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 <dali-toolkit/internal/text/shaper.h>
22 #include <dali/devel-api/text-abstraction/script.h>
23 #include <dali/devel-api/text-abstraction/shaping.h>
26 #include <dali-toolkit/internal/text/font-run.h>
27 #include <dali-toolkit/internal/text/logical-model-impl.h>
28 #include <dali-toolkit/internal/text/script-run.h>
29 #include <dali-toolkit/internal/text/visual-model-impl.h>
40 CharacterIndex min( CharacterIndex index0,
41 CharacterIndex index1 )
43 return ( index0 < index1 ) ? index0 : index1;
46 void ShapeText( const Vector<Character>& text,
47 const Vector<LineBreakInfo>& lineBreakInfo,
48 const Vector<ScriptRun>& scripts,
49 const Vector<FontRun>& fonts,
50 Vector<GlyphInfo>& glyphs,
51 Vector<CharacterIndex>& glyphToCharacterMap,
52 Vector<Length>& charactersPerGlyph,
53 Vector<GlyphIndex>& newParagraphGlyphs )
55 const Length numberOfCharacters = text.Count();
57 if( 0u == numberOfCharacters )
59 // Nothing to do if there are no characters.
64 const Length numberOfFontRuns = fonts.Count();
65 const Length numberOfScriptRuns = scripts.Count();
68 DALI_ASSERT_DEBUG( ( 0u != numberOfFontRuns ) &&
69 ( numberOfCharacters == fonts[numberOfFontRuns - 1u].characterRun.characterIndex + fonts[numberOfFontRuns - 1u].characterRun.numberOfCharacters ) &&
70 "Toolkit::Text::ShapeText. All characters must have a font set." );
72 DALI_ASSERT_DEBUG( ( 0u != numberOfScriptRuns ) &&
73 ( numberOfCharacters == scripts[numberOfScriptRuns - 1u].characterRun.characterIndex + scripts[numberOfScriptRuns - 1u].characterRun.numberOfCharacters ) &&
74 "Toolkit::Text::ShapeText. All characters must have a script set." );
76 // The text needs to be split in chunks of consecutive characters.
77 // Each chunk must contain characters with the same font id and script set.
78 // A chunk of consecutive characters must not contain a LINE_MUST_BREAK, if there is one a new chunk has to be created.
80 TextAbstraction::Shaping shaping = TextAbstraction::Shaping::Get();
82 // To shape the text a font and an script is needed.
83 Vector<FontRun>::ConstIterator fontRunIt = fonts.Begin();
84 Vector<ScriptRun>::ConstIterator scriptRunIt = scripts.Begin();
86 // Index to the the next one to be shaped. Is pointing the character after the last one it was shaped.
87 CharacterIndex previousIndex = 0u;
89 // The current font id and script used to shape the text.
90 FontId currentFontId = 0u;
91 Script currentScript = TextAbstraction::UNKNOWN;
93 // Reserve some space to allocate the glyphs and the glyph to character map.
94 // There is no way to know the number of glyphs before shaping the text.
95 // To avoid reallocations it's reserved space for a slightly biger number of glyphs than the number of characters.
97 Length numberOfGlyphsReserved = static_cast<Length>( numberOfCharacters * 1.3f );
98 glyphs.Resize( numberOfGlyphsReserved );
99 glyphToCharacterMap.Resize( numberOfGlyphsReserved );
101 // The actual number of glyphs.
102 Length totalNumberOfGlyphs = 0u;
104 const Character* const textBuffer = text.Begin();
105 const LineBreakInfo* const lineBreakInfoBuffer = lineBreakInfo.Begin();
106 GlyphInfo* glyphsBuffer = glyphs.Begin();
107 CharacterIndex* glyphToCharacterMapBuffer = glyphToCharacterMap.Begin();
109 // Traverse the characters and shape the text.
110 for( previousIndex = 0; previousIndex < numberOfCharacters; )
112 // Get the font id and the script.
113 const FontRun& fontRun = *fontRunIt;
114 const ScriptRun& scriptRun = *scriptRunIt;
116 currentFontId = fontRun.fontId;
117 currentScript = scriptRun.script;
119 // Get the min index to the last character of both runs.
120 CharacterIndex currentIndex = min( fontRun.characterRun.characterIndex + fontRun.characterRun.numberOfCharacters,
121 scriptRun.characterRun.characterIndex + scriptRun.characterRun.numberOfCharacters );
123 // Check if there is a line must break.
124 bool mustBreak = false;
126 // Check if the current index is a new paragraph character.
127 // A new paragraph character is going to be shaped in order to not to mess the conversion tables.
128 // However, the metrics need to be changed in order to not to draw a square.
129 bool isNewParagraph = false;
131 for( CharacterIndex index = previousIndex; index < currentIndex; ++index )
133 mustBreak = TextAbstraction::LINE_MUST_BREAK == *( lineBreakInfoBuffer + index );
136 isNewParagraph = TextAbstraction::IsNewParagraph( *( textBuffer + index ) );
137 currentIndex = index + 1u;
142 // Shape the text for the current chunk.
143 const Length numberOfGlyphs = shaping.Shape( textBuffer + previousIndex,
144 ( currentIndex - previousIndex ), // The number of characters to shape.
148 const Length glyphIndex = totalNumberOfGlyphs;
149 totalNumberOfGlyphs += numberOfGlyphs;
151 if( totalNumberOfGlyphs > numberOfGlyphsReserved )
153 // Resize the vectors to get enough space.
154 numberOfGlyphsReserved = static_cast<Length>( totalNumberOfGlyphs * 1.3f );
155 glyphs.Resize( numberOfGlyphsReserved );
156 glyphToCharacterMap.Resize( numberOfGlyphsReserved );
158 // Iterators are not valid anymore, set them again.
159 glyphsBuffer = glyphs.Begin();
160 glyphToCharacterMapBuffer = glyphToCharacterMap.Begin();
163 // Retrieve the glyphs and the glyph to character conversion map.
164 shaping.GetGlyphs( glyphsBuffer + glyphIndex,
165 glyphToCharacterMapBuffer + glyphIndex );
169 // Add the index of the new paragraph glyph to a vector.
170 // Their metrics will be updated in a following step.
171 newParagraphGlyphs.PushBack( totalNumberOfGlyphs - 1u );
175 if( 0u != glyphIndex )
177 for( Length index = glyphIndex; index < glyphIndex + numberOfGlyphs; ++index )
179 CharacterIndex& characterIndex = *( glyphToCharacterMapBuffer + index );
180 characterIndex += previousIndex;
184 // Update the iterators to get the next font or script run.
185 if( currentIndex == fontRun.characterRun.characterIndex + fontRun.characterRun.numberOfCharacters )
189 if( currentIndex == scriptRun.characterRun.characterIndex + scriptRun.characterRun.numberOfCharacters )
194 // Update the previous index.
195 previousIndex = currentIndex;
198 // Add the number of characters per glyph.
199 charactersPerGlyph.Reserve( totalNumberOfGlyphs );
201 for( Length index = 1u; index < totalNumberOfGlyphs; ++index )
203 const CharacterIndex characterIndex = *( glyphToCharacterMapBuffer + index );
205 charactersPerGlyph.PushBack( characterIndex - previousIndex );
207 previousIndex = characterIndex;
210 charactersPerGlyph.PushBack( numberOfCharacters - previousIndex );
212 // Resize the vectors to set the right number of items.
213 glyphs.Resize( totalNumberOfGlyphs );
214 glyphToCharacterMap.Resize( totalNumberOfGlyphs );
219 } // namespace Toolkit