/*

 * Copyright © 2009  Red Hat, Inc.

 * Copyright © 2009  Keith Stribley

 * Copyright © 2015  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.

 *

 * Red Hat Author(s): Behdad Esfahbod

 * Google Author(s): Behdad Esfahbod

 */

#include "hb-private.hh"

#include "hb-ft.h"

#include "hb-font-private.hh"

#include FT_ADVANCES_H

#include FT_TRUETYPE_TABLES_H

#ifndef HB_DEBUG_FT

#define HB_DEBUG_FT (HB_DEBUG+0)

#endif

/* TODO:

 *

 * In general, this file does a fine job of what it's supposed to do.

 * There are, however, things that need more work:

 *

 *   - I remember seeing FT_Get_Advance() without the NO_HINTING flag to be buggy.

 *     Have not investigated.

 *

 *   - FreeType works in 26.6 mode.  Clients can decide to use that mode, and everything

 *     would work fine.  However, we also abuse this API for performing in font-space,

 *     but don't pass the correct flags to FreeType.  We just abuse the no-hinting mode

 *     for that, such that no rounding etc happens.  As such, we don't set ppem, and

 *     pass NO_HINTING as load_flags.  Would be much better to use NO_SCALE, and scale

 *     ourselves, like we do in uniscribe, etc.

 *

 *   - We don't handle / allow for emboldening / obliqueing.

 *

 *   - In the future, we should add constructors to create fonts in font space?

 *

 *   - FT_Load_Glyph() is exteremely costly.  Do something about it?

 */

struct hb_ft_font_t

{

  FT_Face ft_face;

  int load_flags;

  bool unref; /* Whether to destroy ft_face when done. */

};

static hb_ft_font_t *

_hb_ft_font_create (FT_Face ft_face, bool unref)

{

  hb_ft_font_t *ft_font = (hb_ft_font_t *) calloc (1, sizeof (hb_ft_font_t));

  if (unlikely (!ft_font))

    return NULL;

  ft_font->ft_face = ft_face;

  ft_font->unref = unref;

  ft_font->load_flags = FT_LOAD_DEFAULT | FT_LOAD_NO_HINTING;

  return ft_font;

}

static void

_hb_ft_font_destroy (hb_ft_font_t *ft_font)

{

  if (ft_font->unref)

    FT_Done_Face (ft_font->ft_face);

  free (ft_font);

}

/**

 * hb_ft_font_set_load_flags:

 * @font:

 * @load_flags:

 *

 *

 *

 * Since: 1.0.5

 **/

void

hb_ft_font_set_load_flags (hb_font_t *font, int load_flags)

{

  if (font->immutable)

    return;

  if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)

    return;

  hb_ft_font_t *ft_font = (hb_ft_font_t *) font->user_data;

  ft_font->load_flags = load_flags;

}

/**

 * hb_ft_font_get_load_flags:

 * @font:

 *

 *

 *

 * Return value:

 * Since: 1.0.5

 **/

int

hb_ft_font_get_load_flags (hb_font_t *font)

{

  if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)

    return 0;

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font->user_data;

  return ft_font->load_flags;

}

FT_Face

hb_ft_font_get_face (hb_font_t *font)

{

  if (font->destroy != (hb_destroy_func_t) _hb_ft_font_destroy)

    return NULL;

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font->user_data;

  return ft_font->ft_face;

}

static hb_bool_t

hb_ft_get_glyph (hb_font_t *font HB_UNUSED,

                 void *font_data,

                 hb_codepoint_t unicode,

                 hb_codepoint_t variation_selector,

                 hb_codepoint_t *glyph,

                 void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  unsigned int g;

  if (likely (!variation_selector))

    g = FT_Get_Char_Index (ft_font->ft_face, unicode);

  else

    g = FT_Face_GetCharVariantIndex (ft_font->ft_face, unicode, variation_selector);

  if (unlikely (!g))

    return false;

  *glyph = g;

  return true;

}

static hb_position_t

hb_ft_get_glyph_h_advance (hb_font_t *font HB_UNUSED,

                           void *font_data,

                           hb_codepoint_t glyph,

                           void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Fixed v;

  if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags, &v)))

    return 0;

  if (font->x_scale < 0)

    v = -v;

  return (v + (1<<9)) >> 10;

}

static hb_position_t

hb_ft_get_glyph_v_advance (hb_font_t *font HB_UNUSED,

                           void *font_data,

                           hb_codepoint_t glyph,

                           void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Fixed v;

  if (unlikely (FT_Get_Advance (ft_font->ft_face, glyph, ft_font->load_flags | FT_LOAD_VERTICAL_LAYOUT, &v)))

    return 0;

  if (font->y_scale < 0)

    v = -v;

