* src/libavoid/*: Add a couple of missing files.

diff --git a/src/libavoid/region.cpp b/src/libavoid/region.cpp
new file mode 100644 (file)
index 0000000..c4ef904
--- /dev/null
+++ b/src/libavoid/region.cpp
@@ -0,0 +1,857 @@
+/*
+ * vim: ts=4 sw=4 et tw=0 wm=0
+ *
+ * libavoid - Fast, Incremental, Object-avoiding Line Router
+ * Copyright (C) 2004-2006  Michael Wybrow <mjwybrow@users.sourceforge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * 
+*/
+
+#include <cstdlib>
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+
+#include "libavoid/shape.h"
+#include "libavoid/region.h"
+
+
+namespace Avoid {
+
+Region *centerRegion = NULL;
+
+static const BBox screenBBox =
+        {Point(-INFINITY, -INFINITY), Point(INFINITY, INFINITY)};
+
+
+Region::Region()
+    : _bbox(screenBBox)
+    , _left(NULL), _right(NULL), _up(NULL), _down(NULL)
+{
+    _blocks.clear();
+}
+
+
+Region::Region(double x1, double y1, double x2, double y2)
+    : _left(NULL), _right(NULL), _up(NULL), _down(NULL)
+{
+    _bbox.a.x = x1;
+    _bbox.a.y = y1;
+    _bbox.b.x = x2;
+    _bbox.b.y = y2;
+
+    _blocks.clear();
+}
+
+
+static const unsigned int R_INSIDE = 0;
+static const unsigned int R_LEFT   = 1;
+static const unsigned int R_LEDGE  = 2;
+static const unsigned int R_RIGHT  = 4;
+static const unsigned int R_REDGE  = 8;
+static const unsigned int R_ABOVE  = 16;
+static const unsigned int R_TEDGE  = 32;
+static const unsigned int R_BELOW  = 64;
+static const unsigned int R_BEDGE  = 128;
+
+static const unsigned int R_NONE   = R_INSIDE;
+static const unsigned int R_UP     = R_ABOVE;
+static const unsigned int R_DOWN   = R_BELOW;
+static const unsigned int R_HORI   = R_LEFT | R_RIGHT;
+static const unsigned int R_VERT   = R_UP | R_DOWN;
+
+
+static void printBBox(const char *label, const BBox &bbox)
+{
+    if (label)
+    {
+        printf("%s: ", label);
+    }
+    printf("(%.2f, %.2f)-(%.2f, %.2f)\n", bbox.a.x, bbox.a.y,
+            bbox.b.x, bbox.b.y);
+}
+
+
+bool Region::overlapCheck(BBox& bbox, unsigned int& p)
+{
+    p = R_INSIDE;
+    Point& a = bbox.a;
+    Point& b = bbox.b;
+    Point& r = _bbox.a;
+    Point& s = _bbox.b;
+    
+    if (s.x <= a.x)
+    {
+        // Wholly right.
+        p = R_RIGHT;
+        return false;
+    }
+    else if (r.x >= b.x)
+    {
+        // Wholly left.
+        p = R_LEFT;
+        return false;
+    }
+    
+    if (s.y <= a.y)
+    {
+        // Wholly below.
+        p = R_BELOW;
+        return false;
+    }
+    else if (r.y >= b.y)
+    {
+        // Wholly above.
+        p = R_ABOVE;
+        return false;
+    }
+    
+    if (a.y == r.y)
+    {
+        // Shared top edge.
+        p |= R_TEDGE;
+    }
+    else if (a.y < r.y)
+    {
+        // Need to split above.
+        p |= R_ABOVE;
+    }
+    
+    if (b.y == s.y)
+    {
+        // Shared bottom edge.
+        p |= R_BEDGE;
+    }
+    else if (b.y > s.y)
+    {
+        // Need to split below.
+        p |= R_BELOW;
+    }
+
+    if (a.x == r.x)
+    {
+        // Shared left edge.
+        p |= R_LEDGE;
+    }
+    else if (a.x < r.x)
+    {
+        // Need to split left.
+        p |= R_LEFT;
+    }
+
+    if (b.x == s.x)
+    {
+        // Shared right edge.
