CopperSpice API  1.8.1
QRawFont Class Reference

Provides access to a single physical instance of a given font. More...

## Public Types

enum  AntialiasingType

## Public Methods

QRawFont ()

QRawFont (const QByteArray &fontData, qreal pixelSize, QFont::HintingPreference hintingPreference=QFont::PreferDefaultHinting)

QRawFont (const QRawFont &other)

QRawFont (const QString &fileName, qreal pixelSize, QFont::HintingPreference hintingPreference=QFont::PreferDefaultHinting)

~QRawFont ()

bool advancesForGlyphIndexes (const quint32 *glyphIndexes, QPointF *advances, int numGlyphs, LayoutFlags layoutFlags) const

QVector< QPointFadvancesForGlyphIndexes (const QVector< quint32 > &glyphIndexes) const

QVector< QPointFadvancesForGlyphIndexes (const QVector< quint32 > &glyphIndexes, LayoutFlags layoutFlags) const

QImage alphaMapForGlyph (quint32 glyphIndex, AntialiasingType antialiasingType=SubPixelAntialiasing, const QTransform &transform=QTransform ()) const

qreal ascent () const

qreal averageCharWidth () const

QRectF boundingRect (quint32 glyphIndex) const

qreal descent () const

QString familyName () const

QByteArray fontTable (const char *tagName) const

bool glyphIndexesForChars (QStringView str, quint32 *glyphIndexes, int *numGlyphs) const

QVector< quint32glyphIndexesForString (const QString &text) const

QFont::HintingPreference hintingPreference () const

bool isValid () const

qreal lineThickness () const

void loadFromData (const QByteArray &fontData, qreal pixelSize, QFont::HintingPreference hintingPreference)

void loadFromFile (const QString &fileName, qreal pixelSize, QFont::HintingPreference hintingPreference)

qreal maxCharWidth () const

bool operator!= (const QRawFont &other) const

QRawFont & operator= (const QRawFont &other)

QRawFont & operator= (QRawFont &&other)

bool operator== (const QRawFont &other) const

QPainterPath pathForGlyph (quint32 glyphIndex) const

qreal pixelSize () const

void setPixelSize (qreal pixelSize)

QFont::Style style () const

QString styleName () const

QList< QFontDatabase::WritingSystemsupportedWritingSystems () const

bool supportsCharacter (QChar character) const

bool supportsCharacter (quint32 ucs4) const

void swap (QRawFont &other)

qreal underlinePosition () const

qreal unitsPerEm () const

int weight () const

qreal xHeight () const

## Static Public Methods

static QRawFont fromFont (const QFont &font, QFontDatabase::WritingSystem writingSystem=QFontDatabase::Any)

## Friends

class QTextLayout

## Detailed Description

The QRawFont class provides access to a single specific font using an existing font file. The font family, point size, and font style are all required when specifying a QRawFont. An example would be "Helvetica 14 Bold". This is a low level class and for most use cased using the QFont class will be a better choice.

When using the QFont class to display text the rendering system will attempt to find each character in the specified font. If there is no match a different font may be used. This happens on a character by character basis. This may not produce the desired result. If your application needs to select a specific font then using QRawFont will be necessary.

This class can be used in combination with the QGlyphRun class to draw specific glyph indexes at specific positions.

### Constructiong a QRawFont

A QRawFont object can be constructed in one of the following ways. The object belongs to the thread where it was constructed and can not be moved to a different thread.

• Calling QTextLayout::glyphs() or QTextFragment::glyphs(). The returned QGlyphs objects will contain QRawFont objects which represent the actual fonts used to render each portion of the text.
• Passing a QFont object to QRawFont::fromFont(). The function will return a QRawFont object representing the font that will be selected as response to the QFont query and the selected writing system.
• Passing a file name or QByteArray directly to the QRawFont constructor, or by calling loadFromFile() or loadFromData(). In this case, the font will not be registered in QFontDatabase, and it will not be available as part of regular font selection.

## Member Enumeration Documentation

This enum represents the different ways a glyph can be rasterized in the function alphaMapForGlyph().

ConstantValueDescription
QRawFont::PixelAntialiasing 0 Will rasterize by measuring the coverage of the shape on whole pixels. The returned image contains the alpha values of each pixel based on the coverage of the glyph shape.
QRawFont::SubPixelAntialiasing 1Will rasterize by measuring the coverage of each subpixel, returning a separate alpha value for each of the red, green and blue components of each pixel.

## Constructor & Destructor Documentation

 QRawFont::QRawFont ( )

Constructs an invalid QRawFont.

