]> git.saurik.com Git - wxWidgets.git/blobdiff - src/generic/regiong.cpp
don't take EVT_HEADER_END_DRAG into account if it indicates the the drag was cancelled
[wxWidgets.git] / src / generic / regiong.cpp
index 3027f4a213bf025d96066b96802119913d06be17..d9ee1d95dea5c6d9a6a5e0c3678551eacfe634f6 100644 (file)
@@ -1,16 +1,27 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        generic/region.cpp
+// Name:        src/generic/region.cpp
 // Purpose:     generic wxRegion class
 // Author:      David Elliott
 // Modified by:
 // Created:     2004/04/12
 // RCS-ID:      $Id$
 // Copyright:   (c) 2004 David Elliott
-// Licence:    wxWidgets licence
+// Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
-#include "wx/generic/region.h"
-#include "wx/utils.h"
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __BORLANDC__
+    #pragma hdrstop
+#endif
+
+#include "wx/region.h"
+
+#ifndef WX_PRECOMP
+    #include "wx/utils.h"
+#endif
 
 // ========================================================================
 // Classes to interface with X.org code
@@ -28,6 +39,7 @@ struct REGION
 public:
     // Default constructor initializes nothing
     REGION() {}
+
     REGION(const wxRect& rect)
     {
         rects = &extents;
@@ -38,7 +50,11 @@ public:
         extents.y2 = rect.y + rect.height;
         size = 1;
     }
-    BoxPtr GetBox(int i) { if(i<numRects) return rects+i; else return NULL; }
+
+    BoxPtr GetBox(int i)
+    {
+        return i < numRects ? rects + i : NULL;
+    }
 
     // X.org methods
     static bool XClipBox(
@@ -49,17 +65,17 @@ public:
         register int x,
         register int y);
     static bool XIntersectRegion(
-        Region                 reg1,
-        Region         reg2,          /* source regions     */
-        register Region        newReg);               /* destination Region */
+        Region reg1,
+        Region reg2,          /* source regions     */
+        register Region newReg);               /* destination Region */
     static bool XUnionRegion(
-        Region           reg1,
-        Region   reg2,             /* source regions     */
-        Region           newReg);                  /* destination Region */
+        Region reg1,
+        Region reg2,             /* source regions     */
+        Region newReg);                  /* destination Region */
     static bool XSubtractRegion(
-        Region                 regM,
-        Region         regS,          
-        register Region        regD);
+        Region regM,
+        Region regS,
+        register Region regD);
     static bool XXorRegion(Region sra, Region srb, Region dr);
     static bool XEmptyRegion(
         Region r);
@@ -68,87 +84,87 @@ public:
         Region pRegion,
         int x, int y);
     static wxRegionContain XRectInRegion(
-        register Region        region,
+        register Region region,
         int rx, int ry,
         unsigned int rwidth, unsigned int rheight);
 
