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