gfxGlyphExtents Class Reference

This stores glyph bounds information for a particular gfxFont, at a particular appunits-per-dev-pixel ratio (because the compressed glyph width array is stored in appunits). More...

#include <gfxFont.h>

Collaboration diagram for gfxGlyphExtents:

List of all members.

Classes
class	GlyphWidths
class	HashEntry
Public Types
enum	{ INVALID_WIDTH = 0xFFFF }
Public Member Functions
	gfxGlyphExtents (PRUint32 aAppUnitsPerDevUnit)
	~gfxGlyphExtents ()
PRUint16	GetContainedGlyphWidthAppUnits (PRUint32 aGlyphID) const
PRBool	IsGlyphKnown (PRUint32 aGlyphID) const
PRBool	IsGlyphKnownWithTightExtents (PRUint32 aGlyphID) const
PRBool	GetTightGlyphExtentsAppUnits (gfxFont *aFont, gfxContext *aContext, PRUint32 aGlyphID, gfxRect *aExtents)
void	SetContainedGlyphWidthAppUnits (PRUint32 aGlyphID, PRUint16 aWidth)
void	SetTightGlyphExtents (PRUint32 aGlyphID, const gfxRect &aExtentsAppUnits)
PRUint32	GetAppUnitsPerDevUnit ()

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Detailed Description

This stores glyph bounds information for a particular gfxFont, at a particular appunits-per-dev-pixel ratio (because the compressed glyph width array is stored in appunits).

We store a hashtable from glyph IDs to float bounding rects. For the common case where the glyph has no horizontal left bearing, and no y overflow above the font ascent or below the font descent, and tight bounding boxes are not required, we avoid storing the glyph ID in the hashtable and instead consult an array of 16-bit glyph XMost values (in appunits). This array always has an entry for the font's space glyph --- the width is assumed to be zero.

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Member Enumeration Documentation

anonymous enum

Enumerator:

INVALID_WIDTH

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Constructor & Destructor Documentation

gfxGlyphExtents::gfxGlyphExtents

(

PRUint32

aAppUnitsPerDevUnit

)

[inline]

gfxGlyphExtents::~gfxGlyphExtents

(

)

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Member Function Documentation

PRUint32 gfxGlyphExtents::GetAppUnitsPerDevUnit

(

)

[inline]

PRUint16 gfxGlyphExtents::GetContainedGlyphWidthAppUnits

(

PRUint32

aGlyphID

)

const [inline]

PRBool gfxGlyphExtents::GetTightGlyphExtentsAppUnits	(	gfxFont *	aFont,
		gfxContext *	aContext,
		PRUint32	aGlyphID,
		gfxRect *	aExtents
	)

PRBool gfxGlyphExtents::IsGlyphKnown

(

PRUint32

aGlyphID

)

const [inline]

PRBool gfxGlyphExtents::IsGlyphKnownWithTightExtents

(

PRUint32

aGlyphID

)

const [inline]

void gfxGlyphExtents::SetContainedGlyphWidthAppUnits	(	PRUint32	aGlyphID,
		PRUint16	aWidth
	)			[inline]

void gfxGlyphExtents::SetTightGlyphExtents	(	PRUint32	aGlyphID,
		const gfxRect &	aExtentsAppUnits
	)

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The documentation for this class was generated from the following file:

• gfxFont.h