 protected:
     static Region XCreateRegion(void);
     static void miSetExtents (
-        Region         pReg);
+        Region pReg);
     static bool XDestroyRegion(Region r);
     static int miIntersectO (
-        register Region        pReg,
-        register BoxPtr        r1,
-        BoxPtr                 r1End,
-        register BoxPtr        r2,
-        BoxPtr                 r2End,
-        wxCoord                y1,
-        wxCoord                y2);
+        register Region pReg,
+        register BoxPtr r1,
+        BoxPtr r1End,
+        register BoxPtr r2,
+        BoxPtr r2End,
+        wxCoord y1,
+        wxCoord y2);
     static void miRegionCopy(
         register Region dstrgn,
         register Region rgn);
     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 Region pReg, /* Region to coalesce */
+        int prevStart, /* Index of start of previous band */
+        int curStart); /* Index of start of current band */
     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 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,
-            wxCoord               y1,
-            wxCoord               y2),            /* Function to call for over-
-                                                * lapping bands */
-        int                    (*nonOverlap1Func)(
+            wxCoord             y1,
+            wxCoord             y2), /* Function to call for over-
+                                      * lapping bands */
+        int (*nonOverlap1Func)(
             register Region     pReg,
             register BoxPtr     r,
             BoxPtr              rEnd,
-            register wxCoord      y1,
-            register wxCoord      y2),            /* Function to call for non-
-                                                * overlapping bands in region
-                                                * 1 */
-        int                    (*nonOverlap2Func)(
+            register wxCoord    y1,
+            register wxCoord    y2), /* Function to call for non-
+                                      * overlapping bands in region
+                                      * 1 */
+        int (*nonOverlap2Func)(
             register Region     pReg,
             register BoxPtr     r,
             BoxPtr              rEnd,
-            register wxCoord      y1,
-            register wxCoord      y2));           /* Function to call for non-
-                                                * overlapping bands in region
-                                                * 2 */
+            register wxCoord    y1,
+            register wxCoord    y2)); /* Function to call for non-
+                                       * overlapping bands in region
+                                       * 2 */
     static int miUnionNonO (
-        register Region        pReg,
-        register BoxPtr        r,
-        BoxPtr                 rEnd,
-        register wxCoord       y1,
-        register wxCoord       y2);
+        register Region pReg,
+        register BoxPtr r,
+        BoxPtr rEnd,
+        register wxCoord y1,
+        register wxCoord y2);
     static int miUnionO (
-        register Region        pReg,
-        register BoxPtr        r1,
-        BoxPtr                 r1End,
-        register BoxPtr        r2,
-        BoxPtr                 r2End,
-        register wxCoord       y1,
-        register wxCoord       y2);
+        register Region pReg,
+        register BoxPtr r1,
+        BoxPtr r1End,
+        register BoxPtr r2,
+        BoxPtr r2End,
+        register wxCoord y1,
+        register wxCoord y2);
     static int miSubtractNonO1 (
-        register Region        pReg,
-        register BoxPtr        r,
-        BoxPtr                 rEnd,
-        register wxCoord       y1,
-        register wxCoord       y2);
+        register Region pReg,
+        register BoxPtr r,
+        BoxPtr rEnd,
+        register wxCoord y1,
+        register wxCoord y2);
     static int miSubtractO (
-        register Region        pReg,
-        register BoxPtr        r1,
-        BoxPtr                 r1End,
-        register BoxPtr        r2,
-        BoxPtr                 r2End,
-        register wxCoord       y1,
-        register wxCoord       y2);
+        register Region pReg,
+        register BoxPtr r1,
+        BoxPtr r1End,
+        register BoxPtr r2,
+        BoxPtr r2End,
+        register wxCoord y1,
+        register wxCoord y2);
 protected:
     long size;
     long numRects;
@@ -159,12 +175,16 @@ protected:
 // ========================================================================
 // wxRegionRefData
 // ========================================================================
-class wxRegionRefData : public wxObjectRefData, public REGION
+
+class wxRegionRefData : public wxGDIRefData,
+                        public REGION
 {
 public:
     wxRegionRefData()
-    /* XCreateRegion */
-    {   size = 1;
+        : wxGDIRefData(),
+          REGION()
+    {
+        size = 1;
         numRects = 0;
         rects = ( BOX * )malloc( (unsigned) sizeof( BOX ));
         extents.x1 = 0;
@@ -172,10 +192,12 @@ public:
         extents.y1 = 0;
         extents.y2 = 0;
     }
+
     wxRegionRefData(const wxPoint& topLeft, const wxPoint& bottomRight)
-    :   wxObjectRefData()
-    ,   REGION()
-    {   rects = (BOX*)malloc(sizeof(BOX));
+        : wxGDIRefData(),
+          REGION()
+    {
+        rects = (BOX*)malloc(sizeof(BOX));
         size = 1;
         numRects = 1;
         extents.x1 = topLeft.x;
@@ -184,25 +206,31 @@ public:
         extents.y2 = bottomRight.y;
         *rects = extents;
     }
+
     wxRegionRefData(const wxRect& rect)
-    :   wxObjectRefData()
-    ,   REGION(rect)
-    {   rects = (BOX*)malloc(sizeof(BOX));
+        : wxGDIRefData(),
+          REGION(rect)
+    {
+        rects = (BOX*)malloc(sizeof(BOX));
         *rects = extents;
     }
+
     wxRegionRefData(const wxRegionRefData& refData)
-    :   wxObjectRefData()
-    ,   REGION()
+        : wxGDIRefData(),
+          REGION()
     {
         size = refData.size;
         numRects = refData.numRects;
         rects = (Box*)malloc(numRects*sizeof(Box));
+        memcpy(rects, refData.rects, numRects*sizeof(Box));
         extents = refData.extents;
     }
-    ~wxRegionRefData()
+
+    virtual ~wxRegionRefData()
     {
         free(rects);
     }
+
 private:
     // Don't allow this
     wxRegionRefData(const REGION&);
@@ -211,7 +239,7 @@ private:
 // ========================================================================
 // wxRegionGeneric
 // ========================================================================
-//IMPLEMENT_DYNAMIC_CLASS(wxRegionGeneric, wxGDIObject);
+//IMPLEMENT_DYNAMIC_CLASS(wxRegionGeneric, wxGDIObject)
 
 #define M_REGIONDATA ((wxRegionRefData *)m_refData)
 #define M_REGIONDATA_OF(rgn) ((wxRegionRefData *)(rgn.m_refData))
@@ -246,112 +274,86 @@ wxRegionGeneric::wxRegionGeneric(const wxPoint& topLeft, const wxPoint& bottomRi
 void wxRegionGeneric::Clear()
 {
     UnRef();
+    if (!m_refData)
+        m_refData = new wxRegionRefData(wxRect(0,0,0,0));
 }
 
-wxObjectRefData *wxRegionGeneric::CreateRefData() const
+wxGDIRefData *wxRegionGeneric::CreateGDIRefData() const
 {
     return new wxRegionRefData;
 }
 
-wxObjectRefData *wxRegionGeneric::CloneRefData(const wxObjectRefData *data) const
+wxGDIRefData *wxRegionGeneric::CloneGDIRefData(const wxGDIRefData *data) const
 {
     return new wxRegionRefData(*(wxRegionRefData *)data);
 }
 
-bool wxRegionGeneric::operator== (const wxRegionGeneric& region)
+bool wxRegionGeneric::DoIsEqual(const wxRegion& region) const
 {
-    wxASSERT(m_refData && region.m_refData);
     return REGION::XEqualRegion(M_REGIONDATA,M_REGIONDATA_OF(region));
 }
 
-wxRect wxRegionGeneric::GetBox() const
+bool wxRegionGeneric::DoGetBox(wxCoord& x, wxCoord& y, wxCoord&w, wxCoord &h) const
 {
-    wxASSERT(m_refData);
-    wxRect rect;
-    REGION::XClipBox(M_REGIONDATA,&rect);
-    return rect;
-}
+    if ( !m_refData )
+        return false;
 
