pangoft2.c

GTK+-2.0源码之pango-1.15.6.tar.gz

  PangoFT2GlyphInfo *info;

  info = g_hash_table_lookup (ft2font->glyph_info, GUINT_TO_POINTER (glyph));

  if ((info == NULL) && create)
    {
      info = g_slice_new0 (PangoFT2GlyphInfo);

      pango_fc_font_get_raw_extents (fcfont, ft2font->load_flags,
				     glyph,
				     &info->ink_rect,
				     &info->logical_rect);

      g_hash_table_insert (ft2font->glyph_info, GUINT_TO_POINTER(glyph), info);
    }

  return info;
}

static void
pango_ft2_font_get_glyph_extents (PangoFont      *font,
				  PangoGlyph      glyph,
				  PangoRectangle *ink_rect,
				  PangoRectangle *logical_rect)
{
  PangoFT2GlyphInfo *info;

  if (glyph == PANGO_GLYPH_EMPTY)
    {
      if (ink_rect)
	ink_rect->x = ink_rect->y = ink_rect->height = ink_rect->width = 0;
      if (logical_rect)
	logical_rect->x = logical_rect->y = logical_rect->height = logical_rect->width = 0;
      return;
    }

  if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
    {
      glyph = pango_ft2_get_unknown_glyph (font);
      if (glyph == PANGO_GLYPH_EMPTY)
	{
	  /* No unknown glyph found for the font, draw a box */
	  PangoFontMetrics *metrics = pango_font_get_metrics (font, NULL);

	  if (metrics)
	    {
	      if (ink_rect)
		{
		  ink_rect->x = PANGO_SCALE;
		  ink_rect->width = metrics->approximate_char_width - 2 * PANGO_SCALE;
		  ink_rect->y = - (metrics->ascent - PANGO_SCALE);
		  ink_rect->height = metrics->ascent + metrics->descent - 2 * PANGO_SCALE;
		}
	      if (logical_rect)
		{
		  logical_rect->x = 0;
		  logical_rect->width = metrics->approximate_char_width;
		  logical_rect->y = -metrics->ascent;
		  logical_rect->height = metrics->ascent + metrics->descent;
		}

	      pango_font_metrics_unref (metrics);
	    }
	  else
	    {
	      if (ink_rect)
		ink_rect->x = ink_rect->y = ink_rect->height = ink_rect->width = 0;
	      if (logical_rect)
		logical_rect->x = logical_rect->y = logical_rect->height = logical_rect->width = 0;
	    }
	  return;
	}
    }

  info = pango_ft2_font_get_glyph_info (font, glyph, TRUE);

  if (ink_rect)
    *ink_rect = info->ink_rect;
  if (logical_rect)
    *logical_rect = info->logical_rect;
}

/**
 * pango_ft2_font_get_kerning:
 * @font: a #PangoFont
 * @left: the left #PangoGlyph
 * @right: the right #PangoGlyph
 *
 * Retrieves kerning information for a combination of two glyphs.
 *
 * Use pango_fc_font_kern_glyphs() instead.
 *
 * Return value: The amount of kerning (in Pango units) to apply for
 * the given combination of glyphs.
 **/
int
pango_ft2_font_get_kerning (PangoFont *font,
			    PangoGlyph left,
			    PangoGlyph right)
{
  PangoFcFont *fc_font = PANGO_FC_FONT (font);

  FT_Face face;
  FT_Error error;
  FT_Vector kerning;

  face = pango_fc_font_lock_face (fc_font);
  if (!face)
    return 0;

  if (!FT_HAS_KERNING (face))
    {
      pango_fc_font_unlock_face (fc_font);
      return 0;
    }

  error = FT_Get_Kerning (face, left, right, ft_kerning_default, &kerning);
  if (error != FT_Err_Ok)
    {
      pango_fc_font_unlock_face (fc_font);
      return 0;
    }

  pango_fc_font_unlock_face (fc_font);
  return PANGO_UNITS_26_6 (kerning.x);
}

static FT_Face
pango_ft2_font_real_lock_face (PangoFcFont *font)
{
  return pango_ft2_font_get_face ((PangoFont *)font);
}

static void
pango_ft2_font_real_unlock_face (PangoFcFont *font)
{
}

static gboolean
pango_ft2_free_glyph_info_callback (gpointer key,
				    gpointer value,
				    gpointer data)
{
  PangoFT2Font *font = PANGO_FT2_FONT (data);
  PangoFT2GlyphInfo *info = value;

  if (font->glyph_cache_destroy && info->cached_glyph)
    (*font->glyph_cache_destroy) (info->cached_glyph);

  g_slice_free (PangoFT2GlyphInfo, info);
  return TRUE;
}

static void
pango_ft2_font_finalize (GObject *object)
{
  PangoFT2Font *ft2font = (PangoFT2Font *)object;

  if (ft2font->face)
    {
      FT_Done_Face (ft2font->face);
      ft2font->face = NULL;
    }

  g_hash_table_foreach_remove (ft2font->glyph_info,
			       pango_ft2_free_glyph_info_callback, object);
  g_hash_table_destroy (ft2font->glyph_info);

