Migrating to new directory structure adopted from the RealVNC's source tree. More changes will follow.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@589 3789f03b-4d11-0410-bbf8-ca57d06f2519

5 files changed, 2243 insertions, 0 deletions

diff --git a/common/Xregion/Makefile.in b/common/Xregion/Makefile.in
new file mode 100644
index 00000000..878a29b6
--- /dev/null
+++ b/common/Xregion/Makefile.in
@@ -0,0 +1,15 @@
+
+SRCS = Region.c
+
+OBJS = $(SRCS:.c=.o)
+
+library = libXregion.a
+
+all:: $(library)
+
+$(library): $(OBJS)
+	rm -f $(library)
+	$(AR) $(library) $(OBJS)
+	$(RANLIB) $(library)
+
+# followed by boilerplate.mk
diff --git a/common/Xregion/Region.c b/common/Xregion/Region.c
new file mode 100644
index 00000000..c0b1e5a2
--- /dev/null
+++ b/common/Xregion/Region.c
@@ -0,0 +1,1694 @@
+/* $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 1.8 2001/12/14 19:54:05 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...
+ */
+
+#include "Xregion.h"
+//#include "Xlibint.h"
+//#include "Xutil.h"
+#include "region.h"
+//#include "poly.h"
+
+#ifndef min
+#define min(a,b)            (((a) < (b)) ? (a) : (b))
+#endif
+#ifndef max
+#define max(a,b)            (((a) > (b)) ? (a) : (b))
+#endif
+
+#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 void (*voidProcp)();
+
+static void miRegionOp();
+/*	Create a new empty region	*/
+Region
+XCreateRegion()
+{
+    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( r, rect )
+    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(rect, source, dest)
+    register XRectangle *rect;
+    Region source, dest;
+{
+    REGION region;
+
+    if (!rect->width || !rect->height)
+	return 0;
+    region.rects = &region.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(&region, 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 (pReg)
+    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);
+}
+
+extern void _XSetClipRectangles();
+
+#if 0
+int
+XSetRegion( dpy, gc, r )
+    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;
+}
+#endif
+
+int
+XDestroyRegion( r )
+    Region r;
+{
+    Xfree( (char *) r->rects );
+    Xfree( (char *) r );
+    return 1;
+}
+
+
+/* TranslateRegion(pRegion, x, y)
+   translates in place
+   added by raymond
+*/
+
+int
+XOffsetRegion(pRegion, x, y)
+    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(r, s, t, dx, xdir, grow)
+    Region r, s, t;
+    register unsigned dx;
+    register int xdir, 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(r, dx, dy)
+    Region r;
+    int dx, 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(rects, numRects, y)
+    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 (pReg, r1, r1End, r2, r2End, y1, y2)
+    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(reg1, reg2, newReg)
+    Region 	  	reg1;
+    Region	  	reg2;          /* source regions     */
+    register Region 	newReg;               /* destination Region */
+{
+   /* check for trivial reject */
+    if ( (!(reg1->numRects)) || (!(reg2->numRects))  ||
+	(!EXTENTCHECK(&reg1->extents, &reg2->extents)))
+        newReg->numRects = 0;
+    else
+	miRegionOp (newReg, reg1, reg2, 
+    		(voidProcp) miIntersectO, (voidProcp) NULL, (voidProcp) 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(dstrgn, rgn)
+    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(newReg, reg1, reg2)
+    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(&reg2->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(newReg, reg1, reg2)
+    Region newReg, reg1, 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(newReg, rects, reg1, reg2, FirstRect)
+    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 (pReg, prevStart, curStart)
+    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(newReg, reg1, reg2, overlapFunc,  nonOverlap1Func, nonOverlap2Func)
+    register Region 	newReg;	    	    	/* Place to store result */
+    Region	  	reg1;	    	    	/* First region in operation */
+    Region	  	reg2;	    	    	/* 2d region in operation */
+    void    	  	(*overlapFunc)();   	/* Function to call for over-
+						 * lapping bands */
+    void    	  	(*nonOverlap1Func)();	/* Function to call for non-
+						 * overlapping bands in region
+						 * 1 */
+    void    	  	(*nonOverlap2Func)();	/* 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 != (void (*)())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 != (void (*)())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 != (void (*)())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 != (void (*)())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 (pReg, r, rEnd, y1, y2)
+    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 (pReg, r1, r1End, r2, r2End, y1, y2)
+    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(reg1, reg2, newReg)
+    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, (voidProcp) miUnionO, 
+    		(voidProcp) miUnionNonO, (voidProcp) 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 (pReg, r, rEnd, y1, y2)
+    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 (pReg, r1, r1End, r2, r2End, y1, y2)
+    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(regM, regS, regD)
+    Region 	  	regM;
+    Region	  	regS;          
+    register Region	regD;
+{
+   /* check for trivial reject */
+    if ( (!(regM->numRects)) || (!(regS->numRects))  ||
+	(!EXTENTCHECK(&regM->extents, &regS->extents)) )
+    {
+	miRegionCopy(regD, regM);
+        return 1;
+    }
+ 
+    miRegionOp (regD, regM, regS, (voidProcp) miSubtractO, 
+    		(voidProcp) miSubtractNonO1, (voidProcp) 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( sra, srb, dr )
+    Region sra, srb, 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( r )
+    Region r;
+{
+    if( r->numRects == 0 ) return TRUE;
+    else  return FALSE;
+}
+
+/*
+ *	Check to see if two regions are equal	
+ */
+int 
+XEqualRegion( r1, r2 )
+    Region r1, 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( pRegion, x, y )
+    Region pRegion;
+    int x, 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(region, rx, ry, rwidth, rheight)
+    register Region	region;
+    int rx, ry;
+    unsigned int rwidth, rheight;
+{
+    register BoxPtr pbox;
+    register BoxPtr pboxEnd;
+    Box rect;
+    register BoxPtr prect = &rect;
+    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(&region->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);
+}
diff --git a/common/Xregion/Xregion.dsp b/common/Xregion/Xregion.dsp
new file mode 100644
index 00000000..e30b5180
--- /dev/null
+++ b/common/Xregion/Xregion.dsp
@@ -0,0 +1,132 @@
+# Microsoft Developer Studio Project File - Name="Xregion" - Package Owner=<4>

