// ----------------------------------------------------------------------------------------
// Name : RectPlacement.cpp
// Description : A class that fits subrectangles into a power-of-2 rectangle
// (C) Copyright 2000-2002 by Javier Arevalo
// This code is free to use and modify for all purposes
// ----------------------------------------------------------------------------------------
/*
* You have a bunch of rectangular pieces. You need to arrange them in a
* rectangular surface so that they don't overlap, keeping the total area of the
* rectangle as small as possible. This is fairly common when arranging characters
* in a bitmapped font, lightmaps for a 3D engine, and I guess other situations as
* well.
*
* The idea of this algorithm is that, as we add rectangles, we can pre-select
* "interesting" places where we can try to add the next rectangles. For optimal
* results, the rectangles should be added in order. I initially tried using area
* as a sorting criteria, but it didn't work well with very tall or very flat
* rectangles. I then tried using the longest dimension as a selector, and it
* worked much better. So much for intuition...
*
* These "interesting" places are just to the right and just below the currently
* added rectangle. The first rectangle, obviously, goes at the top left, the next
* one would go either to the right or below this one, and so on. It is a weird way
* to do it, but it seems to work very nicely.
*
* The way we search here is fairly brute-force, the fact being that for most off-
* line purposes the performance seems more than adequate. I have generated a
* japanese font with around 8500 characters and all the time was spent generating
* the bitmaps.
*
* Also, for all we care, we could grow the parent rectangle in a different way
* than power of two. It just happens that power of 2 is very convenient for
* graphics hardware textures.
*
* I'd be interested in hearing of other approaches to this problem. Make sure
* to post them on http://www.flipcode.com
*/
public RectPacker(int _w, int _h)
{
size = new PackerRect(0, 0, _w, _h, null);
vRects = new List <PackerRect>();
vPositions = new List <PackerPos>();
vPositions.Add(new PackerPos(0, 0));
area = 0;
}
// --------------------------------------------------------------------------------
// Name : AddRect
// Description : Add the given rect and updates anchor points
// --------------------------------------------------------------------------------
public void addRect(PackerRect r)
{
vRects.Add(r);
area += r.w * r.h;
// Add two new anchor points
addPosition(new PackerPos(r.x, r.y + r.h));
addPosition(new PackerPos(r.x + r.w, r.y));
}
// --------------------------------------------------------------------------------
// Name : AddAtEmptySpot
// Description : Add the given rectangle
// --------------------------------------------------------------------------------
public bool addAtEmptySpot(PackerRect r)
{
// Find a valid spot among available anchors.
bool bFound = false;
int pos = 0;
foreach (PackerPos it in vPositions)
{
PackerRect rect = new PackerRect(it.x, it.y, r.w, r.h, r.obj);
if (isFree(rect))
{
r = rect;
bFound = true;
break; // Don't let the loop increase the iterator.
}
pos++;
}
if (bFound)
{
// Remove the used anchor point
vPositions.RemoveAt(pos);
// Sometimes, anchors end up displaced from the optimal position
// due to irregular sizes of the subrects.
// So, try to adjut it up & left as much as possible.
int x, y;
for (x = 1; x <= r.x; x++)
{
if (!isFree(new PackerRect(r.x - x, r.y, r.w, r.h, r.obj)))
{
break;
}
}
for (y = 1; y <= r.y; y++)
{
if (!isFree(new PackerRect(r.x, r.y - y, r.w, r.h, r.obj)))
{
break;
}
}
if (y > x)
{
r.y -= y - 1;
}
else
{
r.x -= x - 1;
}
addRect(r);
}
return(bFound);
}
// --------------------------------------------------------------------------------
// Name : IsFree
// Description : Check if the given rectangle is partially or totally used
// --------------------------------------------------------------------------------
public bool isFree(PackerRect r)
{
if (!size.containsRect(r))
{
return(false);
}
foreach (PackerRect it in vRects)
{
if (it.intersects(r))
{
return(false);
}
}
return(true);
}
// Greater rect area. Not as good as the next heuristic
// static bool Greater(const TRect &a, const TRect &b) { return a.w*a.h > b.w*b.h; }
// Greater size in at least one dim.
public static bool greater(PackerRect a, PackerRect b)
{
return (a.w > b.w && a.w > b.h) ||
(a.h > b.w && a.h > b.h);
}
public bool intersects(PackerRect r)
{
return w > 0 && h > 0 && r.w > 0 && r.h > 0 &&
((r.x + r.w) > x && r.x < (x + w) &&
(r.y + r.h) > y && r.y < (y + h));
}
public bool containsRect(PackerRect r)
{
return (r.x >= x && r.y >= y &&
(r.x + r.w) <= (x + w) && (r.y + r.h) <= (y + h));
}
// --------------------------------------------------------------------------------
// Name : AddAtEmptySpotAutoGrow
// Description : Add a rectangle of the given size, growing our area if needed
// Area grows only until the max given.
