#include <dali-toolkit/internal/text/layouts/layout-engine.h>
// EXTERNAL INCLUDES
+#include <limits>
#include <dali/public-api/math/vector2.h>
#include <dali/public-api/text-abstraction/font-client.h>
namespace Text
{
+namespace
+{
+
+const float MAX_FLOAT = std::numeric_limits<float>::max();
+const bool RTL = true;
+
+} //namespace
+
/**
* @brief Stores temporary layout info of the line.
*/
struct LineLayout
{
+ LineLayout()
+ : glyphIndex( 0u ),
+ characterIndex( 0u ),
+ numberOfCharacters( 0u ),
+ numberOfGlyphs( 0u ),
+ length( 0.f ),
+ widthAdvanceDiff( 0.f ),
+ wsLengthEndOfLine( 0.f ),
+ ascender( 0.f ),
+ descender( MAX_FLOAT )
+ {}
+
+ ~LineLayout()
+ {}
+
+ void Clear()
+ {
+ glyphIndex = 0u;
+ characterIndex = 0u;
+ numberOfCharacters = 0u;
+ numberOfGlyphs = 0u;
+ length = 0.f;
+ widthAdvanceDiff = 0.f;
+ wsLengthEndOfLine = 0.f;
+ ascender = 0.f;
+ descender = MAX_FLOAT;
+ }
+
GlyphIndex glyphIndex; ///< Index of the first glyph to be laid-out.
CharacterIndex characterIndex; ///< Index of the first character to be laid-out.
Length numberOfCharacters; ///< The number of characters which fit in one line.
Length numberOfGlyphs; ///< The number of glyph which fit in one line.
float length; ///< The length of the glyphs which fit in one line.
- float widthAdvanceDiff; ///< The difference between the width and the advance of the last glyph.
+ float widthAdvanceDiff; ///< The difference between the xBearing + width and the advance of the last glyph.
float wsLengthEndOfLine; ///< The length of the white spaces at the end of the line.
float ascender; ///< The maximum ascender of all fonts in the line.
- float descender; ///< The maximum descender of all fonts in the line.
+ float descender; ///< The minimum descender of all fonts in the line.
};
struct LayoutEngine::Impl
}
/**
- * Retrieves the line layout for a given box width.
+ * @brief Updates the line ascender and descender with the metrics of a new font.
+ *
+ * @param[in] fontId The id of the new font.
+ * @param[in,out] lineLayout The line layout.
*/
- void GetLineLayoutForBox( const LayoutParameters& parameters,
- LineLayout& lineLayout )
+ void UpdateLineHeight( FontId fontId, LineLayout& lineLayout )
{
- // Initializes the line layout.
- lineLayout.numberOfCharacters = 0u;
- lineLayout.numberOfGlyphs = 0u;
- lineLayout.length = 0.f;
- lineLayout.wsLengthEndOfLine = 0.f;
- lineLayout.ascender = 0.f;
- lineLayout.descender = 0.f;
-
- // Get the last glyph index.
- const GlyphIndex lastGlyphIndex = parameters.totalNumberOfGlyphs - 1u;
+ Text::FontMetrics fontMetrics;
+ mFontClient.GetFontMetrics( fontId, fontMetrics );
- FontId lastFontId = 0u;
- for( GlyphIndex glyphIndex = lineLayout.glyphIndex;
- glyphIndex < parameters.totalNumberOfGlyphs;
- ++glyphIndex )
+ // Sets the maximum ascender.
+ if( fontMetrics.ascender > lineLayout.ascender )
{
- // Get the glyph info.
- const GlyphInfo& glyphInfo = *( parameters.glyphsBuffer + glyphIndex );
-
- // Check whether is a white space.
- const Character character = *( parameters.textBuffer + lineLayout.numberOfCharacters );
- const bool isWhiteSpace = TextAbstraction::IsWhiteSpace( character );
-
- // Get the character indices for the current glyph. The last character index is needed
- // because there are glyphs formed by more than one character but their break info is
- // given only for the last character.
- const Length charactersPerGlyph = *( parameters.charactersPerGlyphBuffer + glyphIndex );
-
- // Increase the number of characters.
- lineLayout.numberOfCharacters += charactersPerGlyph;
-
- // Increase the number of glyphs.
