Improve the lexical scoping in #'block, #'return-from. lisp/ChangeLog addition: 2011-02-07 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el: * bytecomp.el (byte-compile-initial-macro-environment): Shadow `block', `return-from' here, we implement them differently when byte-compiling. * bytecomp.el (byte-compile-active-blocks): New. * bytecomp.el (byte-compile-block-1): New. * bytecomp.el (byte-compile-return-from-1): New. * bytecomp.el (return-from-1): New. * bytecomp.el (block-1): New. These are two aliases that exist to have their own associated byte-compile functions, which functions implement `block' and `return-from'. * cl-extra.el (cl-macroexpand-all): Fix a bug here when macros in the environment have been compiled. * cl-macs.el (block): * cl-macs.el (return): * cl-macs.el (return-from): Be more careful about lexical scope in these macros. * cl.el: * cl.el ('cl-block-wrapper): Removed. * cl.el ('cl-block-throw): Removed. These aren't needed in code generated by this XEmacs. They shouldn't be needed in code generated by XEmacs 21.4, but if it turns out the packages do need them, we can put them back. 2011-01-30 Mike Sperber <mike@xemacs.org> * font-lock.el (font-lock-fontify-pending-extents): Don't fail if `font-lock-mode' is unset, which can happen in the middle of `revert-buffer'. 2011-01-23 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (delete): * cl-macs.el (delq): * cl-macs.el (remove): * cl-macs.el (remq): Don't use the compiler macro if these functions were given the wrong number of arguments, as happens in lisp-tests.el. * cl-seq.el (remove, remq): Removed. I added these to subr.el, and forgot to remove them from here. 2011-01-22 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-setq, byte-compile-set): Remove kludge allowing keywords' values to be set, all the code that does that is gone. * cl-compat.el (elt-satisfies-test-p): * faces.el (set-face-parent): * faces.el (face-doc-string): * gtk-font-menu.el: * gtk-font-menu.el (gtk-reset-device-font-menus): * msw-font-menu.el: * msw-font-menu.el (mswindows-reset-device-font-menus): * package-get.el (package-get-installedp): * select.el (select-convert-from-image-data): * sound.el: * sound.el (load-sound-file): * x-font-menu.el (x-reset-device-font-menus-core): Don't quote keywords, they're self-quoting, and the win from backward-compatibility is sufficiently small now that the style problem overrides it. 2011-01-22 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (block, return-from): Require that NAME be a symbol in these macros, as always documented in the #'block docstring and as required by Common Lisp. * descr-text.el (unidata-initialize-unihan-database): Correct the use of non-symbols in #'block and #'return-from in this function. 2011-01-15 Aidan Kehoe <kehoea@parhasard.net> * cl-extra.el (concatenate): Accept more complicated TYPEs in this function, handing the sequences over to #'coerce if we don't understand them here. * cl-macs.el (inline): Don't proclaim #'concatenate as inline, its compiler macro is more useful than doing that. 2011-01-11 Aidan Kehoe <kehoea@parhasard.net> * subr.el (delete, delq, remove, remq): Move #'remove, #'remq here, they don't belong in cl-seq.el; move #'delete, #'delq here from fns.c, implement them in terms of #'delete*, allowing support for sequences generally. * update-elc.el (do-autoload-commands): Use #'delete*, not #'delq here, now the latter's no longer dumped. * cl-macs.el (delete, delq): Add compiler macros transforming #'delete and #'delq to #'delete* calls. 2011-01-10 Aidan Kehoe <kehoea@parhasard.net> * dialog.el (make-dialog-box): Correct a misplaced parenthesis here, thank you Mats Lidell in 87zkr9gqrh.fsf@mail.contactor.se ! 2011-01-02 Aidan Kehoe <kehoea@parhasard.net> * dialog.el (make-dialog-box): * list-mode.el (display-completion-list): These functions used to use cl-parsing-keywords; change them to use defun* instead, fixing the build. (Not sure what led to me not including this change in d1b17a33450b!) 2011-01-02 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (define-star-compiler-macros): Make sure the form has ITEM and LIST specified before attempting to change to calls with explicit tests; necessary for some tests in lisp-tests.el to compile correctly. (stable-union, stable-intersection): Add compiler macros for these functions, in the same way we do for most of the other functions in cl-seq.el. 2011-01-01 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (dolist, dotimes, do-symbols, macrolet) (symbol-macrolet): Define these macros with defmacro* instead of parsing the argument list by hand, for the sake of style and readability; use backquote where appropriate, instead of calling #'list and and friends, for the same reason. