptr->top >= ptr->bottom) return 0; /* empty rectangle */
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if (ptr == end - 1) break;
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if (ptr[0].top == ptr[1].top) /* same band */
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{
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if (ptr[0].bottom != ptr[1].bottom) return 0; /* not same y extent */
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if (ptr[0].right >= ptr[1].left) return 0; /* not properly x ordered */
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}
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else /* new band */
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{
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if (ptr[0].bottom > ptr[1].top) return 0; /* not properly y ordered */
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}
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}
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return 1;
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}
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/* attempt to merge the rects in the current band with those in the */
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/* previous one. Used only by region_op. */
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static int coalesce_region( struct region *pReg, int prevStart, int curStart )
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{
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int curNumRects;
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rectangle_t *pRegEnd = &pReg->rects[pReg->num_rects];
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rectangle_t *pPrevRect = &pReg->rects[prevStart];
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rectangle_t *pCurRect = &pReg->rects[curStart];
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int prevNumRects = curStart - prevStart;
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int bandtop = pCurRect->top;
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for (curNumRects = 0;
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(pCurRect != pRegEnd) && (pCurRect->top == bandtop);
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curNumRects++)
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{
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pCurRect++;
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}
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if (pCurRect != pRegEnd)
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{
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pRegEnd--;
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while (pRegEnd[-1].top == pRegEnd->top) pRegEnd--;
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curStart = pRegEnd - pReg->rects;
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pRegEnd = pReg->rects + pReg->num_rects;
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}
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if ((curNumRects == prevNumRects) && (curNumRects != 0))
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{
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pCurRect -= curNumRects;
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if (pPrevRect->bottom == pCurRect->top)
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{
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do
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{
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if ((pPrevRect->left != pCurRect->left) ||
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(pPrevRect->right != pCurRect->right)) return curStart;
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pPrevRect++;
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pCurRect++;
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prevNumRects -= 1;
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} while (prevNumRects != 0);
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pReg->num_rects -= curNumRects;
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pCurRect -= curNumRects;
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pPrevRect -= curNumRects;
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do
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{
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pPrevRect->bottom = pCurRect->bottom;
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pPrevRect++;
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pCurRect++;
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curNumRects -= 1;
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} while (curNumRects != 0);
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if (pCurRect == pRegEnd) curStart = prevStart;
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else do { *pPrevRect++ = *pCurRect++; } while (pCurRect != pRegEnd);
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}
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}
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return curStart;
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}
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/* apply an operation to two regions */
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/* check the GDI version of the code for explanations */
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static int region_op( struct region *newReg, const struct region *reg1, const struct region *reg2,
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overlap_func_t overlap_func,
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non_overlap_func_t non_overlap1_func,
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non_overlap_func_t non_overlap2_func )
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{
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int ybot, ytop, top, bot, prevBand, curBand;
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const rectangle_t *r1BandEnd, *r2BandEnd;
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const rectangle_t *r1 = reg1->rects;
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const rectangle_t *r2 = reg2->rects;
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const rectangle_t *r1End = r1 + reg1->num_rects;
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const rectangle_t *r2End = r2 + reg2->num_rects;
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rectangle_t *new_rects, *old_rects = newReg->rects;
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int new_size, ret = 0;
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new_size = max( reg1->num_rects, reg2->num_rects ) * 2;
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if (!(new_rects = mem_alloc( new_size * sizeof(*newReg->rects) ))) return 0;
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newReg->size = new_size;
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newReg->rects = new_rects;