- lineLayout.numberOfGlyphs++;
-
- // Increase the accumulated length.
- const float glyphLength = ( glyphIndex == lastGlyphIndex ) ? glyphInfo.width : glyphInfo.advance;
+ lineLayout.ascender = fontMetrics.ascender;
+ }
- if( isWhiteSpace )
- {
- // Add the length to the length of white spaces at the end of the line.
- lineLayout.wsLengthEndOfLine += glyphLength;
- }
- else
- {
- // Add as well any previous white space length.
- lineLayout.length += lineLayout.wsLengthEndOfLine + glyphLength;
+ // Sets the minimum descender.
+ if( fontMetrics.descender < lineLayout.descender )
+ {
+ lineLayout.descender = fontMetrics.descender;
+ }
+ }
- // Clear the white space length at the end of the line.
- lineLayout.wsLengthEndOfLine = 0.f;
- }
+ /**
+ * @brief Merges a temporary line layout into the line layout.
+ *
+ * @param[in,out] lineLayout The line layout.
+ * @param[in] tmpLineLayout A temporary line layout.
+ */
+ void MergeLineLayout( LineLayout& lineLayout,
+ const LineLayout& tmpLineLayout )
+ {
+ lineLayout.numberOfCharacters += tmpLineLayout.numberOfCharacters;
+ lineLayout.numberOfGlyphs += tmpLineLayout.numberOfGlyphs;
+ lineLayout.length += tmpLineLayout.length;
- if( lastFontId != glyphInfo.fontId )
- {
- Text::FontMetrics fontMetrics;
- mFontClient.GetFontMetrics( glyphInfo.fontId, fontMetrics );
+ if( 0.f < tmpLineLayout.length )
+ {
+ lineLayout.length += lineLayout.wsLengthEndOfLine;
- // Sets the maximum ascender.
- if( fontMetrics.ascender > lineLayout.ascender )
- {
- lineLayout.ascender = fontMetrics.ascender;
- }
+ lineLayout.wsLengthEndOfLine = tmpLineLayout.wsLengthEndOfLine;
+ lineLayout.widthAdvanceDiff = tmpLineLayout.widthAdvanceDiff;
+ }
+ else
+ {
+ lineLayout.wsLengthEndOfLine += tmpLineLayout.wsLengthEndOfLine;
+ }
- // Sets the maximum descender.
- if( fontMetrics.descender > lineLayout.descender )
- {
- lineLayout.descender = fontMetrics.descender;
- }
+ if( tmpLineLayout.ascender > lineLayout.ascender )
+ {
+ lineLayout.ascender = tmpLineLayout.ascender;
+ }
- lastFontId = glyphInfo.fontId;
- }
+ if( tmpLineLayout.descender < lineLayout.descender )
+ {
+ lineLayout.descender = tmpLineLayout.descender;
}
}
/**
* Retrieves the line layout for a given box width.
*/
- void GetMultiLineLayoutForBox( const LayoutParameters& parameters,
- LineLayout& lineLayout )
+ void GetLineLayoutForBox( const LayoutParameters& parameters,
+ LineLayout& lineLayout )
{
- // Initializes the line layout.
- lineLayout.numberOfCharacters = 0u;
- lineLayout.numberOfGlyphs = 0u;
- lineLayout.length = 0.f;
- lineLayout.widthAdvanceDiff = 0.f;
- lineLayout.wsLengthEndOfLine = 0.f;
- lineLayout.ascender = 0.f;
- lineLayout.descender = 0.f;
-
// Stores temporary line layout which has not been added to the final line layout.
LineLayout tmpLineLayout;
- tmpLineLayout.numberOfCharacters = 0u;
- tmpLineLayout.numberOfGlyphs = 0u;
- tmpLineLayout.length = 0.f;
- tmpLineLayout.widthAdvanceDiff = 0.f;
- tmpLineLayout.wsLengthEndOfLine = 0.f;
- tmpLineLayout.ascender = 0.f;
- tmpLineLayout.descender = 0.f;
-
- FontId lastFontId = 0u;
+
+ const bool isMultiline = mLayout == MULTI_LINE_BOX;
+ const GlyphIndex lastGlyphIndex = parameters.totalNumberOfGlyphs - 1u;
+
+ // If the first glyph has a negative bearing its absolute value needs to be added to the line length.