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * x-misc.el (device-x-display): Provide this function, documented in the Lispref for years, but not existing previously. Thank you Julian Bradfield, thank you Jeff Mincy. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * cl-seq.el: Move the heavy lifting from this file to C. Dump the cl-parsing-keywords macro, but don't use defun* for the functions we define that do take keywords, dynamic scope lossage makes that not practical. * subr.el (sort, fillarray): Move these aliases here. (map-plist): #'nsublis is now built-in, but at this point #'eql isn't necessarily available as a test; use #'eq. * obsolete.el (cl-delete-duplicates): Make this available for old compiler macros and old code. (memql): Document that this is equivalent to #'member*, and worse. * cl.el (adjoin, subst): Removed. These are in C. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * simple.el (assoc-ignore-case): Remove a duplicate definition of this function (it's already in subr.el). * iso8859-1.el (char-width): On non-Mule, make this function equivalent to that produced by (constantly 1), but preserve its docstring. * subr.el (subst-char-in-string): Define this in terms of #'substitute, #'nsubstitute. (string-width): Define this using #'reduce and #'char-width. (char-width): Give this a simpler definition, it makes far more sense to check for mule at load time and redefine, as we do in iso8859-1.el. (store-substring): Implement this in terms of #'replace, now #'replace is cheap. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * update-elc.el (lisp-files-needed-for-byte-compilation) (lisp-files-needing-early-byte-compilation): cl-macs belongs in the former, not the latter, it is as fundamental as bytecomp.el. 2010-12-30 Aidan Kehoe <kehoea@parhasard.net> * cl.el: Provde the Common Lisp program-error, type-error as error symbols. This doesn't nearly go far enough for anyone using the Common Lisp errors. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (delete-duplicates): If the form has an incorrect number of arguments, don't attempt a compiler macroexpansion. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (cl-safe-expr-p): Forms that start with the symbol lambda are also safe. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (= < > <= >=): For these functions' compiler macros, the optimisation is safe even if the first and the last arguments have side effects, since they're only used the once. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (inline-side-effect-free-compiler-macros): Unroll a loop here at macro-expansion time, so these compiler macros are compiled. Use #'eql instead of #'eq in a couple of places for better style. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * cl-extra.el (notany, notevery): Avoid some dynamic scope stupidity with local variable names in these functions, when they weren't prefixed with cl-; go into some more detail in the doc strings. 2010-12-29 Aidan Kehoe <kehoea@parhasard.net> * byte-optimize.el (side-effect-free-fns): #'remove, #'remq are free of side-effects. (side-effect-and-error-free-fns): Drop dot, dot-marker from the list. 2010-11-17 Aidan Kehoe <kehoea@parhasard.net> * cl-extra.el (coerce): In the argument list, name the first argument OBJECT, not X; the former name was always used in the doc string and is clearer. Handle vector type specifications which include the length of the target sequence, error if there's a mismatch. * cl-macs.el (cl-make-type-test): Handle type specifications starting with the symbol 'eql. 2010-11-14 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (eql): Don't remove the byte-compile property of this symbol. That was necessary to override a bug in bytecomp.el where #'eql was confused with #'eq, which bug we no longer have. If neither expression is constant, don't attempt to handle the expression in this compiler macro, leave it to byte-compile-eql, which produces better code anyway. * bytecomp.el (eq): #'eql is not the function associated with the byte-eq byte code. (byte-compile-eql): Add an explicit compile method for this function, for cases where the cl-macs compiler macro hasn't reduced it to #'eq or #'equal. 