src/os/windows/string_uniscribe.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD 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.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file string_uniscribe.h Functions related to laying out text on Win32. */
   9
  10 #ifndef STRING_UNISCRIBE_H
  11 #define STRING_UNISCRIBE_H
  12
  13 #include "../../gfx_layout.h"
  14 #include "../../string_base.h"
  15
  16
  17 void UniscribeResetScriptCache(FontSize size);
  18
  19
  20 /**
  21  * Helper class to construct a new #UniscribeParagraphLayout.
  22  */
  23 class UniscribeParagraphLayoutFactory {
  24 public:
  25         /** Helper for GetLayouter, to get the right type. */
  26         typedef wchar_t CharType;
  27         /** Helper for GetLayouter, to get whether the layouter supports RTL. */
  28         static const bool SUPPORTS_RTL = true;
  29
  30         /**
  31          * Get the actual ParagraphLayout for the given buffer.
  32          * @param buff The begin of the buffer.
  33          * @param buff_end The location after the last element in the buffer.
  34          * @param fontMapping THe mapping of the fonts.
  35          * @return The ParagraphLayout instance.
  36          */
  37         static ParagraphLayouter *GetParagraphLayout(CharType *buff, CharType *buff_end, FontMap &fontMapping);
  38
  39         /**
  40          * Append a wide character to the internal buffer.
  41          * @param buff        The buffer to append to.
  42          * @param buffer_last The end of the buffer.
  43          * @param c           The character to add.
  44          * @return The number of buffer spaces that were used.
  45          */
  46         static size_t AppendToBuffer(CharType *buff, const CharType *buffer_last, char32_t c)
  47         {
  48                 assert(buff < buffer_last);
  49                 if (c >= 0x010000U) {
  50                         /* Character is encoded using surrogates in UTF-16. */
  51                         if (buff + 1 <= buffer_last) {
  52                                 buff[0] = (CharType)(((c - 0x010000U) >> 10) + 0xD800);
  53                                 buff[1] = (CharType)(((c - 0x010000U) & 0x3FF) + 0xDC00);
  54                         } else {
  55                                 /* Not enough space in buffer. */
  56                                 *buff = 0;
  57                         }
  58                         return 2;
  59                 } else {
  60                         *buff = (CharType)(c & 0xFFFF);
  61                         return 1;
  62                 }
  63         }
  64 };
  65
  66 /** String iterator using Uniscribe as a backend. */
  67 class UniscribeStringIterator : public StringIterator {
  68         /** */
  69         struct CharInfo {
  70                 bool word_stop : 1; ///< Code point is suitable as a word break.
  71                 bool char_stop : 1; ///< Code point is the start of a grapheme cluster, i.e. a "character".
  72         };
  73
  74         std::vector<CharInfo> str_info;      ///< Break information for each code point.
  75         std::vector<size_t>   utf16_to_utf8; ///< Mapping from UTF-16 code point position to index in the UTF-8 source string.
  76
  77         size_t cur_pos; ///< Current iteration position.
  78
  79 public:
  80         void SetString(const char *s) override;
  81         size_t SetCurPosition(size_t pos) override;
  82         size_t Next(IterType what) override;
  83         size_t Prev(IterType what) override;
  84 };
  85
  86 #endif /* STRING_UNISCRIBE_H */