+# Microsoft Developer Studio Generated Build File, Format Version 6.00

+# ** DO NOT EDIT **

+

+# TARGTYPE "Win32 (x86) Static Library" 0x0104

+

+CFG=Xregion - Win32 Debug Unicode

+!MESSAGE This is not a valid makefile. To build this project using NMAKE,

+!MESSAGE use the Export Makefile command and run

+!MESSAGE 

+!MESSAGE NMAKE /f "Xregion.mak".

+!MESSAGE 

+!MESSAGE You can specify a configuration when running NMAKE

+!MESSAGE by defining the macro CFG on the command line. For example:

+!MESSAGE 

+!MESSAGE NMAKE /f "Xregion.mak" CFG="Xregion - Win32 Debug Unicode"

+!MESSAGE 

+!MESSAGE Possible choices for configuration are:

+!MESSAGE 

+!MESSAGE "Xregion - Win32 Release" (based on "Win32 (x86) Static Library")

+!MESSAGE "Xregion - Win32 Debug" (based on "Win32 (x86) Static Library")

+!MESSAGE "Xregion - Win32 Debug Unicode" (based on "Win32 (x86) Static Library")

+!MESSAGE 

+

+# Begin Project

+# PROP AllowPerConfigDependencies 0

+# PROP Scc_ProjName ""

+# PROP Scc_LocalPath ""

+CPP=cl.exe

+RSC=rc.exe

+

+!IF  "$(CFG)" == "Xregion - Win32 Release"

+

+# PROP BASE Use_MFC 0

+# PROP BASE Use_Debug_Libraries 0

+# PROP BASE Output_Dir "Release"

+# PROP BASE Intermediate_Dir "Release"

+# PROP BASE Target_Dir ""

+# PROP Use_MFC 0

+# PROP Use_Debug_Libraries 0

+# PROP Output_Dir "..\Release"

+# PROP Intermediate_Dir "..\Release\Xregion"

+# PROP Target_Dir ""

+# ADD BASE CPP /nologo /W3 /GX /O2 /D "WIN32" /D "NDEBUG" /D "_MBCS" /D "_LIB" /YX /FD /c

+# ADD CPP /nologo /MT /W3 /GX /O2 /I ".." /D "NDEBUG" /D "_LIB" /D "WIN32" /D "_MBCS" /YX /FD /c

+# ADD BASE RSC /l 0x809 /d "NDEBUG"

+# ADD RSC /l 0x809 /d "NDEBUG"

+BSC32=bscmake.exe

+# ADD BASE BSC32 /nologo

+# ADD BSC32 /nologo

+LIB32=link.exe -lib

+# ADD BASE LIB32 /nologo

+# ADD LIB32 /nologo

+

+!ELSEIF  "$(CFG)" == "Xregion - Win32 Debug"