 QRawFont::QRawFont ( const QString & fileName, qreal pixelSize, QFont::HintingPreference hintingPreference = QFont::PreferDefaultHinting )

Constructs a QRawFont representing the font contained in the file referenced by fileName for the size (in pixels) given by pixelSize, and using the hinting preference specified by hintingPreference.

Note
The referenced file must contain a TrueType or OpenType font.
 QRawFont::QRawFont ( const QByteArray & fontData, qreal pixelSize, QFont::HintingPreference hintingPreference = QFont::PreferDefaultHinting )

Constructs a QRawFont representing the font contained in the supplied fontData for the size (in pixels) given by pixelSize, and using the hinting preference specified by hintingPreference.

Note
The data must contain a TrueType or OpenType font.
 QRawFont::QRawFont ( const QRawFont & other )

Creates a QRawFont which is a copy of other.

 QRawFont::~QRawFont ( )

Destroys the QRawFont

## Method Documentation

 bool QRawFont::advancesForGlyphIndexes ( const quint32 * glyphIndexes, QPointF * advances, int numGlyphs ) const

Returns the QRawFont's advances for each of the glyphIndexes in pixel units. The advances give the distance from the position of a given glyph to where the next glyph should be drawn to make it appear as if the two glyphs are unspaced. The glyph indexes are given with the array glyphIndexes while the results are returned through advances, both of them must have numGlyphs elements.

 bool QRawFont::advancesForGlyphIndexes ( const quint32 * glyphIndexes, QPointF * advances, int numGlyphs, LayoutFlags layoutFlags ) const

Returns the QRawFont's advances for each of the glyphIndexes in pixel units. The advances give the distance from the position of a given glyph to where the next glyph should be drawn to make it appear as if the two glyphs are unspaced. The glyph indexes are given with the array glyphIndexes while the results are returned through advances, both of them must have numGlyphs elements. How the advances are calculated is controlled by layoutFlags.

 QVector< QPointF > QRawFont::advancesForGlyphIndexes ( const QVector< quint32 > & glyphIndexes ) const
inline

Returns the QRawFont's advances for each of the glyphIndexes in pixel units. The advances give the distance from the position of a given glyph to where the next glyph should be drawn to make it appear as if the two glyphs are unspaced.

 QVector< QPointF > QRawFont::advancesForGlyphIndexes ( const QVector< quint32 > & glyphIndexes, QRawFont::LayoutFlags layoutFlags ) const
inline

Returns the QRawFont's advances for each of the glyphIndexes in pixel units. The advances give the distance from the position of a given glyph to where the next glyph should be drawn to make it appear as if the two glyphs are unspaced. How the advances are calculated is controlled by layoutFlags.

 QImage QRawFont::alphaMapForGlyph ( quint32 glyphIndex, AntialiasingType antialiasingType = SubPixelAntialiasing, const QTransform & transform = QTransform() ) const

This method returns a rasterized image of the glyph at the given glyphIndex in the underlying font, using the transform specified. If the QRawFont is not valid, this function will return an invalid QImage.

If antialiasingType is set to QRawFont::SubPixelAntialiasing, then the resulting image will be in QImage::Format_RGB32 and the RGB values of each pixel will represent the subpixel opacities of the pixel in the rasterization of the glyph. Otherwise, the image will be in the format of QImage::Format_Indexed8 and each pixel will contain the opacity of the pixel in the rasterization.

pathForGlyph(), QPainter::drawGlyphRun()
 qreal QRawFont::ascent ( ) const

Returns the ascent of this QRawFont in pixel units.

QFontMetricsF::ascent()
 qreal QRawFont::averageCharWidth ( ) const

Returns the average character width of this QRawFont in pixel units.

QFontMetricsF::averageCharWidth()
 QRectF QRawFont::boundingRect ( quint32 glyphIndex ) const

Returns the smallest rectangle containing the glyph with the given glyphIndex.

 qreal QRawFont::descent ( ) const

Returns the descent of this QRawFont in pixel units.

QFontMetricsF::descent()
 QString QRawFont::familyName ( ) const

Returns the family name of this QRawFont.

 QByteArray QRawFont::fontTable ( const char * tagName ) const

Retrieves the sfnt table named tagName from the underlying physical font, or an empty byte array if no such table was found. The returned font table's byte order is Big Endian, like the sfnt format specifies. The tagName must be four characters long and should be formatted in the default endianness of the current platform.

 QRawFont QRawFont::fromFont ( const QFont & font, QFontDatabase::WritingSystem writingSystem = QFontDatabase::Any )
static

Fetches the physical representation based on a font query. The physical font returned is the font that will be preferred by CopperSpice in order to display text in the selected writingSystem.

 bool QRawFont::glyphIndexesForChars ( QStringView str, quint32 * glyphIndexes, int * numGlyphs ) const

Converts a string of unicode points to glyph indexes using the CMAP table in the underlying font. The method works like glyphIndexesForString() except it receive an array (char), the results will be returned though glyphIndexes array and number of glyphs will be set in numGlyphs.