2010-10-25 Aidan Kehoe <kehoea@parhasard.net> Add compiler macros and compilation sanity-checking for various functions that take keywords. * byte-optimize.el (side-effect-free-fns): #'symbol-value is side-effect free and not error free. * bytecomp.el (byte-compile-normal-call): Check keyword argument lists for sanity; store information about the positions where keyword arguments start using the new byte-compile-keyword-start property. * cl-macs.el (cl-const-expr-val): Take a new optional argument, cl-not-constant, defaulting to nil, in this function; return it if the expression is not constant. (cl-non-fixnum-number-p): Make this into a separate function, we want to pass it to #'every. (eql): Use it. (define-star-compiler-macros): Use the same code to generate the member*, assoc* and rassoc* compiler macros; special-case some code in #'add-to-list in subr.el. (remove, remq): Add compiler macros for these two functions, in preparation for #'remove being in C. (define-foo-if-compiler-macros): Transform (remove-if-not ...) calls to (remove ... :if-not) at compile time, which will be a real win once the latter is in C. (define-substitute-if-compiler-macros) (define-subst-if-compiler-macros): Similarly for these functions. (delete-duplicates): Change this compiler macro to use #'plists-equal; if we don't have information about the type of SEQUENCE at compile time, don't bother attempting to inline the call, the function will be in C soon enough. (equalp): Remove an old commented-out compiler macro for this, if we want to see it it's in version control. (subst-char-in-string): Transform this to a call to nsubstitute or nsubstitute, if that is appropriate. * cl.el (ldiff): Don't call setf here, this makes for a load-time dependency problem in cl-macs.el 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * term/vt100.el: Refer to XEmacs, not GNU Emacs, in permissions. * term/bg-mouse.el: * term/sup-mouse.el: Put copyright notice in canonical "Copyright DATE AUTHOR" form. Refer to XEmacs, not GNU Emacs, in permissions. * site-load.el: Add permission boilerplate. * mule/canna-leim.el: * alist.el: Refer to XEmacs, not APEL/this program, in permissions. * mule/canna-leim.el: Remove my copyright, I've assigned it to the FSF. 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * gtk.el: * gtk-widget-accessors.el: * gtk-package.el: * gtk-marshal.el: * gtk-compose.el: * gnome.el: Add copyright notice based on internal evidence. 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * easymenu.el: Add reference to COPYING to permission notice. * gutter.el: * gutter-items.el: * menubar-items.el: Fix typo "Xmacs" in permissions notice. 2010-06-14 Stephen J. Turnbull <stephen@xemacs.org> * auto-save.el: * font.el: * fontconfig.el: * mule/kinsoku.el: Add "part of XEmacs" text to permission notice. 2010-10-14 Aidan Kehoe <kehoea@parhasard.net> * byte-optimize.el (side-effect-free-fns): * cl-macs.el (remf, getf): * cl-extra.el (tailp, cl-set-getf, cl-do-remf): * cl.el (ldiff, endp): Tighten up Common Lisp compatibility for #'ldiff, #'endp, #'tailp; add circularity checking for the first two. #'cl-set-getf and #'cl-do-remf were Lisp implementations of #'plist-put and #'plist-remprop; change the names to aliases, changes the macros that use them to using #'plist-put and #'plist-remprop directly. 2010-10-12 Aidan Kehoe <kehoea@parhasard.net> * abbrev.el (fundamental-mode-abbrev-table, global-abbrev-table): Create both these abbrev tables using the usual #'define-abbrev-table calls, rather than attempting to special-case them. * cl-extra.el: Force cl-macs to be loaded here, if cl-extra.el is being loaded interpreted. Previously other, later files would redundantly call (load "cl-macs") when interpreted, it's more reasonable to do it here, once. * cmdloop.el (read-quoted-char-radix): Use defcustom here, we don't have any dump-order dependencies that would prevent that. * custom.el (eval-when-compile): Don't load cl-macs when interpreted or when byte-compiling, rely on cl-extra.el in the former case and the appropriate entry in bytecomp-load-hook in the latter. Get rid of custom-declare-variable-list, we have no dump-time dependencies that would require it. * faces.el (eval-when-compile): Don't load cl-macs when interpreted or when byte-compiling. * packages.el: Remove some inaccurate comments. * post-gc.el (cleanup-simple-finalizers): Use #'delete-if-not here, now the order of preloaded-file-list has been changed to make it available. * subr.el (custom-declare-variable-list): Remove. No need for it. Also remove a stub define-abbrev-table from