ConstFont

touchgfx/ConstFont.hpp

A ConstFont is a Font implementation that has its contents defined at compile-time and usually placed in read-only memory.

See: Font

Note: Pure virtual class. Create an application-specific implementation of getPixelData().

Inherits from: Font

Inherited by: InternalFlashFont

Public Functions

	ConstFont(const GlyphNode * glyphs, uint16_t numGlyphs, uint16_t height, uint16_t baseline, uint8_t pixAboveTop, uint8_t pixBelowBottom, uint8_t bitsPerPixel, uint8_t byteAlignRow, uint8_t maxLeft, uint8_t maxRight, const Unicode::UnicodeChar fallbackChar, const Unicode::UnicodeChar ellipsisChar)
	Initializes a new instance of the ConstFont class.
const GlyphNode *	find(Unicode::UnicodeChar unicode) const
	Finds the glyph data associated with the specified unicode.
const GlyphNode *	getGlyph(Unicode::UnicodeChar unicode)
	Gets the glyph data associated with the specified Unicode.
virtual const GlyphNode *	getGlyph(Unicode::UnicodeChar unicode, const uint8_t *& pixelData, uint8_t & bitsPerPixel) const
	Gets the glyph data associated with the specified Unicode.
const GlyphNode *	getGlyph(Unicode::UnicodeChar unicode, const uint8_t *& pixelData, uint8_t & bitsPerPixel)
	Gets the glyph data associated with the specified Unicode.
virtual int8_t	getKerning(Unicode::UnicodeChar prevChar, const GlyphNode * glyph) const =0
	Gets the kerning distance between two characters.
virtual const uint8_t *	getPixelData(const GlyphNode * glyph) const =0
	Gets the pixel date associated with this glyph.

Protected Attributes

const GlyphNode *	glyphList
	The list of glyphs.
uint16_t	listSize
	The size of the list of glyphs.

Additional inherited members

Public Functions inherited from Font

virtual FORCE_INLINE_FUNCTION uint16_t	getBaseline() const
	Returns the position of the baseline of this font in pixels from the top of the line.
virtual FORCE_INLINE_FUNCTION uint8_t	getBitsPerPixel() const
	Gets bits per pixel for this font.
virtual FORCE_INLINE_FUNCTION uint8_t	getByteAlignRow() const
	Are the glyphs saved with each glyph row byte aligned?
virtual uint16_t	getCharWidth(const Unicode::UnicodeChar c) const
	Gets the width in pixels of the specified character.
virtual const FontContextualFormsTable *	getContextualFormsTable() const
	Gets the contextual forms table used in arabic fonts.
virtual Unicode::UnicodeChar	getEllipsisChar() const
	Gets ellipsis character for the given font.
virtual Unicode::UnicodeChar	getFallbackChar() const
	Gets fallback character for the given font.
virtual const uint16_t *	getGSUBTable() const
	Gets GSUB table.
virtual FORCE_INLINE_FUNCTION uint16_t	getHeight() const
	Returns the height of a font.
FORCE_INLINE_FUNCTION uint8_t	getMaxPixelsLeft() const
	Gets maximum pixels left of any glyph in the font.
FORCE_INLINE_FUNCTION uint8_t	getMaxPixelsRight() const
	Gets maximum pixels right of any glyph in the font.
virtual uint16_t	getNumberOfLines(const Unicode::UnicodeChar * text, ... ) const
	Count the number of lines in a given text.
FORCE_INLINE_FUNCTION uint16_t	getPixelsAboveTop() const
	Gets pixels above top of the normal text height.
FORCE_INLINE_FUNCTION uint16_t	getPixelsBelowBottom() const
	Gets number of pixel rows below the bottom of the font.
virtual float	getScaleFactor() const
	Returns the scale factor.
virtual int16_t	getSpacingAbove(const Unicode::UnicodeChar * text, ... ) const
	Gets the number of blank pixels at the top of the given text.
virtual uint16_t	getStringWidth(const Unicode::UnicodeChar * text, ... ) const
	Gets the width in pixels of the specified string.
virtual uint16_t	getStringWidth(TextDirection textDirection, const Unicode::UnicodeChar * text, ... ) const
	Gets the width in pixels of the specified string.
virtual bool	isVectorBasedFont() const
	Returns true if this Font is vector based.
	TOUCHGFX_DEPRECATED("Please use getBaseline() instead." , virtual uint16_t getFontHeight() const )
	Returns the height in pixels of this font.
	TOUCHGFX_DEPRECATED("Please use getHeight() instead." , virtual uint16_t getMaxTextHeight(const Unicode::UnicodeChar *text,...) const )
	Gets the height of the highest character in a given string.
	TOUCHGFX_DEPRECATED("Please use getHeight() instead." , virtual uint16_t getMinimumTextHeight() const )
	Returns the height of a font.
virtual	~Font()
	Finalizes an instance of the Font class.
FORCE_INLINE_FUNCTION bool	isInvisibleZeroWidth(Unicode::UnicodeChar character)
	Query if 'character' is invisible, zero width.

Protected Functions inherited from Font

	Font(uint16_t height, uint16_t baseline, uint8_t pixAboveTop, uint8_t pixBelowBottom, uint8_t bitsPerPixel, uint8_t byteAlignRow, uint8_t maxLeft, uint8_t maxRight, const Unicode::UnicodeChar fallbackChar, const Unicode::UnicodeChar ellipsisChar)
	Initializes a new instance of the Font class.
uint16_t	getStringWidthLTR(TextDirection textDirection, const Unicode::UnicodeChar * text, va_list pArg) const
	Gets the width in pixels of the specified string.
uint16_t	getStringWidthRTL(TextDirection textDirection, const Unicode::UnicodeChar * text, va_list pArg) const
	Gets the width in pixels of the specified string.