-void wxRegionGeneric::GetBox(wxCoord& x, wxCoord& y, wxCoord&w, wxCoord &h) const
-{
-    wxASSERT(m_refData);
     wxRect rect;
     REGION::XClipBox(M_REGIONDATA,&rect);
     x = rect.x;
     y = rect.y;
     w = rect.width;
     h = rect.height;
+    return true;
 }
 
 // ----------------------------------------------------------------------------
 // wxRegionGeneric operations
 // ----------------------------------------------------------------------------
 
-bool wxRegionGeneric::Union(const wxRect& rect)
-/* XUnionRectWithRegion */
+bool wxRegionGeneric::DoUnionWithRect(const wxRect& rect)
 {
-    if (!rect.width || !rect.height)
-       return false;
+    if ( rect.IsEmpty() )
+    {
+        // nothing to do
+        return true;
+    }
 
     AllocExclusive();
     REGION region(rect);
     return REGION::XUnionRegion(&region,M_REGIONDATA,M_REGIONDATA);
 }
 
-bool wxRegionGeneric::Union(const wxRegionGeneric& region)
+bool wxRegionGeneric::DoUnionWithRegion(const wxRegion& region)
 {
     AllocExclusive();
     return REGION::XUnionRegion(M_REGIONDATA_OF(region),M_REGIONDATA,M_REGIONDATA);
 }
 
-bool wxRegionGeneric::Intersect(const wxRect& rect)
-{
-    if (!rect.width || !rect.height)
-       return false;
-    AllocExclusive();
-    REGION region(rect);
-
-    return REGION::XIntersectRegion(&region,M_REGIONDATA,M_REGIONDATA);
-}
-
-bool wxRegionGeneric::Intersect(const wxRegionGeneric& region)
+bool wxRegionGeneric::DoIntersect(const wxRegion& region)
 {
     AllocExclusive();
     return REGION::XIntersectRegion(M_REGIONDATA_OF(region),M_REGIONDATA,M_REGIONDATA);
 }
 
-bool wxRegionGeneric::Subtract(const wxRect& rect)
+bool wxRegionGeneric::DoSubtract(const wxRegion& region)
 {
-    if (!rect.width || !rect.height)
-       return false;
-    AllocExclusive();
-    REGION region(rect);
-
-    return REGION::XSubtractRegion(&region,M_REGIONDATA,M_REGIONDATA);
-}
+    if ( region.IsEmpty() )
+    {
+        // nothing to do
+        return true;
+    }
 
-bool wxRegionGeneric::Subtract(const wxRegionGeneric& region)
-{
     return REGION::XSubtractRegion(M_REGIONDATA_OF(region),M_REGIONDATA,M_REGIONDATA);
 }
 
-bool wxRegionGeneric::Xor(const wxRect& rect)
-{
-    if (!rect.width || !rect.height)
-       return false;
-    AllocExclusive();
-    REGION region(rect);
-
-    return REGION::XXorRegion(&region,M_REGIONDATA,M_REGIONDATA);
-}
-
-bool wxRegionGeneric::Xor(const wxRegionGeneric& region)
+bool wxRegionGeneric::DoXor(const wxRegion& region)
 {
     AllocExclusive();
     return REGION::XXorRegion(M_REGIONDATA_OF(region),M_REGIONDATA,M_REGIONDATA);
 }
 
-bool wxRegionGeneric::Offset(wxCoord x, wxCoord y)
+bool wxRegionGeneric::DoOffset(wxCoord x, wxCoord y)
 {
     AllocExclusive();
     return REGION::XOffsetRegion(M_REGIONDATA, x, y);
@@ -361,44 +363,30 @@ bool wxRegionGeneric::Offset(wxCoord x, wxCoord y)
 // wxRegionGeneric comparison
 // ----------------------------------------------------------------------------
 
-bool wxRegionGeneric::Empty() const
+bool wxRegionGeneric::IsEmpty() const
 {
     wxASSERT(m_refData);
     return REGION::XEmptyRegion(M_REGIONDATA);
 }
 
 // Does the region contain the point (x,y)?
-wxRegionContain wxRegionGeneric::Contains(long x, long y) const
+wxRegionContain wxRegionGeneric::DoContainsPoint(wxCoord x, wxCoord y) const
 {
     wxASSERT(m_refData);
-    return REGION::XPointInRegion(M_REGIONDATA,x,y)?wxInRegion:wxOutRegion;
+    return REGION::XPointInRegion(M_REGIONDATA,x,y) ? wxInRegion : wxOutRegion;
 }
-    
-// Does the region contain the point pt?
-wxRegionContain wxRegionGeneric::Contains(const wxPoint& pt) const
-{
-    wxASSERT(m_refData);
-    return REGION::XPointInRegion(M_REGIONDATA,pt.x,pt.y)?wxInRegion:wxOutRegion;
-}
-    
-// Does the region contain the rectangle (x, y, w, h)?
-wxRegionContain wxRegionGeneric::Contains(long x, long y, long w, long h) const
-{
-    wxASSERT(m_refData);
-    return REGION::XRectInRegion(M_REGIONDATA,x,y,w,h);
-}
-    
+
 // Does the region contain the rectangle rect?
-wxRegionContain wxRegionGeneric::Contains(const wxRect& rect) const
+wxRegionContain wxRegionGeneric::DoContainsRect(const wxRect& rect) const
 {
     wxASSERT(m_refData);
     return REGION::XRectInRegion(M_REGIONDATA,rect.x,rect.y,rect.width,rect.height);
 }
-    
+
 // ========================================================================
 // wxRegionIteratorGeneric
 // ========================================================================
-//IMPLEMENT_DYNAMIC_CLASS(wxRegionIteratorGeneric,wxObject);
+//IMPLEMENT_DYNAMIC_CLASS(wxRegionIteratorGeneric,wxObject)
 