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newReg->num_rects = 0;
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if (reg1->extents.top < reg2->extents.top)
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ybot = reg1->extents.top;
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else
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ybot = reg2->extents.top;
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prevBand = 0;
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do
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{
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curBand = newReg->num_rects;
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r1BandEnd = r1;
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while ((r1BandEnd != r1End) && (r1BandEnd->top == r1->top)) r1BandEnd++;
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r2BandEnd = r2;
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while ((r2BandEnd != r2End) && (r2BandEnd->top == r2->top)) r2BandEnd++;
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if (r1->top < r2->top)
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{
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top = max(r1->top,ybot);
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bot = min(r1->bottom,r2->top);
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if ((top != bot) && non_overlap1_func)
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{
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if (!non_overlap1_func( newReg, r1, r1BandEnd, top, bot )) goto done;
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}
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ytop = r2->top;
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}
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else if (r2->top < r1->top)
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{
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top = max(r2->top,ybot);
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bot = min(r2->bottom,r1->top);
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if ((top != bot) && non_overlap2_func)
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{
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if (!non_overlap2_func( newReg, r2, r2BandEnd, top, bot )) goto done;
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}
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ytop = r1->top;
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}
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else
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{
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ytop = r1->top;
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}
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if (newReg->num_rects != curBand)
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prevBand = coalesce_region(newReg, prevBand, curBand);
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ybot = min(r1->bottom, r2->bottom);
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curBand = newReg->num_rects;
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if (ybot > ytop)
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{
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if (!overlap_func( newReg, r1, r1BandEnd, r2, r2BandEnd, ytop, ybot )) goto done;
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}
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if (newReg->num_rects != curBand)
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prevBand = coalesce_region(newReg, prevBand, curBand);
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if (r1->bottom == ybot) r1 = r1BandEnd;
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if (r2->bottom == ybot) r2 = r2BandEnd;
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} while ((r1 != r1End) && (r2 != r2End));
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curBand = newReg->num_rects;
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if (r1 != r1End)
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{
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if (non_overlap1_func)
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{
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do
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{
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r1BandEnd = r1;
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while ((r1BandEnd < r1End) && (r1BandEnd->top == r1->top)) r1BandEnd++;
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if (!non_overlap1_func( newReg, r1, r1BandEnd, max(r1->top,ybot), r1->bottom ))
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goto done;
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r1 = r1BandEnd;
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} while (r1 != r1End);
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}
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}
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else if ((r2 != r2End) && non_overlap2_func)
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{
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do
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{
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r2BandEnd = r2;
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while ((r2BandEnd < r2End) && (r2BandEnd->top == r2->top)) r2BandEnd++;
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if (!non_overlap2_func( newReg, r2, r2BandEnd, max(r2->top,ybot), r2->bottom ))
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goto done;
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r2 = r2BandEnd;
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} while (r2 != r2End);
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}
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if (newReg->num_rects != curBand) coalesce_region(newReg, prevBand, curBand);
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if ((newReg->num_rects < (newReg->size / 2)) && (newReg->size > 2))
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{
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new_size = max( newReg->num_rects, RGN_DEFAULT_RECTS );
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if ((new_rects = realloc( newReg->rects, sizeof(*newReg->rects) * new_size )))
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{
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newReg->rects = new_rects;
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newReg->size = new_size;
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}
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}
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ret = 1;
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done:
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free( old_rects );
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return ret;
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}
