kc3-lang/harfbuzz/util/view-cairo.cc

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• Hash : 42255814
  Author :
  Date : 2011-09-19T17:57:02
  

  [util] Account for line-space in surface size
  

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• util/view-cairo.cc

• /*
   * Copyright © 2011  Google, Inc.
   *
   *  This is part of HarfBuzz, a text shaping library.
   *
   * Permission is hereby granted, without written agreement and without
   * license or royalty fees, to use, copy, modify, and distribute this
   * software and its documentation for any purpose, provided that the
   * above copyright notice and the following two paragraphs appear in
   * all copies of this software.
   *
   * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
   * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
   * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
   * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
   * DAMAGE.
   *
   * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
   * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
   * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
   * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
   * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
   *
   * Google Author(s): Behdad Esfahbod
   */
  
  #include "view-cairo.hh"
  
  void
  view_cairo_t::init (const font_options_t *font_opts)
  {
    lines = g_array_new (FALSE, FALSE, sizeof (helper_cairo_line_t));
    scale = double (font_size) / hb_face_get_upem (hb_font_get_face (font_opts->get_font ()));
  }
  
  void
  view_cairo_t::consume_line (hb_buffer_t  *buffer,
  			    const char   *text,
  			    unsigned int  text_len)
  {
    helper_cairo_line_t l;
    helper_cairo_line_from_buffer (&l, buffer, text, text_len, scale);
    g_array_append_val (lines, l);
  }
  
  void
  view_cairo_t::finish (const font_options_t *font_opts)
  {
    render (font_opts);
  
    for (unsigned int i = 0; i < lines->len; i++) {
      helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
      line.finish ();
    }
    g_array_unref (lines);
  }
  
  void
  view_cairo_t::get_surface_size (cairo_scaled_font_t *scaled_font,
  				double *w, double *h)
  {
    cairo_font_extents_t font_extents;
  
    cairo_scaled_font_extents (scaled_font, &font_extents);
  
    *h = font_extents.ascent
       + font_extents.descent
       + ((int) lines->len - 1) * (font_extents.height + line_space);
    *w = 0;
    for (unsigned int i = 0; i < lines->len; i++) {
      helper_cairo_line_t &line = g_array_index (lines, helper_cairo_line_t, i);
      double line_width = line.get_width ();
      *w = MAX (*w, line_width);
    }
  
    *w += margin.l + margin.r;
    *h += margin.t + margin.b;
  }
  
  void
  view_cairo_t::render (const font_options_t *font_opts)
  {
    cairo_scaled_font_t *scaled_font = helper_cairo_create_scaled_font (font_opts, font_size);
    double w, h;
    get_surface_size (scaled_font, &w, &h);
    cairo_t *cr = helper_cairo_create_context (w, h, this, this);
    cairo_set_scaled_font (cr, scaled_font);
    cairo_scaled_font_destroy (scaled_font);
  
    draw (cr);
  
    helper_cairo_destroy_context (cr);
  }
  
  void
  view_cairo_t::draw (cairo_t *cr)
  {
    cairo_save (cr);
  
    cairo_font_extents_t font_extents;
    cairo_font_extents (cr, &font_extents);
    cairo_translate (cr, margin.l, margin.t);
    for (unsigned int i = 0; i < lines->len; i++)
    {
      helper_cairo_line_t &l = g_array_index (lines, helper_cairo_line_t, i);
  
      if (i)
        cairo_translate (cr, 0, line_space);
  
      cairo_translate (cr, 0, font_extents.ascent);
  
      if (annotate) {
        cairo_save (cr);
  
        /* Draw actual glyph origins */
        cairo_set_source_rgba (cr, 1., 0., 0., .5);
        cairo_set_line_width (cr, 5);
        cairo_set_line_cap (cr, CAIRO_LINE_CAP_ROUND);
        for (unsigned i = 0; i < l.num_glyphs; i++) {
  	cairo_move_to (cr, l.glyphs[i].x, l.glyphs[i].y);
  	cairo_rel_line_to (cr, 0, 0);
        }
        cairo_stroke (cr);
  
        cairo_restore (cr);
      }
  
      if (cairo_surface_get_type (cairo_get_target (cr)) == CAIRO_SURFACE_TYPE_IMAGE) {
        /* cairo_show_glyphs() doesn't support subpixel positioning */
        cairo_glyph_path (cr, l.glyphs, l.num_glyphs);
        cairo_fill (cr);
      } else if (l.num_clusters)
        cairo_show_text_glyphs (cr,
  			      l.utf8, l.utf8_len,
  			      l.glyphs, l.num_glyphs,
  			      l.clusters, l.num_clusters,
  			      l.cluster_flags);
      else
        cairo_show_glyphs (cr, l.glyphs, l.num_glyphs);
  
      cairo_translate (cr, 0, font_extents.height - font_extents.ascent);
    }
  
    cairo_restore (cr);
  }
  

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