Protected Attributes inherited from Font

uint8_t	bAlignRow
	The glyphs are saved with each row byte aligned.
uint16_t	baselineHeight
	The baseline.
uint8_t	bPerPixel
	The number of bits per pixel.
Unicode::UnicodeChar	ellipsisCharacter
	The ellipsis character used for truncating long texts.
Unicode::UnicodeChar	fallbackCharacter
	The fallback character to use when no glyph exists for the wanted character.
uint16_t	fontHeight
	The font height in pixels.
uint8_t	maxPixelsLeft
	The maximum number of pixels a glyph extends to the left.
uint8_t	maxPixelsRight
	The maximum number of pixels a glyph extends to the right.
uint8_t	pixelsAboveTop
	The number of pixels above the top.
uint8_t	pixelsBelowBottom
	The number of pixels below the bottom.

Public Functions Documentation

ConstFont

ConstFont	(	const GlyphNode *	glyphs ,
		uint16_t	numGlyphs ,
		uint16_t	height ,
		uint16_t	baseline ,
		uint8_t	pixAboveTop ,
		uint8_t	pixBelowBottom ,
		uint8_t	bitsPerPixel ,
		uint8_t	byteAlignRow ,
		uint8_t	maxLeft ,
		uint8_t	maxRight ,
		const Unicode::UnicodeChar	fallbackChar ,
		const Unicode::UnicodeChar	ellipsisChar
		)

Initializes a new instance of the ConstFont class.

Parameters:

glyphs	The array of glyphs known to this font.
numGlyphs	The number of glyphs in list.
height	The height of the font.
baseline	The pixel position of the baseline.
pixAboveTop	The maximum number of pixels above the top of the text.
pixBelowBottom	The maximum number of pixels that can be drawn below the baseline in this font.
bitsPerPixel	The number of bits per pixel in this font.
byteAlignRow	The glyphs are saved with each row byte aligned.
maxLeft	The maximum a character extends to the left.
maxRight	The maximum a character extends to the right.
fallbackChar	The fallback character for the typography in case no glyph is available.
ellipsisChar	The ellipsis character used for truncating long texts.

find

const GlyphNode * find	(	Unicode::UnicodeChar	unicode	)

Finds the glyph data associated with the specified unicode.

Parameters:

unicode	The character to look up.

Returns:

A pointer to the glyph node or null if the glyph was not found.

getGlyph

const GlyphNode * getGlyph	(	Unicode::UnicodeChar	unicode	)

Gets the glyph data associated with the specified Unicode.

Please note that in case of Thai letters and Arabic letters where diacritics can be placed relative to the previous character(s), please use TextProvider::getNextLigature() instead as it will create a temporary GlyphNode that will be adjusted with respect to X/Y position.

Parameters:

unicode	The character to look up.

Returns:

A pointer to the glyph node or null if the glyph was not found.

See also:

TextProvider::getNextLigature

getGlyph

virtual const GlyphNode * getGlyph	(	Unicode::UnicodeChar	unicode ,		const
		const uint8_t *&	pixelData ,		const
		uint8_t &	bitsPerPixel		const
		)	const

Gets the glyph data associated with the specified Unicode.

Please note that in case of Thai letters and Arabic letters where diacritics can be placed relative to the previous character(s), please use TextProvider::getNextLigature() instead as it will create a temporary GlyphNode that will be adjusted with respect to X/Y position.

Parameters:

unicode	The character to look up.
pixelData	Pointer to the pixel data for the glyph if the glyph is found. This is set by this method.
bitsPerPixel	Reference where to place the number of bits per pixel.

Returns:

A pointer to the glyph node or null if the glyph was not found.

Reimplements: touchgfx::Font::getGlyph

getGlyph

const GlyphNode * getGlyph	(	Unicode::UnicodeChar	unicode ,
		const uint8_t *&	pixelData ,
		uint8_t &	bitsPerPixel
		)

Gets the glyph data associated with the specified Unicode.

Please note that in case of Thai letters and Arabic letters where diacritics can be placed relative to the previous character(s), please use TextProvider::getNextLigature() instead as it will create a temporary GlyphNode that will be adjusted with respect to X/Y position.

Parameters:

unicode	The character to look up.
pixelData	Pointer to the pixel data for the glyph if the glyph is found. This is set by this method.
bitsPerPixel	Reference where to place the number of bits per pixel.

Returns:

A pointer to the glyph node or null if the glyph was not found.

getKerning

virtual int8_t getKerning	(	Unicode::UnicodeChar	prevChar ,		const =0
		const GlyphNode *	glyph		const =0
		)	const =0

Gets the kerning distance between two characters.

Parameters:

prevChar	The Unicode value of the previous character.
glyph	the glyph object for the current character.

Returns:

The kerning distance between prevChar and glyph char.

Reimplements: touchgfx::Font::getKerning

Reimplemented by: touchgfx::InternalFlashFont::getKerning

getPixelData

virtual const uint8_t * getPixelData	(	const GlyphNode *	glyph	)

Gets the pixel date associated with this glyph.

Parameters:

glyph	The glyph to get the pixels data from.

Returns:

Pointer to the pixel data of this glyph.

Reimplemented by: touchgfx::InternalFlashFont::getPixelData

Protected Attributes Documentation

glyphList

const GlyphNode * glyphList

The list of glyphs.

listSize

uint16_t listSize

The size of the list of glyphs.