gl2ps-print.cc

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////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2009-2025 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// 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
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////
 
#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif
 
// Both header files are required outside of HAVE_GLP2S_H
#include "errwarn.h"
#include "gl2ps-print.h"
 
#if defined (HAVE_GL2PS_H) && defined (HAVE_OPENGL)
 
#include <cstdio>
 
#include <limits>
 
#include <gl2ps.h>
 
#include "file-ops.h"
#include "filepos-wrappers.h"
#include "lo-mappers.h"
#include "oct-locbuf.h"
#include "oct-env.h"
#include "unistd-wrappers.h"
#include "unistr-wrappers.h"
#include "unwind-prot.h"
 
#include "gh-manager.h"
#include "gl-render.h"
#include "interpreter-private.h"
#include "oct-opengl.h"
#include "sighandlers.h"
#include "sysdep.h"
#include "text-renderer.h"
 
OCTAVE_BEGIN_NAMESPACE(octave)
 
class OCTINTERP_API gl2ps_renderer : public opengl_renderer
{
public:
 
  gl2ps_renderer (opengl_functions& glfcns, FILE *_fp,
                  const std::string& _term)
    : opengl_renderer (glfcns), m_fp (_fp), m_term (_term), m_fontsize (),
      m_fontname (), m_buffer_overflow (false), m_svg_def_index (0)
  { }
 
  OCTAVE_DISABLE_CONSTRUCT_COPY_MOVE (gl2ps_renderer)
 
  ~gl2ps_renderer () = default;
 
  // FIXME: should we import the functions from the base class and
  // overload them here, or should we use a different name so we don't
  // have to do this?  Without the using declaration or a name change,
  // the base class functions will be hidden.  That may be OK, but it
  // can also cause some confusion.
  using opengl_renderer::draw;
 
  void draw (const graphics_object& go, const std::string& print_cmd);
 
protected:
 
  Matrix render_text (const std::string& txt,
                      double x, double y, double z,
                      int halign, int valign, double rotation = 0.0);
 
  void set_font (const base_properties& props);
 
  static bool has_alpha (const graphics_handle& h)
  {
    bool retval = false;
 
    gh_manager& gh_mgr = __get_gh_manager__ ();
 
    graphics_object go = gh_mgr.get_object (h);
 
    if (! go.valid_object ())
      return retval;
 
    if (go.isa ("axes") || go.isa ("hggroup"))
      {
        Matrix  children = go.get ("children").matrix_value ();
        for (octave_idx_type ii = 0; ii < children.numel (); ii++)
          {
            retval = has_alpha (graphics_handle (children(ii)));
            if (retval)
              break;
          }
      }
    else if (go.isa ("patch") || go.isa ("surface"))
      {
        octave_value fa = go.get ("facealpha");
        if (fa.is_scalar_type () && fa.is_double_type ()
            && fa.double_value () < 1)
          retval = true;
      }
    else if (go.isa ("scatter"))
      {
        octave_value fa = go.get ("markerfacealpha");
        if (fa.is_scalar_type () && fa.is_double_type ()
            && fa.double_value () < 1)
          retval = true;
      }
 
    return retval;
  }
 
  void draw_axes (const axes::properties& props)
  {
    // Initialize a sorting tree (viewport) in gl2ps for each axes
    GLint vp[4];
    m_glfcns.glGetIntegerv (GL_VIEWPORT, vp);
    gl2psBeginViewport (vp);
 
 
    // Don't remove hidden primitives when some of them are transparent
    GLint opts;
    gl2psGetOptions (&opts);
    if (has_alpha (props.get___myhandle__ ()))
      {
        opts &= ~GL2PS_OCCLUSION_CULL;
        // FIXME: currently the GL2PS_BLEND (which is more an equivalent of
        // GL_ALPHA_TEST than GL_BLEND) is not working on a per primitive
        // basis.  We thus set it once per viewport.
        gl2psEnable (GL2PS_BLEND);
      }
    else
      {
        opts |= GL2PS_OCCLUSION_CULL;
        gl2psDisable (GL2PS_BLEND);
      }
 
    gl2psSetOptions (opts);
 
    // Draw and finish () or there may be primitives missing in the gl2ps
    // output.
    opengl_renderer::draw_axes (props);
    finish ();
 
    // Finalize viewport
    GLint state = gl2psEndViewport ();
    if (state == GL2PS_NO_FEEDBACK && props.is_visible ())
      warning ("gl2ps_renderer::draw_axes: empty feedback buffer and/or nothing else to print");
    else if (state == GL2PS_ERROR)
      error ("gl2ps_renderer::draw_axes: gl2psEndPage returned GL2PS_ERROR");
 
    m_buffer_overflow |= (state == GL2PS_OVERFLOW);
 
    // Don't draw background for subsequent viewports (legends, subplots,
    // etc.)
    gl2psGetOptions (&opts);
    opts &= ~GL2PS_DRAW_BACKGROUND;
    gl2psSetOptions (opts);
  }
 
  void draw_text (const text::properties& props);
 
  void draw_image (const image::properties& props);
  void draw_pixels (int w, int h, const float *data);
  void draw_pixels (int w, int h, const uint8_t *data);
  void draw_pixels (int w, int h, const uint16_t *data);
 
  void init_marker (const std::string& m, double size, float width)
  {
    opengl_renderer::init_marker (m, size, width);
 
    // FIXME: gl2ps can't handle closed contours so we set linecap/linejoin
    //        round to obtain a better looking result for some markers.
    if (m == "o" || m == "v" || m == "^" || m == ">" || m == "<" || m == "h"
        || m == "hexagram" || m == "p" || m == "pentagram")
      {
        set_linejoin ("round");
        set_linecap ("round");
      }
    else
      {
        set_linejoin ("miter");
        set_linecap ("square");
      }
  }
 
  void set_linestyle (const std::string& s, bool use_stipple = false,
                      double linewidth = 0.5)
  {
    opengl_renderer::set_linestyle (s, use_stipple, linewidth);
 
    if (s == "-" && ! use_stipple)
      gl2psDisable (GL2PS_LINE_STIPPLE);
    else
      gl2psEnable (GL2PS_LINE_STIPPLE);
  }
 
  void set_linecap (const std::string& s)
  {
    opengl_renderer::set_linejoin (s);
 
