Add simple TeX parser based on flex/bison. * libinterp/corefcn/oct-tex-lexer.ll, libinterp/corefcn/oct-tex-pareser.yy: New files. * libinterp/Makefile.am (BUILT_SOURCES): Add oct-tex-lexer.cc and oct-tex-parser.cc. * libinterp/corefcn/modules.mk (corefcn/oct-tex-lexer.cc, corefcn/oct-tex-parser.h): New rules. * libinterp/corefcn/txt-eng-ft.h (ft_render::text_to_pixels, ft_render::get_extent): Add interpreter argument. * libinterp/corefcn/txt-eng-ft.cc (ft_render::text_to_pixels, ft_render::get_extent): Likewise. Use text_parser::parse(). * libinterp/corefcn/gl-render.cc (opengl_renderer::text_to_pixels): Use new interpreter argument. * libinterp/corefcn/graphics.cc (axes::properties::get_ticklabel_extents): Likewise. (uicontrol::properties::update_text_extent): Use text_parser::parse. * libinterp/corefcn/txt-eng.h (memory, string, caseless-str.h, dMatrix.h): New includes. (class text_element_subscript): Renamed from text_subscript_element. (class text_element_supserscript): Renamed from text_superscript_element. (class text_element_symbol, class text_element_fontstyle, class text_element_fontname, class text_element_fontsize, class text_element_color): New classes. (text_element_list::text_element_list(text_element*)): New constructor. (text_element_subscript::text_element_subscript(text_element*), text_element_subscript::text_element::subscript(char)): New constructors. (text_element_subscript::elem): New member. (text_element_subscript::get_element): New method. Returns it. (text_element_subscript::~text_element_subscript): New destructor. Delete it. (text_element_subscript::text_element_subscript()): Make default constructor private. (text_element_superscript::text_element_superscript(text_element*), text_element_superscript::text_element::superscript(char)): New constructors. (text_element_superscript::elem): New member. (text_element_superscript::get_element): New method. Returns it. (text_element_superscript::~text_element_superscript): New destructor. Delete it. (text_element_superscript::text_element_superscript()): Make default constructor private. (text_processor::visit(text_element_symbol), text_processor::visit(text_element_fontstyle), text_processor::visit(text_element_fontname), text_processor::visit(text_element_fontsize), text_processor::visit(text_element_color)): New methods. (text_parser::parse): New static method. (class text_parser_tex): New class.

--- a/libinterp/corefcn/graphics.cc
+++ b/libinterp/corefcn/graphics.cc
@@ -6292,7 +6292,7 @@
           label.erase (0, label.find_first_not_of (" "));
           label = label.substr (0, label.find_last_not_of (" ")+1);
 #ifdef HAVE_FREETYPE
-          ext = text_renderer.get_extent (label);
+          ext = text_renderer.get_extent (label, 0.0, "none");
           wmax = std::max (wmax, ext(0));
           hmax = std::max (hmax, ext(1));
 #else
@@ -7573,7 +7573,7 @@
   // FIXME: parsed content should be cached for efficiency
   // FIXME: support multiline text
 
-  elt = text_parser_none ().parse (get_string_string ());
+  elt = text_parser::parse (get_string_string (), "none");
 #ifdef HAVE_FONTCONFIG
   text_renderer.set_font (get_fontname (),
                           get_fontweight (),