harfbuzz/src/hb-ot-name.cc

/*
 * Copyright © 2018  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
 */

#include "hb.hh"

#include "hb-ot-name-table.hh"

#include "hb-ot-face.hh"
#include "hb-utf.hh"


/**
 * SECTION:hb-ot-name
 * @title: hb-ot-name
 * @short_description: OpenType font name information
 * @include: hb-ot.h
 *
 * Functions for fetching name strings from OpenType fonts.
 **/


/**
 * hb_ot_name_list_names:
 * @face: font face.
 * @num_entries: (out) (allow-none): number of returned entries.
 *
 * Enumerates all available name IDs and language combinations. Returned
 * array is owned by the @face and should not be modified.  It can be
 * used as long as @face is alive.
 *
 * Returns: (out) (transfer none) (array length=num_entries): Array of available name entries.
 * Since: 2.1.0
 **/
const hb_ot_name_entry_t *
hb_ot_name_list_names (hb_face_t    *face,
		       unsigned int *num_entries /* OUT */)
{
  const OT::name_accelerator_t &name = *face->table.name;
  if (num_entries) *num_entries = name.names.length;
  return (const hb_ot_name_entry_t *) name.names;
}


template <typename in_utf_t, typename out_utf_t>
static inline unsigned int
hb_ot_name_convert_utf (hb_bytes_t                       bytes,
			unsigned int                    *text_size /* IN/OUT */,
			typename out_utf_t::codepoint_t *text /* OUT */)
{
  unsigned int src_len = bytes.length / sizeof (typename in_utf_t::codepoint_t);
  const typename in_utf_t::codepoint_t *src = (const typename in_utf_t::codepoint_t *) bytes.arrayZ;
  const typename in_utf_t::codepoint_t *src_end = src + src_len;

  typename out_utf_t::codepoint_t *dst = text;

  hb_codepoint_t unicode;
  const hb_codepoint_t replacement = HB_BUFFER_REPLACEMENT_CODEPOINT_DEFAULT;

  if (text_size && *text_size)
  {
    (*text_size)--; /* Same room for NUL-termination. */
    const typename out_utf_t::codepoint_t *dst_end = text + *text_size;

    while (src < src_end && dst < dst_end)
    {
      const typename in_utf_t::codepoint_t *src_next = in_utf_t::next (src, src_end, &unicode, replacement);
      typename out_utf_t::codepoint_t *dst_next = out_utf_t::encode (dst, dst_end, unicode);
      if (dst_next == dst)
        break; /* Out-of-room. */

      dst = dst_next;
      src = src_next;
    };

    *text_size = dst - text;
    *dst = 0; /* NUL-terminate. */
  }

  /* Accumulate length of rest. */
  unsigned int dst_len = dst - text;
  while (src < src_end)
  {
    src = in_utf_t::next (src, src_end, &unicode, replacement);
    dst_len += out_utf_t::encode_len (unicode);
  };
  return dst_len;
}

template <typename utf_t>
static inline unsigned int
hb_ot_name_get_utf (hb_face_t       *face,
		    hb_ot_name_id_t  name_id,
		    hb_language_t    language,
		    unsigned int    *text_size /* IN/OUT */,
		    typename utf_t::codepoint_t *text /* OUT */)
{
  const OT::name_accelerator_t &name = *face->table.name;

  if (!language)
    language = hb_language_from_string ("en", 2);

  unsigned int width;
  int idx = name.get_index (name_id, language, &width);
  if (idx != -1)
  {
    hb_bytes_t bytes = name.get_name (idx);

    if (width == 2) /* UTF16-BE */
      return hb_ot_name_convert_utf<hb_utf16_be_t, utf_t> (bytes, text_size, text);

    if (width == 1) /* ASCII */
      return hb_ot_name_convert_utf<hb_ascii_t, utf_t> (bytes, text_size, text);
  }

  if (text_size)
  {
    if (*text_size)
      *text = 0;
    *text_size = 0;
  }
  return 0;
}

/**
 * hb_ot_name_get_utf8:
 * @face: font face.
 * @name_id: OpenType name identifier to fetch.
 * @language: language to fetch the name for.
 * @text_size: (inout) (allow-none): input size of @text buffer, and output size of
 *                                   text written to buffer.
 * @text: (out caller-allocates) (array length=text_size): buffer to write fetched name into.
 *
 * Fetches a font name from the OpenType 'name' table.
 * If @language is #HB_LANGUAGE_INVALID, English ("en") is assumed.
 * Returns string in UTF-8 encoding.
 *
 * Returns: full length of the requested string, or 0 if not found.
 * Since: 2.1.0
 **/
unsigned int
hb_ot_name_get_utf8 (hb_face_t       *face,
		     hb_ot_name_id_t  name_id,
		     hb_language_t    language,
		     unsigned int    *text_size /* IN/OUT */,
		     char            *text      /* OUT */)
{
  return hb_ot_name_get_utf<hb_utf8_t> (face, name_id, language, text_size,
					(hb_utf8_t::codepoint_t *) text);
}

/**
 * hb_ot_name_get_utf16:
 * @face: font face.
 * @name_id: OpenType name identifier to fetch.
 * @language: language to fetch the name for.
 * @text_size: (inout) (allow-none): input size of @text buffer, and output size of
 *                                   text written to buffer.
 * @text: (out caller-allocates) (array length=text_size): buffer to write fetched name into.
 *
 * Fetches a font name from the OpenType 'name' table.
 * If @language is #HB_LANGUAGE_INVALID, English ("en") is assumed.
 * Returns string in UTF-16 encoding.
 *
 * Returns: full length of the requested string, or 0 if not found.
 * Since: 2.1.0
 **/
unsigned int
hb_ot_name_get_utf16 (hb_face_t       *face,
		      hb_ot_name_id_t  name_id,
		      hb_language_t    language,
		      unsigned int    *text_size /* IN/OUT */,
		      uint16_t        *text      /* OUT */)
{
  return hb_ot_name_get_utf<hb_utf16_t> (face, name_id, language, text_size, text);
}

/**
 * hb_ot_name_get_utf32:
 * @face: font face.
 * @name_id: OpenType name identifier to fetch.
 * @language: language to fetch the name for.
 * @text_size: (inout) (allow-none): input size of @text buffer, and output size of
 *                                   text written to buffer.
 * @text: (out caller-allocates) (array length=text_size): buffer to write fetched name into.
 *
 * Fetches a font name from the OpenType 'name' table.
 * If @language is #HB_LANGUAGE_INVALID, English ("en") is assumed.
 * Returns string in UTF-32 encoding.
 *
 * Returns: full length of the requested string, or 0 if not found.
 * Since: 2.1.0
 **/
unsigned int
hb_ot_name_get_utf32 (hb_face_t       *face,
		      hb_ot_name_id_t  name_id,
		      hb_language_t    language,
		      unsigned int    *text_size /* IN/OUT */,
		      uint32_t        *text      /* OUT */)
{
  return hb_ot_name_get_utf<hb_utf32_t> (face, name_id, language, text_size, text);
}