+        p |= R_REDGE;
+    }
+    else if (b.x > s.x)
+    {
+        // Need to split right.
+        p |= R_RIGHT;
+    }
+    
+    return true;
+}
+
+
+void Region::getBBox(BBox& bb)
+{
+    bb.a = _bbox.a;
+    bb.b = _bbox.b;
+}
+
+
+Region *Region::up(void)
+{
+    return _up;
+}
+
+
+Region *Region::down(void)
+{
+    return _down;
+}
+
+
+Region *Region::left(void)
+{
+    return _left;
+}
+
+
+Region *Region::right(void)
+{
+    return _right;
+}
+
+
+bool Region::isBlock(void)
+{
+    return !(_blocks.empty());
+}
+
+
+void Region::initialSplit(BBox& bbox, unsigned int pos, unsigned int& shapeId)
+{
+    Point& n1 = bbox.a;
+    Point& n2 = bbox.b;
+    Region *newR = this;
+    Region *left, *right, *top, *bottom;
+    
+    if (pos == R_INSIDE)
+    {
+        split(n2.y, R_HORI);
+        split(n2.x, R_VERT);
+        newR = split(n1.y, R_HORI);
+        newR = newR->split(n1.x, R_VERT);
+        
+        printf("%X - list %d add %d\n", (int) newR,
+                (int) newR->_blocks.size(), shapeId);
+        newR->_blocks.push_back((int) shapeId);
+        newR->_blocks.sort();
+        newR->_blocks.unique();
+    }
+    else
+    {
+        Region *tar = NULL;
+        tar = newR->findRegion(n1.x, R_VERT);
+        if (pos & R_LEFT)
+        {
+            if (n1.x == tar->_bbox.a.x)
+            {
+                newR = tar->_right;
+            }
+            else if (n1.x == tar->_bbox.b.x)
+            {
+                newR = tar;
+            }
+            else
+            {
+                newR = tar->split(n1.x, R_VERT);
+            }
+        }
+        else if (!(pos & R_LEDGE))
+        {
+            newR = tar->split(n1.x, R_VERT);
+        }
+        left = newR;
+        
+        tar = left->findRegion(n1.y, R_HORI);
+        if (pos & R_ABOVE)
+        {
+            if (n1.y == tar->_bbox.a.y)
+            {
+                newR = tar->_down;
+            }
+            else if (n1.y == tar->_bbox.b.y)
+            {
+                newR = tar;
+            }
+            else
+            {
+                newR = tar->split(n1.y, R_HORI);
+            }
+        }
+        else if (!(pos & R_TEDGE))
+        {
+            newR = tar->split(n1.y, R_HORI);
+        }
+        top = newR;
+        
+        right = newR;
+        tar = newR->findRegion(n2.x, R_VERT);
+        if (pos & R_RIGHT)
+        {
+        
+            if (n2.x == tar->_bbox.a.x)
+            {
+                right = tar->_left;
+            }
+            else if (n2.x == tar->_bbox.b.x)
+            {
+                right = tar;
+            }
+            else
+            {
+                tar->split(n2.x, R_VERT);
+                right = tar;
+            }
+        }
+        else if (!(pos & R_REDGE))
+        {
+            tar->split(n2.x, R_VERT);
+            right = tar;
+        }
+
+        bottom = right;
+        tar = right->findRegion(n2.y, R_HORI);
+        if (pos & R_BELOW)
+        {
+            if (n2.y == tar->_bbox.a.y)
+            {
+                bottom = tar->_up;
+            }
+            else if (n2.y == tar->_bbox.b.y)
+            {
+                bottom = tar;
+            }
+            else
+            {
+                tar->split(n2.y, R_HORI);
+                bottom = tar;
+            }
+        }
+        else if (!(pos & R_BEDGE))
+        {
+            tar->split(n2.y, R_HORI);
+            bottom = tar;
+        } 
+
+        // top is actually top-left, and bottom is bottom-right.