#if defined (HAVE_GL2PSLINEJOIN)
    if (s == "butt")
      gl2psLineCap (GL2PS_LINE_CAP_BUTT);
    else if (s == "square")
      gl2psLineCap (GL2PS_LINE_CAP_SQUARE);
    else if (s == "round")
      gl2psLineCap (GL2PS_LINE_CAP_ROUND);
#endif
  }
 
  void set_linejoin (const std::string& s)
  {
    opengl_renderer::set_linejoin (s);
 
#if defined (HAVE_GL2PSLINEJOIN)
    if (s == "round")
      gl2psLineJoin (GL2PS_LINE_JOIN_ROUND);
    else if (s == "miter")
      gl2psLineJoin (GL2PS_LINE_JOIN_MITER);
    else if (s == "chamfer")
      gl2psLineJoin (GL2PS_LINE_JOIN_BEVEL);
#endif
  }
 
  void set_polygon_offset (bool on, float offset = 0.0f)
  {
    if (on)
      {
        opengl_renderer::set_polygon_offset (on, offset);
        gl2psEnable (GL2PS_POLYGON_OFFSET_FILL);
      }
    else
      {
        gl2psDisable (GL2PS_POLYGON_OFFSET_FILL);
        opengl_renderer::set_polygon_offset (on, offset);
      }
  }
 
  void set_linewidth (float w)
  {
    gl2psLineWidth (w);
  }
 
private:
 
  // Use xform to compute the coordinates of the string list
  // that have been parsed by freetype.
  void fix_strlist_position (double x, double y, double z,
                             Matrix box, double rotation,
                             std::list<text_renderer::string>& lst);
 
  // Build an svg text element from a list of parsed strings
  std::string format_svg_element (std::string str, Matrix bbox,
                                  double rotation, ColumnVector coord_pix,
                                  Matrix color);
 
  std::string strlist_to_svg (double x, double y, double z, Matrix box,
                              double rotation,
                              std::list<text_renderer::string>& lst);
 
  // Build a list of postscript commands from a list of parsed strings.
  std::string strlist_to_ps (double x, double y, double z, Matrix box,
                             double rotation,
                             std::list<text_renderer::string>& lst);
 
  int alignment_to_mode (int ha, int va) const;
 
  FILE *m_fp;
  caseless_str m_term;
  double m_fontsize;
  std::string m_fontname;
  bool m_buffer_overflow;
  std::size_t m_svg_def_index;
};
 
static bool
has_2D_axes (const graphics_handle& h)
{
  bool retval = true;
 
  gh_manager& gh_mgr = __get_gh_manager__ ();
 
  graphics_object go = gh_mgr.get_object (h);
 
  if (! go.valid_object ())
    return retval;
 
  if (go.isa ("figure") || go.isa ("uipanel"))
    {
      Matrix  children = go.get ("children").matrix_value ();
      for (octave_idx_type ii = 0; ii < children.numel (); ii++)
        {
          retval = has_2D_axes (graphics_handle (children(ii)));
          if (! retval)
            break;
        }
    }
  else if (go.isa ("axes"))
    {
      axes::properties& ap
        = reinterpret_cast<axes::properties&> (go.get_properties ());
      retval = ap.get_is2D (true);
    }
 
  return retval;
}
 
static std::string
get_title (const graphics_handle& h)
{
  std::string retval;
 
  gh_manager& gh_mgr = __get_gh_manager__ ();
 
  graphics_object go = gh_mgr.get_object (h);
 
  if (! go.valid_object ())
    return retval;
 
  if (go.isa ("figure"))
    {
      figure::properties& fp
        = reinterpret_cast<figure::properties&> (go.get_properties ());
 
      retval = fp.get_title ();
    }
 
  return retval;
}
 
void
gl2ps_renderer::draw (const graphics_object& go, const std::string& print_cmd)
{
  static bool in_draw = false;
  static std::string old_print_cmd;
  static GLint buffsize;
 
  if (! in_draw)
    {
      unwind_protect frame;
 
      frame.protect_var (in_draw);
 
      in_draw = true;
 
      GLint gl2ps_term = GL2PS_PS;
      if (m_term.find ("eps") != std::string::npos)
        gl2ps_term = GL2PS_EPS;
      else if (m_term.find ("pdf") != std::string::npos)
        gl2ps_term = GL2PS_PDF;
      else if (m_term.find ("ps") != std::string::npos)
        gl2ps_term = GL2PS_PS;
      else if (m_term.find ("svg") != std::string::npos)
        gl2ps_term = GL2PS_SVG;
      else if (m_term.find ("pgf") != std::string::npos)
        gl2ps_term = GL2PS_PGF;
      else if (m_term.find ("tex") != std::string::npos)
        gl2ps_term = GL2PS_TEX;
      else
        warning ("gl2ps_renderer::draw: Unknown terminal %s, using 'ps'",
                 m_term.c_str ());
 
      GLint gl2ps_text = 0;
      if (m_term.find ("notxt") != std::string::npos)
        gl2ps_text = GL2PS_NO_TEXT;
 
      // Find Title for plot
      const graphics_handle& myhandle = go.get ("__myhandle__");
      std::string plot_title = get_title (myhandle);
      if (plot_title.empty ())
        plot_title = "Octave plot";
 
      // Default sort order optimizes for 3D plots
      GLint gl2ps_sort = GL2PS_BSP_SORT;
 
      // FIXME: gl2ps does not provide a way to change the sorting algorithm
      // on a viewport basis, we thus disable sorting only if all axes are 2D
      if (has_2D_axes (myhandle))
        gl2ps_sort = GL2PS_NO_SORT;
 
      // Use a temporary file in case an overflow happens
      std::string tmpfile (sys::tempnam (sys::env::get_temp_directory (),
                                         "oct-"));
      FILE *tmpf = sys::fopen_tmp (tmpfile, "w+b");
 
      if (! tmpf)
        error ("gl2ps_renderer::draw: couldn't open temporary file for printing");
 
      frame.add ([tmpf] () { std::fclose (tmpf); });
 
      // Reset buffsize, unless this is 2nd pass of a texstandalone print.
      if (m_term.find ("tex") == std::string::npos)
        buffsize = 2*1024*1024;
      else
        buffsize /= 2;
 
      m_buffer_overflow = true;
 
      while (m_buffer_overflow)
        {
          m_buffer_overflow = false;
          buffsize *= 2;
 
          octave_fseeko_wrapper (tmpf, 0, SEEK_SET);
          octave_ftruncate_wrapper (fileno (tmpf), 0);
 
