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Diffstat (limited to 'nx-X11/lib/X11/Region.c')
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diff --git a/nx-X11/lib/X11/Region.c b/nx-X11/lib/X11/Region.c new file mode 100644 index 000000000..cdd223b25 --- /dev/null +++ b/nx-X11/lib/X11/Region.c @@ -0,0 +1,1743 @@ +/* $Xorg: Region.c,v 1.6 2001/02/09 02:03:35 xorgcvs Exp $ */ +/************************************************************************ + +Copyright 1987, 1988, 1998 The Open Group + +Permission to use, copy, modify, distribute, and sell this software and its +documentation for any purpose is hereby granted without fee, provided that +the above copyright notice appear in all copies and that both that +copyright notice and this permission notice appear in supporting +documentation. + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN +AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + +Except as contained in this notice, the name of The Open Group shall not be +used in advertising or otherwise to promote the sale, use or other dealings +in this Software without prior written authorization from The Open Group. + + +Copyright 1987, 1988 by Digital Equipment Corporation, Maynard, Massachusetts. + + All Rights Reserved + +Permission to use, copy, modify, and distribute this software and its +documentation for any purpose and without fee is hereby granted, +provided that the above copyright notice appear in all copies and that +both that copyright notice and this permission notice appear in +supporting documentation, and that the name of Digital not be +used in advertising or publicity pertaining to distribution of the +software without specific, written prior permission. + +DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING +ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL +DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR +ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, +WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, +ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS +SOFTWARE. + +************************************************************************/ +/* $XFree86: xc/lib/X11/Region.c,v 1.9 2002/06/04 22:19:57 dawes Exp $ */ +/* + * The functions in this file implement the Region abstraction, similar to one + * used in the X11 sample server. A Region is simply an area, as the name + * implies, and is implemented as a "y-x-banded" array of rectangles. To + * explain: Each Region is made up of a certain number of rectangles sorted + * by y coordinate first, and then by x coordinate. + * + * Furthermore, the rectangles are banded such that every rectangle with a + * given upper-left y coordinate (y1) will have the same lower-right y + * coordinate (y2) and vice versa. If a rectangle has scanlines in a band, it + * will span the entire vertical distance of the band. This means that some + * areas that could be merged into a taller rectangle will be represented as + * several shorter rectangles to account for shorter rectangles to its left + * or right but within its "vertical scope". + * + * An added constraint on the rectangles is that they must cover as much + * horizontal area as possible. E.g. no two rectangles in a band are allowed + * to touch. + * + * Whenever possible, bands will be merged together to cover a greater vertical + * distance (and thus reduce the number of rectangles). Two bands can be merged + * only if the bottom of one touches the top of the other and they have + * rectangles in the same places (of the same width, of course). This maintains + * the y-x-banding that's so nice to have... + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include "Xlibint.h" +#include "Xutil.h" +#include <X11/Xregion.h> +#include "poly.h" + +#ifdef DEBUG +#include <stdio.h> +#define assert(expr) {if (!(expr)) fprintf(stderr,\ +"Assertion failed file %s, line %d: expr\n", __FILE__, __LINE__); } +#else +#define assert(expr) +#endif + +typedef int (*overlapProcp)( + register Region pReg, + register BoxPtr r1, + BoxPtr r1End, + register BoxPtr r2, + BoxPtr r2End, + short y1, + short y2); + +typedef int (*nonOverlapProcp)( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2); + +static void miRegionOp( + register Region newReg, /* Place to store result */ + Region reg1, /* First region in operation */ + Region reg2, /* 2d region in operation */ + int (*overlapFunc)( + register Region pReg, + register BoxPtr r1, + BoxPtr r1End, + register BoxPtr r2, + BoxPtr r2End, + short y1, + short y2), /* Function to call for over- + * lapping bands */ + int (*nonOverlap1Func)( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2), /* Function to call for non- + * overlapping bands in region + * 1 */ + int (*nonOverlap2Func)( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2)); /* Function to call for non- + * overlapping bands in region + * 2 */ + + +/* Create a new empty region */ +Region +XCreateRegion(void) +{ + Region temp; + + if (! (temp = ( Region )Xmalloc( (unsigned) sizeof( REGION )))) + return (Region) NULL; + if (! (temp->rects = ( BOX * )Xmalloc( (unsigned) sizeof( BOX )))) { + Xfree((char *) temp); + return (Region) NULL; + } + temp->numRects = 0; + temp->extents.x1 = 0; + temp->extents.y1 = 0; + temp->extents.x2 = 0; + temp->extents.y2 = 