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/* recalculate the extents of a region */
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static void set_region_extents( struct region *region )
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{
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rectangle_t *pRect, *pRectEnd;
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if (region->num_rects == 0)
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{
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region->extents.left = 0;
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region->extents.top = 0;
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region->extents.right = 0;
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region->extents.bottom = 0;
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return;
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}
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pRect = region->rects;
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pRectEnd = &pRect[region->num_rects - 1];
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region->extents.left = pRect->left;
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region->extents.top = pRect->top;
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region->extents.right = pRectEnd->right;
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region->extents.bottom = pRectEnd->bottom;
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while (pRect <= pRectEnd)
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{
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if (pRect->left < region->extents.left) region->extents.left = pRect->left;
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if (pRect->right > region->extents.right) region->extents.right = pRect->right;
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pRect++;
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}
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}
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/* handle an overlapping band for intersect_region */
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static int intersect_overlapping( struct region *pReg,
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const rectangle_t *r1, const rectangle_t *r1End,
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const rectangle_t *r2, const rectangle_t *r2End,
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int top, int bottom )
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{
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int left, right;
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while ((r1 != r1End) && (r2 != r2End))
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{
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left = max(r1->left, r2->left);
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right = min(r1->right, r2->right);
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if (left < right)
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{
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rectangle_t *rect = add_rect( pReg );
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if (!rect) return 0;
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rect->left = left;
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rect->top = top;
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rect->right = right;
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rect->bottom = bottom;
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}
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if (r1->right < r2->right) r1++;
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else if (r2->right < r1->right) r2++;
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else
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{
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r1++;
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r2++;
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}
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}
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return 1;
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}
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/* handle a non-overlapping band for subtract_region */
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static int subtract_non_overlapping( struct region *pReg, const rectangle_t *r,
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const rectangle_t *rEnd, int top, int bottom )
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{
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while (r != rEnd)
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{
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rectangle_t *rect = add_rect( pReg );
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if (!rect) return 0;
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rect->left = r->left;
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rect->top = top;
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rect->right = r->right;
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rect->bottom = bottom;
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r++;
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}
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return 1;
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}
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/* handle an overlapping band for subtract_region */
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static int subtract_overlapping( struct region *pReg,
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const rectangle_t *r1, const rectangle_t *r1End,
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const rectangle_t *r2, const rectangle_t *r2End,
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int top, int bottom )
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{
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int left = r1->left;
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while ((r1 != r1End) && (r2 != r2End))
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{
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if (r2->right <= left) r2++;
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else if (r2->left <= left)
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{
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left = r2->right;
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if (left >= r1->right)
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{
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r1++;
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if (r1 != r1End)
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left = r1->left;
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}
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else r2++;
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}