          // For LaTeX output the print process uses 2 drawnow() commands.
          // The first one is for the pdf/ps/eps graph to be included.  The
          // print_cmd is saved as old_print_cmd.  Then the second drawnow()
          // outputs the tex-file and the graphic filename to be included is
          // extracted from old_print_cmd.
 
          std::string include_graph;
 
          std::size_t found_redirect = old_print_cmd.find ('>');
 
          if (found_redirect != std::string::npos)
            include_graph = old_print_cmd.substr (found_redirect + 1);
          else
            include_graph = old_print_cmd;
 
          std::size_t n_begin = include_graph.find_first_not_of (R"( "')");
 
          if (n_begin != std::string::npos)
            {
              // Strip any quote characters characters around filename
              std::size_t n_end = include_graph.find_last_not_of (R"( "')");
              include_graph = include_graph.substr (n_begin,
                                                    n_end - n_begin + 1);
              // Strip path from filename
              n_begin = include_graph.find_last_of (sys::file_ops::dir_sep_chars ());
              include_graph = include_graph.substr (n_begin + 1);
            }
          else
            include_graph = "foobar-inc";
 
          // FIXME: workaround gl2ps drawing 2 background planes, the first
          //        eventually being black and producing visual artifacts
          const figure::properties& fprop
            = dynamic_cast<const figure::properties&> (go.get_properties ());
          Matrix c = fprop.get_color_rgb ();
          m_glfcns.glClearColor (c(0), c(1), c(2), 1);
 
          // Allow figures to be printed at arbitrary resolution
          set_device_pixel_ratio (fprop.get___device_pixel_ratio__ ());
 
          // GL2PS_SILENT was removed to allow gl2ps to print errors on stderr
          GLint ret = gl2psBeginPage (plot_title.c_str (), "Octave",
                                      nullptr, gl2ps_term, gl2ps_sort,
                                      (GL2PS_BEST_ROOT
                                       | gl2ps_text
                                       | GL2PS_DRAW_BACKGROUND
                                       | GL2PS_NO_PS3_SHADING
                                       | GL2PS_USE_CURRENT_VIEWPORT),
                                      GL_RGBA, 0, nullptr, 0, 0, 0,
                                      buffsize, tmpf, include_graph.c_str ());
          if (ret == GL2PS_ERROR)
            {
              old_print_cmd.clear ();
              error ("gl2ps_renderer::draw: gl2psBeginPage returned GL2PS_ERROR");
            }
 
          opengl_renderer::draw (go);
 
          if (m_buffer_overflow)
            warning ("gl2ps_renderer::draw: retrying with buffer size: %.1E B\n", double (2*buffsize));
 
          if (! m_buffer_overflow)
            old_print_cmd = print_cmd;
 
          // Don't check return value of gl2psEndPage, it is not meaningful.
          // Errors and warnings are checked after gl2psEndViewport in
          // gl2ps_renderer::draw_axes instead.
          gl2psEndPage ();
        }
 
      // Copy temporary file to pipe
      octave_fseeko_wrapper (tmpf, 0, SEEK_SET);
      char str[8192];  // 8 kB is a common kernel buffersize
      std::size_t nread, nwrite;
      nread = 1;
 
      // In EPS terminal read the header line by line and insert a
      // new procedure
      const char *fcn = "/SRX  { gsave FCT moveto rotate xshow grestore } BD\n";
      bool header_found = ! (m_term.find ("eps") != std::string::npos
                             || m_term.find ("svg") != std::string::npos);
 
      while (! feof (tmpf) && nread)
        {
          if (! header_found && std::fgets (str, 8192, tmpf))
            nread = strlen (str);
          else
            nread = std::fread (str, 1, 8192, tmpf);
 
          if (nread)
            {
              if (! header_found && std::strncmp (str, "/SBCR", 5) == 0)
                {
                  header_found = true;
                  nwrite = std::fwrite (fcn, 1, strlen (fcn), m_fp);
                  if (nwrite != strlen (fcn))
                    {
                      // FIXME: is this the best thing to do here?
                      respond_to_pending_signals ();
                      error ("gl2ps_renderer::draw: internal pipe error");
                    }
                }
              else if (m_term.find ("svg") != std::string::npos)
                {
                  // FIXME: gl2ps uses pixel units for SVG format.
                  //        Modify resulting svg to use points instead.
                  //        Remove this "else if" block, and
                  //        make header_found true for SVG if gl2ps is fixed.
 
                  // Specify number of characters because STR may have
                  // come from std::fread and not end with a NUL
                  // character.
                  std::string srchstr (str, nread);
                  std::size_t pos = srchstr.find ("<svg ");
                  if (! header_found && pos != std::string::npos)
                    {
                      header_found = true;
                      pos = srchstr.find ("px");
                      if (pos != std::string::npos)
                        {
                          srchstr[pos+1] = 't';  // "px" -> "pt"
                                                 // Assume the second occurrence is at the same line
                          pos = srchstr.find ("px", pos);
                          srchstr[pos+1] = 't';  // "px" -> "pt"
                          std::strcpy (str, srchstr.c_str ());
                        }
                    }
                }
 
              nwrite = std::fwrite (str, 1, nread, m_fp);
              if (nwrite != nread)
                {
                  // FIXME: is this the best thing to do here?
                  respond_to_pending_signals ();   // Clear SIGPIPE signal
                  error ("gl2ps_renderer::draw: internal pipe error");
                }
            }
        }
    }
  else
    opengl_renderer::draw (go);
}
 
int
gl2ps_renderer::alignment_to_mode (int ha, int va) const
{
  int gl2psa = GL2PS_TEXT_BL;
 
  if (ha == 0)
    {
      if (va == 0 || va == 3)
        gl2psa=GL2PS_TEXT_BL;
      else if (va == 2)
        gl2psa=GL2PS_TEXT_TL;
      else if (va == 1)
        gl2psa=GL2PS_TEXT_CL;
    }
  else if (ha == 2)
    {
      if (va == 0 || va == 3)
        gl2psa=GL2PS_TEXT_BR;
      else if (va == 2)
        gl2psa=GL2PS_TEXT_TR;
      else if (va == 1)
        gl2psa=GL2PS_TEXT_CR;
    }
  else if (ha == 1)
    {
      if (va == 0 || va == 3)
        gl2psa=GL2PS_TEXT_B;
      else if (va == 2)
        gl2psa=GL2PS_TEXT_T;
      else if (va == 1)
        gl2psa=GL2PS_TEXT_C;
    }
 
  return gl2psa;
}
 
void
gl2ps_renderer::fix_strlist_position (double x, double y, double z,
                                      Matrix box, double rotation,
                                      std::list<text_renderer::string>& lst)
{
  for (auto& txtobj : lst)
    {
      // Get pixel coordinates
      ColumnVector coord_pix = get_transform ().transform (x, y, z, false);
 