0; + temp->size = 1; + return( temp ); +} + +int +XClipBox( + Region r, + XRectangle *rect) +{ + rect->x = r->extents.x1; + rect->y = r->extents.y1; + rect->width = r->extents.x2 - r->extents.x1; + rect->height = r->extents.y2 - r->extents.y1; + return 1; +} + +int +XUnionRectWithRegion( + register XRectangle *rect, + Region source, Region dest) +{ + REGION region; + + if (!rect->width || !rect->height) + return 0; + region.rects = ®ion.extents; + region.numRects = 1; + region.extents.x1 = rect->x; + region.extents.y1 = rect->y; + region.extents.x2 = rect->x + rect->width; + region.extents.y2 = rect->y + rect->height; + region.size = 1; + + return XUnionRegion(®ion, source, dest); +} + +/*- + *----------------------------------------------------------------------- + * miSetExtents -- + * Reset the extents of a region to what they should be. Called by + * miSubtract and miIntersect b/c they can't figure it out along the + * way or do so easily, as miUnion can. + * + * Results: + * None. + * + * Side Effects: + * The region's 'extents' structure is overwritten. + * + *----------------------------------------------------------------------- + */ +static void +miSetExtents ( + Region pReg) +{ + register BoxPtr pBox, + pBoxEnd, + pExtents; + + if (pReg->numRects == 0) + { + pReg->extents.x1 = 0; + pReg->extents.y1 = 0; + pReg->extents.x2 = 0; + pReg->extents.y2 = 0; + return; + } + + pExtents = &pReg->extents; + pBox = pReg->rects; + pBoxEnd = &pBox[pReg->numRects - 1]; + + /* + * Since pBox is the first rectangle in the region, it must have the + * smallest y1 and since pBoxEnd is the last rectangle in the region, + * it must have the largest y2, because of banding. Initialize x1 and + * x2 from pBox and pBoxEnd, resp., as good things to initialize them + * to... + */ + pExtents->x1 = pBox->x1; + pExtents->y1 = pBox->y1; + pExtents->x2 = pBoxEnd->x2; + pExtents->y2 = pBoxEnd->y2; + + assert(pExtents->y1 < pExtents->y2); + while (pBox <= pBoxEnd) + { + if (pBox->x1 < pExtents->x1) + { + pExtents->x1 = pBox->x1; + } + if (pBox->x2 > pExtents->x2) + { + pExtents->x2 = pBox->x2; + } + pBox++; + } + assert(pExtents->x1 < pExtents->x2); +} + +int +XSetRegion( + Display *dpy, + GC gc, + register Region r) +{ + register int i; + register XRectangle *xr, *pr; + register BOX *pb; + unsigned long total; + + LockDisplay (dpy); + total = r->numRects * sizeof (XRectangle); + if ((xr = (XRectangle *) _XAllocTemp(dpy, total))) { + for (pr = xr, pb = r->rects, i = r->numRects; --i >= 0; pr++, pb++) { + pr->x = pb->x1; + pr->y = pb->y1; + pr->width = pb->x2 - pb->x1; + pr->height = pb->y2 - pb->y1; + } + } + if (xr || !r->numRects) + _XSetClipRectangles(dpy, gc, 0, 0, xr, r->numRects, YXBanded); + if (xr) + _XFreeTemp(dpy, (char *)xr, total); + UnlockDisplay(dpy); + SyncHandle(); + return 1; +} + +int +XDestroyRegion( + Region r) +{ + Xfree( (char *) r->rects ); + Xfree( (char *) r ); + return 1; +} + + +/* TranslateRegion(pRegion, x, y) + translates in place + added by raymond +*/ + +int +XOffsetRegion( + register Region pRegion, + register int x, + register int y) +{ + register int nbox; + register BOX *pbox; + + pbox = pRegion->rects; + nbox = pRegion->numRects; + + while(nbox--) + { + pbox->x1 += x; + pbox->x2 += x; + pbox->y1 += y; + pbox->y2 += y; + pbox++; + } + pRegion->extents.x1 += x; + pRegion->extents.x2 += x; + pRegion->extents.y1 += y; + pRegion->extents.y2 += y; + return 1; +} + +/* + Utility procedure Compress: + Replace r by the region r', where + p in r' iff (Quantifer m <= dx) (p + m in r), and + Quantifier is Exists if grow is TRUE, For all if grow is FALSE, and + (x,y) + m = (x+m,y) if xdir is TRUE; (x,y+m) if xdir is FALSE. + + Thus, if xdir is TRUE and grow is FALSE, r is replaced by the region + of all points p such that p and the next dx points on the same + horizontal scan line are all in r. We do this using by noting + that p is the head of a run of length 2^i + k iff p is the head + of a run of length 2^i and p+2^i is the head of a run of length + k. Thus, the loop invariant: s contains the region corresponding + to the runs of length shift. r contains the region corresponding + to the runs of length 1 + dxo & (shift-1), where dxo is the original + value of dx. dx = dxo & ~(shift-1). As parameters, s and t are + scratch regions, so that we don't have to allocate them on every + call. +*/ + +#define ZOpRegion(a,b,c) if (grow) XUnionRegion(a,b,c); \ + else XIntersectRegion(a,b,c) +#define ZShiftRegion(a,b) if (xdir) XOffsetRegion(a,b,0); \ + else XOffsetRegion(a,0,b) +#define ZCopyRegion(a,b) XUnionRegion(a,a,b) + +static void +Compress( + Region r, Region s, Region t, + register unsigned dx, + register int xdir, register int grow) +{ + register unsigned shift = 1; + + ZCopyRegion(r, s); + while (dx) { + if (dx & shift) { + ZShiftRegion(r, -(int)shift); + ZOpRegion(r, s, r); + dx -= shift; + if (!dx) break; + } + ZCopyRegion(s, t); + ZShiftRegion(s, -(int)shift); + ZOpRegion(s, t, s); + shift <<= 1; + } +} + +#undef ZOpRegion +#undef ZShiftRegion +#undef ZCopyRegion + +int +XShrinkRegion( + Region r, + int dx, int dy) +{ + Region s, t; + int grow; + + if (!dx && !dy) return 0; + if ((! (s = XCreateRegion())) || (! (t = XCreateRegion()))) return 0; + if ((grow = (dx < 0))) dx = -dx; + if (dx) Compress(r, s, t, (unsigned) 