this file, given the current order of preloaded-file-list there's no need for it. 2010-10-10 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-constp) Forms quoted with FUNCTION are also constant. (byte-compile-initial-macro-environment): In #'the, if FORM is constant and does not match TYPE, warn at byte-compile time. 2010-10-10 Aidan Kehoe <kehoea@parhasard.net> * backquote.el (bq-vector-contents, bq-list*): Remove; the former is equivalent to (append VECTOR nil), the latter to (list* ...). (bq-process-2): Use (append VECTOR nil) instead of using #'bq-vector-contents to convert to a list. (bq-process-1): Now we use list* instead of bq-list * subr.el (list*): Moved from cl.el, since it is now required to be available the first time a backquoted form is encountered. * cl.el (list*): Move to subr.el. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * test-harness.el (Check-Message): Add an omitted comma here, thank you the buildbot. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * hash-table.el (hash-table-key-list, hash-table-value-list) (hash-table-key-value-alist, hash-table-key-value-plist): Remove some useless #'nreverse calls in these files; our hash tables have no order, it's not helpful to pretend they do. * behavior.el (read-behavior): Do the same in this file, in some code evidently copied from hash-table.el. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * info.el (Info-insert-dir): * format.el (format-deannotate-region): * files.el (cd, save-buffers-kill-emacs): Use #'some, #'every and related functions for applying boolean operations to lists, instead of rolling our own ones that cons and don't short-circuit. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-initial-macro-environment): * cl-macs.el (the): Rephrase the docstring, make its implementation when compiling files a little nicer. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * descr-text.el (unidata-initialize-unicodedata-database) (unidata-initialize-unihan-database, describe-char-unicode-data) (describe-char-unicode-data): Wrap calls to the database functions with (with-fboundp ...), avoiding byte compile warnings on builds without support for the database functions. (describe-char): (reduce #'max ...), not (apply #'max ...), no need to cons needlessly. (describe-char): Remove a redundant lambda wrapping #'extent-properties. (describe-char-unicode-data): Call #'nsubst when replacing "" with nil in the result of #'split-string, instead of consing inside mapcar. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * x-faces.el (x-available-font-sizes): * specifier.el (let-specifier): * package-ui.el (pui-add-required-packages): * msw-faces.el (mswindows-available-font-sizes): * modeline.el (modeline-minor-mode-menu): * minibuf.el (minibuf-directory-files): Replace the O2N (delq nil (mapcar (lambda (W) (and X Y)) Z)) with the ON (mapcan (lambda (W) (and X (list Y))) Z) in these files. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * cl-macs.el (= < > <= >=): When these functions are handed more than two arguments, and those arguments have no side effects, transform to a series of two argument calls, avoiding funcall in the byte-compiled code. * mule/mule-cmds.el (finish-set-language-environment): Take advantage of this change in a function called 256 times at startup. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * bytecomp.el (byte-compile-function-form, byte-compile-quote) (byte-compile-quote-form): Warn at compile time, and error at runtime, if a (quote ...) or a (function ...) form attempts to quote more than one object. 2010-09-16 Aidan Kehoe <kehoea@parhasard.net> * byte-optimize.el (byte-optimize-apply): Transform (apply 'nconc (mapcar ...)) to (mapcan ...); warn about use of the first idiom. * update-elc.el (do-autoload-commands): * packages.el (packages-find-package-library-path): * frame.el (frame-list): * extents.el (extent-descendants): * etags.el (buffer-tag-table-files): * dumped-lisp.el (preloaded-file-list): * device.el (device-list): * bytecomp-runtime.el (proclaim-inline, proclaim-notinline) Use #'mapcan, not (apply #'nconc (mapcar ...) in all these files. * bytecomp-runtime.el (eval-when-compile, eval-and-compile): In passing, mention that these macros also evaluate the body when interpreted. tests/ChangeLog addition: 2011-02-07 Aidan Kehoe <kehoea@parhasard.net> * automated/lisp-tests.el: Test lexical scope for `block', `return-from'; add a Known-Bug-Expect-Failure for a contorted example that fails when byte-compiled.

