Support TeX elements in FreeType renderer. * libinterp/corefcn/txt-eng.cc: New file. Contains mapping from symbol name to character code, in Unicode and MS symbol. * libinterp/corefcn/modules.mk (COREFCN_SRC): Add txt-eng.cc. * libinterp/corefcn/oct-tex-lexer.ll: Add "\n" to rules applicable to ".", as the latter does not include new line characters. * libinterp/corefcn/oct-tex-parser.yy: Remove debug statements. * libinterp/corefcn/txt-eng.ft.cc (gripe_missing_glyph, gripe_glyph_render): Change signature from char to FT_ULong. (ft_render::ft_render): Adapt to new/removed members. (ft_render::~ft_render): Remove use of fonts member. (ft_render::set_font): Likewise. Use font instead. (ft_render::push_new_line): Likewise. Change meaning of yoffset and initialize line_yoffset. (ft_render::update_line_bbox): New method. (ft_render::set_mode): Change meaning of yoffset and initialize line_yoffset. (ft_render::process_character): New method. (ft_render::visit(text_element_string)): Use it. (ft_render::visit(text_element_list), ft_render::visit(text_element_subscript), ft_render::visit(text_element_superscript), ft_render::visit(text_element_color), ft_render::visit(text_element_fontsize), ft_render::visit(text_element_fontname), ft_render::visit(text_element_fontstyle), ft_render::visit(text_element_symbol)): New methods. (ft_render::set_color): Use color member instead of red/green/blue. * libinterp/corefcn/txt-eng-ft.h (ft_render::visit(text_element_list), ft_render::visit(text_element_subscript), ft_render::visit(text_element_superscript), ft_render::visit(text_element_color), ft_render::visit(text_element_fontsize), ft_render::visit(text_element_fontname), ft_render::visit(text_element_fontstyle), ft_render::visit(text_element_symbol)): New methods. (ft_render::update_line_bbox, ft_render::process_character): New methods. (ft_render::current_face): Removed method.i (ft_render::font): New member, replaces obsolete ft_render::fonts. (ft_render::line_yoffset): New member. (ft_render::color): New member, replaces obsolete red, green and blue. (ft_render::ft_font::ft_font()): Implement default constructor. (ft_render::ft_font::operator=): Fix incorrect use of FT_Reference_Face return value. (ft_render::ft_font::is_valid): New method. * libinterp/corefcn/txt-eng.h (class text_element_symbol, class text_element_fontname, class text_element_fontsize, class text_element_fontname, class text_element_fontstyle, class text_element_color): Add forward definition. (text_element_symbol::invalid_code): New enum. (text_element_symbol::code): New member. (text_element_symbol::text_element_symbol): Initialize it. (text_element_symbol::get_symbol_code): New method. (text_element_fontstyle::get_fontstyle): New method. (text_element_fontname::get_fontname): Renamed from fontname. (text_element_fontsize::get_fontsize): Renamed from fontsize.

## Copyright (C) 1999-2012 Kai Habel
##
## This file is part of Octave.
##
## Octave 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 3 of the License, or (at
## your option) any later version.
##
## Octave 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 Octave; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn  {Function File} {@var{map} =} bone ()
## @deftypefnx {Function File} {@var{map} =} bone (@var{n})
## Create color colormap.  This colormap varies from black to white with
## gray-blue shades.
## The argument @var{n} must be a scalar.
## If unspecified, the length of the current colormap, or 64, is used.
## @seealso{colormap}
## @end deftypefn

## Author:  Kai Habel <kai.habel@gmx.de>

## PKG_ADD: colormap ("register", "bone");
## PKG_DEL: colormap ("unregister", "bone");

function map = bone (n)

  if (nargin == 0)
    n = rows (colormap);
  elseif (nargin == 1)
    if (! isscalar (n))
      error ("bone: N must be a scalar");
    endif
  else
    print_usage ();
  endif

  if (n == 1)
    map = [1/8 1/8 1/8];
  elseif (n == 2)
    map = [1/16 1/8 1/8
            1    1   1 ];
  elseif (n > 2)
    x = [0:n-1]' / (n-1);

    idx = floor (3/4*n);
    nel = n - idx + 1;    # number of elements
    rem = mod (n, 8);
    switch (rem)
      case {2, 4}
        base = 1 / (16 + 2*(n-rem));
      case {5, 7}
        base = 1 / (24 + 2*(n-rem));
      otherwise
        base = 0;
    endswitch
    r(1:idx,1) = 7/8 * x(1:idx);
    r(idx:n,1) = linspace (7/8 * x(idx) + base, 1, nel);

    idx = floor (3/8 * n);
    nel = idx + 1;
    g(1:idx,1) = 7/8 * x(1:idx);
    g(idx:2*idx,1) = linspace (7/8 * x(idx), 7/8 * x(2*idx) + 1/8, nel);
    g(2*idx+1:n,1) = 7/8 * x(2*idx+1:n) + 1/8;
    
    base = 1 / (8*idx);
    nel = idx;
    b(1:idx,1) = linspace (base, 7/8 * x(idx) + 1/8, nel);
    b(idx:n,1) = 7/8 * x(idx:n) + 1/8;

    map = [r, g, b];
  else
    map = zeros (0, 3);
  endif

endfunction


%!demo
%! ## Show the 'bone' colormap as an image
%! image (1:64, linspace (0, 1, 64), repmat ((1:64)', 1, 64));
%! axis ([1, 64, 0, 1], "ticy", "xy");
%! colormap (bone (64));