  /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates

   * have a Y growing upward.  Hence the extra negation. */

  return (-v + (1<<9)) >> 10;

}

static hb_bool_t

hb_ft_get_glyph_h_origin (hb_font_t *font HB_UNUSED,

                          void *font_data HB_UNUSED,

                          hb_codepoint_t glyph HB_UNUSED,

                          hb_position_t *x HB_UNUSED,

                          hb_position_t *y HB_UNUSED,

                          void *user_data HB_UNUSED)

{

  /* We always work in the horizontal coordinates. */

  return true;

}

static hb_bool_t

hb_ft_get_glyph_v_origin (hb_font_t *font HB_UNUSED,

                          void *font_data,

                          hb_codepoint_t glyph,

                          hb_position_t *x,

                          hb_position_t *y,

                          void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Face ft_face = ft_font->ft_face;

  if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))

    return false;

  /* Note: FreeType's vertical metrics grows downward while other FreeType coordinates

   * have a Y growing upward.  Hence the extra negation. */

  *x = ft_face->glyph->metrics.horiBearingX -   ft_face->glyph->metrics.vertBearingX;

  *y = ft_face->glyph->metrics.horiBearingY - (-ft_face->glyph->metrics.vertBearingY);

  if (font->x_scale < 0)

    *x = -*x;

  if (font->y_scale < 0)

    *y = -*y;

  return true;

}

static hb_position_t

hb_ft_get_glyph_h_kerning (hb_font_t *font,

                           void *font_data,

                           hb_codepoint_t left_glyph,

                           hb_codepoint_t right_glyph,

                           void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Vector kerningv;

  FT_Kerning_Mode mode = font->x_ppem ? FT_KERNING_DEFAULT : FT_KERNING_UNFITTED;

  if (FT_Get_Kerning (ft_font->ft_face, left_glyph, right_glyph, mode, &kerningv))

    return 0;

  return kerningv.x;

}

static hb_position_t

hb_ft_get_glyph_v_kerning (hb_font_t *font HB_UNUSED,

                           void *font_data HB_UNUSED,

                           hb_codepoint_t top_glyph HB_UNUSED,

                           hb_codepoint_t bottom_glyph HB_UNUSED,

                           void *user_data HB_UNUSED)

{

  /* FreeType API doesn't support vertical kerning */

  return 0;

}

static hb_bool_t

hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,

                         void *font_data,

                         hb_codepoint_t glyph,

                         hb_glyph_extents_t *extents,

                         void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Face ft_face = ft_font->ft_face;

  if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))

    return false;

  extents->x_bearing = ft_face->glyph->metrics.horiBearingX;

  extents->y_bearing = ft_face->glyph->metrics.horiBearingY;

  extents->width = ft_face->glyph->metrics.width;

  extents->height = -ft_face->glyph->metrics.height;

  return true;

}

static hb_bool_t

hb_ft_get_glyph_contour_point (hb_font_t *font HB_UNUSED,

                               void *font_data,

                               hb_codepoint_t glyph,

                               unsigned int point_index,

                               hb_position_t *x,

                               hb_position_t *y,

                               void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Face ft_face = ft_font->ft_face;

  if (unlikely (FT_Load_Glyph (ft_face, glyph, ft_font->load_flags)))

      return false;

  if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))

      return false;

  if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))

      return false;

  *x = ft_face->glyph->outline.points[point_index].x;

  *y = ft_face->glyph->outline.points[point_index].y;

  return true;

}

static hb_bool_t

hb_ft_get_glyph_name (hb_font_t *font HB_UNUSED,

                      void *font_data,

                      hb_codepoint_t glyph,

                      char *name, unsigned int size,

                      void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  hb_bool_t ret = !FT_Get_Glyph_Name (ft_font->ft_face, glyph, name, size);

  if (ret && (size && !*name))

    ret = false;

  return ret;

}

static hb_bool_t

hb_ft_get_glyph_from_name (hb_font_t *font HB_UNUSED,

                           void *font_data,

                           const char *name, int len, /* -1 means nul-terminated */

                           hb_codepoint_t *glyph,

                           void *user_data HB_UNUSED)

{

  const hb_ft_font_t *ft_font = (const hb_ft_font_t *) font_data;

  FT_Face ft_face = ft_font->ft_face;

  if (len < 0)