+ // In the case the line starts with a right to left character the bearing needs to be substracted to the line length.
+ const GlyphInfo& glyphInfo = *( parameters.glyphsBuffer + lineLayout.glyphIndex );
+ float initialHorizontalBearing = glyphInfo.xBearing;
+
+ lineLayout.characterIndex = *( parameters.glyphsToCharactersBuffer + lineLayout.glyphIndex );
+ const CharacterDirection firstCharacterDirection = ( NULL == parameters.characterDirectionBuffer ) ? false : *( parameters.characterDirectionBuffer + lineLayout.characterIndex );
+
+ if( RTL == firstCharacterDirection )
+ {
+ initialHorizontalBearing = -initialHorizontalBearing;
+
+ if( 0.f < glyphInfo.xBearing )
+ {
+ tmpLineLayout.length = glyphInfo.xBearing;
+ initialHorizontalBearing = 0.f;
+ }
+ }
+ else
+ {
+ if( 0.f > glyphInfo.xBearing )
+ {
+ tmpLineLayout.length = -glyphInfo.xBearing;
+ initialHorizontalBearing = 0.f;
+ }
+ }
+
+ // Calculate the line height if there is no characters.
+ FontId lastFontId = glyphInfo.fontId;
+ UpdateLineHeight( lastFontId, tmpLineLayout );
+
+ const float boundingBoxWidth = parameters.boundingBox.width - initialHorizontalBearing;
+
+ bool oneWordLaidOut = false;
+
for( GlyphIndex glyphIndex = lineLayout.glyphIndex;
glyphIndex < parameters.totalNumberOfGlyphs;
++glyphIndex )
{
+ const bool isLastGlyph = glyphIndex == lastGlyphIndex;
+
// Get the glyph info.
const GlyphInfo& glyphInfo = *( parameters.glyphsBuffer + glyphIndex );
if( isWhiteSpace )
{
// Add the length to the length of white spaces at the end of the line.
- tmpLineLayout.wsLengthEndOfLine += glyphInfo.advance; // I use the advance as the width is always zero for the white spaces.
- tmpLineLayout.widthAdvanceDiff = 0.f;
+ tmpLineLayout.wsLengthEndOfLine += glyphInfo.advance; // The advance is used as the width is always zero for the white spaces.
}
else
{
// Add as well any previous white space length.
tmpLineLayout.length += tmpLineLayout.wsLengthEndOfLine + glyphInfo.advance;
- tmpLineLayout.widthAdvanceDiff = glyphInfo.width - glyphInfo.advance;
+ if( RTL == firstCharacterDirection )
+ {
+ tmpLineLayout.widthAdvanceDiff = -glyphInfo.xBearing;
+ }
+ else
+ {
+ tmpLineLayout.widthAdvanceDiff = glyphInfo.xBearing + glyphInfo.width - glyphInfo.advance;
+ }
// Clear the white space length at the end of the line.
tmpLineLayout.wsLengthEndOfLine = 0.f;
}
// Check if the accumulated length fits in the width of the box.
- if( lineLayout.length + tmpLineLayout.length + tmpLineLayout.widthAdvanceDiff + ( ( 0.f < tmpLineLayout.length ) ? lineLayout.wsLengthEndOfLine : 0.f ) > parameters.boundingBox.width )
+ if( isMultiline && oneWordLaidOut && !isWhiteSpace &&
+ ( lineLayout.length + lineLayout.wsLengthEndOfLine + tmpLineLayout.length + tmpLineLayout.widthAdvanceDiff > boundingBoxWidth ) )
{
// Current word does not fit in the box's width.
return;
}
- if( TextAbstraction::LINE_MUST_BREAK == lineBreakInfo )
+ if( ( isMultiline || isLastGlyph ) &&
+ ( TextAbstraction::LINE_MUST_BREAK == lineBreakInfo ) )
{
// Must break the line. Update the line layout and return.
