text/dali/internal/text-abstraction/shaping-impl.cpp

   1 /*
   2  * Copyright (c) 2015 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 // CLASS  HEADER
  19 #include "shaping-impl.h"
  20
  21 // INTERNAL INCLUDES
  22 #include <singleton-service-impl.h>
  23 #include <dali/devel-api/text-abstraction/font-client.h>
  24 #include <dali/devel-api/text-abstraction/glyph-info.h>
  25 #include <dali/integration-api/debug.h>
  26
  27 // EXTERNAL INCLUDES
  28 #include <harfbuzz/hb.h>
  29 #include <harfbuzz/hb-ft.h>
  30
  31 #include <ft2build.h>
  32
  33 namespace Dali
  34 {
  35
  36 namespace TextAbstraction
  37 {
  38
  39 namespace Internal
  40 {
  41
  42 const char*        DEFAULT_LANGUAGE = "en";
  43 const unsigned int DEFAULT_LANGUAGE_LENGTH = 2u;
  44 const float        FROM_266 = 1.0f / 64.0f;
  45
  46 const hb_script_t SCRIPT_TO_HARFBUZZ[] =
  47 {
  48   HB_SCRIPT_CYRILLIC,
  49   HB_SCRIPT_GREEK,
  50   HB_SCRIPT_LATIN,
  51
  52   HB_SCRIPT_ARABIC,
  53   HB_SCRIPT_HEBREW,
  54
  55   HB_SCRIPT_ARMENIAN,
  56   HB_SCRIPT_GEORGIAN,
  57
  58   HB_SCRIPT_HAN,
  59   HB_SCRIPT_HANGUL,
  60   HB_SCRIPT_HIRAGANA,
  61   HB_SCRIPT_KATAKANA,
  62
  63   HB_SCRIPT_BENGALI,
  64   HB_SCRIPT_MYANMAR,
  65   HB_SCRIPT_DEVANAGARI,
  66   HB_SCRIPT_GUJARATI,
  67   HB_SCRIPT_GURMUKHI,
  68   HB_SCRIPT_KANNADA,
  69   HB_SCRIPT_MALAYALAM,
  70   HB_SCRIPT_ORIYA,
  71   HB_SCRIPT_SINHALA,
  72   HB_SCRIPT_TAMIL,
  73   HB_SCRIPT_TELUGU,
  74
  75   HB_SCRIPT_LAO,
  76   HB_SCRIPT_THAI,
  77   HB_SCRIPT_KHMER,
  78
  79   HB_SCRIPT_UNKNOWN, // EMOJI
  80   HB_SCRIPT_UNKNOWN
  81 };
  82
  83 struct Shaping::Plugin
  84 {
  85   Plugin()
  86   : mFreeTypeLibrary( NULL ),
  87     mIndices(),
  88     mAdvance(),
  89     mCharacterMap(),
  90     mFontId( 0u )
  91   {
  92   }
  93
  94   ~Plugin()
  95   {
  96     FT_Done_FreeType( mFreeTypeLibrary );
  97   }
  98
  99   void Initialize()
 100   {
 101     int error = FT_Init_FreeType( &mFreeTypeLibrary );
 102     if( FT_Err_Ok != error )
 103     {
 104       DALI_LOG_ERROR( "FreeType Init error: %d\n", error );
 105     }
 106   }
 107
 108   Length Shape( const Character* const text,
 109                 Length numberOfCharacters,
 110                 FontId fontId,
 111                 Script script )
 112   {
 113     // Clear previoursly shaped texts.
 114     mIndices.Clear();
 115     mAdvance.Clear();
 116     mCharacterMap.Clear();
 117     mOffset.Clear();
 118     mFontId = fontId;
 119
 120     // Reserve some space to avoid reallocations.
 121     const Length numberOfGlyphs = static_cast<Length>( 1.3f * static_cast<float>( numberOfCharacters ) );
 122     mIndices.Reserve( numberOfGlyphs );
 123     mAdvance.Reserve( numberOfGlyphs );
 124     mCharacterMap.Reserve( numberOfGlyphs );
 125     mOffset.Reserve( 2u * numberOfGlyphs );
 126
 127     TextAbstraction::FontClient fontClient = TextAbstraction::FontClient::Get();
 128
 129     // Get the font's path file name from the font Id.
 130     FontDescription fontDescription;
 131     fontClient.GetDescription( fontId, fontDescription );
 132
 133     // Create a FreeType font's face.