2*dx, TRUE, grow); + if ((grow = (dy < 0))) dy = -dy; + if (dy) Compress(r, s, t, (unsigned) 2*dy, FALSE, grow); + XOffsetRegion(r, dx, dy); + XDestroyRegion(s); + XDestroyRegion(t); + return 0; +} + +#ifdef notdef +/*********************************************************** + * Bop down the array of rects until we have passed + * scanline y. numRects is the size of the array. + ***********************************************************/ + +static BOX +*IndexRects( + register BOX *rects, + register int numRects, + register int y) +{ + while ((numRects--) && (rects->y2 <= y)) + rects++; + return(rects); +} +#endif + +/*====================================================================== + * Region Intersection + *====================================================================*/ +/*- + *----------------------------------------------------------------------- + * miIntersectO -- + * Handle an overlapping band for miIntersect. + * + * Results: + * None. + * + * Side Effects: + * Rectangles may be added to the region. + * + *----------------------------------------------------------------------- + */ +/* static void*/ +static int +miIntersectO ( + register Region pReg, + register BoxPtr r1, + BoxPtr r1End, + register BoxPtr r2, + BoxPtr r2End, + short y1, + short y2) +{ + register short x1; + register short x2; + register BoxPtr pNextRect; + + pNextRect = &pReg->rects[pReg->numRects]; + + while ((r1 != r1End) && (r2 != r2End)) + { + x1 = max(r1->x1,r2->x1); + x2 = min(r1->x2,r2->x2); + + /* + * If there's any overlap between the two rectangles, add that + * overlap to the new region. + * There's no need to check for subsumption because the only way + * such a need could arise is if some region has two rectangles + * right next to each other. Since that should never happen... + */ + if (x1 < x2) + { + assert(y1<y2); + + MEMCHECK(pReg, pNextRect, pReg->rects); + pNextRect->x1 = x1; + pNextRect->y1 = y1; + pNextRect->x2 = x2; + pNextRect->y2 = y2; + pReg->numRects += 1; + pNextRect++; + assert(pReg->numRects <= pReg->size); + } + + /* + * Need to advance the pointers. Shift the one that extends + * to the right the least, since the other still has a chance to + * overlap with that region's next rectangle, if you see what I mean. + */ + if (r1->x2 < r2->x2) + { + r1++; + } + else if (r2->x2 < r1->x2) + { + r2++; + } + else + { + r1++; + r2++; + } + } + return 0; /* lint */ +} + +int +XIntersectRegion( + Region reg1, + Region reg2, /* source regions */ + register Region newReg) /* destination Region */ +{ + /* check for trivial reject */ + if ( (!(reg1->numRects)) || (!(reg2->numRects)) || + (!EXTENTCHECK(®1->extents, ®2->extents))) + newReg->numRects = 0; + else + miRegionOp (newReg, reg1, reg2, + miIntersectO, NULL, NULL); + + /* + * Can't alter newReg's extents before we call miRegionOp because + * it might be one of the source regions and miRegionOp depends + * on the extents of those regions being the same. Besides, this + * way there's no checking against rectangles that will be nuked + * due to coalescing, so we have to examine fewer rectangles. + */ + miSetExtents(newReg); + return 1; +} + +static void +miRegionCopy( + register Region dstrgn, + register Region rgn) + +{ + if (dstrgn != rgn) /* don't want to copy to itself */ + { + if (dstrgn->size < rgn->numRects) + { + if (dstrgn->rects) + { + BOX *prevRects = dstrgn->rects; + + if (! (dstrgn->rects = (BOX *) + Xrealloc((char *) dstrgn->rects, + (unsigned) rgn->numRects * (sizeof(BOX))))) { + Xfree(prevRects); + return; + } + } + dstrgn->size = rgn->numRects; + } + dstrgn->numRects = rgn->numRects; + dstrgn->extents.x1 = rgn->extents.x1; + dstrgn->extents.y1 = rgn->extents.y1; + dstrgn->extents.x2 = rgn->extents.x2; + dstrgn->extents.y2 = rgn->extents.y2; + + memcpy((char *) dstrgn->rects, (char *) rgn->rects, + (int) (rgn->numRects * sizeof(BOX))); + } +} + +#ifdef notdef + +/* + * combinRegs(newReg, reg1, reg2) + * if one region is above or below the other. +*/ + +static void +combineRegs( + register Region newReg, + Region reg1, + Region reg2) +{ + register Region tempReg; + register BOX *rects; + register BOX *rects1; + register BOX *rects2; + register int total; + + rects1 = reg1->rects; + rects2 = reg2->rects; + + total = reg1->numRects + reg2->numRects; + if (! (tempReg = XCreateRegion())) + return; + tempReg->size = total; + /* region 1 is below region 2 */ + if (reg1->extents.y1 > reg2->extents.y1) + { + miRegionCopy(tempReg, reg2); + rects = &tempReg->rects[tempReg->numRects]; + total -= tempReg->numRects; + while (total--) + *rects++ = *rects1++; + } + else + { + miRegionCopy(tempReg, reg1); + rects = &tempReg->rects[tempReg->numRects]; + total -= tempReg->numRects; + while (total--) + *rects++ = *rects2++; + } + tempReg->extents = reg1->extents; + tempReg->numRects = reg1->numRects + reg2->numRects; + EXTENTS(®2->extents, tempReg); + miRegionCopy(newReg, tempReg); + Xfree((char *)tempReg); +} + +/* + * QuickCheck checks to see if it does not have to go through all the + * the ugly code for the region call. It returns 1 if it did all + * the work for Union, otherwise 0 - still work to be done. +*/ + +static int +QuickCheck(Region newReg, Region reg1, Region reg2) +{ + + /* if unioning with itself or no rects to union with */ + if ( (reg1 == reg2) || (!