      // Translate and rotate
      double rot = rotation * 4.0 * atan (1.0) / 180;
      coord_pix(0) += (txtobj.get_x () + box(0))* cos (rot)
                      - (txtobj.get_y () + box(1))* sin (rot);
      coord_pix(1) -= (txtobj.get_y () + box(1))* cos (rot)
                      + (txtobj.get_x () + box(0))* sin (rot);
 
      GLint vp[4];
      m_glfcns.glGetIntegerv (GL_VIEWPORT, vp);
 
      txtobj.set_x (coord_pix(0));
      txtobj.set_y (vp[3] - coord_pix(1));
      txtobj.set_z (coord_pix(2));
    }
}
 
static std::string
code_to_symbol (uint32_t code)
{
  std::string retval;
 
  uint32_t idx = code - 945;
  if (idx < 25)
    {
      std::string characters ("abgdezhqiklmnxoprVstufcyw");
      retval = characters[idx];
      return retval;
    }
 
  idx = code - 913;
  if (idx < 25)
    {
      std::string characters ("ABGDEZHQIKLMNXOPRVSTUFCYW");
      retval = characters[idx];
    }
  else if (code == 978)
    retval = "U";
  else if (code == 215)
    retval = "\xb4";
  else if (code == 177)
    retval = "\xb1";
  else if (code == 8501)
    retval = "\xc0";
  else if (code == 8465)
    retval = "\xc1";
  else if (code == 8242)
    retval = "\xa2";
  else if (code == 8736)
    retval = "\xd0";
  else if (code == 172)
    retval = "\xd8";
  else if (code == 9829)
    retval = "\xa9";
  else if (code == 8472)
    retval = "\xc3";
  else if (code == 8706)
    retval = "\xb6";
  else if (code == 8704)
    retval = "\x22";
  else if (code == 9827)
    retval = "\xa7";
  else if (code == 9824)
    retval = "\xaa";
  else if (code == 8476)
    retval = "\xc2";
  else if (code == 8734)
    retval = "\xa5";
  else if (code == 8730)
    retval = "\xd6";
  else if (code == 8707)
    retval = "\x24";
  else if (code == 9830)
    retval = "\xa8";
  else if (code == 8747)
    retval = "\xf2";
  else if (code == 8727)
    retval = "\x2a";
  else if (code == 8744)
    retval = "\xda";
  else if (code == 8855)
    retval = "\xc4";
  else if (code == 8901)
    retval = "\xd7";
  else if (code == 8728)
    retval = "\xb0";
  else if (code == 8745)
    retval = "\xc7";
  else if (code == 8743)
    retval = "\xd9";
  else if (code == 8856)
    retval = "\xc6";
  else if (code == 8729)
    retval = "\xb7";
  else if (code == 8746)
    retval = "\xc8";
  else if (code == 8853)
    retval = "\xc5";
  else if (code == 8804)
    retval = "\xa3";
  else if (code == 8712)
    retval = "\xce";
  else if (code == 8839)
    retval = "\xca";
  else if (code == 8801)
    retval = "\xba";
  else if (code == 8773)
    retval = "\x40";
  else if (code == 8834)
    retval = "\xcc";
  else if (code == 8805)
    retval = "\xb3";
  else if (code == 8715)
    retval = "\x27";
  else if (code == 8764)
    retval = "\x7e";
  else if (code == 8733)
    retval = "\xb5";
  else if (code == 8838)
    retval = "\xcd";
  else if (code == 8835)
    retval = "\xc9";
  else if (code == 8739)
    retval = "\xbd";
  else if (code == 8776)
    retval = "\xbb";
  else if (code == 8869)
    retval = "\x5e";
  else if (code == 8656)
    retval = "\xdc";
  else if (code == 8592)
    retval = "\xac";
  else if (code == 8658)
    retval = "\xde";
  else if (code == 8594)
    retval = "\xae";
  else if (code == 8596)
    retval = "\xab";
  else if (code == 8593)
    retval = "\xad";
  else if (code == 8595)
    retval = "\xaf";
  else if (code == 8970)
    retval = "\xeb";
  else if (code == 8971)
    retval = "\xfb";
  else if (code == 10216)
    retval = "\xe1";
  else if (code == 10217)
    retval = "\xf1";
  else if (code == 8968)
    retval = "\xe9";
  else if (code == 8969)
    retval = "\xf9";
  else if (code == 8800)
    retval = "\xb9";
  else if (code == 8230)
    retval = "\xbc";
  else if (code == 176)
    retval = "\xb0";
  else if (code == 8709)
    retval = "\xc6";
  else if (code == 169)
    retval = "\xd3";
 
  if (retval.empty ())
    warning ("print: unhandled symbol %d", code);
 
  return retval;
}
 
static std::string
select_font (caseless_str fn, bool isbold, bool isitalic)
{
  std::transform (fn.begin (), fn.end (), fn.begin (), ::tolower);
  std::string fontname;
  if (fn == "times" || fn == "times-roman")
    {
      if (isitalic && isbold)
        fontname = "Times-BoldItalic";
      else if (isitalic)
        fontname = "Times-Italic";
      else if (isbold)
        fontname = "Times-Bold";
      else
        fontname = "Times-Roman";
    }
  else if (fn == "courier")
    {
      if (isitalic && isbold)
        fontname = "Courier-BoldOblique";
      else if (isitalic)
        fontname = "Courier-Oblique";
      else if (isbold)
        fontname = "Courier-Bold";
      else
        fontname = "Courier";
    }
  else if (fn == "symbol")
    fontname = "Symbol";
  else if (fn == "zapfdingbats")
    fontname = "ZapfDingbats";
  else
    {
      if (isitalic && isbold)
        fontname = "Helvetica-BoldOblique";
      else if (isitalic)
        fontname = "Helvetica-Oblique";
      else if (isbold)
        fontname = "Helvetica-Bold";
      else
        fontname = "Helvetica";
    }
  return fontname;
}
 
static void
escape_character (const std::string chr, std::string& str)
{
  std::size_t idx = str.find (chr);
  while (idx != std::string::npos)
    {
      str.insert (idx, 1, '\\');
      idx = str.find (chr, idx + 2);
    }
}
 
