pangocairo-win32font.c

GTK+-2.0源码之pango-1.15.6.tar.gz

static int
max_glyph_width (PangoLayout *layout)
{
  int max_width = 0;
  GSList *l, *r;

  for (l = pango_layout_get_lines_readonly (layout); l; l = l->next)
    {
      PangoLayoutLine *line = l->data;

      for (r = line->runs; r; r = r->next)
	{
	  PangoGlyphString *glyphs = ((PangoGlyphItem *)r->data)->glyphs;
	  int i;

	  for (i = 0; i < glyphs->num_glyphs; i++)
	    if (glyphs->glyphs[i].geometry.width > max_width)
	      max_width = glyphs->glyphs[i].geometry.width;
	}
    }

  return max_width;
}

static PangoFontMetrics *
create_metrics_for_context (PangoFont    *font,
			    PangoContext *context)
{
  PangoCairoWin32Font *cwfont = PANGO_CAIRO_WIN32_FONT (font);
  PangoFontMetrics *metrics;
  PangoFontDescription *font_desc;
  PangoLayout *layout;
  PangoRectangle extents;
  PangoLanguage *language = pango_context_get_language (context);
  const char *sample_str = pango_language_get_sample_string (language);
  cairo_scaled_font_t *scaled_font;
  cairo_font_extents_t font_extents;
  double height;

  metrics = pango_font_metrics_new ();

  scaled_font = pango_cairo_win32_font_get_scaled_font (PANGO_CAIRO_FONT (cwfont));

  cairo_scaled_font_extents (scaled_font, &font_extents);
  cairo_win32_scaled_font_done_font (scaled_font);

  metrics->ascent = font_extents.ascent * PANGO_SCALE;
  metrics->descent = font_extents.descent * PANGO_SCALE;

  /* FIXME: Should get the real settings for these from the TrueType
   * font file.
   */
  height = metrics->ascent + metrics->descent;
  metrics->underline_thickness = height / 14;
  metrics->underline_position = - metrics->underline_thickness;
  metrics->strikethrough_thickness = metrics->underline_thickness;
  metrics->strikethrough_position = height / 4;

  pango_quantize_line_geometry (&metrics->underline_thickness,
				&metrics->underline_position);
  pango_quantize_line_geometry (&metrics->strikethrough_thickness,
				&metrics->strikethrough_position);

  layout = pango_layout_new (context);
  font_desc = pango_font_describe_with_absolute_size (font);
  pango_layout_set_font_description (layout, font_desc);
  pango_layout_set_text (layout, sample_str, -1);
  pango_layout_get_extents (layout, NULL, &extents);

  metrics->approximate_char_width = extents.width / g_utf8_strlen (sample_str, -1);

  pango_layout_set_text (layout, "0123456789", -1);
  metrics->approximate_digit_width = max_glyph_width (layout);

  pango_font_description_free (font_desc);
  g_object_unref (layout);

  return metrics;
}

static PangoFontMetrics *
pango_cairo_win32_font_get_metrics (PangoFont        *font,
				    PangoLanguage    *language)
{
  PangoWin32Font *win32font = PANGO_WIN32_FONT (font);
  PangoCairoWin32Font *cwfont = PANGO_CAIRO_WIN32_FONT (font);
  PangoWin32MetricsInfo *info = NULL; /* Quiet gcc */
  GSList *tmp_list;
  const char *sample_str = pango_language_get_sample_string (language);

  tmp_list = cwfont->metrics_by_lang;
  while (tmp_list)
    {
      info = tmp_list->data;

      if (info->sample_str == sample_str)    /* We _don't_ need strcmp */
	break;

      tmp_list = tmp_list->next;
    }

  if (!tmp_list)
    {
      PangoContext *context;

      if (!win32font->fontmap)
	return pango_font_metrics_new ();

      info = g_slice_new0 (PangoWin32MetricsInfo);

      cwfont->metrics_by_lang = g_slist_prepend (cwfont->metrics_by_lang,
						 info);

      info->sample_str = sample_str;

      context = pango_context_new ();
      pango_context_set_font_map (context, win32font->fontmap);
      pango_context_set_language (context, language);
      pango_cairo_context_set_font_options (context, cwfont->options);

      info->metrics = create_metrics_for_context (font, context);

      g_object_unref (context);
    }

  return pango_font_metrics_ref (info->metrics);
}

static gboolean
pango_cairo_win32_font_select_font (PangoFont *font,
				    HDC        hdc)
{
  cairo_scaled_font_t *scaled_font = pango_cairo_win32_font_get_scaled_font (PANGO_CAIRO_FONT (font));

  return cairo_win32_scaled_font_select_font (scaled_font, hdc) == CAIRO_STATUS_SUCCESS;
}