/* Image processing functions
   Copyright (C) 1998 Jareth Hein

This file is a part of XEmacs

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs 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 General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Not in FSF. */

/* Original author: Jareth Hein */

/* Parts of this file are based on code from Sam Leffler's tiff library,
   with the original copyright displayed here:

   Copyright (c) 1988-1997 Sam Leffler
   Copyright (c) 1991-1997 Silicon Graphics, Inc.
   Copyright (C) 2010 Ben Wing.
   
   Permission to use, copy, modify, distribute, and sell this software and 
   its documentation for any purpose is hereby granted without fee, provided
   that (i) the above copyright notices and this permission notice appear in
   all copies of the software and related documentation, and (ii) the names of
   Sam Leffler and Silicon Graphics may not be used in any advertising or
   publicity relating to the software without the specific, prior written
   permission of Sam Leffler and Silicon Graphics. */

/* Quantizing code based off of the paper 
   Color Image Quantization for Frame Buffer Display, Paul Heckbert,
   Siggraph '82 proceedings, pp. 297-307 */

#include <config.h>
#include "lisp.h"
#include "imgproc.h"

static void
get_histogram(quant_table *qt, Binbyte *pic,
	      int width, int height, Colorbox* box)
{
  register Binbyte *inptr;
  register int red, green, blue;
  register int j, i;

  box->rmin = box->gmin = box->bmin = 999;
  box->rmax = box->gmax = box->bmax = -1;
  box->total = width * height;

  inptr = pic;
  for (i = 0; i < height; i++)
    {
      for (j = width; j-- > 0;)
	{
	  red = *inptr++ >> COLOR_SHIFT;
	  green = *inptr++ >> COLOR_SHIFT;
	  blue = *inptr++ >> COLOR_SHIFT;
	  if (red < box->rmin)
	    box->rmin = red;
	  if (red > box->rmax)
	    box->rmax = red;
	  if (green < box->gmin)
	    box->gmin = green;
	  if (green > box->gmax)
	    box->gmax = green;
	  if (blue < box->bmin)
	    box->bmin = blue;
	  if (blue > box->bmax)
	    box->bmax = blue;
	  qt->histogram[red][green][blue]++;
	}
    }
}

static Colorbox *
largest_box(quant_table *qt)
{
  register Colorbox *p, *b;
  register int size;

  b = NULL;
  size = -1;
  for (p = qt->usedboxes; p != NULL; p = p->next)
    if ((p->rmax > p->rmin || p->gmax > p->gmin ||
	 p->bmax > p->bmin) &&  p->total > size)
      size = (b = p)->total;
  return (b);
}

static void
shrinkbox(quant_table *qt, Colorbox* box)
{
  register int *histp, ir, ig, ib;

  if (box->rmax > box->rmin)
    {
      for (ir = box->rmin; ir <= box->rmax; ++ir)
	for (ig = box->gmin; ig <= box->gmax; ++ig)
	  {
	    histp = &(qt->histogram[ir][ig][box->bmin]);
	    for (ib = box->bmin; ib <= box->bmax; ++ib)
	      if (*histp++ != 0)
		{
		  box->rmin = ir;
		  goto have_rmin;
		}
	  }
    have_rmin:
      if (box->rmax > box->rmin)
	for (ir = box->rmax; ir >= box->rmin; --ir)
	  for (ig = box->gmin; ig <= box->gmax; ++ig)
	    {
	      histp = &(qt->histogram[ir][ig][box->bmin]);
	      ib = box->bmin;
	      for (; ib <= box->bmax; ++ib)
		if (*histp++ != 0)
		  {
		    box->rmax = ir;
		    goto have_rmax;
		  }
	    }
    }
 have_rmax:
  if (box->gmax > box->gmin)
    {
      for (ig = box->gmin; ig <= box->gmax; ++ig)
	for (ir = box->rmin; ir <= box->rmax; ++ir)
	  {
	    histp = &(qt->histogram[ir][ig][box->bmin]);
	    for (ib = box->bmin; ib <= box->bmax; ++ib)
	      if (*histp++ != 0)
		{
		  box->gmin = ig;
		  goto have_gmin;
		}
	  }
    have_gmin:
      if (box->gmax > box->gmin)
	for (ig = box->gmax; ig >= box->gmin; --ig)
	  for (ir = box->rmin; ir <= box->rmax; ++ir)
	    {
	      histp = &(qt->histogram[ir][ig][box->bmin]);
	      ib = box->bmin;
	      for (; ib <= box->bmax; ++ib)
		if (*histp++ != 0)
		  {
		    box->gmax = ig;
		    goto have_gmax;
		  }
	    }
    }
 have_gmax:
  if (box->bmax > box->bmin)
    {
      for (ib = box->bmin; ib <= box->bmax; ++ib)
	for (ir = box->rmin; ir <= box->rmax; ++ir)
	  {
	    histp = &(qt->histogram[ir][box->gmin][ib]);
	    for (ig = box->gmin; ig <= box->gmax; ++ig)
	      {
		if (*histp != 0)
		  {
		    box->bmin = ib;
		    goto have_bmin;
		  }
		histp += B_LEN;
	      }
	  }
    have_bmin:
      if (box->bmax > box->bmin)
	for (ib = box->bmax; ib >= box->bmin; --ib)
	  for (ir = box->rmin; ir <= box->rmax; ++ir)
	    {
	      histp = &(qt->histogram[ir][box->gmin][ib]);
	      ig = box->gmin;
	      for (; ig <= box->gmax; ++ig)
		{
		  if (*histp != 0)
		    {
		      box->bmax = ib;
		      goto have_bmax;
		    }
		  histp += B_LEN;
		}
	    }
    }
 have_bmax:
  ;
}

static void
splitbox(quant_table *qt, Colorbox* ptr)
{
  int		hist2[B_LEN];
  int		first = 0, last = 0;
  register Colorbox	*new_;
  register int	*iptr, *histp;
  register int	i, j;
  register int	ir,ig,ib;
  register int sum, sum1, sum2;
  enum { RED, GREEN, BLUE } axis;