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else if (r2->left < r1->right)
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{
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rectangle_t *rect = add_rect( pReg );
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if (!rect) return 0;
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rect->left = left;
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rect->top = top;
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rect->right = r2->left;
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rect->bottom = bottom;
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left = r2->right;
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if (left >= r1->right)
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{
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r1++;
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if (r1 != r1End)
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left = r1->left;
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}
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else r2++;
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}
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else
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{
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if (r1->right > left)
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{
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rectangle_t *rect = add_rect( pReg );
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if (!rect) return 0;
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rect->left = left;
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rect->top = top;
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rect->right = r1->right;
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rect->bottom = bottom;
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}
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r1++;
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left = r1->left;
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}
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}
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while (r1 != r1End)
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{
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rectangle_t *rect = add_rect( pReg );
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if (!rect) return 0;
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rect->left = left;
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rect->top = top;
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rect->right = r1->right;
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rect->bottom = bottom;
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r1++;
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if (r1 != r1End) left = r1->left;
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}
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return 1;
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}
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/* handle a non-overlapping band for union_region */
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static int union_non_overlapping( struct region *pReg, const rectangle_t *r,
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const rectangle_t *rEnd, int top, int bottom )
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{
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while (r != rEnd)
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{
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rectangle_t *rect = add_rect( pReg );
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if (!rect) return 0;
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rect->left = r->left;
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rect->top = top;
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rect->right = r->right;
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rect->bottom = bottom;
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r++;
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}
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return 1;
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}
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/* handle an overlapping band for union_region */
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static int union_overlapping( struct region *pReg,
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const rectangle_t *r1, const rectangle_t *r1End,
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const rectangle_t *r2, const rectangle_t *r2End,
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int top, int bottom )
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{
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#define MERGERECT(r) \
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if ((pReg->num_rects != 0) && \
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(pReg->rects[pReg->num_rects-1].top == top) && \
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(pReg->rects[pReg->num_rects-1].bottom == bottom) && \
|
|
(pReg->rects[pReg->num_rects-1].right >= r->left)) \
|
|
{ \
|
|
if (pReg->rects[pReg->num_rects-1].right < r->right) \
|
|
{ \
|
|
pReg->rects[pReg->num_rects-1].right = r->right; \
|
|
} \
|
|
} \
|
|
else \
|
|
{ \
|
|
rectangle_t *rect = add_rect( pReg ); \
|
|
if (!rect) return 0; \
|
|
rect->top = top; \
|
|
rect->bottom = bottom; \
|
|
rect->left = r->left; \
|
|
rect->right = r->right; \
|
|
} \
|
|
r++;
|
|
|
|
while ((r1 != r1End) && (r2 != r2End))
|
|
{
|
|
if (r1->left < r2->left)
|
|
{
|
|
MERGERECT(r1);
|
|
}
|
|
else
|
|
{
|
|
MERGERECT(r2);
|
|
}
|
|
}
|
|
|
|
if (r1 != r1End)
|
|
{
|
|
do
|
|
{
|
|
MERGERECT(r1);
|
|
} while (r1 != r1End);
|
|
}
|
|
else while (r2 != r2End)
|
|
{
|
|
MERGERECT(r2);
|
|
}
|
|
return 1;
|
|
#undef MERGERECT
|
|
}
|
|
|
|
|
|
/* create a region from an array of rectangles */
|
|
struct region *create_region( const rectangle_t *rects, unsigned int nb_rects )
|
|
{
|
|
struct region *region;
|
|
unsigned int size = max( nb_rects, RGN_DEFAULT_RECTS );
|
|
|
|
if (!validate_rectangles( rects, nb_rects ))
|
|
{
|
|
set_error( STATUS_INVALID_PARAMETER );
|
|
return NULL;
|
|
}
|
|
if (!(region = mem_alloc( sizeof(*region) ))) return NULL;
|
|
if (!(region->rects = mem_alloc( size * sizeof(*region->rects) )))
|
|
{
|
|
free( region );
|
|
return NULL;
|
|
}
|
|
region->size = size;
|
|
region->num_rects = nb_rects;
|
|
memcpy( region->rects, rects, nb_rects * sizeof(*rects) );
|
|
set_region_extents( region );
|
|
return region;
|
|
}
|
|
|
|
/* create a region from request data */
|
|
struct region *create_region_from_req_data( const void *data, size_t size )
|
|
{
|
|
const rectangle_t *rects = data;
|
|
int nb_rects = size / sizeof(rectangle_t);
|
|
|
|
/* special case: empty region can be specified by a single all-zero rectangle */
|
|