 wxRegionIteratorGeneric::wxRegionIteratorGeneric()
 {
@@ -443,7 +431,7 @@ wxRegionIteratorGeneric wxRegionIteratorGeneric::operator++(int)
 
 wxRect wxRegionIteratorGeneric::GetRect() const
 {
-    wxASSERT(m_refData);
+    wxASSERT(m_region.m_refData);
     const Box *box = M_REGIONDATA_OF(m_region)->GetBox(m_current);
     wxASSERT(box);
     return wxRect
@@ -456,7 +444,7 @@ wxRect wxRegionIteratorGeneric::GetRect() const
 
 long wxRegionIteratorGeneric::GetX() const
 {
-    wxASSERT(m_refData);
+    wxASSERT(m_region.m_refData);
     const Box *box = M_REGIONDATA_OF(m_region)->GetBox(m_current);
     wxASSERT(box);
     return box->x1;
@@ -464,7 +452,7 @@ long wxRegionIteratorGeneric::GetX() const
 
 long wxRegionIteratorGeneric::GetY() const
 {
-    wxASSERT(m_refData);
+    wxASSERT(m_region.m_refData);
     const Box *box = M_REGIONDATA_OF(m_region)->GetBox(m_current);
     wxASSERT(box);
     return box->y1;
@@ -472,7 +460,7 @@ long wxRegionIteratorGeneric::GetY() const
 
 long wxRegionIteratorGeneric::GetW() const
 {
-    wxASSERT(m_refData);
+    wxASSERT(m_region.m_refData);
     const Box *box = M_REGIONDATA_OF(m_region)->GetBox(m_current);
     wxASSERT(box);
     return box->x2 - box->x1;
@@ -480,7 +468,7 @@ long wxRegionIteratorGeneric::GetW() const
 
 long wxRegionIteratorGeneric::GetH() const
 {
-    wxASSERT(m_refData);
+    wxASSERT(m_region.m_refData);
     const Box *box = M_REGIONDATA_OF(m_region)->GetBox(m_current);
     wxASSERT(box);
     return box->y2 - box->y1;
@@ -524,13 +512,13 @@ 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, 
+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 
+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.  
+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
@@ -544,13 +532,13 @@ SOFTWARE.
 
 /*  1 if two BOXs overlap.
  *  0 if two BOXs do not overlap.
- *  Remember, x2 and y2 are not in the region 
+ *  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)
+    ((r1)->x2 > (r2)->x1 && \
+     (r1)->x1 < (r2)->x2 && \
+     (r1)->y2 > (r2)->y1 && \
+     (r1)->y1 < (r2)->y2)
 
 /*
  *   Check to see if there is enough memory in the present region.
@@ -602,17 +590,20 @@ SOFTWARE.
  * the y-x-banding that's so nice to have...
  */
 
-/*     Create a new empty region       */
-Region REGION::
-XCreateRegion(void)
+/* Create a new empty region */
+Region REGION::XCreateRegion(void)
 {
-    Region temp;
+    Region temp = new REGION;
+
+    if (!temp)
+        return (Region) NULL;
+
+    temp->rects = ( BOX * )malloc( (unsigned) sizeof( BOX ));
 
-    if (! (temp = new REGION))
-       return (Region) NULL;
-    if (! (temp->rects = ( BOX * )malloc( (unsigned) sizeof( BOX )))) {
-       free((char *) temp);
-       return (Region) NULL;
+    if (!temp->rects)
+    {
+        free((char *) temp);
+        return (Region) NULL;
     }
     temp->numRects = 0;
     temp->extents.x1 = 0;
@@ -623,10 +614,7 @@ XCreateRegion(void)
     return( temp );
 }
 
-bool REGION::
-XClipBox(
-    Region r,
-    wxRect *rect)
+bool REGION::XClipBox(Region r, wxRect *rect)
 {
     rect->x = r->extents.x1;
     rect->y = r->extents.y1;
@@ -638,33 +626,32 @@ XClipBox(
 /*-
  *-----------------------------------------------------------------------
  * 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.
+ *    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.
+ *    None.
  *
  * Side Effects:
- *     The region's 'extents' structure is overwritten.
+ *    The region's 'extents' structure is overwritten.
  *
  *-----------------------------------------------------------------------
  */
 void REGION::
-miSetExtents (
-    Region             pReg)
+miSetExtents (Region pReg)
 {
-    register BoxPtr    pBox,
-                       pBoxEnd,
-                       pExtents;
+    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;
+        pReg->extents.x1 = 0;
+        pReg->extents.y1 = 0;
+        pReg->extents.x2 = 0;
+        pReg->extents.y2 = 0;
+        return;
     }
 
     pExtents = &pReg->extents;
@@ -686,15 +673,15 @@ miSetExtents (
     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++;
+        if (pBox->x1 < pExtents->x1)
+        {
+            pExtents->x1 = pBox->x1;
+        }
+        if (pBox->x2 > pExtents->x2)
+        {
+            pExtents->x2 = pBox->x2;
+        }
+        pBox++;
     }
     assert(pExtents->x1 < pExtents->x2);
 }
@@ -727,11 +714,11 @@ XOffsetRegion(
 
     while(nbox--)
     {
-       pbox->x1 += x;
-       pbox->x2 += x;
-       pbox->y1 += y;
-       pbox->y2 += y;
-       pbox++;
+        pbox->x1 += x;
+        pbox->x2 += x;
+        pbox->y1 += y;
+        pbox->y2 += y;
+        pbox++;
     }
     pRegion->extents.x1 += x;
     pRegion->extents.x2 += x;
@@ -741,100 +728,100 @@ XOffsetRegion(
 }
 