std::string
gl2ps_renderer::format_svg_element (std::string str, Matrix box,
                                    double rotation, ColumnVector coord_pix,
                                    Matrix color)
{
  // Extract <defs> elements and change their id to avoid conflict with
  // defs coming from another svg string
  std::string::size_type n1 = str.find ("<defs>");
  if (n1 == std::string::npos)
    return std::string ();
 
  std::string id, new_id;
  n1 = str.find ("<path", ++n1);
  std::string::size_type n2;
 
  while (n1 != std::string::npos)
    {
      // Extract the identifier id='identifier'
      n1 = str.find ("id='", n1) + 4;
      n2 = str.find ("'", n1);
      id = str.substr (n1, n2-n1);
 
      new_id = std::to_string (m_svg_def_index) + "-" + id ;
 
      str.replace (n1, n2-n1, new_id);
 
      std::string::size_type n_ref = str.find ("#" + id);
 
      while (n_ref != std::string::npos)
        {
          str.replace (n_ref + 1, id.length (), new_id);
          n_ref = str.find ("#" + id);
        }
 
      n1 = str.find ("<path", n1);
    }
 
  m_svg_def_index++;
 
  n1 = str.find ("<defs>");
  n2 = str.find ("</defs>") + 7;
 
  std::string defs = str.substr (n1, n2-n1);
 
  // Extract the group containing the <use> elements and transform its
  // coordinates using the bbox and coordinates info.
 
  // Extract the original viewBox anchor
  n1 = str.find ("viewBox='") + 9;
  if (n1 == std::string::npos)
    return std::string ();
 
  n2 = str.find (" ", n1);
  double original_x0 = std::stod (str.substr (n1, n2-n1));
 
  n1 = n2+1;
  n2 = str.find (" ", n1);
  double original_y0 = std::stod (str.substr (n1, n2-n1));
 
  // First look for local transform in the original svg
  std::string orig_trans;
  n1 = str.find ("<g id='page1' transform='");
  if (n1 != std::string::npos)
    {
      n1 += 25;
      n2 = str.find ("'", n1);
      orig_trans = str.substr (n1, n2-n1);
      n1 = n2 + 1;
    }
  else
    {
      n1 = str.find ("<g id='page1'");
      n1 += 13;
    }
 
  n2 = str.find ("</g>", n1) + 4;
 
  // The first applied transformation is the right-most
  // 1* Apply original transform
  std::string tform = orig_trans;
 
  // 2* Move the anchor to the final position
  tform = std::string ("translate")
          + "(" + std::to_string (box(0) - original_x0 + coord_pix(0))
          + "," + std::to_string (-(box(3) + box(1)) - original_y0 + coord_pix(1))
          + ") " + tform;
 
  // 3* Rotate around the final position
  if (rotation != 0)
    tform = std::string ("rotate")
            + "(" + std::to_string (-rotation)
            + "," + std::to_string (coord_pix(0))
            + "," + std::to_string (coord_pix(1))
            + ") " + tform;
 
  // Fill color
  std::string fill = "fill='rgb("
                     + std::to_string (static_cast<uint8_t> (color(0) * 255.0)) + ","
                     + std::to_string (static_cast<uint8_t> (color(1) * 255.0)) + ","
                     + std::to_string (static_cast<uint8_t> (color(2) * 255.0)) + ")' ";
 
  std::string use_group = "<g "
                          + fill
                          + "transform='" + tform + "'"
                          + str.substr (n1, n2-n1);
 
  return defs + "\n" + use_group;
}
 
std::string
gl2ps_renderer::strlist_to_svg (double x, double y, double z,
                                Matrix box, double rotation,
                                std::list<text_renderer::string>& lst)
{
  //Use pixel coordinates to conform to gl2ps
  ColumnVector coord_pix = get_transform ().transform (x, y, z, false);
 
  if (lst.empty ())
    return "";
 
  // This may already be an svg image.
  std::string svg = lst.front ().get_svg_element ();
  if (! svg.empty ())
    return format_svg_element (svg, box, rotation, coord_pix,
                               lst.front ().get_color ());
 
  // Rotation and translation are applied to the whole group
  std::ostringstream os;
  os << R"(<g xml:space="preserve" )";
  os << "transform=\""
     << "translate(" << coord_pix(0) + box(0) << "," << coord_pix(1) - box(1)
     << ") rotate(" << -rotation << "," << -box(0) << "," << box(1)
     << ")\" ";
 
  // Use the first entry for the base text font
  auto p = lst.begin ();
  std::string name = p->get_family ();
  std::string weight = p->get_weight ();
  std::string angle = p->get_angle ();
  double size = p->get_size ();
 
  os << "font-family=\"" << name << "\" "
     << "font-weight=\"" << weight << "\" "
     << "font-style=\"" << angle << "\" "
     << "font-size=\"" << size << "\">";
 
 
  // Build a text element for each element in the strlist
  for (p = lst.begin (); p != lst.end (); p++)
    {
      os << "<text ";
 
      if (name.compare (p->get_family ()))
        os << "font-family=\"" << p->get_family () << "\" ";
 
      if (weight.compare (p->get_weight ()))
        os << "font-weight=\"" << p->get_weight () << "\" ";
 
      if (angle.compare (p->get_angle ()))
        os << "font-style=\"" << p->get_angle () << "\" ";
 
      if (size != p->get_size ())
        os << "font-size=\"" << p->get_size () << "\" ";
 
      os << "y=\"" << - p->get_y () << "\" ";
 
      Matrix col = p->get_color ();
      os << "fill=\"rgb(" << col(0)*255 << ","
         << col(1)*255 << "," << col(2)*255 << ")\" ";
 
      // provide an x coordinate for each character in the string
      os << "x=\"";
      std::vector<double> xdata = p->get_xdata ();
      for (const auto& q : xdata)
        os << q << " ";
      os << '"';
 
      os << '>';
 