// Returns the placement of the rect in the rect's x,y coords
// --------------------------------------------------------------------------------
public bool addAtEmptySpotAutoGrow(PackerRect pRect, int maxW, int maxH)
{
if (pRect.w <= 0)
return true;
int orgW = size.w;
int orgH = size.h;
// Try to add it in the existing space
while (!addAtEmptySpot(pRect))
{
int pw = size.w;
int ph = size.h;
// Sanity check - if area is complete.
if (pw >= maxW && ph >= maxH)
{
size.w = orgW;
size.h = orgH;
return false;
}
// Try growing the smallest dim
if (pw < maxW && (pw < ph || ((pw == ph) && (pRect.w >= pRect.h))))
size.w = Math.Min(maxW, pw + 10); //*2;
else
size.h = Math.Min(maxH, ph + 10); //*2;
if (addAtEmptySpot(pRect))
break;
// Try growing the other dim instead
if (pw != size.w)
{
size.w = pw;
if (ph < maxW)
size.h = Math.Min(maxH, ph + 10); //*2;
}
else
{
size.h = ph;
if (pw < maxW)
size.w = Math.Min(maxW, pw + 10); //*2;
}
if (pw != size.w || ph != size.h)
if (addAtEmptySpot(pRect))
break;
// Grow both if possible, and reloop.
size.w = pw;
size.h = ph;
if (pw < maxW)
size.w = Math.Min(maxW, pw + 10); //*2;
if (ph < maxH)
size.h = Math.Min(maxH, ph + 10); //*2;
}
return true;
}
// --------------------------------------------------------------------------------
// Name : AddAtEmptySpot
// Description : Add the given rectangle
// --------------------------------------------------------------------------------
public bool addAtEmptySpot(PackerRect r)
{
// Find a valid spot among available anchors.
bool bFound = false;
int pos = 0;
foreach (PackerPos it in vPositions)
{
PackerRect rect = new PackerRect(it.x, it.y, r.w, r.h, r.obj);
if (isFree(rect))
{
r = rect;
bFound = true;
break; // Don't let the loop increase the iterator.
}
pos++;
}
if (bFound)
{
// Remove the used anchor point
vPositions.RemoveAt(pos);
// Sometimes, anchors end up displaced from the optimal position
// due to irregular sizes of the subrects.
// So, try to adjut it up & left as much as possible.
int x, y;
for (x = 1; x <= r.x; x++)
if (!isFree(new PackerRect(r.x - x, r.y, r.w, r.h, r.obj)))
break;
for (y = 1; y <= r.y; y++)
if (!isFree(new PackerRect(r.x, r.y - y, r.w, r.h, r.obj)))
break;
if (y > x)
r.y -= y - 1;
else
r.x -= x - 1;
addRect(r);
}
return bFound;
}
// --------------------------------------------------------------------------------
// Name : AddRect
// Description : Add the given rect and updates anchor points
// --------------------------------------------------------------------------------
public void addRect(PackerRect r)
{
vRects.Add(r);
area += r.w * r.h;
// Add two new anchor points
addPosition(new PackerPos(r.x, r.y + r.h));
addPosition(new PackerPos(r.x + r.w, r.y));
}
// --------------------------------------------------------------------------------
// Name : IsFree
// Description : Check if the given rectangle is partially or totally used
// --------------------------------------------------------------------------------
public bool isFree(PackerRect r)
{
if (!size.containsRect(r))
return false;
foreach (PackerRect it in vRects)
if (it.intersects(r))
return false;
return true;
}
// ----------------------------------------------------------------------------------------
// Name : RectPlacement.cpp
// Description : A class that fits subrectangles into a power-of-2 rectangle
// (C) Copyright 2000-2002 by Javier Arevalo
// This code is free to use and modify for all purposes
// ----------------------------------------------------------------------------------------
/*
You have a bunch of rectangular pieces. You need to arrange them in a
rectangular surface so that they don't overlap, keeping the total area of the
rectangle as small as possible. This is fairly common when arranging characters
in a bitmapped font, lightmaps for a 3D engine, and I guess other situations as
well.