 /*======================================================================
- *         Region Intersection
+ *  Region Intersection
  *====================================================================*/
 /*-
  *-----------------------------------------------------------------------
  * miIntersectO --
- *     Handle an overlapping band for miIntersect.
+ *    Handle an overlapping band for miIntersect.
  *
  * Results:
- *     None.
+ *    None.
  *
  * Side Effects:
- *     Rectangles may be added to the region.
+ *    Rectangles may be added to the region.
  *
  *-----------------------------------------------------------------------
  */
 /* static void*/
 int REGION::
 miIntersectO (
-    register Region    pReg,
-    register BoxPtr    r1,
-    BoxPtr             r1End,
-    register BoxPtr    r2,
-    BoxPtr             r2End,
-    wxCoord                    y1,
-    wxCoord                    y2)
+    register Region     pReg,
+    register BoxPtr     r1,
+    BoxPtr              r1End,
+    register BoxPtr     r2,
+    BoxPtr              r2End,
+    wxCoord             y1,
+    wxCoord             y2)
 {
-    register wxCoord   x1;
-    register wxCoord   x2;
-    register BoxPtr    pNextRect;
+    register wxCoord    x1;
+    register wxCoord    x2;
+    register BoxPtr     pNextRect;
 
     pNextRect = &pReg->rects[pReg->numRects];
 
     while ((r1 != r1End) && (r2 != r2End))
     {
-       x1 = wxMax(r1->x1,r2->x1);
-       x2 = wxMin(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++;
-       }
+        x1 = wxMax(r1->x1,r2->x1);
+        x2 = wxMin(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 */
+    return 0; /* lint */
 }
 
 bool REGION::
 XIntersectRegion(
-    Region             reg1,
-    Region             reg2,          /* source regions     */
-    register Region    newReg)               /* destination Region */
+    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)))
+        (!EXTENTCHECK(&reg1->extents, &reg2->extents)))
         newReg->numRects = 0;
     else
-       miRegionOp (newReg, reg1, reg2, 
-               miIntersectO, NULL, NULL);
-    
+        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
@@ -853,69 +840,71 @@ miRegionCopy(
 
 {
     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 *)
-                      realloc((char *) dstrgn->rects,
-                               (unsigned) rgn->numRects * (sizeof(BOX))))) {
-                   free(prevRects);
-                   return;
-               }
+                BOX *prevRects = dstrgn->rects;
+
+                dstrgn->rects = (BOX *)
+                       realloc((char *) dstrgn->rects,
+                               (unsigned) rgn->numRects * (sizeof(BOX)));
+                if (!dstrgn->rects)
+                {
+                    free(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)));
+        memcpy((char *) dstrgn->rects, (char *) rgn->rects,
+                (int) (rgn->numRects * sizeof(BOX)));
     }
 }
 
 /*======================================================================
- *         Generic Region Operator
+ * Generic Region Operator
  *====================================================================*/
 
 /*-
  *-----------------------------------------------------------------------
  * miCoalesce --
- *     Attempt to merge the boxes in the current band with those in the
- *     previous one. Used only by miRegionOp.
+ *    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.
+ *    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.
+ *    If coalescing takes place:
+ *        - rectangles in the previous band will have their y2 fields
+ *          altered.
+ *        - pReg->numRects will be decreased.
  *
  *-----------------------------------------------------------------------
  */
 /* static int*/
 int REGION::
 miCoalesce(
-    register Region    pReg,           /* Region to coalesce */
-    int                        prevStart,      /* Index of start of previous band */
-    int                        curStart)       /* Index of start of current band */
+    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 */
+    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];
 