if (nb_rects == 1 && !memcmp( rects, &empty_rect, sizeof(empty_rect) )) nb_rects = 0;
|
|
return create_region( rects, nb_rects );
|
|
}
|
|
|
|
/* free a region */
|
|
void free_region( struct region *region )
|
|
{
|
|
free( region->rects );
|
|
free( region );
|
|
}
|
|
|
|
/* set region to a simple rectangle */
|
|
void set_region_rect( struct region *region, const rectangle_t *rect )
|
|
{
|
|
if (rect->left < rect->right && rect->top < rect->bottom)
|
|
{
|
|
region->num_rects = 1;
|
|
region->rects[0] = region->extents = *rect;
|
|
}
|
|
else
|
|
{
|
|
region->num_rects = 0;
|
|
region->extents.left = 0;
|
|
region->extents.top = 0;
|
|
region->extents.right = 0;
|
|
region->extents.bottom = 0;
|
|
}
|
|
}
|
|
|
|
/* retrieve the region data for sending to the client */
|
|
rectangle_t *get_region_data( const struct region *region, size_t *total_size )
|
|
{
|
|
if (!(*total_size = region->num_rects * sizeof(rectangle_t)))
|
|
{
|
|
/* return a single empty rect for empty regions */
|
|
*total_size = sizeof(empty_rect);
|
|
return memdup( &empty_rect, sizeof(empty_rect) );
|
|
}
|
|
return memdup( region->rects, *total_size );
|
|
}
|
|
|
|
/* retrieve the region data for sending to the client and free the region at the same time */
|
|
rectangle_t *get_region_data_and_free( struct region *region, size_t *total_size )
|
|
{
|
|
rectangle_t *ret = region->rects;
|
|
|
|
if (!(*total_size = region->num_rects * sizeof(rectangle_t)))
|
|
{
|
|
/* return a single empty rect for empty regions */
|
|
*total_size = sizeof(empty_rect);
|
|
ret = memdup( &empty_rect, sizeof(empty_rect) );
|
|
}
|
|
free( region );
|
|
return ret;
|
|
}
|
|
|
|
/* check if a given region is empty */
|
|
int is_region_empty( const struct region *region )
|
|
{
|
|
return region->num_rects == 0;
|
|
}
|
|
|
|
|
|
/* get the extents rect of a region */
|
|
void get_region_extents( const struct region *region, rectangle_t *rect )
|
|
{
|
|
*rect = region->extents;
|
|
}
|
|
|
|
/* add an offset to a region */
|
|
void offset_region( struct region *region, int x, int y )
|
|
{
|
|
rectangle_t *rect, *end;
|
|
|
|
for (rect = region->rects, end = rect + region->num_rects; rect < end; rect++)
|
|
{
|
|
rect->left += x;
|
|
rect->right += x;
|
|
rect->top += y;
|
|
rect->bottom += y;
|
|
}
|
|
region->extents.left += x;
|
|
region->extents.right += x;
|
|
region->extents.top += y;
|
|
region->extents.bottom += y;
|
|
}
|
|
|
|
/* make a copy of a region; returns dst or NULL on error */
|
|
struct region *copy_region( struct region *dst, const struct region *src )
|
|
{
|
|
if (dst == src) return dst;
|
|
|
|
if (dst->size < src->num_rects)
|
|
{
|
|
rectangle_t *rect = realloc( dst->rects, src->num_rects * sizeof(*rect) );
|
|
if (!rect)
|
|
{
|
|
set_error( STATUS_NO_MEMORY );
|
|
return NULL;
|
|
}
|
|
dst->rects = rect;
|
|
dst->size = src->num_rects;
|
|
}
|
|
dst->num_rects = src->num_rects;
|
|
dst->extents = src->extents;
|
|
memcpy( dst->rects, src->rects, src->num_rects * sizeof(*dst->rects) );
|
|
return dst;
|
|
}
|
|
|
|
/* compute the intersection of two regions into dst, which can be one of the source regions */
|
|
struct region *intersect_region( struct region *dst, const struct region *src1,
|
|
const struct region *src2 )
|
|
{
|
|
if (!src1->num_rects || !src2->num_rects || !EXTENTCHECK(&src1->extents, &src2->extents))
|
|
{
|
|
dst->num_rects = 0;
|
|
dst->extents.left = 0;
|
|
dst->extents.top = 0;
|
|
dst->extents.right = 0;
|
|
dst->extents.bottom = 0;
|
|
return dst;
|
|
}
|
|
if (!region_op( dst, src1, src2, intersect_overlapping, NULL, NULL )) return NULL;
|
|
set_region_extents( dst );
|
|
return dst;
|
|
}
|
|
|
|
/* compute the subtraction of two regions into dst, which can be one of the source regions */
|
|
struct region *subtract_region( struct region *dst, const struct region *src1,
|
|
const struct region *src2 )
|
|
{
|
|
if (!src1->num_rects || !src2->num_rects || !EXTENTCHECK(&src1->extents, &src2->extents))
|
|
return copy_region( dst, src1 );
|
|
|
|
if (!region_op( dst, src1, src2, subtract_overlapping,
|
|
subtract_non_overlapping, NULL )) return NULL;
|
|
set_region_extents( dst );
|
|
return dst;
|
|
}
|
|
|
|
/* compute the union of two regions into dst, which can be one of the source regions */
|
|
struct region *union_region( struct region *dst, const struct region *src1,
|
|
const struct region *src2 )
|
|
{
|
|
if (src1 == src2) return copy_region( dst, src1 );
|
|
if (!src1->num_rects) return copy_region( dst, src2 );
|
|
if (!src2->num_rects) return copy_region( dst, src1 );
|
|
|
|
if ((src1->num_rects == 1) &&
|
|
(src1->extents.left <= src2->extents.left) &&
|
|
(src1->extents.top <= src2->extents.top) &&
|
|
(src1->extents.right >= src2->extents.right) &&
|
|
(src1->extents.bottom >= src2->extents.bottom))
|
|
return copy_region( dst, src1 );
|
|
|
|
if ((src2->num_rects == 1) &&
|
|
(src2->extents.left <= src1->extents.left) &&
|
|
(src2->extents.top <= src1->extents.top) &&
|
|
(src2->extents.right >= src1->extents.right) &&
|
|
(src2->extents.bottom >= src1->extents.bottom))
|
|
return copy_region( dst, src2 );
|
|
|
|
if (!region_op( dst, src1, src2, union_overlapping,
|
|
union_non_overlapping, union_non_overlapping )) return NULL;
|
|
|
|
dst->extents.left = min(src1->extents.left, src2->extents.left);
|
|
dst->extents.top = min(src1->extents.top, src2->extents.top);
|
|
dst->extents.right = max(src1->extents.right, src2->extents.right);
|
|
dst->extents.bottom = max(src1->extents.bottom, src2->extents.bottom);
|
|
return dst;
|
|
}
|
|
|
|
/* compute the exclusive or of two regions into dst, which can be one of the source regions */
|
|
struct region *xor_region( struct region *dst, const struct region *src1,
|
|
const struct region *src2 )
|
|
{
|
|
struct region *tmp = create_empty_region();
|
|
|
|
if (!tmp) return NULL;
|
|
|
|
if (!subtract_region( tmp, src1, src2 ) ||
|
|
!subtract_region( dst, src2, src1 ) ||
|
|
!union_region( dst, dst, tmp ))
|
|
dst = NULL;
|
|
|
|
free_region( tmp );
|
|
return dst;
|
|
}
|
|
|
|
/* check if the given point is inside the region */
|
|
int point_in_region( struct region *region, int x, int y )
|
|
{
|
|
const rectangle_t *ptr, *end;
|
|
|
|
for (ptr = region->rects, end = region->rects + region->num_rects; ptr < end; ptr++)
|
|
{
|
|
if (ptr->top > y) return 0;
|
|
if (ptr->bottom <= y) continue;
|
|
/* now we are in the correct band */
|
|
if (ptr->left > x) return 0;
|
|
if (ptr->right <= x) continue;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* check if the given rectangle is (at least partially) inside the region */
|
|
int rect_in_region( struct region *region, const rectangle_t *rect )
|
|
{
|
|
const rectangle_t *ptr, *end;
|
|
|
|
for (ptr = region->rects, end = region->rects + region->num_rects; ptr < end; ptr++)
|
|
{
|
|
if (ptr->top >= rect->bottom) return 0;
|
|
if (ptr->bottom <= rect->top) continue;
|
|
if (ptr->left >= rect->right) continue;
|
|
if (ptr->right <= rect->left) continue;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|