  /*
   * See which axis is the largest, do a histogram along that
   * axis.  Split at median point.  Contract both new boxes to
   * fit points and return
   */
  i = ptr->rmax - ptr->rmin;
  if (i >= ptr->gmax - ptr->gmin  && i >= ptr->bmax - ptr->bmin)
    axis = RED;
  else if (ptr->gmax - ptr->gmin >= ptr->bmax - ptr->bmin)
    axis = GREEN;
  else
    axis = BLUE;
  /* get histogram along longest axis */
  switch (axis)
    {
    case RED:
      histp = &hist2[ptr->rmin];
      for (ir = ptr->rmin; ir <= ptr->rmax; ++ir)
	{
	  *histp = 0;
	  for (ig = ptr->gmin; ig <= ptr->gmax; ++ig)
	    {
	      iptr = &(qt->histogram[ir][ig][ptr->bmin]);
	      for (ib = ptr->bmin; ib <= ptr->bmax; ++ib)
		*histp += *iptr++;
	    }
	  histp++;
	}
      first = ptr->rmin;
      last = ptr->rmax;
      break;
    case GREEN:
      histp = &hist2[ptr->gmin];
      for (ig = ptr->gmin; ig <= ptr->gmax; ++ig)
	{
	  *histp = 0;
	  for (ir = ptr->rmin; ir <= ptr->rmax; ++ir)
	    {
	      iptr = &(qt->histogram[ir][ig][ptr->bmin]);
	      for (ib = ptr->bmin; ib <= ptr->bmax; ++ib)
		*histp += *iptr++;
	    }
	  histp++;
	}
      first = ptr->gmin;
      last = ptr->gmax;
      break;
    case BLUE:
      histp = &hist2[ptr->bmin];
      for (ib = ptr->bmin; ib <= ptr->bmax; ++ib)
	{
	  *histp = 0;
	  for (ir = ptr->rmin; ir <= ptr->rmax; ++ir)
	    {
	      iptr = &(qt->histogram[ir][ptr->gmin][ib]);
	      for (ig = ptr->gmin; ig <= ptr->gmax; ++ig)
		{
		  *histp += *iptr;
		  iptr += B_LEN;
		}
	    }
	  histp++;
	}
      first = ptr->bmin;
      last = ptr->bmax;
      break;
    }
  /* find median point */
  sum2 = ptr->total / 2;
  histp = &hist2[first];
  sum = 0;
  for (i = first; i <= last && (sum += *histp++) < sum2; ++i)
    ;
  if (i == first)
    i++;

  /* Create new box, re-allocate points */
  new_ = qt->freeboxes;
  qt->freeboxes = new_->next;
  if (qt->freeboxes)
    qt->freeboxes->prev = NULL;
  if (qt->usedboxes)
    qt->usedboxes->prev = new_;
  new_->next = qt->usedboxes;
  qt->usedboxes = new_;

  histp = &hist2[first];
  for (sum1 = 0, j = first; j < i; j++)
    sum1 += *histp++;
  for (sum2 = 0, j = i; j <= last; j++)
    sum2 += *histp++;
  new_->total = sum1;
  ptr->total = sum2;

  new_->rmin = ptr->rmin;
  new_->rmax = ptr->rmax;
  new_->gmin = ptr->gmin;
  new_->gmax = ptr->gmax;
  new_->bmin = ptr->bmin;
  new_->bmax = ptr->bmax;
  switch (axis)
    {
    case RED:
      new_->rmax = i-1;
      ptr->rmin = i;
      break;
    case GREEN:
      new_->gmax = i-1;
      ptr->gmin = i;
      break;
    case BLUE:
      new_->bmax = i-1;
      ptr->bmin = i;
      break;
    }
  shrinkbox (qt, new_);
  shrinkbox (qt, ptr);
}


static C_cell *
create_colorcell(quant_table *qt, int num_colors, int red, int green, int blue)
{
  register int ir, ig, ib, i;
  register C_cell *ptr;
  int mindist, next_n;
  register int tmp, dist, n;

  ir = red >> (COLOR_DEPTH-C_DEPTH);
  ig = green >> (COLOR_DEPTH-C_DEPTH);
  ib = blue >> (COLOR_DEPTH-C_DEPTH);
  ptr = xnew (C_cell);
  *(qt->ColorCells + ir*C_LEN*C_LEN + ig*C_LEN + ib) = ptr;
  ptr->num_ents = 0;