(reg1->numRects)) ) + { + miRegionCopy(newReg, reg2); + return TRUE; + } + + /* if nothing to union */ + if (!(reg2->numRects)) + { + miRegionCopy(newReg, reg1); + return TRUE; + } + + /* could put an extent check to see if add above or below */ + + if ((reg1->extents.y1 >= reg2->extents.y2) || + (reg2->extents.y1 >= reg1->extents.y2) ) + { + combineRegs(newReg, reg1, reg2); + return TRUE; + } + return FALSE; +} + +/* TopRects(rects, reg1, reg2) + * N.B. We now assume that reg1 and reg2 intersect. Therefore we are + * NOT checking in the two while loops for stepping off the end of the + * region. + */ + +static int +TopRects( + register Region newReg, + register BOX *rects, + register Region reg1, + register Region reg2, + BOX *FirstRect) +{ + register BOX *tempRects; + + /* need to add some rects from region 1 */ + if (reg1->extents.y1 < reg2->extents.y1) + { + tempRects = reg1->rects; + while(tempRects->y1 < reg2->extents.y1) + { + MEMCHECK(newReg, rects, FirstRect); + ADDRECTNOX(newReg,rects, tempRects->x1, tempRects->y1, + tempRects->x2, MIN(tempRects->y2, reg2->extents.y1)); + tempRects++; + } + } + /* need to add some rects from region 2 */ + if (reg2->extents.y1 < reg1->extents.y1) + { + tempRects = reg2->rects; + while (tempRects->y1 < reg1->extents.y1) + { + MEMCHECK(newReg, rects, FirstRect); + ADDRECTNOX(newReg, rects, tempRects->x1,tempRects->y1, + tempRects->x2, MIN(tempRects->y2, reg1->extents.y1)); + tempRects++; + } + } + return 1; +} +#endif + +/*====================================================================== + * Generic Region Operator + *====================================================================*/ + +/*- + *----------------------------------------------------------------------- + * miCoalesce -- + * Attempt to merge the boxes in the current band with those in the + * previous one. Used only by miRegionOp. + * + * Results: + * The new index for the previous band. + * + * Side Effects: + * If coalescing takes place: + * - rectangles in the previous band will have their y2 fields + * altered. + * - pReg->numRects will be decreased. + * + *----------------------------------------------------------------------- + */ +/* static int*/ +static int +miCoalesce( + register Region pReg, /* Region to coalesce */ + int prevStart, /* Index of start of previous band */ + int curStart) /* Index of start of current band */ +{ + register BoxPtr pPrevBox; /* Current box in previous band */ + register BoxPtr pCurBox; /* Current box in current band */ + register BoxPtr pRegEnd; /* End of region */ + int curNumRects; /* Number of rectangles in current + * band */ + int prevNumRects; /* Number of rectangles in previous + * band */ + int bandY1; /* Y1 coordinate for current band */ + + pRegEnd = &pReg->rects[pReg->numRects]; + + pPrevBox = &pReg->rects[prevStart]; + prevNumRects = curStart - prevStart; + + /* + * Figure out how many rectangles are in the current band. Have to do + * this because multiple bands could have been added in miRegionOp + * at the end when one region has been exhausted. + */ + pCurBox = &pReg->rects[curStart]; + bandY1 = pCurBox->y1; + for (curNumRects = 0; + (pCurBox != pRegEnd) && (pCurBox->y1 == bandY1); + curNumRects++) + { + pCurBox++; + } + + if (pCurBox != pRegEnd) + { + /* + * If more than one band was added, we have to find the start + * of the last band added so the next coalescing job can start + * at the right place... (given when multiple bands are added, + * this may be pointless -- see above). + */ + pRegEnd--; + while (pRegEnd[-1].y1 == pRegEnd->y1) + { + pRegEnd--; + } + curStart = pRegEnd - pReg->rects; + pRegEnd = pReg->rects + pReg->numRects; + } + + if ((curNumRects == prevNumRects) && (curNumRects != 0)) { + pCurBox -= curNumRects; + /* + * The bands may only be coalesced if the bottom of the previous + * matches the top scanline of the current. + */ + if (pPrevBox->y2 == pCurBox->y1) + { + /* + * Make sure the bands have boxes in the same places. This + * assumes that boxes have been added in such a way that they + * cover the most area possible. I.e. two boxes in a band must + * have some horizontal space between them. + */ + do + { + if ((pPrevBox->x1 != pCurBox->x1) || + (pPrevBox->x2 != pCurBox->x2)) + { + /* + * The bands don't line up so they can't be coalesced. + */ + return (curStart); + } + pPrevBox++; + pCurBox++; + prevNumRects -= 1; + } while (prevNumRects != 0); + + pReg->numRects -= curNumRects; + pCurBox -= curNumRects; + pPrevBox -= curNumRects; + + /* + * The bands may be merged, so set the bottom y of each box + * in the previous band to that of the corresponding box in + * the current band. + */ + do + { + pPrevBox->y2 = pCurBox->y2; + pPrevBox++; + pCurBox++; + curNumRects -= 1; + } while (curNumRects != 0); + + /* + * If only one band was added to the region, we have to backup + * curStart to the start of the previous band. + * + * If more than one band was added to the region, copy the + * other bands down. The assumption here is that the other bands + * came from the same region as the current one and no further + * coalescing can be done on them since it's all been done + * already... curStart is already in the right place. + */ + if (pCurBox == pRegEnd) + { + curStart = prevStart; + } + else + { + do + { + *pPrevBox++ = *pCurBox++; + } while (pCurBox != pRegEnd); + } + + } + } + return (curStart); +} + +/*- + *----------------------------------------------------------------------- + * miRegionOp -- + * Apply an operation to two regions. Called by miUnion, miInverse, + * miSubtract, miIntersect... + * + * Results: + * None. + * + * Side Effects: + * The new region is overwritten. + * + * Notes: + * The idea behind this function is to view the two regions as sets. + * Together they cover a rectangle of area that this function divides + * into horizontal bands where points are covered only by one region + * or by both. For the first case, the nonOverlapFunc is called with + * each the band and the band's upper and lower extents. For the + * second, the overlapFunc is called to process the entire band. It + * is responsible for clipping the rectangles in the band, though + * this function provides the boundaries. + * At the end of each band, the new region is coalesced, if possible, + * to reduce the number of rectangles in the region. + * + *----------------------------------------------------------------------- + */ +/* static void*/ +static void +miRegionOp( + register Region newReg, /* Place to store result */ + Region reg1, /* First region in operation */ + Region reg2, /* 2d region in operation */ + int (*overlapFunc)( + register Region pReg, + register BoxPtr r1, + BoxPtr r1End, + register BoxPtr r2, + BoxPtr r2End, + short y1, + short y2), /* Function to call for over- + * lapping bands */ + int (*nonOverlap1Func)( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2), /* Function to call for non- + * overlapping bands in region + * 1 */ + int (*nonOverlap2Func)( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2)) /* Function to call for non- + * overlapping bands in region + * 2 */ +{ + register BoxPtr r1; /* Pointer into first region */ + register BoxPtr r2; /* Pointer into 2d region */ + BoxPtr r1End; /* End of 1st region */ + BoxPtr r2End; /* End of 2d region */ + register short ybot; /* Bottom of intersection */ + register short ytop; /* Top of intersection */ + BoxPtr oldRects; /* Old rects for newReg */ + int prevBand; /* Index of start of + * previous band in newReg */ + int curBand; /* Index of start of current + * band in newReg */ + register BoxPtr r1BandEnd; /* End of current band in r1 */ + register BoxPtr r2BandEnd; /* End of current band in r2 */ + short top; /* Top of non-overlapping + * band */ + short bot; /* Bottom of non-overlapping + * band */ + + /* + * Initialization: + * set r1, r2, r1End and r2End appropriately, preserve the important + * parts of the destination region until the end in case it's one of + * the two source regions, then mark the "new" region empty, allocating + * another array of rectangles for it to use. + */ + r1 = reg1->rects; + r2 = reg2->rects; + r1End = r1 + reg1->numRects; + r2End = r2 + reg2->numRects; + + oldRects = newReg->rects; + + EMPTY_REGION(newReg); + + /* + * Allocate a reasonable number of rectangles for the new region. The idea + * is to allocate enough so the individual functions don't need to + * reallocate and copy the array, which is time consuming, yet we don't + * have to worry about using too much memory. I hope to be able to + * nuke the Xrealloc() at the end of this function eventually. + */ + newReg->size = max(reg1->numRects,reg2->numRects) * 2; + + if (! (newReg->rects = (BoxPtr) + Xmalloc ((unsigned) (sizeof(BoxRec) * newReg->size)))) { + newReg->size = 0; + return; + } + + /* + * Initialize ybot and ytop. + * In the upcoming loop, ybot and ytop serve different functions depending + * on whether the band being handled is an overlapping or non-overlapping + * band. + * In the case of a non-overlapping band (only one of the regions + * has points in the band), ybot is the bottom of the most recent + * intersection and thus clips the top of the rectangles in that band. + * ytop is the top of the next intersection between the two regions and + * serves to clip the bottom of the rectangles in the current band. + * For an overlapping band (where the two regions intersect), ytop clips + * the top of the rectangles of both regions and ybot clips the bottoms. + */ + if (reg1->extents.y1 < reg2->extents.y1) + ybot = reg1->extents.y1; + else + ybot = reg2->extents.y1; + + /* + * prevBand serves to mark the start of the previous band so rectangles + * can be coalesced into larger rectangles. qv. miCoalesce, above. + * In the beginning, there is no previous band, so prevBand == curBand + * (curBand is set later on, of course, but the first band will always + * start at index 0). prevBand and curBand must be indices because of + * the possible expansion, and resultant moving, of the new region's + * array of rectangles. + */ + prevBand = 0; + + do + { + curBand = newReg->numRects; + + /* + * This algorithm proceeds one source-band (as opposed to a + * destination band, which is determined by where the two regions + * intersect) at a time. r1BandEnd and r2BandEnd serve to mark the + * rectangle after the last one in the current band for their + * respective regions. + */ + r1BandEnd = r1; + while ((r1BandEnd != r1End) && (r1BandEnd->y1 == r1->y1)) + { + r1BandEnd++; + } + + r2BandEnd = r2; + while ((r2BandEnd != r2End) && (r2BandEnd->y1 == r2->y1)) + { + r2BandEnd++; + } + + /* + * First