@@ -930,98 +919,99 @@ miCoalesce(
     pCurBox = &pReg->rects[curStart];
     bandY1 = pCurBox->y1;
     for (curNumRects = 0;
-        (pCurBox != pRegEnd) && (pCurBox->y1 == bandY1);
-        curNumRects++)
+         (pCurBox != pRegEnd) && (pCurBox->y1 == bandY1);
+         curNumRects++)
     {
-       pCurBox++;
+        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 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);
-           }
-           
-       }
+
+    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);
 }
@@ -1029,82 +1019,82 @@ miCoalesce(
 /*-
  *-----------------------------------------------------------------------
  * miRegionOp --
- *     Apply an operation to two regions. Called by miUnion, miInverse,
- *     miSubtract, miIntersect...
+ *        Apply an operation to two regions. Called by miUnion, miInverse,
+ *        miSubtract, miIntersect...
  *
  * Results:
- *     None.
+ *        None.
  *
  * Side Effects:
- *     The new region is overwritten.
+ *        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.
+ *        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*/
 void REGION::
 miRegionOp(
-    register Region    newReg,                 /* Place to store result */
-    Region             reg1,                   /* First region in operation */
-    Region             reg2,                   /* 2d region in operation */
-    int                (*overlapFunc)(
+    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,
         wxCoord               y1,
-        wxCoord               y2),                /* Function to call for over-
-                                                * lapping bands */
-    int                (*nonOverlap1Func)(
+        wxCoord               y2),              /* Function to call for over-
+                                                 * lapping bands */
+    int                      (*nonOverlap1Func)(
         register Region     pReg,
         register BoxPtr     r,
         BoxPtr              rEnd,
         register wxCoord      y1,
-        register wxCoord      y2),                /* Function to call for non-
-                                                * overlapping bands in region
-                                                * 1 */
-    int                (*nonOverlap2Func)(
+        register wxCoord      y2),              /* Function to call for non-
+                                                 * overlapping bands in region
+                                                 * 1 */
+    int                      (*nonOverlap2Func)(
         register Region     pReg,
         register BoxPtr     r,
         BoxPtr              rEnd,
         register wxCoord      y1,
-        register wxCoord      y2))                /* Function to call for non-
-                                                * overlapping bands in region
-                                                * 2 */
+        register wxCoord      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 wxCoord   ybot;                   /* Bottom of intersection */
-    register wxCoord   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 */
-    wxCoord                    top;                    /* Top of non-overlapping
-                                                * band */
-    wxCoord                    bot;                    /* Bottom of non-overlapping
-                                                * band */
-    
+    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 wxCoord     ybot; /* Bottom of intersection */
+    register wxCoord     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 */
+    wxCoord               top; /* Top of non-overlapping
+                                * band */
+    wxCoord               bot; /* Bottom of non-overlapping
+                                * band */
+
     /*
      * Initialization:
-     * set r1, r2, r1End and r2End appropriately, preserve the important
+     *        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.
@@ -1113,9 +1103,9 @@ miRegionOp(
     r2 = reg2->rects;
     r1End = r1 + reg1->numRects;
     r2End = r2 + reg2->numRects;
-    
+
     oldRects = newReg->rects;
-    
+
     EMPTY_REGION(newReg);
 
     /*
@@ -1127,30 +1117,32 @@ miRegionOp(
      */
     newReg->size = wxMax(reg1->numRects,reg2->numRects) * 2;
 
-    if (! (newReg->rects = (BoxPtr)
-          malloc ((unsigned) (sizeof(BoxRec) * newReg->size)))) {
-       newReg->size = 0;
-       return;
+    newReg->rects = (BoxPtr)malloc((unsigned) (sizeof(BoxRec) * newReg->size));
+
+    if (!newReg->rects)
+    {
+        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
+     *         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
+     *        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;
+        ybot = reg1->extents.y1;
     else
-       ybot = reg2->extents.y1;
-    
+        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.
@@ -1161,107 +1153,107 @@ miRegionOp(
      * 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 = wxMax(r1->y1,ybot);
-           bot = wxMin(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 = wxMax(r2->y1,ybot);
-           bot = wxMin(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 = wxMin(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;
-       }
+        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 = wxMax(r1->y1,ybot);
+            bot = wxMin(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 = wxMax(r2->y1,ybot);
+            bot = wxMin(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 = wxMin(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));
 
     /*
@@ -1270,39 +1262,39 @@ miRegionOp(
     curBand = newReg->numRects;
     if (r1 != r1End)
     {
-       if (nonOverlap1Func != NULL)
-       {
-           do
-           {
-               r1BandEnd = r1;
-               while ((r1BandEnd < r1End) && (r1BandEnd->y1 == r1->y1))
-               {
-                   r1BandEnd++;
-               }
-               (* nonOverlap1Func) (newReg, r1, r1BandEnd,
-                                    wxMax(r1->y1,ybot), r1->y2);
-               r1 = r1BandEnd;
-           } while (r1 != r1End);
-       }
+        if (nonOverlap1Func != NULL)
+        {
+            do
+            {
+                r1BandEnd = r1;
+                while ((r1BandEnd < r1End) && (r1BandEnd->y1 == r1->y1))
+                {
+                    r1BandEnd++;
+                }
+                (* nonOverlap1Func) (newReg, r1, r1BandEnd,
+                                     wxMax(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,
-                               wxMax(r2->y1,ybot), r2->y2);
-           r2 = r2BandEnd;
-       } while (r2 != r2End);
+        do
+        {
+            r2BandEnd = r2;
+            while ((r2BandEnd < r2End) && (r2BandEnd->y1 == r2->y1))
+            {
+                 r2BandEnd++;
+            }
+            (* nonOverlap2Func) (newReg, r2, r2BandEnd,
+                                wxMax(r2->y1,ybot), r2->y2);
+            r2 = r2BandEnd;
+        } while (r2 != r2End);
     }
 
     if (newReg->numRects != curBand)
     {
-       (void) miCoalesce (newReg, prevBand, curBand);
+        (void) miCoalesce (newReg, prevBand, curBand);
     }
 