  /*
   * Step 1: find all colors inside this cell, while we're at
   *	   it, find distance of centermost point to furthest corner
   */
  mindist = 99999999;
  for (i = 0; i < num_colors; ++i)
    {
      if (qt->rm[i]>>(COLOR_DEPTH-C_DEPTH) != ir  ||
	  qt->gm[i]>>(COLOR_DEPTH-C_DEPTH) != ig  ||
	  qt->bm[i]>>(COLOR_DEPTH-C_DEPTH) != ib)
	continue;
      ptr->entries[ptr->num_ents][0] = i;
      ptr->entries[ptr->num_ents][1] = 0;
      ++ptr->num_ents;
      tmp = qt->rm[i] - red;
      if (tmp < (MAX_COLOR/C_LEN/2))
	tmp = MAX_COLOR/C_LEN-1 - tmp;
      dist = tmp*tmp;
      tmp = qt->gm[i] - green;
      if (tmp < (MAX_COLOR/C_LEN/2))
	tmp = MAX_COLOR/C_LEN-1 - tmp;
      dist += tmp*tmp;
      tmp = qt->bm[i] - blue;
      if (tmp < (MAX_COLOR/C_LEN/2))
	tmp = MAX_COLOR/C_LEN-1 - tmp;
      dist += tmp*tmp;
      if (dist < mindist)
	mindist = dist;
    }

  /*
   * Step 3: find all points within that distance to cell.
   */
  for (i = 0; i < num_colors; ++i)
    {
      if (qt->rm[i] >> (COLOR_DEPTH-C_DEPTH) == ir  &&
	  qt->gm[i] >> (COLOR_DEPTH-C_DEPTH) == ig  &&
	  qt->bm[i] >> (COLOR_DEPTH-C_DEPTH) == ib)
	continue;
      dist = 0;
      if ((tmp = red - qt->rm[i]) > 0 ||
	  (tmp = qt->rm[i] - (red + MAX_COLOR/C_LEN-1)) > 0 )
	dist += tmp*tmp;
      if ((tmp = green - qt->gm[i]) > 0 ||
	  (tmp = qt->gm[i] - (green + MAX_COLOR/C_LEN-1)) > 0 )
	dist += tmp*tmp;
      if ((tmp = blue - qt->bm[i]) > 0 ||
	  (tmp = qt->bm[i] - (blue + MAX_COLOR/C_LEN-1)) > 0 )
	dist += tmp*tmp;
      if (dist < mindist)
	{
	  ptr->entries[ptr->num_ents][0] = i;
	  ptr->entries[ptr->num_ents][1] = dist;
	  ++ptr->num_ents;
	}
    }

  /*
   * Sort color cells by distance, use cheap exchange sort
   */
  for (n = ptr->num_ents - 1; n > 0; n = next_n)
    {
      next_n = 0;
      for (i = 0; i < n; ++i)
	if (ptr->entries[i][1] > ptr->entries[i+1][1])
	  {
	    tmp = ptr->entries[i][0];
	    ptr->entries[i][0] = ptr->entries[i+1][0];
	    ptr->entries[i+1][0] = tmp;
	    tmp = ptr->entries[i][1];
	    ptr->entries[i][1] = ptr->entries[i+1][1];
	    ptr->entries[i+1][1] = tmp;
	    next_n = i;
	  }
    }
  return (ptr);
}

static int
map_colortable(quant_table *qt, int num_colors)
{
  register int *histp = &(qt->histogram[0][0][0]);
  register C_cell *cell;
  register int j, tmp, d2, dist;
  int ir, ig, ib, i;