handle the band that doesn't intersect, if any. + * + * Note that attention is restricted to one band in the + * non-intersecting region at once, so if a region has n + * bands between the current position and the next place it overlaps + * the other, this entire loop will be passed through n times. + */ + if (r1->y1 < r2->y1) + { + top = max(r1->y1,ybot); + bot = min(r1->y2,r2->y1); + + if ((top != bot) && (nonOverlap1Func != NULL)) + { + (* nonOverlap1Func) (newReg, r1, r1BandEnd, top, bot); + } + + ytop = r2->y1; + } + else if (r2->y1 < r1->y1) + { + top = max(r2->y1,ybot); + bot = min(r2->y2,r1->y1); + + if ((top != bot) && (nonOverlap2Func != NULL)) + { + (* nonOverlap2Func) (newReg, r2, r2BandEnd, top, bot); + } + + ytop = r1->y1; + } + else + { + ytop = r1->y1; + } + + /* + * If any rectangles got added to the region, try and coalesce them + * with rectangles from the previous band. Note we could just do + * this test in miCoalesce, but some machines incur a not + * inconsiderable cost for function calls, so... + */ + if (newReg->numRects != curBand) + { + prevBand = miCoalesce (newReg, prevBand, curBand); + } + + /* + * Now see if we've hit an intersecting band. The two bands only + * intersect if ybot > ytop + */ + ybot = min(r1->y2, r2->y2); + curBand = newReg->numRects; + if (ybot > ytop) + { + (* overlapFunc) (newReg, r1, r1BandEnd, r2, r2BandEnd, ytop, ybot); + + } + + if (newReg->numRects != curBand) + { + prevBand = miCoalesce (newReg, prevBand, curBand); + } + + /* + * If we've finished with a band (y2 == ybot) we skip forward + * in the region to the next band. + */ + if (r1->y2 == ybot) + { + r1 = r1BandEnd; + } + if (r2->y2 == ybot) + { + r2 = r2BandEnd; + } + } while ((r1 != r1End) && (r2 != r2End)); + + /* + * Deal with whichever region still has rectangles left. + */ + curBand = newReg->numRects; + if (r1 != r1End) + { + if (nonOverlap1Func != NULL) + { + do + { + r1BandEnd = r1; + while ((r1BandEnd < r1End) && (r1BandEnd->y1 == r1->y1)) + { + r1BandEnd++; + } + (* nonOverlap1Func) (newReg, r1, r1BandEnd, + max(r1->y1,ybot), r1->y2); + r1 = r1BandEnd; + } while (r1 != r1End); + } + } + else if ((r2 != r2End) && (nonOverlap2Func != NULL)) + { + do + { + r2BandEnd = r2; + while ((r2BandEnd < r2End) && (r2BandEnd->y1 == r2->y1)) + { + r2BandEnd++; + } + (* nonOverlap2Func) (newReg, r2, r2BandEnd, + max(r2->y1,ybot), r2->y2); + r2 = r2BandEnd; + } while (r2 != r2End); + } + + if (newReg->numRects != curBand) + { + (void) miCoalesce (newReg, prevBand, curBand); + } + + /* + * A bit of cleanup. To keep regions from growing without bound, + * we shrink the array of rectangles to match the new number of + * rectangles in the region. This never goes to 0, however... + * + * Only do this stuff if the number of rectangles allocated is more than + * twice the number of rectangles in the region (a simple optimization...). + */ + if (newReg->numRects < (newReg->size >> 1)) + { + if (REGION_NOT_EMPTY(newReg)) + { + BoxPtr prev_rects = newReg->rects; + newReg->size = newReg->numRects; + newReg->rects = (BoxPtr) Xrealloc ((char *) newReg->rects, + (unsigned) (sizeof(BoxRec) * newReg->size)); + if (! newReg->rects) + newReg->rects = prev_rects; + } + else + { + /* + * No point in doing the extra work involved in an Xrealloc if + * the region is empty + */ + newReg->size = 1; + Xfree((char *) newReg->rects); + newReg->rects = (BoxPtr) Xmalloc(sizeof(BoxRec)); + } + } + Xfree ((char *) oldRects); + return; +} + + +/*====================================================================== + * Region Union + *====================================================================*/ + +/*- + *----------------------------------------------------------------------- + * miUnionNonO -- + * Handle a non-overlapping band for the union operation. Just + * Adds the rectangles into the region. Doesn't have to check for + * subsumption or anything. + * + * Results: + * None. + * + * Side Effects: + * pReg->numRects is incremented and the final rectangles overwritten + * with the rectangles we're passed. + * + *----------------------------------------------------------------------- + */ +/* static void*/ +static int +miUnionNonO ( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2) +{ + register BoxPtr pNextRect; + + pNextRect = &pReg->rects[pReg->numRects]; + + assert(y1 < y2); + + while (r != rEnd) + { + assert(r->x1 < r->x2); + MEMCHECK(pReg, pNextRect, pReg->rects); + pNextRect->x1 = r->x1; + pNextRect->y1 = y1; + pNextRect->x2 = r->x2; + pNextRect->y2 = y2; + pReg->numRects += 1; + pNextRect++; + + assert(pReg->numRects<=pReg->size); + r++; + } + return 0; /* lint */ +} + + +/*- + *----------------------------------------------------------------------- + * miUnionO -- + * Handle an overlapping band for the union operation. Picks the + * left-most rectangle each time and merges it into the region. + * + * Results: + * None. + * + * Side Effects: + * Rectangles are overwritten in pReg->rects and pReg->numRects will + * be changed. + * + *----------------------------------------------------------------------- + */ + +/* static void*/ +static int +miUnionO ( + register Region pReg, + register BoxPtr r1, + BoxPtr r1End, + register BoxPtr r2, + BoxPtr r2End, + register short y1, + register short y2) +{ + register