The size of glyphIndexes array must be at least numChars, if that not large enough this method will return false, then resize glyphIndexes from the size returned in numGlyphs.

 QVector< quint32 > QRawFont::glyphIndexesForString ( const QString & text ) const

Converts the string of unicode points given by text to glyph indexes using the CMAP table in the underlying font, and returns a vector containing the result.

Note that, in cases where there are other tables in the font that affect the shaping of the text, the returned glyph indexes will not correctly represent the rendering of the text. To get the correctly shaped text, you can use QTextLayout to lay out and shape the text, then call QTextLayout::glyphs() to get the set of glyph index list and QRawFont pairs.

 QFont::HintingPreference QRawFont::hintingPreference ( ) const

Returns the hinting preference used to construct this QRawFont.

QFont::hintingPreference()
 bool QRawFont::isValid ( ) const

Returns true if the QRawFont is valid and false otherwise.

Returns the leading of this QRawFont in pixel units.

 qreal QRawFont::lineThickness ( ) const

Returns the thickness for drawing lines (underline, overline, etc.) along with text drawn in this font.

 void QRawFont::loadFromData ( const QByteArray & fontData, qreal pixelSize, QFont::HintingPreference hintingPreference )

Replaces the current QRawFont with the font contained in the supplied fontData for the size (in pixels) given by pixelSize, and using the hinting preference specified by hintingPreference. The fontData must contain a TrueType or OpenType font.

 void QRawFont::loadFromFile ( const QString & fileName, qreal pixelSize, QFont::HintingPreference hintingPreference )

Replaces the current QRawFont with the contents of the file referenced by fileName for the size (in pixels) given by pixelSize, and using the hinting preference specified by hintingPreference. The file must reference a TrueType or OpenType font.

 qreal QRawFont::maxCharWidth ( ) const

Returns the width of the widest character in the font.

QFontMetricsF::maxWidth()
 bool QRawFont::operator!= ( const QRawFont & other ) const
inline

Returns true if this QRawFont is not equal to other. Otherwise, returns false.

 QRawFont & QRawFont::operator= ( const QRawFont & other )

Copy assigns from other and returns a reference to this object.

 QRawFont & QRawFont::operator= ( QRawFont && other )
inline

Move assigns from other and returns a reference to this object.

 bool QRawFont::operator== ( const QRawFont & other ) const

Returns true if this QRawFont is equal to other. Otherwise, returns false.

 QPainterPath QRawFont::pathForGlyph ( quint32 glyphIndex ) const

This function returns the shape of the glyph at a given glyphIndex in the underlying font if the QRawFont is valid. Otherwise, it returns an empty QPainterPath. The returned glyph will always be unhinted.

 qreal QRawFont::pixelSize ( ) const

Returns the pixel size set for this QRawFont. The pixel size affects how glyphs are rasterized, the size of glyphs returned by pathForGlyph(), and is used to convert internal metrics from design units to logical pixel units.

setPixelSize()
 void QRawFont::setPixelSize ( qreal pixelSize )

Sets the pixel size with which this font should be rendered to pixelSize.

pixelSize()
 QFont::Style QRawFont::style ( ) const

Returns the style of this QRawFont.

QFont::style()
 QString QRawFont::styleName ( ) const

Returns the style name of this QRawFont.

QFont::styleName()
 QList< QFontDatabase::WritingSystem > QRawFont::supportedWritingSystems ( ) const

Returns a list of writing systems supported by the font according to designer supplied information in the font file. Please note that this does not guarantee support for a specific unicode point in the font. You can use the supportsCharacter() to check support for a single, specific character.

supportsCharacter()
 bool QRawFont::supportsCharacter ( QChar character ) const

Returns true if the font has a glyph that corresponds to the given character.

supportedWritingSystems()
 bool QRawFont::supportsCharacter ( quint32 ucs4 ) const

Returns true if the font has a glyph that corresponds to the UCS-4 encoded character ucs4.

supportedWritingSystems()
 void QRawFont::swap ( QRawFont & other )
inline

Swaps the raw font other with this raw font. This operation is very fast and never fails.

 qreal QRawFont::underlinePosition ( ) const

Returns the position from baseline for drawing underlines below the text rendered with this font.

 qreal QRawFont::unitsPerEm ( ) const

Returns the number of design units define the width and height of the em square for this QRawFont. This value is used together with the pixel size when converting design metrics to pixel units, as the internal metrics are specified in design units and the pixel size gives the size of 1 em in pixels.