+        Region *curr = top, *cptr = NULL;
+        while (curr->_bbox.b.y <= bottom->_bbox.b.y)
+        {
+            cptr = curr;
+            while (cptr->_bbox.b.x <= bottom->_bbox.b.x)
+            {
+                printf("%X - list %d add %d\n", (int) cptr,
+                        (int) cptr->_blocks.size(), shapeId);
+                cptr->_blocks.push_back((int) shapeId);
+                cptr->_blocks.sort();
+                cptr->_blocks.unique();
+
+                cptr = cptr->_right;
+            }
+
+            curr = curr->_down;
+        }
+    }
+}
+
+
+// Returns the region containing the value 'pos' in the direction 'dir'.
+// Thus, if looking for the x value 55, you would pass R_VERT as 'dir'.
+// 'forMerge' specifies that the left or top block of a pair of regions
+// with the split value of 'pos' should be returned.
+Region *Region::findRegion(double pos, unsigned int dir, const bool forMerge)
+{
+    Region *curr = this;
+
+    if (dir & R_VERT)
+    {
+        while (pos > curr->_bbox.b.x)
+        {
+            curr = curr->_right;
+        }
+        while (pos < curr->_bbox.a.x)
+        {
+            curr = curr->_left;
+        }
+        if (forMerge)
+        {
+            if (pos == curr->_bbox.a.x)
+            {
+                curr = curr->_left;
+            }
+            if (pos != curr->_bbox.b.x)
+            {
+                // 'pos' is not on the boundary.
+                return NULL;
+            }
+        }
+    }
+    else if (dir & R_HORI)
+    {
+        while (pos > curr->_bbox.b.y)
+        {
+            curr = curr->_down;
+        }
+        while (pos < curr->_bbox.a.y)
+        {
+            curr = curr->_up;
+        }
+        if (forMerge)
+        {
+            if (pos == curr->_bbox.a.y)
+            {
+                curr = curr->_up;
+            }
+            if (pos != curr->_bbox.b.y)
+            {
+                // 'pos' is not on the boundary.
+                return NULL;
+            }
+        }
+    }
+    return curr;
+}
+
+
+Region *Region::split(double pos, unsigned int dir)
+{
+    Region *newR = NULL;
+    bool first = true;
+
+    if (dir & R_VERT)
+    {
+        newR = splitDir(pos, R_UP, first);
+        if (_down) _down->splitDir(pos, R_DOWN);
+    }
+    else if (dir & R_HORI)
+    {
+        newR = splitDir(pos, R_RIGHT, first);
+        if (_left)  _left->splitDir(pos, R_LEFT);
+    }
+    return newR;
+}
+
+
+void Region::merge(unsigned int dir)
+{
+    bool first = true;
+
+    if (dir & R_VERT)
+    {
+        mergeDir(R_UP, first);
+        if (_down) _down->mergeDir(R_DOWN);
+    }
+    else if (dir & R_HORI)
+    {
+        mergeDir(R_RIGHT, first);
+        if (_left)  _left->mergeDir(R_LEFT);
+    }
+}
+
+
+void Region::mergeRegion(Region *src)
+{
+    assert(src != NULL);
+
+    if (src == _left)
+    {
+        pairHor(src->_left, this);
+        _bbox.a.x = src->_bbox.a.x;
+    }
+    else if (src == _right)
+    {
+        pairHor(this, src->_right);
+        _bbox.b.x = src->_bbox.b.x;
+    }
+    else if (src == _up)
+    {
+        pairVer(src->_up, this);
+        _bbox.a.y = src->_bbox.a.y;
+    }
+    else if (src == _down)
+    {
+        pairVer(this, src->_down);
+        _bbox.b.y = src->_bbox.b.y;
+    }
+    else
+    {
+        fprintf(stderr, "Error: Avoid::Region::merge(): "
+                "Argument not adjoining region.\n");
+        abort();
+    }
+    mergeAttributes(src);
+    printf("DEL %X\n", (int) src);
+    delete src;
+}
+
+
+Region *Region::splitDir(double pos, unsigned int dir, bool first)
+{
+    Point& o1 = _bbox.a;
+    Point& o2 = _bbox.b;
+
+    Region *newR = NULL;
+    
+    if (dir & R_VERT)
+    {
+        assert(pos > _bbox.a.x);
+        assert(pos < _bbox.b.x);
+        
+        // Vertical recursion:
+       
+        // Create new block.
