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/public-api/text-abstraction/font-client.h>
  24 #include <dali/public-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 unsigned int HIGH_QUALITY_PIXEL_SIZE = 200u;  // Pixel size sent to FreeType2 FT_Set_Char_Size() for high quality glyphs.
  43 const char*        DEFAULT_LANGUAGE = "en";
  44 const unsigned int DEFAULT_LANGUAGE_LENGTH = 2u;
  45 const float        TO_PIXELS = 64.f;
  46
  47 const hb_script_t SCRIPT_TO_HARFBUZZ[] =
  48 {
  49   HB_SCRIPT_LATIN,
  50   HB_SCRIPT_ARABIC,
  51   HB_SCRIPT_DEVANAGARI,
  52   HB_SCRIPT_BENGALI,
  53   HB_SCRIPT_GURMUKHI,
  54   HB_SCRIPT_GUJARATI,
  55   HB_SCRIPT_ORIYA,
  56   HB_SCRIPT_TAMIL,
  57   HB_SCRIPT_TELUGU,
  58   HB_SCRIPT_KANNADA,
  59   HB_SCRIPT_MALAYALAM,
  60   HB_SCRIPT_SINHALA,
  61   HB_SCRIPT_HAN,
  62   HB_SCRIPT_HANGUL,
  63   HB_SCRIPT_KHMER,
  64   HB_SCRIPT_LAO,
  65   HB_SCRIPT_THAI,
  66   HB_SCRIPT_MYANMAR,
  67   HB_SCRIPT_UNKNOWN
  68 };
  69
  70 struct Shaping::Plugin
  71 {
  72   Plugin()
  73   : mFreeTypeLibrary( NULL ),
  74     mIndices(),
  75     mAdvance(),
  76     mCharacterMap(),
  77     mFontId( 0u )
  78   {
  79   }
  80
  81   ~Plugin()
  82   {
  83     FT_Done_FreeType( mFreeTypeLibrary );
  84   }
  85
  86   void Initialize()
  87   {
  88     int error = FT_Init_FreeType( &mFreeTypeLibrary );
  89     if( FT_Err_Ok != error )
  90     {
  91       DALI_LOG_ERROR( "FreeType Init error: %d\n", error );
  92     }
  93   }
  94
  95   Length Shape( const Character* const text,
  96                 Length numberOfCharacters,
  97                 FontId fontId,
  98                 Script script )
  99   {
 100     // Clear previoursly shaped texts.
 101     mIndices.Clear();
 102     mAdvance.Clear();
 103     mCharacterMap.Clear();
 104     mFontId = fontId;
 105
 106     TextAbstraction::FontClient fontClient = TextAbstraction::FontClient::Get();
 107
 108     // Get the font's path file name from the font Id.
 109     FontDescription fontDescription;
 110     fontClient.GetDescription( fontId, fontDescription );
 111
 112     // Create a FreeType font's face.
 113     FT_Face face;
 114     FT_Error retVal = FT_New_Face( mFreeTypeLibrary, fontDescription.path.c_str(), 0u, &face );
 115     if( FT_Err_Ok != retVal )
 116     {
 117       DALI_LOG_ERROR( "Failed to open face: %s\n", fontDescription.path.c_str() );
 118       return 0u;
 119     }
 120
 121     FT_Set_Pixel_Sizes( face, HIGH_QUALITY_PIXEL_SIZE, HIGH_QUALITY_PIXEL_SIZE );
 122
 123     /* Get our harfbuzz font struct */
 124     hb_font_t* harfBuzzFont;
 125     harfBuzzFont = hb_ft_font_create( face, NULL );
 126
 127     /* Create a buffer for harfbuzz to use */
 128     hb_buffer_t* harfBuzzBuffer = hb_buffer_create();
 129
 130     hb_buffer_set_direction( harfBuzzBuffer,
 131                              ( ARABIC == script ) ? HB_DIRECTION_RTL : HB_DIRECTION_LTR ); /* or LTR */
 132
 133     hb_buffer_set_script( harfBuzzBuffer,
 134                           SCRIPT_TO_HARFBUZZ[ script ] ); /* see hb-unicode.h */
 135
 136     hb_buffer_set_language( harfBuzzBuffer,
 137                             hb_language_from_string( DEFAULT_LANGUAGE,
 138                                                      DEFAULT_LANGUAGE_LENGTH ) );
 139
 140     /* Layout the text */
 141     hb_buffer_add_utf32( harfBuzzBuffer, text, numberOfCharacters, 0u, numberOfCharacters );
 142
 143     hb_shape( harfBuzzFont, harfBuzzBuffer, NULL, 0u );
 144
 145     /* Get glyph data */
 146     unsigned int glyphCount;