- lineLayout.numberOfCharacters += tmpLineLayout.numberOfCharacters;
- lineLayout.numberOfGlyphs += tmpLineLayout.numberOfGlyphs;
- lineLayout.length += tmpLineLayout.length;
- lineLayout.widthAdvanceDiff = tmpLineLayout.widthAdvanceDiff;
-
- if( 0.f < tmpLineLayout.length )
- {
- lineLayout.length += lineLayout.wsLengthEndOfLine;
+ MergeLineLayout( lineLayout, tmpLineLayout );
- lineLayout.wsLengthEndOfLine = tmpLineLayout.wsLengthEndOfLine;
- }
- else
- {
- lineLayout.wsLengthEndOfLine += tmpLineLayout.wsLengthEndOfLine;
- }
-
- if( tmpLineLayout.ascender > lineLayout.ascender )
- {
- lineLayout.ascender = tmpLineLayout.ascender;
- }
-
- if( tmpLineLayout.descender > lineLayout.descender )
- {
- lineLayout.descender = tmpLineLayout.descender;
- }
-
- tmpLineLayout.numberOfCharacters = 0u;
- tmpLineLayout.numberOfGlyphs = 0u;
- tmpLineLayout.length = 0u;
- tmpLineLayout.widthAdvanceDiff = 0u;
- tmpLineLayout.wsLengthEndOfLine = 0u;
- tmpLineLayout.ascender = 0.f;
- tmpLineLayout.descender = 0.f;
return;
}
- if( TextAbstraction::WORD_BREAK == wordBreakInfo )
+ if( isMultiline &&
+ ( TextAbstraction::WORD_BREAK == wordBreakInfo ) )
{
- // Current glyph is the last one of the current word.
- // Add the temporal layout to the current one.
- lineLayout.numberOfCharacters += tmpLineLayout.numberOfCharacters;
- lineLayout.numberOfGlyphs += tmpLineLayout.numberOfGlyphs;
- lineLayout.length += tmpLineLayout.length;
- lineLayout.widthAdvanceDiff = tmpLineLayout.widthAdvanceDiff;
-
- if( 0.f < tmpLineLayout.length )
- {
- lineLayout.length += lineLayout.wsLengthEndOfLine;
-
- lineLayout.wsLengthEndOfLine = tmpLineLayout.wsLengthEndOfLine;
- }
- else
- {
- lineLayout.wsLengthEndOfLine += tmpLineLayout.wsLengthEndOfLine;
- }
-
- if( tmpLineLayout.ascender > lineLayout.ascender )
+ if( !oneWordLaidOut && !isWhiteSpace )
{
- lineLayout.ascender = tmpLineLayout.ascender;
+ oneWordLaidOut = true;
}
- if( tmpLineLayout.descender > lineLayout.descender )
- {
- lineLayout.descender = tmpLineLayout.descender;
- }
+ // Current glyph is the last one of the current word.
+ // Add the temporal layout to the current one.
+ MergeLineLayout( lineLayout, tmpLineLayout );
- tmpLineLayout.numberOfCharacters = 0u;
- tmpLineLayout.numberOfGlyphs = 0u;
- tmpLineLayout.length = 0u;
- tmpLineLayout.widthAdvanceDiff = 0u;
- tmpLineLayout.wsLengthEndOfLine = 0u;
- tmpLineLayout.ascender = 0.f;
- tmpLineLayout.descender = 0.f;
+ tmpLineLayout.Clear();
}
+ // Check if the font of the current glyph is the same of the previous one.
+ // If it's different the ascender and descender need to be updated.
if( lastFontId != glyphInfo.fontId )
{
- Text::FontMetrics fontMetrics;
- mFontClient.GetFontMetrics( glyphInfo.fontId, fontMetrics );
-
- // Sets the maximum ascender.
- if( fontMetrics.ascender > tmpLineLayout.ascender )
- {
- tmpLineLayout.ascender = fontMetrics.ascender;
- }
-
- // Sets the maximum descender.
- if( -fontMetrics.descender > tmpLineLayout.descender )
- {
- tmpLineLayout.descender = -fontMetrics.descender;
- }
-
+ UpdateLineHeight( glyphInfo.fontId, tmpLineLayout );
lastFontId = glyphInfo.fontId;
}
}
Vector<LineRun>& lines,
Size& actualSize )
{
- // TODO Switch between different layouts
- bool update = false;
+ Vector2* glyphPositionsBuffer = glyphPositions.Begin();
- switch( mLayout )
+ float penY = 0.f;
+ for( GlyphIndex index = 0u; index < layoutParameters.totalNumberOfGlyphs; )
{
- case LayoutEngine::SINGLE_LINE_BOX:
+ // Get the layout for the line.