    *glyph = FT_Get_Name_Index (ft_face, (FT_String *) name);

  else {

    /* Make a nul-terminated version. */

    char buf[128];

    len = MIN (len, (int) sizeof (buf) - 1);

    strncpy (buf, name, len);

    buf[len] = '\0';

    *glyph = FT_Get_Name_Index (ft_face, buf);

  }

  if (*glyph == 0)

  {

    /* Check whether the given name was actually the name of glyph 0. */

    char buf[128];

    if (!FT_Get_Glyph_Name(ft_face, 0, buf, sizeof (buf)) &&

        len < 0 ? !strcmp (buf, name) : !strncmp (buf, name, len))

      return true;

  }

  return *glyph != 0;

}

static void

_hb_ft_font_set_funcs (hb_font_t *font, FT_Face ft_face, bool unref)

{

  static const hb_font_funcs_t ft_ffuncs = {

    HB_OBJECT_HEADER_STATIC,

    true, /* immutable */

    {

#define HB_FONT_FUNC_IMPLEMENT(name) hb_ft_get_##name,

      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS

#undef HB_FONT_FUNC_IMPLEMENT

    }

  };

  hb_font_set_funcs (font,

                     const_cast<hb_font_funcs_t *> (&ft_ffuncs),

                     _hb_ft_font_create (ft_face, unref),

                     (hb_destroy_func_t) _hb_ft_font_destroy);

}

static hb_blob_t *

reference_table  (hb_face_t *face HB_UNUSED, hb_tag_t tag, void *user_data)

{

  FT_Face ft_face = (FT_Face) user_data;

  FT_Byte *buffer;

  FT_ULong  length = 0;

  FT_Error error;

  /* Note: FreeType like HarfBuzz uses the NONE tag for fetching the entire blob */

  error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);

  if (error)

    return NULL;

  buffer = (FT_Byte *) malloc (length);

  if (buffer == NULL)

    return NULL;

  error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);

  if (error)

    return NULL;

  return hb_blob_create ((const char *) buffer, length,

                         HB_MEMORY_MODE_WRITABLE,

                         buffer, free);

}

/**

 * hb_ft_face_create:

 * @ft_face: (destroy destroy) (scope notified):

 * @destroy:

 *

 *

 *

 * Return value: (transfer full):

 * Since: 0.9.2

 **/

hb_face_t *

hb_ft_face_create (FT_Face           ft_face,

                   hb_destroy_func_t destroy)

{

  hb_face_t *face;

  if (ft_face->stream->read == NULL) {

    hb_blob_t *blob;

    blob = hb_blob_create ((const char *) ft_face->stream->base,

                           (unsigned int) ft_face->stream->size,

                           HB_MEMORY_MODE_READONLY,

                           ft_face, destroy);

    face = hb_face_create (blob, ft_face->face_index);

    hb_blob_destroy (blob);

  } else {

    face = hb_face_create_for_tables (reference_table, ft_face, destroy);

  }

  hb_face_set_index (face, ft_face->face_index);

  hb_face_set_upem (face, ft_face->units_per_EM);

  return face;

}

/**

 * hb_ft_face_create_referenced:

 * @ft_face:

 *

 *

 *

 * Return value: (transfer full):

 * Since: 0.9.38

 **/

hb_face_t *

hb_ft_face_create_referenced (FT_Face ft_face)

{

  FT_Reference_Face (ft_face);

  return hb_ft_face_create (ft_face, (hb_destroy_func_t) FT_Done_Face);

}

static void

hb_ft_face_finalize (FT_Face ft_face)

{

  hb_face_destroy ((hb_face_t *) ft_face->generic.data);

}

/**

 * hb_ft_face_create_cached:

 * @ft_face:

 *

 *

 *

 * Return value: (transfer full):

 * Since: 0.9.2

 **/

hb_face_t *

hb_ft_face_create_cached (FT_Face ft_face)

{

  if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))

  {

    if (ft_face->generic.finalizer)

      ft_face->generic.finalizer (ft_face);

    ft_face->generic.data = hb_ft_face_create (ft_face, NULL);

    ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;

  }

  return hb_face_reference ((hb_face_t *) ft_face->generic.data);

}

/**

 * hb_ft_font_create:

 * @ft_face: (destroy destroy) (scope notified):

 * @destroy:

 *

 *

 *

 * Return value: (transfer full):

 * Since: 0.9.2

 **/

hb_font_t *

hb_ft_font_create (FT_Face           ft_face,

                   hb_destroy_func_t destroy)

{

  hb_font_t *font;

  hb_face_t *face;