 147     hb_glyph_info_t* glyphInfo = hb_buffer_get_glyph_infos( harfBuzzBuffer, &glyphCount );
 148     hb_glyph_position_t *glyphPositions = hb_buffer_get_glyph_positions( harfBuzzBuffer, &glyphCount );
 149
 150     for( Length i = 0u; i < glyphCount; ++i )
 151     {
 152       mIndices.PushBack( glyphInfo[i].codepoint );
 153       mAdvance.PushBack( glyphPositions[i].x_advance / TO_PIXELS );
 154       mCharacterMap.PushBack( glyphInfo[i].cluster );
 155     }
 156
 157     /* Cleanup */
 158     hb_buffer_destroy( harfBuzzBuffer );
 159     hb_font_destroy( harfBuzzFont );
 160     FT_Done_Face( face );
 161
 162     return mIndices.Count();
 163   }
 164
 165   void GetGlyphs( GlyphInfo* glyphInfo,
 166                   CharacterIndex* glyphToCharacterMap )
 167   {
 168     Vector<CharacterIndex>::ConstIterator indicesIt = mIndices.Begin();
 169     Vector<float>::ConstIterator advanceIt = mAdvance.Begin();
 170     Vector<CharacterIndex>::ConstIterator characterMapIt = mCharacterMap.Begin();
 171
 172     for( Length index = 0u, size = mIndices.Count(); index < size; ++index )
 173     {
 174       GlyphInfo& glyph = *( glyphInfo + index );
 175       CharacterIndex& glyphToCharacter = *( glyphToCharacterMap + index );
 176
 177       glyph.fontId = mFontId;
 178       glyph.index = *( indicesIt + index );
 179       glyph.advance = *( advanceIt + index );
 180
 181       glyphToCharacter = *( characterMapIt + index );
 182     }
 183   }
 184
 185   FT_Library             mFreeTypeLibrary;
 186
 187   Vector<CharacterIndex> mIndices;
 188   Vector<float>          mAdvance;
 189   Vector<CharacterIndex> mCharacterMap;
 190   FontId                 mFontId;
 191 };
 192
 193 Shaping::Shaping()
 194 : mPlugin( NULL )
 195 {
 196 }
 197
 198 Shaping::~Shaping()
 199 {
 200   delete mPlugin;
 201 }
 202
 203 TextAbstraction::Shaping Shaping::Get()
 204 {
 205   TextAbstraction::Shaping shapingHandle;
 206
 207   SingletonService service( SingletonService::Get() );
 208   if( service )
 209   {
 210     // Check whether the singleton is already created
 211     Dali::BaseHandle handle = service.GetSingleton( typeid( TextAbstraction::Shaping ) );
 212     if( handle )
 213     {
 214       // If so, downcast the handle
 215       Shaping* impl = dynamic_cast< Internal::Shaping* >( handle.GetObjectPtr() );
 216       shapingHandle = TextAbstraction::Shaping( impl );
 217     }
 218     else // create and register the object
 219     {
 220       shapingHandle = TextAbstraction::Shaping( new Shaping );
 221       service.Register( typeid( shapingHandle ), shapingHandle );
 222     }
 223   }
 224
 225   return shapingHandle;
 226 }
 227
 228 Length Shaping::Shape( const Character* const text,
 229                        Length numberOfCharacters,
 230                        FontId fontId,
 231                        Script script )
 232 {
 233   CreatePlugin();
 234
 235   return mPlugin->Shape( text,
 236                          numberOfCharacters,
 237                          fontId,
 238                          script );
 239 }
 240
 241 void Shaping::GetGlyphs( GlyphInfo* glyphInfo,
 242                          CharacterIndex* glyphToCharacterMap )
 243 {
 244   CreatePlugin();
 245
 246   mPlugin->GetGlyphs( glyphInfo,
 247                       glyphToCharacterMap );
 248 }
 249
 250 void Shaping::CreatePlugin()
 251 {
 252   if( !mPlugin )
 253   {
 254     mPlugin = new Plugin();
 255     mPlugin->Initialize();
 256   }
 257 }
 258
 259 } // namespace Internal
 260
 261 } // namespace TextAbstraction
 262
 263 } // namespace Dali