+

+# PROP BASE Use_MFC 0

+# PROP BASE Use_Debug_Libraries 1

+# PROP BASE Output_Dir "Debug"

+# PROP BASE Intermediate_Dir "Debug"

+# PROP BASE Target_Dir ""

+# PROP Use_MFC 0

+# PROP Use_Debug_Libraries 1

+# PROP Output_Dir "..\Debug"

+# PROP Intermediate_Dir "..\Debug\Xregion"

+# PROP Target_Dir ""

+# ADD BASE CPP /nologo /W3 /Gm /GX /ZI /Od /D "WIN32" /D "_DEBUG" /D "_MBCS" /D "_LIB" /YX /FD /GZ /c

+# ADD CPP /nologo /MTd /W3 /Gm /GX /ZI /Od /I ".." /D "_DEBUG" /D "_LIB" /D "WIN32" /D "_MBCS" /FD /GZ /c

+# SUBTRACT CPP /YX

+# ADD BASE RSC /l 0x809 /d "_DEBUG"

+# ADD RSC /l 0x809 /d "_DEBUG"

+BSC32=bscmake.exe

+# ADD BASE BSC32 /nologo

+# ADD BSC32 /nologo

+LIB32=link.exe -lib

+# ADD BASE LIB32 /nologo

+# ADD LIB32 /nologo

+

+!ELSEIF  "$(CFG)" == "Xregion - Win32 Debug Unicode"

+

+# PROP BASE Use_MFC 0

+# PROP BASE Use_Debug_Libraries 1

+# PROP BASE Output_Dir "Xregion___Win32_Debug_Unicode"

+# PROP BASE Intermediate_Dir "Xregion___Win32_Debug_Unicode"

+# PROP BASE Target_Dir ""

+# PROP Use_MFC 0

+# PROP Use_Debug_Libraries 1

+# PROP Output_Dir "..\Debug_Unicode"

+# PROP Intermediate_Dir "..\Debug_Unicode\Xregion"

+# PROP Target_Dir ""

+# ADD BASE CPP /nologo /MTd /W3 /Gm /GX /ZI /Od /I ".." /D "_DEBUG" /D "_LIB" /D "WIN32" /D "_MBCS" /FD /GZ /c

+# SUBTRACT BASE CPP /YX

+# ADD CPP /nologo /MTd /W3 /Gm /GX /ZI /Od /I ".." /D "_LIB" /D "_DEBUG" /D "WIN32" /D "_UNICODE" /D "UNICODE" /FD /GZ /c

+# SUBTRACT CPP /YX

+# ADD BASE RSC /l 0x809 /d "_DEBUG"

+# ADD RSC /l 0x809 /d "_DEBUG"

+BSC32=bscmake.exe

+# ADD BASE BSC32 /nologo

+# ADD BSC32 /nologo

+LIB32=link.exe -lib

+# ADD BASE LIB32 /nologo

+# ADD LIB32 /nologo

+

+!ENDIF 

+

+# Begin Target

+

+# Name "Xregion - Win32 Release"

+# Name "Xregion - Win32 Debug"

+# Name "Xregion - Win32 Debug Unicode"

+# Begin Group "Source Files"

+

+# PROP Default_Filter "cpp;c;cxx;rc;def;r;odl;idl;hpj;bat"

+# Begin Source File

+

+SOURCE=.\Region.c

+# End Source File

+# End Group

+# Begin Group "Header Files"

+

+# PROP Default_Filter "h;hpp;hxx;hm;inl"