 134     FT_Face face;
 135     FT_Error retVal = FT_New_Face( mFreeTypeLibrary, fontDescription.path.c_str(), 0u, &face );
 136     if( FT_Err_Ok != retVal )
 137     {
 138       DALI_LOG_ERROR( "Failed to open face: %s\n", fontDescription.path.c_str() );
 139       return 0u;
 140     }
 141
 142     unsigned int horizontalDpi = 0u;
 143     unsigned int verticalDpi = 0u;
 144     fontClient.GetDpi( horizontalDpi, verticalDpi );
 145
 146     FT_Set_Char_Size( face,
 147                       0u,
 148                       fontClient.GetPointSize( fontId ),
 149                       horizontalDpi,
 150                       verticalDpi );
 151
 152     /* Get our harfbuzz font struct */
 153     hb_font_t* harfBuzzFont;
 154     harfBuzzFont = hb_ft_font_create( face, NULL );
 155
 156     /* Create a buffer for harfbuzz to use */
 157     hb_buffer_t* harfBuzzBuffer = hb_buffer_create();
 158
 159     const bool rtlDirection = IsRightToLeftScript( script );
 160     hb_buffer_set_direction( harfBuzzBuffer,
 161                              rtlDirection ? HB_DIRECTION_RTL : HB_DIRECTION_LTR ); /* or LTR */
 162
 163     hb_buffer_set_script( harfBuzzBuffer,
 164                           SCRIPT_TO_HARFBUZZ[ script ] ); /* see hb-unicode.h */
 165
 166     hb_buffer_set_language( harfBuzzBuffer,
 167                             hb_language_from_string( DEFAULT_LANGUAGE,
 168                                                      DEFAULT_LANGUAGE_LENGTH ) );
 169
 170     /* Layout the text */
 171     hb_buffer_add_utf32( harfBuzzBuffer, text, numberOfCharacters, 0u, numberOfCharacters );
 172
 173     hb_shape( harfBuzzFont, harfBuzzBuffer, NULL, 0u );
 174
 175     /* Get glyph data */
 176     unsigned int glyphCount;
 177     hb_glyph_info_t* glyphInfo = hb_buffer_get_glyph_infos( harfBuzzBuffer, &glyphCount );
 178     hb_glyph_position_t *glyphPositions = hb_buffer_get_glyph_positions( harfBuzzBuffer, &glyphCount );
 179     const GlyphIndex lastGlyphIndex = glyphCount - 1u;
 180     for( GlyphIndex i = 0u; i < glyphCount; )
 181     {
 182       if( rtlDirection )
 183       {
 184         // If the direction is right to left, Harfbuzz retrieves the glyphs in the visual order.
 185         // The glyphs are needed in the logical order to layout the text in lines.
 186         // Do not change the order of the glyphs if they belong to the same cluster.
 187         GlyphIndex rtlIndex = lastGlyphIndex - i;
 188
 189         unsigned int cluster = glyphInfo[rtlIndex].cluster;
 190         unsigned int previousCluster = cluster;
 191         Length numberOfGlyphsInCluster = 0u;
 192
 193         while( ( cluster == previousCluster ) )
 194         {
 195           ++numberOfGlyphsInCluster;
 196           previousCluster = cluster;
 197
 198           if( rtlIndex > 0u )
 199           {
 200             --rtlIndex;
 201
 202             cluster = glyphInfo[rtlIndex].cluster;
 203           }
 204           else
 205           {
 206             break;
 207           }
 208         }
 209
 210         rtlIndex = lastGlyphIndex - ( i + ( numberOfGlyphsInCluster - 1u ) );
 211
 212         for( GlyphIndex j = 0u; j < numberOfGlyphsInCluster; ++j )
 213         {
 214           const GlyphIndex index = rtlIndex + j;
 215
 216           mIndices.PushBack( glyphInfo[index].codepoint );
 217           mAdvance.PushBack( floor( glyphPositions[index].x_advance * FROM_266 ) );
 218           mCharacterMap.PushBack( glyphInfo[index].cluster );
 219           mOffset.PushBack( floor( glyphPositions[index].x_offset * FROM_266 ) );
 220           mOffset.PushBack( floor( glyphPositions[index].y_offset * FROM_266 ) );
 221         }
 222
 223         i += numberOfGlyphsInCluster;
 224       }
 225       else
 226       {
