2 * Copyright (c) 2015 Samsung Electronics Co., Ltd.
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
19 #include "shaping-impl.h"
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>
28 #include <harfbuzz/hb.h>
29 #include <harfbuzz/hb-ft.h>
36 namespace TextAbstraction
42 const char* DEFAULT_LANGUAGE = "en";
43 const unsigned int DEFAULT_LANGUAGE_LENGTH = 2u;
44 const float FROM_266 = 1.0f / 64.0f;
46 const hb_script_t SCRIPT_TO_HARFBUZZ[] =
69 struct Shaping::Plugin
72 : mFreeTypeLibrary( NULL ),
82 FT_Done_FreeType( mFreeTypeLibrary );
87 int error = FT_Init_FreeType( &mFreeTypeLibrary );
88 if( FT_Err_Ok != error )
90 DALI_LOG_ERROR( "FreeType Init error: %d\n", error );
94 Length Shape( const Character* const text,
95 Length numberOfCharacters,
99 // Clear previoursly shaped texts.
102 mCharacterMap.Clear();
106 // Reserve some space to avoid reallocations.
107 const Length numberOfGlyphs = static_cast<Length>( 1.3f * static_cast<float>( numberOfCharacters ) );
108 mIndices.Reserve( numberOfGlyphs );
109 mAdvance.Reserve( numberOfGlyphs );
110 mCharacterMap.Reserve( numberOfGlyphs );
111 mOffset.Reserve( 2u * numberOfGlyphs );
113 TextAbstraction::FontClient fontClient = TextAbstraction::FontClient::Get();
115 // Get the font's path file name from the font Id.
116 FontDescription fontDescription;
117 fontClient.GetDescription( fontId, fontDescription );
119 // Create a FreeType font's face.
121 FT_Error retVal = FT_New_Face( mFreeTypeLibrary, fontDescription.path.c_str(), 0u, &face );
122 if( FT_Err_Ok != retVal )
124 DALI_LOG_ERROR( "Failed to open face: %s\n", fontDescription.path.c_str() );
128 unsigned int horizontalDpi = 0u;
129 unsigned int verticalDpi = 0u;
130 fontClient.GetDpi( horizontalDpi, verticalDpi );
132 FT_Set_Char_Size( face,
134 fontClient.GetPointSize( fontId ),
138 /* Get our harfbuzz font struct */
139 hb_font_t* harfBuzzFont;
140 harfBuzzFont = hb_ft_font_create( face, NULL );
142 /* Create a buffer for harfbuzz to use */
143 hb_buffer_t* harfBuzzBuffer = hb_buffer_create();
145 const bool rtlDirection = IsRightToLeftScript( script );
146 hb_buffer_set_direction( harfBuzzBuffer,
147 rtlDirection ? HB_DIRECTION_RTL : HB_DIRECTION_LTR ); /* or LTR */
149 hb_buffer_set_script( harfBuzzBuffer,
150 SCRIPT_TO_HARFBUZZ[ script ] ); /* see hb-unicode.h */
152 hb_buffer_set_language( harfBuzzBuffer,
153 hb_language_from_string( DEFAULT_LANGUAGE,
154 DEFAULT_LANGUAGE_LENGTH ) );
156 /* Layout the text */
157 hb_buffer_add_utf32( harfBuzzBuffer, text, numberOfCharacters, 0u, numberOfCharacters );
159 hb_shape( harfBuzzFont, harfBuzzBuffer, NULL, 0u );
162 unsigned int glyphCount;
163 hb_glyph_info_t* glyphInfo = hb_buffer_get_glyph_infos( harfBuzzBuffer, &glyphCount );
164 hb_glyph_position_t *glyphPositions = hb_buffer_get_glyph_positions( harfBuzzBuffer, &glyphCount );
165 const GlyphIndex lastGlyphIndex = glyphCount - 1u;
166 for( GlyphIndex i = 0u; i < glyphCount; )
170 // If the direction is right to left, Harfbuzz retrieves the glyphs in the visual order.
171 // The glyphs are needed in the logical order to layout the text in lines.
172 // Do not change the order of the glyphs if they belong to the same cluster.