+        Region *r  = new Region(pos, o1.y, o2.x, o2.y);
+        printf("NEW %X\n", (int) r);
+        r->copyAttributes(this);
+
+        Region *o_up    = _up;
+        Region *o_down  = _down;
+
+        // Resize old block.
+        o2.x = pos;
+
+        pairHor(r, _right);
+        pairHor(this, r);
+        
+        if (dir & R_UP)
+        {
+            if (!first)  pairVer(r, _down->_right);
+        
+            if (o_up)    o_up->splitDir(pos, R_UP);
+        }
+        else if (dir & R_DOWN)
+        {
+            if (!first)  pairVer(_up->_right, r);
+        
+            if (o_down)  o_down->splitDir(pos, R_DOWN);
+        }
+        newR = r;
+    }
+    else if (dir & R_HORI)
+    {
+        // Vertical recursion:
+
+        // Create new block.
+        Region *b  = new Region(o1.x, pos, o2.x, o2.y);
+        printf("NEW %X\n", (int) b);
+        b->copyAttributes(this);
+
+        Region *o_left  = _left;
+        Region *o_right = _right;
+    
+        // Resize old block.
+        o2.y = pos;
+        
+        pairVer(b, _down);
+        pairVer(this, b);
+
+        if (dir & R_LEFT)
+        {
+            if (!first)  pairHor(b, _right->_down);
+        
+            if (o_left)  o_left->splitDir(pos, R_LEFT);
+        }
+        else if (dir & R_RIGHT)
+        {
+            if (!first)  pairHor(_left->_down, b);
+        
+            if (o_right) o_right->splitDir(pos, R_RIGHT);
+        }
+        newR = b;
+    }
+    return newR;
+}
+
+
+void Region::mergeDir(unsigned int dir, bool first)
+{
+    if (dir & R_VERT)
+    {
+        assert(_right != NULL);
+
+        mergeRegion(_right);
+
+        if (dir & R_UP)
+        {
+            if (_up)    _up->mergeDir(dir, R_UP);
+        }
+        else if (dir & R_DOWN)
+        {
+            if (_down)  _down->mergeDir(dir, R_DOWN);
+        }
+    }
+    else if (dir & R_HORI)
+    {
+        assert(_down != NULL);
+
+        mergeRegion(_down);
+
+        if (dir & R_LEFT)
+        {
+            if (_left)  _left->mergeDir(dir, R_LEFT);
+        }
+        else if (dir & R_RIGHT)
+        {
+            if (_right) _right->mergeDir(dir, R_RIGHT);
+        }
+    }
+}
+
+
+void Region::copyAttributes(Region *src)
+{
+    _blocks = src->_blocks;
+}
+
+
+void Region::mergeAttributes(Region *src)
+{
+    _blocks.merge(src->_blocks);
+    _blocks.sort();
+    _blocks.unique();
+}
+
+
+//---------------------------
+// Static member functions:
+
+
+void Region::pairHor(Region *l, Region *r)
+{
+    if (l)  l->_right = r;
+    if (r)  r->_left  = l;
+}
+
+
+void Region::pairVer(Region *a, Region *b)
+{
+    if (a)  a->_down = b;
+    if (b)  b->_up   = a;
+}
+
+
+void Region::addShape(ShapeRef *shape)
+{
+    if (!centerRegion)
+    {
+        // Add new default region.
+        centerRegion = new Region();
+        printf("NEW %X\n", (int) centerRegion);
+    }
+    BBox bbox;
+    // Get bounding box for added shape.
+    shape->boundingBox(bbox);
+    printBBox("Add", bbox);
+    
+    unsigned int shapeId = shape->id();
+
+    // Find starting point for overlap
+    Region *curr = centerRegion;
+    unsigned int pos = R_INSIDE;
+    while (!(curr->overlapCheck(bbox, pos)))
+    {
+        if (pos & R_LEFT)
+        {
+            curr = curr->_left;
+        }
+        else if (pos & R_RIGHT)
+        {
+            curr = curr->_right;
+        }
+        else if (pos & R_ABOVE)
+        {
+            curr = curr->_up;
+        }
+        else if (pos & R_BELOW)
+        {
+            curr = curr->_down;
+        }
+    }
+    
+    curr->initialSplit(bbox, pos, shapeId);
+    centerRegion = curr;
+}
+
+
+void Region::removeShape(ShapeRef *shape)
+{
+    const bool forMerge = true;
+
+    BBox bbox;
+    // Get bounding box for added shape.