+ LineLayout layout;
+ layout.glyphIndex = index;
+ GetLineLayoutForBox( layoutParameters,
+ layout );
+
+ if( 0u == layout.numberOfGlyphs )
{
- update = SingleLineLayout( layoutParameters,
- glyphPositions,
- lines,
- actualSize );
- break;
+ // The width is too small and no characters are laid-out.
+ return false;
}
- case LayoutEngine::MULTI_LINE_BOX:
+
+ LineRun lineRun;
+ lineRun.glyphIndex = index;
+ lineRun.numberOfGlyphs = layout.numberOfGlyphs;
+ lineRun.characterRun.characterIndex = layout.characterIndex;
+ lineRun.characterRun.numberOfCharacters = layout.numberOfCharacters;
+ lineRun.width = layout.length + layout.widthAdvanceDiff;
+ lineRun.ascender = layout.ascender;
+ lineRun.descender = layout.descender;
+ lineRun.extraLength = layout.wsLengthEndOfLine > 0.f ? layout.wsLengthEndOfLine - layout.widthAdvanceDiff : 0.f;
+ lineRun.direction = false;
+
+ lines.PushBack( lineRun );
+
+ // Update the actual size.
+ if( lineRun.width > actualSize.width )
{
- update = MultiLineLayout( layoutParameters,
- glyphPositions,
- lines,
- actualSize );
- break;
+ actualSize.width = lineRun.width;
}
- default:
- break;
+
+ actualSize.height += ( lineRun.ascender + -lineRun.descender );
+
+ // Traverse the glyphs and set the positions.
+
+ penY += layout.ascender;
+
+ // Check if the x bearing of the first character is negative.
+ // If it has a negative x bearing, it will exceed the boundaries of the actor,
+ // so the penX position needs to be moved to the right.
+ float penX = 0.f;
+
+ const GlyphInfo& glyph = *( layoutParameters.glyphsBuffer + index );
+ if( 0.f > glyph.xBearing )
+ {
+ penX = -glyph.xBearing;
+ }
+
+ for( GlyphIndex i = index; i < index + layout.numberOfGlyphs; ++i )
+ {
+ const GlyphInfo& glyph = *( layoutParameters.glyphsBuffer + i );
+ Vector2& position = *( glyphPositionsBuffer + i );
+
+ position.x = penX + glyph.xBearing;
+ position.y = penY - glyph.yBearing;
+
+ penX += glyph.advance;
+ }
+
+ penY += -layout.descender;
+
+ // Increase the glyph index.
+ index += layout.numberOfGlyphs;
}
- return update;
+ return true;
}
void ReLayoutRightToLeftLines( const LayoutParameters& layoutParameters,
float penX = 0.f;
+ const CharacterIndex characterVisualIndex = bidiLine.characterRun.characterIndex + *bidiLine.visualToLogicalMap;
+ const GlyphInfo& glyph = *( layoutParameters.glyphsBuffer + *( layoutParameters.charactersToGlyphsBuffer + characterVisualIndex ) );
+
+ penX = -glyph.xBearing;
+
Vector2* glyphPositionsBuffer = glyphPositions.Begin();
// Traverses the characters of the right to left paragraph.
// 2) Calculate the alignment offset accordingly with the align option,
// the box width, line length, and the paragraphs direction.
float alignOffset = CalculateHorizontalAlignment( layoutSize.width,
- line.lineSize.width,
+ line.width,
line.extraLength,
paragraphDirection );
}
}
- bool SingleLineLayout( const LayoutParameters& layoutParameters,
- Vector<Vector2>& glyphPositions,
- Vector<LineRun>& lines,
- Size& actualSize )
- {
- LineLayout layout;
- layout.glyphIndex = 0u;
- GetLineLayoutForBox( layoutParameters,
- layout );
-
- // Create a line run and add it to the lines.