BoxPtr pNextRect; + + pNextRect = &pReg->rects[pReg->numRects]; + +#define MERGERECT(r) \ + if ((pReg->numRects != 0) && \ + (pNextRect[-1].y1 == y1) && \ + (pNextRect[-1].y2 == y2) && \ + (pNextRect[-1].x2 >= r->x1)) \ + { \ + if (pNextRect[-1].x2 < r->x2) \ + { \ + pNextRect[-1].x2 = r->x2; \ + assert(pNextRect[-1].x1<pNextRect[-1].x2); \ + } \ + } \ + else \ + { \ + MEMCHECK(pReg, pNextRect, pReg->rects); \ + pNextRect->y1 = y1; \ + pNextRect->y2 = y2; \ + pNextRect->x1 = r->x1; \ + pNextRect->x2 = r->x2; \ + pReg->numRects += 1; \ + pNextRect += 1; \ + } \ + assert(pReg->numRects<=pReg->size);\ + r++; + + assert (y1<y2); + while ((r1 != r1End) && (r2 != r2End)) + { + if (r1->x1 < r2->x1) + { + MERGERECT(r1); + } + else + { + MERGERECT(r2); + } + } + + if (r1 != r1End) + { + do + { + MERGERECT(r1); + } while (r1 != r1End); + } + else while (r2 != r2End) + { + MERGERECT(r2); + } + return 0; /* lint */ +} + +int +XUnionRegion( + Region reg1, + Region reg2, /* source regions */ + Region newReg) /* destination Region */ +{ + /* checks all the simple cases */ + + /* + * Region 1 and 2 are the same or region 1 is empty + */ + if ( (reg1 == reg2) || (!(reg1->numRects)) ) + { + if (newReg != reg2) + miRegionCopy(newReg, reg2); + return 1; + } + + /* + * if nothing to union (region 2 empty) + */ + if (!(reg2->numRects)) + { + if (newReg != reg1) + miRegionCopy(newReg, reg1); + return 1; + } + + /* + * Region 1 completely subsumes region 2 + */ + if ((reg1->numRects == 1) && + (reg1->extents.x1 <= reg2->extents.x1) && + (reg1->extents.y1 <= reg2->extents.y1) && + (reg1->extents.x2 >= reg2->extents.x2) && + (reg1->extents.y2 >= reg2->extents.y2)) + { + if (newReg != reg1) + miRegionCopy(newReg, reg1); + return 1; + } + + /* + * Region 2 completely subsumes region 1 + */ + if ((reg2->numRects == 1) && + (reg2->extents.x1 <= reg1->extents.x1) && + (reg2->extents.y1 <= reg1->extents.y1) && + (reg2->extents.x2 >= reg1->extents.x2) && + (reg2->extents.y2 >= reg1->extents.y2)) + { + if (newReg != reg2) + miRegionCopy(newReg, reg2); + return 1; + } + + miRegionOp (newReg, reg1, reg2, miUnionO, + miUnionNonO, miUnionNonO); + + newReg->extents.x1 = min(reg1->extents.x1, reg2->extents.x1); + newReg->extents.y1 = min(reg1->extents.y1, reg2->extents.y1); + newReg->extents.x2 = max(reg1->extents.x2, reg2->extents.x2); + newReg->extents.y2 = max(reg1->extents.y2, reg2->extents.y2); + + return 1; +} + + +/*====================================================================== + * Region Subtraction + *====================================================================*/ + +/*- + *----------------------------------------------------------------------- + * miSubtractNonO -- + * Deal with non-overlapping band for subtraction. Any parts from + * region 2 we discard. Anything from region 1 we add to the region. + * + * Results: + * None. + * + * Side Effects: + * pReg may be affected. + * + *----------------------------------------------------------------------- + */ +/* static void*/ +static int +miSubtractNonO1 ( + register Region pReg, + register BoxPtr r, + BoxPtr rEnd, + register short y1, + register short y2) +{ + register BoxPtr pNextRect; + + pNextRect = &pReg->rects[pReg->numRects]; + + assert(y1<y2); + + while (r != rEnd) + { + assert(r->x1<r->x2); + MEMCHECK(pReg, pNextRect, pReg->rects); + pNextRect->x1 = r->x1; + pNextRect->y1 = y1; + pNextRect->x2 = r->x2; + pNextRect->y2 = y2; + pReg->numRects += 1; + pNextRect++; + + assert(pReg->numRects <= pReg->size); + + r++; + } + return 0; /* lint */ +} + +/*- + *----------------------------------------------------------------------- + * miSubtractO -- + * Overlapping band subtraction. x1 is the left-most point not yet + * checked. + * + * Results: + * None. + * + * Side Effects: + * pReg may have rectangles added to it. + * + *----------------------------------------------------------------------- + */ +/* static void*/ +static int +miSubtractO ( + register Region pReg, + register BoxPtr r1, + BoxPtr r1End, + register BoxPtr r2, + BoxPtr r2End, + register short y1, + register short y2) +{ + register BoxPtr pNextRect; + register int x1; + + x1 = r1->x1; + + assert(y1<y2); + pNextRect = &pReg->rects[pReg->numRects]; + + while ((r1 != r1End) && (r2 != r2End)) + { + if (r2->x2 <= x1) + { + /* + * Subtrahend missed the boat: go to next subtrahend. + */ + r2++; + } + else if (r2->x1 <= x1) + { + /* + * Subtrahend preceeds minuend: nuke left edge of minuend. + */ + x1 = r2->x2; + if (x1 >= r1->x2) + { + /* + * Minuend completely covered: advance to next minuend and + * reset left fence to edge of new minuend. + */ + r1++; + if (r1 != r1End) + x1 = r1->x1; + } + else + { + /* + * Subtrahend now used up since it doesn't extend beyond + * minuend + */ + r2++; + } + } + else if (r2->x1 < r1->x2) + { + /* + * Left part of subtrahend covers part of minuend: add uncovered + * part of minuend to region and skip to next subtrahend. + */ + assert(x1<r2->x1); + MEMCHECK(pReg, pNextRect, pReg->rects); + pNextRect->x1 = x1; + pNextRect->y1 = y1; + pNextRect->x2 = r2->x1; + pNextRect->y2 = y2; + pReg->numRects += 1; + pNextRect++; + + assert(pReg->numRects<=pReg->size); + + x1 = r2->x2; + if (x1 >= r1->x2) + { + /* + * Minuend used up: advance to new... + */ + r1++; + if (r1 != r1End) + x1 = r1->x1; + } + else + { + /* + * Subtrahend used up + */ + r2++; + } + } + else + { + /* + * Minuend used up: add any remaining piece before advancing. + */ + if (r1->x2 > x1) + { + MEMCHECK(pReg, pNextRect, pReg->rects); + pNextRect->x1 = x1; + pNextRect->y1 = y1; + pNextRect->x2 = r1->x2; + pNextRect->y2 = y2; + pReg->numRects += 1; + pNextRect++; + assert(pReg->numRects<=pReg->size); + } + r1++; + if (r1 != r1End) + x1 = r1->x1; + } + } + + /* + * Add remaining minuend rectangles to region. + */ + while (r1 != r1End) + { + assert(x1<r1->x2); + MEMCHECK(pReg, pNextRect, pReg->rects); + pNextRect->x1 = x1; + pNextRect->y1 = y1; + pNextRect->x2 = r1->x2; + pNextRect->y2 = y2; + pReg->numRects += 1; + pNextRect++; + + assert(pReg->numRects<=pReg->size); + + r1++; + if (r1 != r1End) + { + x1 = r1->x1; + } + } + return 0; /* lint */ +} + +/*- + *----------------------------------------------------------------------- + * miSubtract -- + * Subtract regS from regM and leave the result in regD. + * S stands for subtrahend, M for minuend and D for difference. + * + * Results: + * TRUE. + * + * Side Effects: + * regD is overwritten. + * + *----------------------------------------------------------------------- + */ + +int +XSubtractRegion( + Region regM, + Region regS, + register Region regD) +{ + /* check for trivial reject */ + if ( (!(regM->numRects)) || (!(regS->numRects)) || + (!EXTENTCHECK(®M->extents, ®S->extents)) ) + { + miRegionCopy(regD, regM); + return 1; + } + + miRegionOp (regD, regM, regS, miSubtractO, + miSubtractNonO1, NULL); + + /* + * Can't alter newReg's extents before we call miRegionOp because + * it might be one of the source regions and miRegionOp depends + * on the extents of those regions being the unaltered. Besides, this + * way there's no checking against rectangles that will be nuked + * due to coalescing, so we have to examine fewer rectangles. + */ + miSetExtents (regD); + return 1; +} + +int +XXorRegion(Region sra, Region srb, Region dr) +{ + Region tra, trb; + + if ((! (tra = XCreateRegion())) || (! (trb = XCreateRegion()))) + return 0; + (void) XSubtractRegion(sra,srb,tra); + (void) XSubtractRegion(srb,sra,trb); + (void) XUnionRegion(tra,trb,dr); + XDestroyRegion(tra); + XDestroyRegion(trb); + return 0; +} + +/* + * Check to see if the region is empty. Assumes a region is passed + * as a parameter + */ +int +XEmptyRegion( + Region r) +{ + if( r->numRects == 0 ) return TRUE; + else return FALSE; +} + +/* + * Check to see if two regions are equal + */ +int +XEqualRegion(Region r1, Region r2) +{ + int i; + + if( r1->numRects != r2->numRects ) return FALSE; + else if( r1->numRects == 0 ) return TRUE; + else if ( r1->extents.x1 != r2->extents.x1 ) return FALSE; + else if ( r1->extents.x2 != r2->extents.x2 ) return FALSE; + else if ( r1->extents.y1 != r2->extents.y1 ) return FALSE; + else if ( r1->extents.y2 != r2->extents.y2 ) return FALSE; + else for( i=0; i < r1->numRects; i++ ) { + if ( r1->rects[i].x1 != r2->rects[i].x1 ) return FALSE; + else if ( r1->rects[i].x2 != r2->rects[i].x2 ) return FALSE; + else if ( r1->rects[i].y1 != r2->rects[i].y1 ) return FALSE; + else if ( r1->rects[i].y2 != r2->rects[i].y2 ) return FALSE; + } + return TRUE; +} + +int +XPointInRegion( + Region pRegion, + int x, int y) +{ + int i; + + if (pRegion->numRects == 0) + return FALSE; + if (!INBOX(pRegion->extents, x, y)) + return FALSE; + for (i=0; i<pRegion->numRects; i++) + { + if (INBOX (pRegion->rects[i], x, y)) + return TRUE; + } + return FALSE; +} + +int +XRectInRegion( + register Region region, + int rx, int ry, + unsigned int rwidth, unsigned int rheight) +{ + register BoxPtr pbox; + register BoxPtr pboxEnd; + Box rect; + register BoxPtr prect = ▭ + int partIn, partOut; + + prect->x1 = rx; + prect->y1 = ry; + prect->x2 = rwidth + rx; + prect->y2 = rheight + ry; + + /* this is (just) a useful optimization */ + if ((region->numRects == 0) || !EXTENTCHECK(®ion->extents, prect)) + return(RectangleOut); + + partOut = FALSE; + partIn = FALSE; + + /* can stop when both partOut and partIn are TRUE, or we reach prect->y2 */ + for (pbox = region->rects, pboxEnd = pbox + region->numRects; + pbox < pboxEnd; + pbox++) + { + + if (pbox->y2 <= ry) + continue; /* getting up to speed or skipping remainder of band */ + + if (pbox->y1 > ry) + { + partOut = TRUE; /* missed part of rectangle above */ + if (partIn || (pbox->y1 >= prect->y2)) + break; + ry = pbox->y1; /* x guaranteed to be == prect->x1 */ + } + + if (pbox->x2 <= rx) + continue; /* not far enough over yet */ + + if (pbox->x1 > rx) + { + partOut = TRUE; /* missed part of rectangle to left */ + if (partIn) + break; + } + + if (pbox->x1 < prect->x2) + { + partIn = TRUE; /* definitely overlap */ + if (partOut) + break; + } + + if (pbox->x2 >= prect->x2) + { + ry = pbox->y2; /* finished with this band */ + if (ry >= prect->y2) + break; + rx = prect->x1; /* reset x out to left again */ + } else + { + /* + * Because boxes in a band are maximal width, if the first box + * to overlap the rectangle doesn't completely cover it in that + * band, the rectangle must be partially out, since some of it + * will be uncovered in that band. partIn will have been set true + * by now... + */ + break; + } + + } + + return(partIn ? ((ry < prect->y2) ? RectanglePart : RectangleIn) : + RectangleOut); +} |