  for (ir = 0; ir < B_LEN; ++ir)
    for (ig = 0; ig < B_LEN; ++ig)
      for (ib = 0; ib < B_LEN; ++ib, histp++)
	{
	  if (*histp == 0)
	    {
	      *histp = -1;
	      continue;
	    }
	  cell = *(qt->ColorCells +
		   (((ir>>(B_DEPTH-C_DEPTH)) << C_DEPTH*2) +
		    ((ig>>(B_DEPTH-C_DEPTH)) << C_DEPTH) +
		    (ib>>(B_DEPTH-C_DEPTH))));
	  if (cell == NULL )
	    cell = create_colorcell (qt, num_colors,
				     ir << COLOR_SHIFT,
				     ig << COLOR_SHIFT,
				     ib << COLOR_SHIFT);
	  if (cell == NULL) /* memory exhausted! punt! */
	    return -1;
	  dist = 9999999;
	  for (i = 0; i < cell->num_ents &&
		 dist > cell->entries[i][1]; ++i)
	    {
	      j = cell->entries[i][0];
	      d2 = qt->rm[j] - (ir << COLOR_SHIFT);
	      d2 *= d2;
	      tmp = qt->gm[j] - (ig << COLOR_SHIFT);
	      d2 += tmp*tmp;
	      tmp = qt->bm[j] - (ib << COLOR_SHIFT);
	      d2 += tmp*tmp;
	      if (d2 < dist)
		{
		  dist = d2;
		  *histp = j;
		}
	    }
	}
  return 0;
}

quant_table *
build_EImage_quantable(Binbyte *eimage, int width, int height, int num_colors)
{
  quant_table *qt;
  Colorbox *box_list, *ptr;
  int i,res;

  qt = (quant_table*)xmalloc_and_zero (sizeof(quant_table));
  if (qt == NULL) return NULL;

  assert (num_colors < 257 && num_colors > 2);
  /*
   * STEP 1:  create empty boxes
   */
  qt->usedboxes = NULL;
  box_list = qt->freeboxes = xnew_array (Colorbox, num_colors);
  qt->freeboxes[0].next = &(qt->freeboxes[1]);
  qt->freeboxes[0].prev = NULL;
  for (i = 1; i < num_colors-1; ++i)
    {
      qt->freeboxes[i].next = &(qt->freeboxes[i+1]);
      qt->freeboxes[i].prev = &(qt->freeboxes[i-1]);
    }
  qt->freeboxes[num_colors-1].next = NULL;
  qt->freeboxes[num_colors-1].prev = &(qt->freeboxes[num_colors-2]);

  /*
   * STEP 2: get histogram, initialize first box
   */
  ptr = qt->freeboxes;
  qt->freeboxes = ptr->next;
  if (qt->freeboxes)
    qt->freeboxes->prev = NULL;
  ptr->next = qt->usedboxes;
  qt->usedboxes = ptr;
  if (ptr->next)
    ptr->next->prev = ptr;
  get_histogram (qt, eimage, width, height, ptr);

  /*
   * STEP 3: continually subdivide boxes until no more free
   * boxes remain or until all colors assigned.
   */
  while (qt->freeboxes != NULL)
    {
      ptr = largest_box(qt);
      if (ptr != NULL)
	splitbox (qt, ptr);
      else
	qt->freeboxes = NULL;
    }

  /*
   * STEP 4: assign colors to all boxes
   */
  for (i = 0, ptr = qt->usedboxes; ptr != NULL; ++i, ptr = ptr->next)
    {
      qt->rm[i] = ((ptr->rmin + ptr->rmax) << COLOR_SHIFT) / 2;
      qt->gm[i] = ((ptr->gmin + ptr->gmax) << COLOR_SHIFT) / 2;
      qt->bm[i] = ((ptr->bmin + ptr->bmax) << COLOR_SHIFT) / 2;
      qt->um[i] = ptr->total;
    }
  qt->num_active_colors = i;

  /* We're done with the boxes now */
  xfree (box_list);
  qt->freeboxes = qt->usedboxes = NULL;

  /*
   * STEP 5: scan histogram and map all values to closest color
   */
  /* 5a: create cell list as described in Heckbert */
  qt->ColorCells = (C_cell **)xmalloc_and_zero (C_LEN*C_LEN*C_LEN*sizeof (C_cell*));
  /* 5b: create mapping from truncated pixel space to color
     table entries */
  res = map_colortable (qt, num_colors);

  /* 5c: done with ColorCells */
  for (i = 0; i < C_LEN*C_LEN*C_LEN; i++)
    if (qt->ColorCells[i])
      {
	xfree (qt->ColorCells[i]);
	qt->ColorCells[i] = 0;
      }
  xfree (qt->ColorCells);
  qt->ColorCells = 0;
  
  if (res)
    {
      /* we failed in memory allocation, so clean up and leave */
      xfree (qt);
      return NULL;
    }
  
  return qt;
}