      // translate unicode and special xml characters
      if (p->get_code ())
        os << "&#" << p->get_code () <<  ";";
      else
        {
          const std::string str = p->get_string ();
          for (const auto& q : str)
            {
              std::stringstream chr;
              chr << q;
              if (chr.str () == "\"")
                os << "&quot;";
              else if (chr.str () == "'")
                os << "&apos;";
              else if (chr.str () == "&")
                os << "&amp;";
              else if (chr.str () == "<")
                os << "&lt;";
              else if (chr.str () == ">")
                os << "&gt;";
              else
                os << chr.str ();
            }
        }
      os << "</text>";
    }
  os << "</g>";
 
  return os.str ();
}
 
std::string
gl2ps_renderer::strlist_to_ps (double x, double y, double z,
                               Matrix box, double rotation,
                               std::list<text_renderer::string>& lst)
{
  if (lst.empty ())
    return "";
  else if (lst.size () == 1)
    {
      static bool warned = false;
      // This may be an svg image, not handled in native eps format.
      if (! lst.front ().get_svg_element ().empty ())
        {
          if (! warned)
            {
              warned = true;
              warning_with_id ("Octave:print:unhandled-svg-content",
                               "print: unhandled LaTeX strings. "
                               "Use -svgconvert option or -d*latex* output "
                               "device.");
            }
          return "";
        }
    }
 
  // Translate and rotate coordinates in order to use bottom-left alignment
  fix_strlist_position (x, y, z, box, rotation, lst);
  Matrix prev_color (1, 3, -1);
 
  std::ostringstream ss;
  ss << "gsave\n";
 
  static bool warned = false;
 
  for (const auto& txtobj : lst)
    {
      // Color
      if (txtobj.get_color () != prev_color)
        {
          prev_color = txtobj.get_color ();
          for (int i = 0; i < 3; i++)
            ss << prev_color(i) << " ";
 
          ss << "C\n";
        }
 
      // String
      std::string str;
      if (txtobj.get_code ())
        {
          m_fontname = "Symbol";
          str = code_to_symbol (txtobj.get_code ());
        }
      else
        {
          m_fontname = select_font (txtobj.get_name (),
                                    txtobj.get_weight () == "bold",
                                    txtobj.get_angle () == "italic");
 
          // Check that the string is composed of single byte characters
          const std::string tmpstr = txtobj.get_string ();
          const uint8_t *c
            = reinterpret_cast<const uint8_t *> (tmpstr.c_str ());
 
          for (std::size_t i = 0; i < tmpstr.size ();)
            {
              int mblen = octave_u8_strmblen_wrapper (c + i);
 
              // Replace multibyte or non ascii characters by a question mark
              if (mblen > 1)
                {
                  str += "?";
                  if (! warned)
                    {
                      warning_with_id ("Octave:print:unsupported-multibyte",
                                       "print: only ASCII characters are "
                                       "supported for EPS and derived "
                                       "formats. Use the '-svgconvert' "
                                       "option for better font support.");
                      warned = true;
                    }
                }
              else if (mblen < 1)
                {
                  mblen = 1;
                  str += "?";
                  if (! warned)
                    {
                      warning_with_id ("Octave:print:unhandled-character",
                                       "print: only ASCII characters are "
                                       "supported for EPS and derived "
                                       "formats. Use the '-svgconvert' "
                                       "option for better font support.");
                      warned = true;
                    }
                }
              else
                str += tmpstr.at (i);
 
              i += mblen;
            }
        }
 
      escape_character ("\\", str);
      escape_character ("(", str);
      escape_character (")", str);
 
      ss << "(" << str << ") [";
 
      std::vector<double> xdata = txtobj.get_xdata ();
      for (std::size_t i = 1; i < xdata.size (); i++)
        ss << xdata[i] - xdata[i-1] << " ";
 
      ss << "10] " << rotation << " " << txtobj.get_x ()
         << " " << txtobj.get_y () << " " << txtobj.get_size ()
         << " /" << m_fontname << " SRX\n";
    }
 
  ss << "grestore\n";
 
  return ss.str ();
}
 
Matrix
gl2ps_renderer::render_text (const std::string& txt,
                             double x, double y, double z,
                             int ha, int va, double rotation)
{
  std::string saved_font = m_fontname;
 
  if (txt.empty ())
    return Matrix (1, 4, 0.0);
 
  Matrix bbox;
  std::string str = txt;
  std::list<text_renderer::string> lst;
 
  text_to_strlist (str, lst, bbox, ha, va, rotation);
  m_glfcns.glRasterPos3d (x, y, z);
 
  // For svg/eps directly dump a preformated text element into gl2ps output
  if (m_term.find ("svg") != std::string::npos)
    {
      std::string elt = strlist_to_svg (x, y, z, bbox, rotation, lst);
      if (! elt.empty ())
        gl2psSpecial (GL2PS_SVG, elt.c_str ());
    }
  else if (m_term.find ("eps") != std::string::npos)
    {
      std::string elt = strlist_to_ps (x, y, z, bbox, rotation, lst);
      if (! elt.empty ())
        gl2psSpecial (GL2PS_EPS, elt.c_str ());
 
    }
  else
    gl2psTextOpt (str.c_str (), m_fontname.c_str (), m_fontsize,
                  alignment_to_mode (ha, va), rotation);
 
  m_fontname = saved_font;
 
  return bbox;
}
 
void
gl2ps_renderer::set_font (const base_properties& props)
{
  opengl_renderer::set_font (props);
 
  // Set the interpreter so that text_to_pixels can parse strings properly
  if (props.has_property ("interpreter"))
    set_interpreter (props.get ("interpreter").string_value ());
 
  m_fontsize = props.get ("__fontsize_points__").double_value ();
 
  caseless_str fn = props.get ("fontname").xtolower ().string_value ();
  bool isbold
    =(props.get ("fontweight").xtolower ().string_value () == "bold");
  bool isitalic
    = (props.get ("fontangle").xtolower ().string_value () == "italic");
 
  m_fontname = select_font (fn, isbold, isitalic);
}
 
void
gl2ps_renderer::draw_image (const image::properties& props)
{
  octave_value cdata = props.get_color_data ();
  const dim_vector& dv = cdata.dims ();
  int h = dv(0);
  int w = dv(1);
 
  Matrix x = props.get_xdata ().matrix_value ();
  Matrix y = props.get_ydata ().matrix_value ();
 
  // Someone wants us to draw an empty image?  No way.
  if (x.isempty () || y.isempty ())
    return;
 
  // Sort x/ydata and mark flipped dimensions
  bool xflip = false;
  if (x(0) > x(1))
    {
      std::swap (x(0), x(1));
      xflip = true;
    }
  else if (w > 1 && x(1) == x(0))
    x(1) = x(1) + (w-1);
 
  bool yflip = false;
  if (y(0) > y(1))
    {
      std::swap (y(0), y(1));
      yflip = true;
    }
  else if (h > 1 && y(1) == y(0))
    y(1) = y(1) + (h-1);
 
 
  const ColumnVector p0 = m_xform.transform (x(0), y(0), 0);
  const ColumnVector p1 = m_xform.transform (x(1), y(1), 0);
 
  if (math::isnan (p0(0)) || math::isnan (p0(1))
      || math::isnan (p1(0)) || math::isnan (p1(1)))
    {
      warning ("opengl_renderer: image X,Y data too large to draw");
      return;
    }
 