  G_OBJECT_CLASS (pango_ft2_font_parent_class)->finalize (object);
}

/**
 * pango_ft2_font_get_coverage:
 * @font: a #PangoFT2Font.
 * @language: a language tag.
 * @returns: a #PangoCoverage.
 *
 * Gets the #PangoCoverage for a #PangoFT2Font. Use pango_font_get_coverage() instead.
 **/
PangoCoverage *
pango_ft2_font_get_coverage (PangoFont     *font,
			     PangoLanguage *language)
{
  return pango_font_get_coverage (font, language);
}

/* Utility functions */

/**
 * pango_ft2_get_unknown_glyph:
 * @font: a #PangoFont
 *
 * Return the index of a glyph suitable for drawing unknown characters with
 * @font, or %PANGO_GLYPH_EMPTY if no suitable glyph found.
 *
 * If you want to draw an unknown-box for a character that is not covered
 * by the font,
 * use PANGO_GET_UNKNOWN_GLYPH() instead.
 *
 * Return value: a glyph index into @font, or %PANGO_GLYPH_EMPTY
 **/
PangoGlyph
pango_ft2_get_unknown_glyph (PangoFont *font)
{
  FT_Face face = pango_ft2_font_get_face (font);
  if (face && FT_IS_SFNT (face))
    /* TrueType fonts have an 'unknown glyph' box on glyph index 0 */
    return 0;
  else
    return PANGO_GLYPH_EMPTY;
}

typedef struct
{
  FT_Error     code;
  const char   msg[40];
} ft_error_description;

static int
ft_error_compare (const void *pkey,
		  const void *pbase)
{
  return ((ft_error_description *) pkey)->code - ((ft_error_description *) pbase)->code;
}

G_CONST_RETURN char *
_pango_ft2_ft_strerror (FT_Error error)
{
#undef __FTERRORS_H__
#define FT_ERRORDEF( e, v, s )  { e, s },
#define FT_ERROR_START_LIST  {
#define FT_ERROR_END_LIST    };

  static const ft_error_description ft_errors[] =
#include FT_ERRORS_H

#undef FT_ERRORDEF
#undef FT_ERROR_START_LIST
#undef FT_ERROR_END_LIST

  ft_error_description *found =
    bsearch (&error, ft_errors, G_N_ELEMENTS (ft_errors),
	     sizeof (ft_errors[0]), ft_error_compare);
  if (found != NULL)
    return found->msg;
  else
    {
      static char *default_msg = NULL;

      if (!default_msg)
	default_msg = g_malloc (60);

      g_sprintf (default_msg, "Unknown FreeType2 error %#x", error);
      return default_msg;
    }
}

void *
_pango_ft2_font_get_cache_glyph_data (PangoFont *font,
				     int        glyph_index)
{
  PangoFT2GlyphInfo *info;

  if (!PANGO_FT2_IS_FONT (font))
    return NULL;

  info = pango_ft2_font_get_glyph_info (font, glyph_index, FALSE);

  if (info == NULL)
    return NULL;

  return info->cached_glyph;
}

void
_pango_ft2_font_set_cache_glyph_data (PangoFont     *font,
				     int            glyph_index,
				     void          *cached_glyph)
{
  PangoFT2GlyphInfo *info;

  if (!PANGO_FT2_IS_FONT (font))
    return;

  info = pango_ft2_font_get_glyph_info (font, glyph_index, TRUE);

  info->cached_glyph = cached_glyph;

  /* TODO: Implement limiting of the number of cached glyphs */
}

void
_pango_ft2_font_set_glyph_cache_destroy (PangoFont      *font,
					 GDestroyNotify  destroy_notify)
{
  if (!PANGO_FT2_IS_FONT (font))
    return;

  PANGO_FT2_FONT (font)->glyph_cache_destroy = destroy_notify;
}