/* Pango
 * pango-impl-utils.h: Macros for get_type() functions
 * Inspired by Jody Goldberg's gsf-impl-utils.h
 *
 * Copyright (C) 2003 Red Hat Software
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifndef __PANGO_IMPL_UTILS_H__
#define __PANGO_IMPL_UTILS_H__

#include <glib.h>
#include <glib-object.h>
#include <pango/pango.h>

G_BEGIN_DECLS


/* String interning for static strings */
#define I_(string) g_intern_static_string (string)


/* Some functions for handling PANGO_ATTR_SHAPE */
void _pango_shape_shape (const char       *text,
			 unsigned int      n_chars,
			 PangoRectangle   *shape_ink,
			 PangoRectangle   *shape_logical,
			 PangoGlyphString *glyphs);

void _pango_shape_get_extents (gint              n_chars,
			       PangoRectangle   *shape_ink,
			       PangoRectangle   *shape_logical,
			       PangoRectangle   *ink_rect,
			       PangoRectangle   *logical_rect);


/* We define these functions static here because we don't want to add public API
 * for them (if anything, it belongs to glib, but glib found it trivial enough
 * not to add API for).  At some point metrics calculations will be
 * centralized and this mess can be minimized.  Or so I hope.
 */

static inline G_GNUC_UNUSED int
pango_unichar_width (gunichar c)
{
  return G_UNLIKELY (g_unichar_iszerowidth (c)) ? 0 :
	   G_UNLIKELY (g_unichar_iswide (c)) ? 2 : 1;
}

static G_GNUC_UNUSED glong
pango_utf8_strwidth (const gchar *p)
{
  glong len = 0;
  g_return_val_if_fail (p != NULL, 0);

  while (*p)
    {
      len += pango_unichar_width (g_utf8_get_char (p));
      p = g_utf8_next_char (p);
    }

  return len;
}

/* Glib's g_utf8_strlen() is broken and stops at embedded NUL's.
 * Wrap it here. */
static G_GNUC_UNUSED glong
pango_utf8_strlen (const gchar *p, gssize max)
{
  glong len = 0;
  const gchar *start = p;
  g_return_val_if_fail (p != NULL || max == 0, 0);

  if (max <= 0)
    return g_utf8_strlen (p, max);

  p = g_utf8_next_char (p);
  while (p - start < max)
    {
      ++len;
      p = g_utf8_next_char (p);
    }

  /* only do the last len increment if we got a complete
   * char (don't count partial chars)
   */
  if (p - start <= max)
    ++len;

  return len;
}


/* To be made public at some point */

static G_GNUC_UNUSED void
pango_glyph_string_reverse_range (PangoGlyphString *glyphs,
				  int start, int end)
{
  int i, j;

  for (i = start, j = end - 1; i < j; i++, j--)
    {
      PangoGlyphInfo glyph_info;
      gint log_cluster;

      glyph_info = glyphs->glyphs[i];
      glyphs->glyphs[i] = glyphs->glyphs[j];
      glyphs->glyphs[j] = glyph_info;

      log_cluster = glyphs->log_clusters[i];
      glyphs->log_clusters[i] = glyphs->log_clusters[j];
      glyphs->log_clusters[j] = log_cluster;
    }
}


G_END_DECLS

#endif /* __PANGO_IMPL_UTILS_H__ */