+# Begin Source File

+

+SOURCE=.\region.h

+# End Source File

+# Begin Source File

+

+SOURCE=.\Xregion.h

+# End Source File

+# End Group

+# End Target

+# End Project

diff --git a/common/Xregion/Xregion.h b/common/Xregion/Xregion.h
new file mode 100644
index 00000000..e8c9a4f9
--- /dev/null
+++ b/common/Xregion/Xregion.h
@@ -0,0 +1,212 @@
+/* $Xorg: Xutil.h,v 1.8 2001/02/09 02:03:39 xorgcvs Exp $ */
+
+/***********************************************************
+
+Copyright 1987, 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 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/Xutil.h,v 3.4 2001/12/14 19:54:10 dawes Exp $ */
+
+#ifndef _XREGION_H_
+#define _XREGION_H_
+
+// - Faked defines to fool the X11 region code
+
+#include <stdlib.h>
+#include <string.h>
+
+#define Bool int
+#define Xmalloc malloc
+#define Xfree free
+#define Xrealloc realloc
+
+#define NeedFunctionPrototypes 1
+
+// - Cribbed from Xlib.h
+
+typedef struct {
+    short x, y;
+} XPoint;
+
+typedef struct {
+    short x, y;
+    unsigned short width, height;
+} XRectangle;
+
+/*
+ * opaque reference to Region data type 
+ */
+typedef struct _XRegion *Region; 
+
+/* Return values from XRectInRegion() */
+ 
+#define RectangleOut 0
+#define RectangleIn  1
+#define RectanglePart 2
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern int XClipBox(
+#if NeedFunctionPrototypes
+    Region		/* r */,
+    XRectangle*		/* rect_return */
+#endif
+);
+
+extern Region XCreateRegion(
+#if NeedFunctionPrototypes
+    void
+#endif
+);
+
+extern const char *XDefaultString (void);
+
+extern int XDestroyRegion(
+#if NeedFunctionPrototypes
+    Region		/* r */
+#endif
+);
+
+extern int XEmptyRegion(
+#if NeedFunctionPrototypes
+    Region		/* r */
+#endif
+);
+
+extern int XEqualRegion(
+#if NeedFunctionPrototypes
+    Region		/* r1 */,
+    Region		/* r2 */
+#endif
+);
+
+extern int XIntersectRegion(
+#if NeedFunctionPrototypes
+    Region		/* sra */,
+    Region		/* srb */,
+    Region		/* dr_return */
+#endif
+);
+
+extern int XOffsetRegion(
+#if NeedFunctionPrototypes
+    Region		/* r */,
+    int			/* dx */,
+    int			/* dy */
+#endif
+);
+
+extern Bool XPointInRegion(
+#if NeedFunctionPrototypes
+    Region		/* r */,
+    int			/* x */,
+    int			/* y */
+#endif
+);
+
+extern Region XPolygonRegion(
+#if NeedFunctionPrototypes
+    XPoint*		/* points */,
+    int			/* n */,
+    int			/* fill_rule */
+#endif
+);
+
+extern int XRectInRegion(
+#if NeedFunctionPrototypes
+    Region		/* r */,
+    int			/* x */,
+    int			/* y */,
+    unsigned int	/* width */,
+    unsigned int	/* height */
+#endif
+);
+
+extern int XShrinkRegion(
+#if NeedFunctionPrototypes
+    Region		/* r */,
+    int			/* dx */,
+    int			/* dy */
+#endif
+);
+
+extern int XSubtractRegion(
+#if NeedFunctionPrototypes
+    Region		/* sra */,
+    Region		/* srb */,
+    Region		/* dr_return */
+#endif
+);
+
+extern int XUnionRectWithRegion(
+#if NeedFunctionPrototypes
+    XRectangle*		/* rectangle */,
+    Region		/* src_region */,
+    Region		/* dest_region_return */
+#endif
+);
+
+extern int XUnionRegion(
+#if NeedFunctionPrototypes
+    Region		/* sra */,
+    Region		/* srb */,
+    Region		/* dr_return */
+#endif
+);
+
+extern int XXorRegion(
+#if NeedFunctionPrototypes
+    Region		/* sra */,
+    Region		/* srb */,
+    Region		/* dr_return */
+#endif
+);
+
+#ifdef __cplusplus
+};
+#endif
+
+#endif /* _XUTIL_H_ */
diff --git a/common/Xregion/region.h b/common/Xregion/region.h
new file mode 100644
index 00000000..2ddf12ca
--- /dev/null
+++ b/common/Xregion/region.h
@@ -0,0 +1,190 @@
+/* $Xorg: region.h,v 1.4 2001/02/09 02:03:40 xorgcvs Exp $ */
+/************************************************************************
+
+Copyright 1987, 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 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.
