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) 2007-2012 David Bateman
##
## 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} {} ezplot3 (@var{fx}, @var{fy}, @var{fz})
## @deftypefnx {Function File} {} ezplot3 (@dots{}, @var{dom})
## @deftypefnx {Function File} {} ezplot3 (@dots{}, @var{n})
## @deftypefnx {Function File} {} ezplot3 (@var{hax}, @dots{})
## @deftypefnx {Function File} {@var{h} =} ezplot3 (@dots{})
##
## Plot a parametrically defined curve in three dimensions.
##
## @var{fx}, @var{fy}, and @var{fz} are strings, inline functions,
## or function handles with one argument defining the function.  By
## default the plot is over the domain @code{0 <= @var{t} <= 2*pi}
## with 500 points.
##
## If @var{dom} is a two element vector, it represents the minimum and maximum
## values of @var{t}.
##
## @var{n} is a scalar defining the number of points to use in plotting the
## function.
##
## If the first argument @var{hax} is an axes handle, then plot into this axis,
## rather than the current axes returned by @code{gca}.
##
## The optional return value @var{h} is a graphics handle to the created plot.
##
## @example
## @group
## fx = @@(t) cos (t);
## fy = @@(t) sin (t);
## fz = @@(t) t;
## ezplot3 (fx, fy, fz, [0, 10*pi], 100);
## @end group
## @end example
##
## @seealso{plot3, ezplot, ezmesh, ezsurf}
## @end deftypefn

function h = ezplot3 (varargin)

  [htmp, needusage] = __ezplot__ ("plot3", varargin{:});

  if (needusage)
    print_usage ();
  endif

  if (nargout > 0)
    h = htmp;
  endif

endfunction


%!demo
%! clf;
%! fx = @(t) cos (t);
%! fy = @(t) sin (t);
%! fz = @(t) t;
%! ezplot3 (fx, fy, fz, [0, 10*pi], 100);

%!demo
%! clf;
%! fx = @(t) cos (t);
%! fy = @(t) sin (t);
%! fz = @(t) t;
%! ezplot3 (fx, fy, fz, [0, 5*pi], 100, 'animate');