- const GlyphIndex lastGlyphIndex = layoutParameters.totalNumberOfGlyphs - 1u;
-
- LineRun lineRun;
- lineRun.glyphIndex = 0u;
- lineRun.numberOfGlyphs = layoutParameters.totalNumberOfGlyphs;
- lineRun.characterRun.characterIndex = 0u;
- lineRun.characterRun.numberOfCharacters = *( layoutParameters.glyphsToCharactersBuffer + lastGlyphIndex ) + *( layoutParameters.charactersPerGlyphBuffer + lastGlyphIndex );
- lineRun.lineSize.width = layout.length;
- lineRun.lineSize.height = layout.ascender + layout.descender;
- lineRun.extraLength = layout.wsLengthEndOfLine;
-
- lines.PushBack( lineRun );
-
- // Update the actual size.
- actualSize.width = layout.length;
- actualSize.height = lineRun.lineSize.height;
-
- float penX = 0.f;
- float penY = layout.ascender;
-
- Vector2* glyphPositionsBuffer = glyphPositions.Begin();
- for( GlyphIndex glyphIndex = 0u; glyphIndex < layout.numberOfGlyphs; ++glyphIndex )
- {
- const GlyphInfo& glyph = *( layoutParameters.glyphsBuffer + glyphIndex );
- Vector2& position = *( glyphPositionsBuffer + glyphIndex );
-
- position.x = penX + glyph.xBearing;
- position.y = penY - glyph.yBearing;
-
- penX += glyph.advance;
- }
-
- return true;
- }
-
- bool MultiLineLayout( const LayoutParameters& layoutParameters,
- Vector<Vector2>& glyphPositions,
- Vector<LineRun>& lines,
- Size& actualSize )
- {
- float penY = 0.f;
- for( GlyphIndex index = 0u; index < layoutParameters.totalNumberOfGlyphs; )
- {
- float penX = 0.f;
-
- // Get the layout for the line.
- LineLayout layout;
- layout.glyphIndex = index;
- GetMultiLineLayoutForBox( layoutParameters,
- layout );
-
- if( 0u == layout.numberOfGlyphs )
- {
- // The width is too small and no characters are laid-out.
- return false;
- }
-
- // Create a line run and add it to the lines.
- const GlyphIndex lastGlyphIndex = index + layout.numberOfGlyphs - 1u;
-
- LineRun lineRun;
- lineRun.glyphIndex = index;
- lineRun.numberOfGlyphs = layout.numberOfGlyphs;
- lineRun.characterRun.characterIndex = *( layoutParameters.glyphsToCharactersBuffer + index );
- lineRun.characterRun.numberOfCharacters = ( *( layoutParameters.glyphsToCharactersBuffer + lastGlyphIndex ) + *( layoutParameters.charactersPerGlyphBuffer + lastGlyphIndex ) ) - lineRun.characterRun.characterIndex;
- lineRun.lineSize.width = layout.length + ( ( layout.widthAdvanceDiff > 0.f ) ? layout.widthAdvanceDiff : 0.f );
- lineRun.lineSize.height = layout.ascender + layout.descender;
- lineRun.extraLength = layout.wsLengthEndOfLine;
-
- lines.PushBack( lineRun );
-
- // Update the actual size.
- if( layout.length + layout.widthAdvanceDiff > actualSize.width )
- {
- actualSize.width = layout.length;
- }
-
- actualSize.height += lineRun.lineSize.height;
-
- // Traverse the glyphs and set the positions.
-
- penY += layout.ascender;
-
- Vector2* glyphPositionsBuffer = glyphPositions.Begin();
- for( GlyphIndex i = index; i < index + layout.numberOfGlyphs; ++i )
- {
- const GlyphInfo& glyph = *( layoutParameters.glyphsBuffer + i );
- Vector2& position = *( glyphPositionsBuffer + i );
-
- position.x = penX + glyph.xBearing;
- position.y = penY - glyph.yBearing;
-
- penX += glyph.advance;
- }
-
- penY += layout.descender;
-
- // Increase the glyph index.
- index += layout.numberOfGlyphs;
- }
-
- return true;
- }
-
float CalculateHorizontalAlignment( float boxWidth,
float lineLength,
float extraLength,