+    shape->boundingBox(bbox);
+    printBBox("Remove", bbox);
+
+    unsigned int shapeId = shape->id();
+    
+    Region *aboveTop = centerRegion->findRegion(bbox.a.y, R_HORI, forMerge);
+    Region *aboveBottom = aboveTop->findRegion(bbox.b.y, R_HORI, forMerge);
+    Region *leftOfLeft = aboveBottom->findRegion(bbox.a.x, R_VERT, forMerge);
+    Region *leftOfRight = leftOfLeft->findRegion(bbox.b.x, R_VERT, forMerge);
+    
+    assert(aboveTop    != NULL);
+    assert(aboveBottom != NULL);
+    assert(leftOfLeft  != NULL);
+    assert(leftOfRight != NULL);
+
+    // Find Top Left.
+    Region *topLeft = leftOfLeft->_right;
+    while (topLeft->_bbox.a.y != aboveTop->_bbox.b.y)
+    {
+        topLeft = topLeft->_up;
+    }
+    
+    // Find Bottom Right.
+    Region *botRight = leftOfRight;
+    while (botRight->_bbox.b.y != aboveBottom->_bbox.b.y)
+    {
+        botRight = botRight->_down;
+    }
+    
+    // Clear blocking flag.
+    Region *curr = topLeft, *cptr = NULL;
+    while (curr->_bbox.b.y <= botRight->_bbox.b.y)
+    {
+        cptr = curr;
+        while (cptr->_bbox.b.x <= botRight->_bbox.b.x)
+        {
+            ShapeList& blocks = cptr->_blocks;
+            
+            assert(std::find(blocks.begin(), blocks.end(), (int) shapeId) !=
+                    blocks.end());
+            printf("%X - list %d remove %d\n", (int) cptr,
+                    (int) blocks.size(), shapeId);
+            cptr->_blocks.remove((int) shapeId);
+
+            cptr = cptr->_right;
+        }
+
+        curr = curr->_down;
+    }
+    
+    // These two are safe since they don't invalidate the pointers
+    // to the regions that are inside the shape.
+    if (aboveBottom->safeToMerge(R_HORI))
+    {
+        aboveBottom->merge(R_HORI);
+    }
+    if (leftOfRight->safeToMerge(R_VERT))
+    {
+        leftOfRight->merge(R_VERT);
+    }
+    
+    // Be a bit more careful with these.
+    double leftX = leftOfLeft->_bbox.b.x;
+    if (aboveTop->safeToMerge(R_HORI))
+    {
+        aboveTop->merge(R_HORI);
+    }
+    // leftOfLeft may have been freed, so look for the new block at
+    // that position.
+    leftOfLeft = aboveTop->findRegion(leftX, R_VERT, forMerge);
+    assert(leftOfLeft);
+    if (leftOfLeft->safeToMerge(R_VERT))
+    {
+        leftOfLeft->merge(R_VERT);
+    }
+}
+
+
+bool Region::safeToMerge(unsigned int dir)
+{
+    bool unsafe = false;
+
+    if (dir == R_HORI)
+    {
+        printf("safeToMerge? y = %.3f... ", _bbox.b.y); 
+        unsafe |= unsafeToMerge(R_RIGHT);
+        if (_left)  unsafe |= _left->unsafeToMerge(R_LEFT);
+    }
+    else if (dir == R_VERT)
+    {
+        printf("safeToMerge? x = %.3f... ", _bbox.b.x); 
+        unsafe |= unsafeToMerge(R_DOWN);
+        if (_up)  unsafe |= _up->unsafeToMerge(R_UP);
+    }
+    printf("%s.\n", (unsafe) ? "no" : "yes");
+        
+    return !unsafe;
+}
+
+
+bool Region::unsafeToMerge(unsigned int dir)
+{
+    bool unsafe = false;
+    
+    if (dir & R_HORI)
+    {
+        // If they are not the same on both sides then we can merge.