  // image pixel size in screen pixel units
  float pix_dx, pix_dy;
  // image pixel size in normalized units
  float nor_dx, nor_dy;
 
  if (w > 1)
    {
      pix_dx = (p1(0) - p0(0)) / (w-1);
      nor_dx = (x(1) - x(0)) / (w-1);
    }
  else
    {
      const ColumnVector p1w = m_xform.transform (x(1) + 1, y(1), 0);
      pix_dx = p1w(0) - p0(0);
      nor_dx = 1;
    }
 
  if (h > 1)
    {
      pix_dy = (p1(1) - p0(1)) / (h-1);
      nor_dy = (y(1) - y(0)) / (h-1);
    }
  else
    {
      const ColumnVector p1h = m_xform.transform (x(1), y(1) + 1, 0);
      pix_dy = p1h(1) - p0(1);
      nor_dy = 1;
    }
 
  // OpenGL won't draw any of the image if its origin is outside the
  // viewport/clipping plane so we must do the clipping ourselves.
 
  int j0, j1, jj, i0, i1, ii;
  j0 = 0, j1 = w;
  i0 = 0, i1 = h;
 
  float im_xmin = x(0) - nor_dx/2;
  float im_xmax = x(1) + nor_dx/2;
  float im_ymin = y(0) - nor_dy/2;
  float im_ymax = y(1) + nor_dy/2;
 
  // Clip to axes or viewport
  bool do_clip = props.is_clipping ();
  Matrix vp = get_viewport_scaled ();
 
  ColumnVector vp_lim_min
    = m_xform.untransform (std::numeric_limits <float>::epsilon (),
                           std::numeric_limits <float>::epsilon ());
  ColumnVector vp_lim_max = m_xform.untransform (vp(2), vp(3));
 
  if (vp_lim_min(0) > vp_lim_max(0))
    std::swap (vp_lim_min(0), vp_lim_max(0));
 
  if (vp_lim_min(1) > vp_lim_max(1))
    std::swap (vp_lim_min(1), vp_lim_max(1));
 
  float clip_xmin
    = do_clip ? (vp_lim_min(0) > m_xmin ? vp_lim_min(0) : m_xmin)
      : vp_lim_min(0);
 
  float clip_ymin
    = do_clip ? (vp_lim_min(1) > m_ymin ? vp_lim_min(1) : m_ymin)
      : vp_lim_min(1);
 
  float clip_xmax
    = do_clip ? (vp_lim_max(0) < m_xmax ? vp_lim_max(0) : m_xmax)
      : vp_lim_max(0);
 
  float clip_ymax
    = do_clip ? (vp_lim_max(1) < m_ymax ? vp_lim_max(1) : m_ymax)
      : vp_lim_max(1);
 
  if (im_xmin < clip_xmin)
    j0 += (clip_xmin - im_xmin)/nor_dx + 1;
 
  if (im_xmax > clip_xmax)
    j1 -= (im_xmax - clip_xmax)/nor_dx;
 
  if (im_ymin < clip_ymin)
    i0 += (clip_ymin - im_ymin)/nor_dy + 1;
 
  if (im_ymax > clip_ymax)
    i1 -= (im_ymax - clip_ymax)/nor_dy;
 
  if (i0 >= i1 || j0 >= j1)
    return;
 
  float zoom_x;
  m_glfcns.glGetFloatv (GL_ZOOM_X, &zoom_x);
  float zoom_y;
  m_glfcns.glGetFloatv (GL_ZOOM_Y, &zoom_y);
 
  m_glfcns.glPixelZoom (m_devpixratio * pix_dx, - m_devpixratio * pix_dy);
  m_glfcns.glRasterPos3d (im_xmin + nor_dx*j0, im_ymin + nor_dy*i0, 0);
 
  // Expect RGB data
  if (dv.ndims () == 3 && dv(2) == 3)
    {
      if (cdata.is_double_type ())
        {
          const NDArray xcdata = cdata.array_value ();
 
          OCTAVE_LOCAL_BUFFER (GLfloat, a,
                               static_cast<size_t> (3)*(j1-j0)*(i1-i0));
 
          for (int i = i0; i < i1; i++)
            {
              for (int j = j0, idx = (i-i0)*(j1-j0)*3; j < j1; j++, idx += 3)
                {
                  if (! yflip)
                    ii = i;
                  else
                    ii = h - i - 1;
 
                  if (! xflip)
                    jj = j;
                  else
                    jj = w - j - 1;
 
                  a[idx]   = xcdata(ii, jj, 0);
                  a[idx+1] = xcdata(ii, jj, 1);
                  a[idx+2] = xcdata(ii, jj, 2);
                }
            }
 
          draw_pixels (j1-j0, i1-i0, a);
 
        }
      else if (cdata.is_single_type ())
        {
          const FloatNDArray xcdata = cdata.float_array_value ();
 
          OCTAVE_LOCAL_BUFFER (GLfloat, a,
                               static_cast<size_t> (3)*(j1-j0)*(i1-i0));
 
          for (int i = i0; i < i1; i++)
            {
              for (int j = j0, idx = (i-i0)*(j1-j0)*3; j < j1; j++, idx += 3)
                {
                  if (! yflip)
                    ii = i;
                  else
                    ii = h - i - 1;
 
                  if (! xflip)
                    jj = j;
                  else
                    jj = w - j - 1;
 
                  a[idx]   = xcdata(ii, jj, 0);
                  a[idx+1] = xcdata(ii, jj, 1);
                  a[idx+2] = xcdata(ii, jj, 2);
                }
            }
 
          draw_pixels (j1-j0, i1-i0, a);
 
        }
      else if (cdata.is_uint8_type ())
        {
          const uint8NDArray xcdata = cdata.uint8_array_value ();
 