static void
pango_cairo_win32_font_done_font (PangoFont *font)
{
  cairo_scaled_font_t *scaled_font = pango_cairo_win32_font_get_scaled_font (PANGO_CAIRO_FONT (font));

  cairo_win32_scaled_font_done_font (scaled_font);
}

static double
pango_cairo_win32_font_get_metrics_factor (PangoFont *font)
{
  PangoWin32Font *win32font = PANGO_WIN32_FONT (font);
  cairo_scaled_font_t *scaled_font = pango_cairo_win32_font_get_scaled_font (PANGO_CAIRO_FONT (font));

  return cairo_win32_scaled_font_get_metrics_factor (scaled_font) * win32font->size;
}

static void
pango_cairo_win32_font_class_init (PangoCairoWin32FontClass *class)
{
  GObjectClass *object_class = G_OBJECT_CLASS (class);
  PangoFontClass *font_class = PANGO_FONT_CLASS (class);
  PangoWin32FontClass *win32_font_class = PANGO_WIN32_FONT_CLASS (class);

  object_class->finalize = pango_cairo_win32_font_finalize;

  font_class->get_glyph_extents = pango_cairo_win32_font_get_glyph_extents;
  font_class->get_metrics = pango_cairo_win32_font_get_metrics;

  win32_font_class->select_font = pango_cairo_win32_font_select_font;
  win32_font_class->done_font = pango_cairo_win32_font_done_font;
  win32_font_class->get_metrics_factor = pango_cairo_win32_font_get_metrics_factor;
}

static void
pango_cairo_win32_font_init (PangoCairoWin32Font *cwfont)
{
  cwfont->glyph_info = g_hash_table_new_full (g_direct_hash,
					      NULL,
					      NULL,
					      (GDestroyNotify)g_free);
}

/********************
 *    Private API   *
 ********************/

PangoFont *
_pango_cairo_win32_font_new (PangoCairoWin32FontMap     *cwfontmap,
			     PangoContext               *context,
			     PangoWin32Face             *face,
			     const PangoFontDescription *desc)
{
  PangoCairoWin32Font *cwfont;
  PangoWin32Font *win32font;
  const PangoMatrix *pango_ctm;
  double size;
  double dpi;
#define USE_FACE_CACHED_FONTS
#ifdef USE_FACE_CACHED_FONTS
  PangoWin32FontMap *win32fontmap;
  GSList *tmp_list;
#endif

  g_return_val_if_fail (PANGO_IS_CAIRO_WIN32_FONT_MAP (cwfontmap), NULL);

  size = (double) pango_font_description_get_size (desc) / PANGO_SCALE;

  if (context)
    {
      dpi = pango_cairo_context_get_resolution (context);

      if (dpi <= 0)
	dpi = cwfontmap->dpi;
    }
  else
    dpi = cwfontmap->dpi;

  if (!pango_font_description_get_size_is_absolute (desc))
    size *= dpi / 72.;

#ifdef USE_FACE_CACHED_FONTS
  win32fontmap = PANGO_WIN32_FONT_MAP (cwfontmap);

  tmp_list = face->cached_fonts;
  while (tmp_list)
    {
      win32font = tmp_list->data;
      if (ABS (win32font->size - size * PANGO_SCALE) < 2)
	{
	  g_object_ref (win32font);
	  if (win32font->in_cache)
	    pango_win32_fontmap_cache_remove (PANGO_FONT_MAP (win32fontmap), win32font);

	  return PANGO_FONT (win32font);
	}
      tmp_list = tmp_list->next;
    }
#endif
  cwfont = g_object_new (PANGO_TYPE_CAIRO_WIN32_FONT, NULL);
  win32font = PANGO_WIN32_FONT (cwfont);

  win32font->fontmap = PANGO_FONT_MAP (cwfontmap);
  g_object_ref (cwfontmap);

  win32font->win32face = face;

#ifdef USE_FACE_CACHED_FONTS
  face->cached_fonts = g_slist_prepend (face->cached_fonts, win32font);
#endif

  /* FIXME: This is a pixel size, so not really what we want for describe(),
   * but it's what we need when computing the scale factor.
   */
  win32font->size = size * PANGO_SCALE;

  cairo_matrix_init_scale (&cwfont->font_matrix,
			   size, size);

  pango_ctm = pango_context_get_matrix (context);
  if (pango_ctm)
    cairo_matrix_init (&cwfont->ctm,
		       pango_ctm->xx,
		       pango_ctm->yx,
		       pango_ctm->xy,
		       pango_ctm->yy,
		       0., 0.);
  else
    cairo_matrix_init_identity (&cwfont->ctm);

  pango_win32_make_matching_logfont (win32font->fontmap,
				     &face->logfont,
				     win32font->size,
				     &win32font->logfont);

  cwfont->options = cairo_font_options_copy (_pango_cairo_context_get_merged_font_options (context));

  return PANGO_FONT (cwfont);
}