The idea of this algorithm is that, as we add rectangles, we can pre-select
"interesting" places where we can try to add the next rectangles. For optimal
results, the rectangles should be added in order. I initially tried using area
as a sorting criteria, but it didn't work well with very tall or very flat
rectangles. I then tried using the longest dimension as a selector, and it
worked much better. So much for intuition...
These "interesting" places are just to the right and just below the currently
added rectangle. The first rectangle, obviously, goes at the top left, the next
one would go either to the right or below this one, and so on. It is a weird way
to do it, but it seems to work very nicely.
The way we search here is fairly brute-force, the fact being that for most off-
line purposes the performance seems more than adequate. I have generated a
japanese font with around 8500 characters and all the time was spent generating
the bitmaps.
Also, for all we care, we could grow the parent rectangle in a different way
than power of two. It just happens that power of 2 is very convenient for
graphics hardware textures.
I'd be interested in hearing of other approaches to this problem. Make sure
to post them on http://www.flipcode.com
*/
public RectPacker(int _w, int _h)
{
size = new PackerRect(0, 0, _w, _h, null);
vRects = new List<PackerRect>();
vPositions = new List<PackerPos>();
vPositions.Add(new PackerPos(0, 0));
area = 0;
}
// Greater rect area. Not as good as the next heuristic
// static bool Greater(const TRect &a, const TRect &b) { return a.w*a.h > b.w*b.h; }
// Greater size in at least one dim.
public static bool greater(PackerRect a, PackerRect b)
{
return((a.w > b.w && a.w > b.h) ||
(a.h > b.w && a.h > b.h));
}
public bool intersects(PackerRect r)
{
return(w > 0 && h > 0 && r.w > 0 && r.h > 0 &&
((r.x + r.w) > x && r.x < (x + w) &&
(r.y + r.h) > y && r.y < (y + h)));
}
public bool containsRect(PackerRect r)
{
return(r.x >= x && r.y >= y &&
(r.x + r.w) <= (x + w) && (r.y + r.h) <= (y + h));
}
// --------------------------------------------------------------------------------
// Name : AddAtEmptySpotAutoGrow
// Description : Add a rectangle of the given size, growing our area if needed
// Area grows only until the max given.
// Returns the placement of the rect in the rect's x,y coords
// --------------------------------------------------------------------------------
public bool addAtEmptySpotAutoGrow(PackerRect pRect, int maxW, int maxH)
{
if (pRect.w <= 0)
{
return(true);
}
int orgW = size.w;
int orgH = size.h;
// Try to add it in the existing space
while (!addAtEmptySpot(pRect))
{
int pw = size.w;
int ph = size.h;
// Sanity check - if area is complete.
if (pw >= maxW && ph >= maxH)
{
size.w = orgW;
size.h = orgH;
return(false);
}
// Try growing the smallest dim
if (pw < maxW && (pw < ph || ((pw == ph) && (pRect.w >= pRect.h))))
{
size.w = Math.Min(maxW, pw + 10); //*2;
}
else
{
size.h = Math.Min(maxH, ph + 10); //*2;
}
if (addAtEmptySpot(pRect))
{
break;
}
// Try growing the other dim instead
if (pw != size.w)
{
size.w = pw;
if (ph < maxW)
{
size.h = Math.Min(maxH, ph + 10); //*2;
}
}
else
{
size.h = ph;
if (pw < maxW)
{
size.w = Math.Min(maxW, pw + 10); //*2;
}
}
if (pw != size.w || ph != size.h)
{
if (addAtEmptySpot(pRect))
{
break;
}
}
// Grow both if possible, and reloop.
size.w = pw;
size.h = ph;
if (pw < maxW)
{
size.w = Math.Min(maxW, pw + 10); //*2;
}
if (ph < maxH)
{
size.h = Math.Min(maxH, ph + 10); //*2;
}
}
return(true);
}