     /*
@@ -1315,60 +1307,60 @@ miRegionOp(
      */
     if (newReg->numRects < (newReg->size >> 1))
     {
-       if (REGION_NOT_EMPTY(newReg))
-       {
-           BoxPtr prev_rects = newReg->rects;
-           newReg->size = newReg->numRects;
-           newReg->rects = (BoxPtr) realloc ((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 realloc if
-            * the region is empty
-            */
-           newReg->size = 1;
-           free((char *) newReg->rects);
-           newReg->rects = (BoxPtr) malloc(sizeof(BoxRec));
-       }
+        if (REGION_NOT_EMPTY(newReg))
+        {
+            BoxPtr prev_rects = newReg->rects;
+            newReg->size = newReg->numRects;
+            newReg->rects = (BoxPtr) realloc ((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 realloc if
+             * the region is empty
+             */
+            newReg->size = 1;
+            free((char *) newReg->rects);
+            newReg->rects = (BoxPtr) malloc(sizeof(BoxRec));
+        }
     }
     free ((char *) oldRects);
     return;
 }
 
 /*======================================================================
- *         Region Union
+ *            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.
+ *        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.
+ *        None.
  *
  * Side Effects:
- *     pReg->numRects is incremented and the final rectangles overwritten
- *     with the rectangles we're passed.
+ *        pReg->numRects is incremented and the final rectangles overwritten
+ *        with the rectangles we're passed.
  *
  *-----------------------------------------------------------------------
  */
 /* static void*/
 int REGION::
 miUnionNonO (
-    register Region    pReg,
-    register BoxPtr    r,
-    BoxPtr             rEnd,
-    register wxCoord   y1,
-    register wxCoord   y2)
+    register Region        pReg,
+    register BoxPtr        r,
+    BoxPtr                 rEnd,
+    register wxCoord       y1,
+    register wxCoord       y2)
 {
-    register BoxPtr    pNextRect;
+    register BoxPtr        pNextRect;
 
     pNextRect = &pReg->rects[pReg->numRects];
 
@@ -1376,34 +1368,34 @@ miUnionNonO (
 
     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++;
+        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 */
+    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.
+ *        Handle an overlapping band for the union operation. Picks the
+ *        left-most rectangle each time and merges it into the region.
  *
  * Results:
- *     None.
+ *        None.
  *
  * Side Effects:
- *     Rectangles are overwritten in pReg->rects and pReg->numRects will
- *     be changed.
+ *        Rectangles are overwritten in pReg->rects and pReg->numRects will
+ *        be changed.
  *
  *-----------------------------------------------------------------------
  */
@@ -1411,75 +1403,75 @@ miUnionNonO (
 /* static void*/
 int REGION::
 miUnionO (
-    register Region    pReg,
-    register BoxPtr    r1,
-    BoxPtr             r1End,
-    register BoxPtr    r2,
-    BoxPtr             r2End,
-    register wxCoord   y1,
-    register wxCoord   y2)
+    register Region        pReg,
+    register BoxPtr        r1,
+    BoxPtr                 r1End,
+    register BoxPtr        r2,
+    BoxPtr                 r2End,
+    register wxCoord       y1,
+    register wxCoord       y2)
 {
-    register BoxPtr    pNextRect;
-    
+    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))  \
+        (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); \
-       }  \
+        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;  \
+        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->x1 < r2->x1)
+        {
+            MERGERECT(r1);
+        }
+        else
+        {
+            MERGERECT(r2);
+        }
     }
-    
+
     if (r1 != r1End)
     {
-       do
-       {
-           MERGERECT(r1);
-       } while (r1 != r1End);
+        do
+        {
+            MERGERECT(r1);
+        } while (r1 != r1End);
     }
     else while (r2 != r2End)
     {
-       MERGERECT(r2);
+        MERGERECT(r2);
     }
-    return 0;  /* lint */
+    return 0;        /* lint */
 }
 
 bool REGION::
 XUnionRegion(
-    Region       reg1,
-    Region       reg2,             /* source regions     */
-    Region       newReg)                  /* destination Region */
+    Region           reg1,
+    Region          reg2,             /* source regions     */
+    Region           newReg)                  /* destination Region */
 {
     /*  checks all the simple cases */
 
@@ -1506,11 +1498,11 @@ XUnionRegion(
     /*
      * 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 ((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);
@@ -1520,19 +1512,19 @@ XUnionRegion(
     /*
      * 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 ((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);
+    miRegionOp (newReg, reg1, reg2, miUnionO,
+                    miUnionNonO, miUnionNonO);
 
     newReg->extents.x1 = wxMin(reg1->extents.x1, reg2->extents.x1);
     newReg->extents.y1 = wxMin(reg1->extents.y1, reg2->extents.y1);
@@ -1543,178 +1535,178 @@ XUnionRegion(
 }
 
 /*======================================================================
- *               Region Subtraction
+ *                       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.
+ *        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.
+ *        None.
  *
  * Side Effects:
- *     pReg may be affected.
+ *        pReg may be affected.
  *
  *-----------------------------------------------------------------------
  */
 /* static void*/
 int REGION::
 miSubtractNonO1 (
-    register Region    pReg,
-    register BoxPtr    r,
-    BoxPtr             rEnd,
-    register wxCoord   y1,
-    register wxCoord           y2)
+    register Region        pReg,
+    register BoxPtr        r,
+    BoxPtr                    rEnd,
+    register wxCoord          y1,
+    register wxCoord           y2)
 {
-    register BoxPtr    pNextRect;
-       
+    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++;
+        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 */
+    return 0;        /* lint */
 }
 