 227         mIndices.PushBack( glyphInfo[i].codepoint );
 228         mAdvance.PushBack( floor( glyphPositions[i].x_advance * FROM_266 ) );
 229         mCharacterMap.PushBack( glyphInfo[i].cluster );
 230         mOffset.PushBack( floor( glyphPositions[i].x_offset * FROM_266 ) );
 231         mOffset.PushBack( floor( glyphPositions[i].y_offset * FROM_266 ) );
 232
 233         ++i;
 234       }
 235     }
 236
 237     /* Cleanup */
 238     hb_buffer_destroy( harfBuzzBuffer );
 239     hb_font_destroy( harfBuzzFont );
 240     FT_Done_Face( face );
 241
 242     return mIndices.Count();
 243   }
 244
 245   void GetGlyphs( GlyphInfo* glyphInfo,
 246                   CharacterIndex* glyphToCharacterMap )
 247   {
 248     Vector<CharacterIndex>::ConstIterator indicesIt = mIndices.Begin();
 249     Vector<float>::ConstIterator advanceIt = mAdvance.Begin();
 250     Vector<float>::ConstIterator offsetIt = mOffset.Begin();
 251     Vector<CharacterIndex>::ConstIterator characterMapIt = mCharacterMap.Begin();
 252
 253     for( GlyphIndex index = 0u, size = mIndices.Count(); index < size; ++index )
 254     {
 255       GlyphInfo& glyph = *( glyphInfo + index );
 256       CharacterIndex& glyphToCharacter = *( glyphToCharacterMap + index );
 257
 258       glyph.fontId = mFontId;
 259       glyph.index = *( indicesIt + index );
 260       glyph.advance = *( advanceIt + index );
 261
 262       const GlyphIndex offsetIndex = 2u * index;
 263       glyph.xBearing = *( offsetIt + offsetIndex );
 264       glyph.yBearing = *( offsetIt + offsetIndex + 1u );
 265
 266       glyphToCharacter = *( characterMapIt + index );
 267     }
 268   }
 269
 270   FT_Library             mFreeTypeLibrary;
 271
 272   Vector<CharacterIndex> mIndices;
 273   Vector<float>          mAdvance;
 274   Vector<float>          mOffset;
 275   Vector<CharacterIndex> mCharacterMap;
 276   FontId                 mFontId;
 277 };
 278
 279 Shaping::Shaping()
 280 : mPlugin( NULL )
 281 {
 282 }
 283
 284 Shaping::~Shaping()
 285 {
 286   delete mPlugin;
 287 }
 288
 289 TextAbstraction::Shaping Shaping::Get()
 290 {
 291   TextAbstraction::Shaping shapingHandle;
 292
 293   SingletonService service( SingletonService::Get() );
 294   if( service )
 295   {
 296     // Check whether the singleton is already created
 297     Dali::BaseHandle handle = service.GetSingleton( typeid( TextAbstraction::Shaping ) );
 298     if( handle )
 299     {
 300       // If so, downcast the handle
 301       Shaping* impl = dynamic_cast< Internal::Shaping* >( handle.GetObjectPtr() );
 302       shapingHandle = TextAbstraction::Shaping( impl );
 303     }
 304     else // create and register the object
 305     {
 306       shapingHandle = TextAbstraction::Shaping( new Shaping );
 307       service.Register( typeid( shapingHandle ), shapingHandle );
 308     }
 309   }
 310
 311   return shapingHandle;
 312 }
 313
 314 Length Shaping::Shape( const Character* const text,
 315                        Length numberOfCharacters,
 316                        FontId fontId,
 317                        Script script )
 318 {
 319   CreatePlugin();
 320
 321   return mPlugin->Shape( text,
 322                          numberOfCharacters,
 323                          fontId,
 324                          script );
 325 }
 326
 327 void Shaping::GetGlyphs( GlyphInfo* glyphInfo,
 328                          CharacterIndex* glyphToCharacterMap )
 329 {
 330   CreatePlugin();
 331
 332   mPlugin->GetGlyphs( glyphInfo,
 333                       glyphToCharacterMap );
 334 }
 335
 336 void Shaping::CreatePlugin()
 337 {
 338   if( !mPlugin )
 339   {
 340     mPlugin = new Plugin();
 341     mPlugin->Initialize();
 342   }
 343 }
 344
 345 } // namespace Internal
 346
 347 } // namespace TextAbstraction
 348
 349 } // namespace Dali