173 GlyphIndex rtlIndex = lastGlyphIndex - i;
175 unsigned int cluster = glyphInfo[rtlIndex].cluster;
176 unsigned int previousCluster = cluster;
177 Length numberOfGlyphsInCluster = 0u;
179 while( ( cluster == previousCluster ) )
181 ++numberOfGlyphsInCluster;
182 previousCluster = cluster;
188 cluster = glyphInfo[rtlIndex].cluster;
196 rtlIndex = lastGlyphIndex - ( i + ( numberOfGlyphsInCluster - 1u ) );
198 for( GlyphIndex j = 0u; j < numberOfGlyphsInCluster; ++j )
200 const GlyphIndex index = rtlIndex + j;
202 mIndices.PushBack( glyphInfo[index].codepoint );
203 mAdvance.PushBack( floor( glyphPositions[index].x_advance * FROM_266 ) );
204 mCharacterMap.PushBack( glyphInfo[index].cluster );
205 mOffset.PushBack( floor( glyphPositions[index].x_offset * FROM_266 ) );
206 mOffset.PushBack( floor( glyphPositions[index].y_offset * FROM_266 ) );
209 i += numberOfGlyphsInCluster;
213 mIndices.PushBack( glyphInfo[i].codepoint );
214 mAdvance.PushBack( floor( glyphPositions[i].x_advance * FROM_266 ) );
215 mCharacterMap.PushBack( glyphInfo[i].cluster );
216 mOffset.PushBack( floor( glyphPositions[i].x_offset * FROM_266 ) );
217 mOffset.PushBack( floor( glyphPositions[i].y_offset * FROM_266 ) );
224 hb_buffer_destroy( harfBuzzBuffer );
225 hb_font_destroy( harfBuzzFont );
226 FT_Done_Face( face );
228 return mIndices.Count();
231 void GetGlyphs( GlyphInfo* glyphInfo,
232 CharacterIndex* glyphToCharacterMap )
234 Vector<CharacterIndex>::ConstIterator indicesIt = mIndices.Begin();
235 Vector<float>::ConstIterator advanceIt = mAdvance.Begin();
236 Vector<float>::ConstIterator offsetIt = mOffset.Begin();
237 Vector<CharacterIndex>::ConstIterator characterMapIt = mCharacterMap.Begin();
239 for( GlyphIndex index = 0u, size = mIndices.Count(); index < size; ++index )
241 GlyphInfo& glyph = *( glyphInfo + index );
242 CharacterIndex& glyphToCharacter = *( glyphToCharacterMap + index );
244 glyph.fontId = mFontId;
245 glyph.index = *( indicesIt + index );
246 glyph.advance = *( advanceIt + index );
248 const GlyphIndex offsetIndex = 2u * index;
249 glyph.xBearing = *( offsetIt + offsetIndex );
250 glyph.yBearing = *( offsetIt + offsetIndex + 1u );
252 glyphToCharacter = *( characterMapIt + index );
256 FT_Library mFreeTypeLibrary;
258 Vector<CharacterIndex> mIndices;
259 Vector<float> mAdvance;
260 Vector<float> mOffset;
261 Vector<CharacterIndex> mCharacterMap;
275 TextAbstraction::Shaping Shaping::Get()
277 TextAbstraction::Shaping shapingHandle;
279 SingletonService service( SingletonService::Get() );
282 // Check whether the singleton is already created
283 Dali::BaseHandle handle = service.GetSingleton( typeid( TextAbstraction::Shaping ) );
286 // If so, downcast the handle
287 Shaping* impl = dynamic_cast< Internal::Shaping* >( handle.GetObjectPtr() );
288 shapingHandle = TextAbstraction::Shaping( impl );
290 else // create and register the object
292 shapingHandle = TextAbstraction::Shaping( new Shaping );
293 service.Register( typeid( shapingHandle ), shapingHandle );
297 return shapingHandle;
300 Length Shaping::Shape( const Character* const text,
301 Length numberOfCharacters,
307 return mPlugin->Shape( text,
313 void Shaping::GetGlyphs( GlyphInfo* glyphInfo,
314 CharacterIndex* glyphToCharacterMap )
318 mPlugin->GetGlyphs( glyphInfo,
319 glyphToCharacterMap );
322 void Shaping::CreatePlugin()
326 mPlugin = new Plugin();
327 mPlugin->Initialize();
331 } // namespace Internal
333 } // namespace TextAbstraction