+        if (_blocks != _down->_blocks)
+        {
+            printf("\n  _blocks:\n    ");
+            for (ShapeList::iterator i = _blocks.begin(); i != _blocks.end();
+                    ++i)
+            {
+                printf("%d ", *i);
+            }
+            printf("\n  _down->_blocks:\n    ");
+            for (ShapeList::iterator i = _down->_blocks.begin();
+                    i != _down->_blocks.end(); ++i)
+            {
+                printf("%d ", *i);
+            }
+            unsafe |= true;
+            printf("\n");
+        }
+
+        if ((dir == R_LEFT) && _left)
+        {
+            unsafe |= _left->unsafeToMerge(dir);
+        }
+        else if ((dir == R_RIGHT) && _right)
+        {
+            unsafe |= _right->unsafeToMerge(dir);
+        }
+    }
+    else if (dir & R_VERT)
+    {
+        if (_blocks !=  _right->_blocks)
+        {
+            printf("\n  _blocks:\n    ");
+            for (ShapeList::iterator i = _blocks.begin(); i != _blocks.end();
+                    ++i)
+            {
+                printf("%d ", *i);
+            }
+            printf("\n  _right->_blocks:\n    ");
+            for (ShapeList::iterator i = _right->_blocks.begin();
+                    i != _right->_blocks.end(); ++i)
+            {
+                printf("%d ", *i);
+            }
+            unsafe |= true;
+            printf("\n");
+        }
+        
+        if ((dir == R_UP) && _up)
+        {
+            unsafe |= _up->unsafeToMerge(dir);
+        }
+        else if ((dir == R_DOWN) && _down)
+        {
+            unsafe |= _down->unsafeToMerge(dir);
+        }
+    }
+    return unsafe;
+        
+}
+
+
+Region *Region::getTopLeftRegion(void)
+{
+    Region *curr = centerRegion;
+
+    while (curr && (curr->_up || curr->_left))
+    {
+        if (curr->_up)
+        {
+            curr = curr->_up;
+        }
+        else
+        {
+            curr = curr->_left;
+        }
+    }
+    return curr;
+}
+
+
+}
+

diff --git a/src/libavoid/region.h b/src/libavoid/region.h
new file mode 100644 (file)
index 0000000..9f00352
--- /dev/null
+++ b/src/libavoid/region.h
@@ -0,0 +1,79 @@
+/*
+ * vim: ts=4 sw=4 et tw=0 wm=0
+ *
+ * libavoid - Fast, Incremental, Object-avoiding Line Router
+ * Copyright (C) 2004-2006  Michael Wybrow <mjwybrow@users.sourceforge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * 
+*/
+
+#ifndef AVOID_REGION_H
+#define AVOID_REGION_H
+
+
+namespace Avoid {
+
+class ShapeRef;
+
+typedef std::list<int> ShapeList;
+
+
+class Region
+{
+    public:
+        Region();
+        Region(double x1, double y1, double x2, double y2);
+
+        bool overlapCheck(BBox& bbox, unsigned int& p);
+        void getBBox(BBox& bb);
+        Region *up(void);
+        Region *down(void);
+        Region *left(void);
+        Region *right(void);
+        void initialSplit(BBox& bbox, unsigned int pos, unsigned int& shapeId);
+        bool isBlock(void);
+        
+        static void pairHor(Region *l, Region *r);
+        static void pairVer(Region *a, Region *b);
+        static void addShape(ShapeRef *shape);
+        static void removeShape(ShapeRef *shape);
+        static Region *getTopLeftRegion(void);
+
+    private:
+        BBox _bbox;
+        Region *_left;
+        Region *_right;
+        Region *_up;
+        Region *_down;
+        ShapeList _blocks;
+        
+        Region *split(double pos, unsigned int dir); 
+        void merge(unsigned int dir);
+        void mergeRegion(Region *src); 
+        Region *findRegion(double pos, unsigned int dir,
+                const bool forMerge = false);
+        Region *splitDir(double pos, unsigned int dir, bool first = false); 
+        void mergeDir(unsigned int dir, bool first = false); 
+        void copyAttributes(Region *src);
+        void mergeAttributes(Region *src);
+        bool safeToMerge(unsigned int dir);
+        bool unsafeToMerge(unsigned int dir);
+};
+
+
+}
+
+#endif