 /*-
  *-----------------------------------------------------------------------
  * miSubtractO --
- *     Overlapping band subtraction. x1 is the left-most point not yet
- *     checked.
+ *        Overlapping band subtraction. x1 is the left-most point not yet
+ *        checked.
  *
  * Results:
- *     None.
+ *        None.
  *
  * Side Effects:
- *     pReg may have rectangles added to it.
+ *        pReg may have rectangles added to it.
  *
  *-----------------------------------------------------------------------
  */
 /* static void*/
 int REGION::
 miSubtractO (
-    register Region    pReg,
-    register BoxPtr    r1,
-    BoxPtr             r1End,
-    register BoxPtr    r2,
-    BoxPtr             r2End,
-    register wxCoord   y1,
-    register wxCoord   y2)
+    register Region        pReg,
+    register BoxPtr        r1,
+    BoxPtr                    r1End,
+    register BoxPtr        r2,
+    BoxPtr                    r2End,
+    register wxCoord          y1,
+    register wxCoord          y2)
 {
-    register BoxPtr    pNextRect;
-    register int       x1;
-    
+    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;
-       }
+        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;
+        }
     }
 
     /*
@@ -1722,57 +1714,53 @@ miSubtractO (
      */
     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;
-       }
+        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 */
+    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.
+ *        Subtract regS from regM and leave the result in regD.
+ *        S stands for subtrahend, M for minuend and D for difference.
  *
  * Results:
- *     true.
+ *        true.
  *
  * Side Effects:
- *     regD is overwritten.
+ *        regD is overwritten.
  *
  *-----------------------------------------------------------------------
  */
 
-bool REGION::
-XSubtractRegion(
-    Region             regM,
-    Region             regS,          
-    register Region    regD)
+bool REGION::XSubtractRegion(Region regM, Region regS, register Region regD)
 {
    /* check for trivial reject */
     if ( (!(regM->numRects)) || (!(regS->numRects))  ||
-       (!EXTENTCHECK(&regM->extents, &regS->extents)) )
+        (!EXTENTCHECK(&regM->extents, &regS->extents)) )
     {
-       miRegionCopy(regD, regM);
+        miRegionCopy(regD, regM);
         return true;
     }
-    miRegionOp (regD, regM, regS, miSubtractO, 
-               miSubtractNonO1, NULL);
+
+    miRegionOp (regD, regM, regS, miSubtractO,
+                    miSubtractNonO1, NULL);
 
     /*
      * Can't alter newReg's extents before we call miRegionOp because
@@ -1785,13 +1773,16 @@ XSubtractRegion(
     return true;
 }
 
-bool REGION::
-XXorRegion(Region sra, Region srb, Region dr)
+bool REGION::XXorRegion(Region sra, Region srb, Region dr)
 {
-    Region tra, trb;
+    Region tra = XCreateRegion();
+
+    wxCHECK_MSG( tra, false, wxT("region not created") );
+
+    Region trb = XCreateRegion();
+
+    wxCHECK_MSG( trb, false, wxT("region not created") );
 
-    if ((! (tra = XCreateRegion())) || (! (trb = XCreateRegion())))
-       return 0;
     (void) XSubtractRegion(sra,srb,tra);
     (void) XSubtractRegion(srb,sra,trb);
     (void) XUnionRegion(tra,trb,dr);
@@ -1801,22 +1792,19 @@ XXorRegion(Region sra, Region srb, Region dr)
 }
 
 /*
- * Check to see if the region is empty.  Assumes a region is passed 
+ * Check to see if the region is empty.  Assumes a region is passed
  * as a parameter
  */
-bool REGION::
-XEmptyRegion(
-    Region r)
+bool REGION::XEmptyRegion(Region r)
 {
     if( r->numRects == 0 ) return true;
     else  return false;
 }
 
 /*
- *     Check to see if two regions are equal   
+ *        Check to see if two regions are equal
  */
-bool REGION::
-XEqualRegion(Region r1, Region r2)
+bool REGION::XEqualRegion(Region r1, Region r2)
 {
     int i;
 
@@ -1827,18 +1815,15 @@ XEqualRegion(Region r1, Region r2)
     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;
+            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;
 }
 
-bool REGION::
-XPointInRegion(
-    Region pRegion,
-    int x, int y)
+bool REGION::XPointInRegion(Region pRegion, int x, int y)
 {
     int i;
 
@@ -1849,16 +1834,15 @@ XPointInRegion(
     for (i=0; i<pRegion->numRects; i++)
     {
         if (INBOX (pRegion->rects[i], x, y))
-           return true;
+            return true;
     }
     return false;
 }
 
-wxRegionContain REGION::
-XRectInRegion(
-    register Region    region,
-    int rx, int ry,
-    unsigned int rwidth, unsigned int rheight)
+wxRegionContain REGION::XRectInRegion(register Region region,
+                                      int rx, int ry,
+                                      unsigned int rwidth,
+                                      unsigned int rheight)
 {
     register BoxPtr pbox;
     register BoxPtr pboxEnd;
@@ -1870,69 +1854,68 @@ XRectInRegion(
     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(wxOutRegion);
 
-    partOut = FALSE;
-    partIn = FALSE;
+    partOut = false;
+    partIn = false;
 
-    /* can stop when both partOut and partIn are TRUE, or we reach prect->y2 */
+    /* 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++)
+         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;
-       }
+        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) ? wxPartRegion : wxInRegion) : 
-               wxOutRegion);
+    return(partIn ? ((ry < prect->y2) ? wxPartRegion : wxInRegion) :
+                wxOutRegion);
 }
-