/*

 * 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

 */

#define HB_SHAPER fallback

#include "hb-shaper-impl-private.hh"

/*

 * shaper face data

 */

struct hb_fallback_shaper_face_data_t {};

hb_fallback_shaper_face_data_t *

_hb_fallback_shaper_face_data_create (hb_face_t *face HB_UNUSED)

{

  return (hb_fallback_shaper_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;

}

void

_hb_fallback_shaper_face_data_destroy (hb_fallback_shaper_face_data_t *data HB_UNUSED)

{

}

/*

 * shaper font data

 */

struct hb_fallback_shaper_font_data_t {};

hb_fallback_shaper_font_data_t *

_hb_fallback_shaper_font_data_create (hb_font_t *font HB_UNUSED)

{

  return (hb_fallback_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;

}

void

_hb_fallback_shaper_font_data_destroy (hb_fallback_shaper_font_data_t *data HB_UNUSED)

{

}

/*

 * shaper shape_plan data

 */

struct hb_fallback_shaper_shape_plan_data_t {};

hb_fallback_shaper_shape_plan_data_t *

_hb_fallback_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,

                                            const hb_feature_t *user_features HB_UNUSED,

                                            unsigned int        num_user_features HB_UNUSED,

                                            const int          *coords HB_UNUSED,

                                            unsigned int        num_coords HB_UNUSED)

{

  return (hb_fallback_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;

}

void

_hb_fallback_shaper_shape_plan_data_destroy (hb_fallback_shaper_shape_plan_data_t *data HB_UNUSED)

{

}

/*

 * shaper

 */

hb_bool_t

_hb_fallback_shape (hb_shape_plan_t    *shape_plan HB_UNUSED,

                    hb_font_t          *font,

                    hb_buffer_t        *buffer,

                    const hb_feature_t *features HB_UNUSED,

                    unsigned int        num_features HB_UNUSED)

{

  /* TODO

   *

   * - Apply fallback kern.

   * - Handle Variation Selectors?

   * - Apply normalization?

   *

   * This will make the fallback shaper into a dumb "TrueType"

   * shaper which many people unfortunately still request.

   */

  hb_codepoint_t space;

  bool has_space = (bool) font->get_nominal_glyph (' ', &space);

  buffer->clear_positions ();

  hb_direction_t direction = buffer->props.direction;

  hb_unicode_funcs_t *unicode = buffer->unicode;

  unsigned int count = buffer->len;

  hb_glyph_info_t *info = buffer->info;

  hb_glyph_position_t *pos = buffer->pos;

  for (unsigned int i = 0; i < count; i++)

  {

    if (has_space && unicode->is_default_ignorable (info[i].codepoint)) {

      info[i].codepoint = space;

      pos[i].x_advance = 0;

      pos[i].y_advance = 0;

      continue;

    }

    font->get_glyph_advance_for_direction (info[i].codepoint,

                                           direction,

                                           &pos[i].x_advance,

                                           &pos[i].y_advance);

    font->subtract_glyph_origin_for_direction (info[i].codepoint,

                                               direction,

                                               &pos[i].x_offset,

                                               &pos[i].y_offset);

  }

  if (HB_DIRECTION_IS_BACKWARD (direction))

    hb_buffer_reverse (buffer);

  return true;

}