          OCTAVE_LOCAL_BUFFER (GLubyte, a,
                               static_cast<size_t> (3)*(j1-j0)*(i1-i0));
 
          for (int i = i0; i < i1; i++)
            {
              for (int j = j0, idx = (i-i0)*(j1-j0)*3; j < j1; j++, idx += 3)
                {
                  if (! yflip)
                    ii = i;
                  else
                    ii = h - i - 1;
 
                  if (! xflip)
                    jj = j;
                  else
                    jj = w - j - 1;
 
                  a[idx]   = xcdata(ii, jj, 0);
                  a[idx+1] = xcdata(ii, jj, 1);
                  a[idx+2] = xcdata(ii, jj, 2);
                }
            }
 
          draw_pixels (j1-j0, i1-i0, a);
 
        }
      else if (cdata.is_uint16_type ())
        {
          const uint16NDArray xcdata = cdata.uint16_array_value ();
 
          OCTAVE_LOCAL_BUFFER (GLushort, a,
                               static_cast<size_t> (3)*(j1-j0)*(i1-i0));
 
          for (int i = i0; i < i1; i++)
            {
              for (int j = j0, idx = (i-i0)*(j1-j0)*3; j < j1; j++, idx += 3)
                {
                  if (! yflip)
                    ii = i;
                  else
                    ii = h - i - 1;
 
                  if (! xflip)
                    jj = j;
                  else
                    jj = w - j - 1;
 
                  a[idx]   = xcdata(ii, jj, 0);
                  a[idx+1] = xcdata(ii, jj, 1);
                  a[idx+2] = xcdata(ii, jj, 2);
                }
            }
 
          draw_pixels (j1-j0, i1-i0, a);
 
        }
      else
        warning ("opengl_renderer: invalid image data type (expected double, single, uint8, or uint16)");
 
      m_glfcns.glPixelZoom (zoom_x, zoom_y);
 
    }
}
 
void
gl2ps_renderer::draw_pixels (int w, int h, const float *data)
{
  // Clip data between 0 and 1 for float values
  OCTAVE_LOCAL_BUFFER (float, tmp_data, static_cast<size_t> (3)*w*h);
 
  for (int i = 0; i < 3*h*w; i++)
    tmp_data[i] = (data[i] < 0.0f ? 0.0f : (data[i] > 1.0f ? 1.0f : data[i]));
 
  gl2psDrawPixels (w, h, 0, 0, GL_RGB, GL_FLOAT, tmp_data);
}
 
void
gl2ps_renderer::draw_pixels (int w, int h, const uint8_t *data)
{
  // gl2psDrawPixels only supports the GL_FLOAT type.
 
  OCTAVE_LOCAL_BUFFER (float, tmp_data, static_cast<size_t> (3)*w*h);
 
  static constexpr float MAXVAL = std::numeric_limits<uint8_t>::max ();
 
  for (int i = 0; i < 3*w*h; i++)
    tmp_data[i] = data[i] / MAXVAL;
 
  draw_pixels (w, h, tmp_data);
}
 
void
gl2ps_renderer::draw_pixels (int w, int h, const uint16_t *data)
{
  // gl2psDrawPixels only supports the GL_FLOAT type.
 
  OCTAVE_LOCAL_BUFFER (float, tmp_data, static_cast<size_t> (3)*w*h);
 
  static constexpr float MAXVAL = std::numeric_limits<uint16_t>::max ();
 
  for (int i = 0; i < 3*w*h; i++)
    tmp_data[i] = data[i] / MAXVAL;
 
  draw_pixels (w, h, tmp_data);
}
 
void
gl2ps_renderer::draw_text (const text::properties& props)
{
  if (props.get_string ().isempty ())
    return;
 
  draw_text_background (props, true);
 
  // First set font properties: freetype will use them to compute
  // coordinates and gl2ps will retrieve the color directly from the
  // feedback buffer
  set_font (props);
  set_color (props.get_color_rgb ());
 
  std::string saved_font = m_fontname;
 
  // Alignment
  int halign = 0;
  int valign = 0;
 
  if (props.horizontalalignment_is ("center"))
    halign = 1;
  else if (props.horizontalalignment_is ("right"))
    halign = 2;
 
  if (props.verticalalignment_is ("top"))
    valign = 2;
  else if (props.verticalalignment_is ("baseline"))
    valign = 3;
  else if (props.verticalalignment_is ("middle"))
    valign = 1;
 
  // FIXME: handle margin and surrounding box
  // Matrix bbox;
 
  const Matrix pos = get_transform ().scale (props.get_data_position ());
  std::string str = props.get_string ().string_vector_value ().join ("\n");
 
  render_text (str, pos(0), pos(1), pos.numel () > 2 ? pos(2) : 0.0,
               halign, valign, props.get_rotation ());
}
 
OCTAVE_END_NAMESPACE(octave)
 
#endif
 
OCTAVE_BEGIN_NAMESPACE(octave)
 
// If the name of the stream begins with '|', open a pipe to the command
// named by the rest of the string.  Otherwise, write to the named file.
 
void
gl2ps_print (opengl_functions& glfcns, const graphics_object& fig,
             const std::string& stream, const std::string& term)
{
#if defined (HAVE_GL2PS_H) && defined (HAVE_OPENGL)
 
  // FIXME: should we have a way to create a file that begins with the
  // character '|'?
 
  bool have_cmd = stream.length () > 1 && stream[0] == '|';
 
  FILE *m_fp = nullptr;
 
  unwind_protect frame;
 
  if (have_cmd)
    {
      // Create process and pipe gl2ps output to it.
 
      std::string cmd = stream.substr (1);
 
      m_fp = popen (cmd.c_str (), "w");
 
      if (! m_fp)
        error (R"(print: failed to open pipe "%s")", stream.c_str ());
 
      // Need octave:: qualifier here to avoid ambiguity.
      frame.add ([m_fp] () { octave::pclose (m_fp); });
    }
  else
    {
      // Write gl2ps output directly to file.
 
      m_fp = sys::fopen (stream.c_str (), "w");
 
      if (! m_fp)
        error (R"(gl2ps_print: failed to create file "%s")", stream.c_str ());
 
      frame.add ([m_fp] () { std::fclose (m_fp); });
    }
 
  gl2ps_renderer rend (glfcns, m_fp, term);
 
  Matrix pos = fig.get ("position").matrix_value ();
  rend.set_viewport (pos(2), pos(3));
  rend.draw (fig, stream);
 
  // Make sure buffered commands are finished!!!
  rend.finish ();
 
#else
 
  octave_unused_parameter (glfcns);
  octave_unused_parameter (fig);
  octave_unused_parameter (stream);
  octave_unused_parameter (term);
 
  err_disabled_feature ("gl2ps_print", "gl2ps");
 
#endif
}
 
OCTAVE_END_NAMESPACE(octave)