+
+************************************************************************/
+
+#ifndef _XREGION_H
+#define _XREGION_H
+
+typedef struct {
+    short x1, x2, y1, y2;
+} Box, BOX, BoxRec, *BoxPtr;
+
+typedef struct {
+    short x, y, width, height;
+}RECTANGLE, RectangleRec, *RectanglePtr;
+
+#define TRUE 1
+#define FALSE 0
+#define MAXSHORT 32767
+#define MINSHORT -MAXSHORT
+#ifndef MAX
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+#endif
+#ifndef MIN
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+#endif
+
+
+/* 
+ *   clip region
+ */
+
+typedef struct _XRegion {
+    long size;
+    long numRects;
+    BOX *rects;
+    BOX extents;
+} REGION;
+
+/* Xutil.h contains the declaration: 
+ * typedef struct _XRegion *Region; 
+ */   
+
+/*  1 if two BOXs overlap.
+ *  0 if two BOXs do not overlap.
+ *  Remember, x2 and y2 are not in the region 
+ */
+#define EXTENTCHECK(r1, r2) \
+	((r1)->x2 > (r2)->x1 && \
+	 (r1)->x1 < (r2)->x2 && \
+	 (r1)->y2 > (r2)->y1 && \
+	 (r1)->y1 < (r2)->y2)
+
+/*
+ *  update region extents
+ */
+#define EXTENTS(r,idRect){\
+            if((r)->x1 < (idRect)->extents.x1)\
+              (idRect)->extents.x1 = (r)->x1;\
+            if((r)->y1 < (idRect)->extents.y1)\
+              (idRect)->extents.y1 = (r)->y1;\
+            if((r)->x2 > (idRect)->extents.x2)\
+              (idRect)->extents.x2 = (r)->x2;\
+            if((r)->y2 > (idRect)->extents.y2)\
+              (idRect)->extents.y2 = (r)->y2;\
+        }
+
+/*
+ *   Check to see if there is enough memory in the present region.
+ */
+#define MEMCHECK(reg, rect, firstrect){\
+        if ((reg)->numRects >= ((reg)->size - 1)){\
+          (firstrect) = (BOX *) Xrealloc \
+          ((char *)(firstrect), (unsigned) (2 * (sizeof(BOX)) * ((reg)->size)));\
+          if ((firstrect) == 0)\
+            return(0);\
+          (reg)->size *= 2;\
+          (rect) = &(firstrect)[(reg)->numRects];\
+         }\
+       }
+
+/*  this routine checks to see if the previous rectangle is the same
+ *  or subsumes the new rectangle to add.
+ */
+
+#define CHECK_PREVIOUS(Reg, R, Rx1, Ry1, Rx2, Ry2)\
+               (!(((Reg)->numRects > 0)&&\
+                  ((R-1)->y1 == (Ry1)) &&\
+                  ((R-1)->y2 == (Ry2)) &&\
+                  ((R-1)->x1 <= (Rx1)) &&\
+                  ((R-1)->x2 >= (Rx2))))
+
+/*  add a rectangle to the given Region */
+#define ADDRECT(reg, r, rx1, ry1, rx2, ry2){\
+    if (((rx1) < (rx2)) && ((ry1) < (ry2)) &&\
+        CHECK_PREVIOUS((reg), (r), (rx1), (ry1), (rx2), (ry2))){\
+              (r)->x1 = (rx1);\
+              (r)->y1 = (ry1);\
+              (r)->x2 = (rx2);\
+              (r)->y2 = (ry2);\
+              EXTENTS((r), (reg));\
+              (reg)->numRects++;\
+              (r)++;\
+            }\
+        }
+
+
+
+/*  add a rectangle to the given Region */
+#define ADDRECTNOX(reg, r, rx1, ry1, rx2, ry2){\
+            if ((rx1 < rx2) && (ry1 < ry2) &&\
+                CHECK_PREVIOUS((reg), (r), (rx1), (ry1), (rx2), (ry2))){\
+              (r)->x1 = (rx1);\
+              (r)->y1 = (ry1);\
+              (r)->x2 = (rx2);\
+              (r)->y2 = (ry2);\
+              (reg)->numRects++;\
+              (r)++;\
+            }\
+        }
+
+#define EMPTY_REGION(pReg) pReg->numRects = 0
+
+#define REGION_NOT_EMPTY(pReg) pReg->numRects
+
+#define INBOX(r, x, y) \
+      ( ( ((r).x2 >  x)) && \
+        ( ((r).x1 <= x)) && \
+        ( ((r).y2 >  y)) && \
+        ( ((r).y1 <= y)) )
+
+/*
+ * number of points to buffer before sending them off
+ * to scanlines() :  Must be an even number
+ */
+#define NUMPTSTOBUFFER 200
+
+/*
+ * used to allocate buffers for points and link
+ * the buffers together
+ */
+typedef struct _POINTBLOCK {
+    XPoint pts[NUMPTSTOBUFFER];
+    struct _POINTBLOCK *next;
+} POINTBLOCK;
+
+#endif