package font

Import Path
	golang.org/x/image/font (on go.dev)

Dependency Relation
	imports 5 packages, and imported by 2 packages


Involved Source Files

	
		Package font defines an interface for font faces, for drawing text on an
		image.
		
		Other packages provide font face implementations. For example, a truetype
		package would provide one based on .ttf font files.


Package-Level Type Names (total 7)


	/* sort by:  |  */
	
		Drawer draws text on a destination image.
		
		A Drawer is not safe for concurrent use by multiple goroutines, since its
		Face is not.

		
			
				Dot is the baseline location to draw the next glyph. The majority of the
				affected pixels will be above and to the right of the dot, but some may
				be below or to the left. For example, drawing a 'j' in an italic face
				may affect pixels below and to the left of the dot.

			
				Dst is the destination image.

			
				Face provides the glyph mask images.

			
				Src is the source image.

		
			
				BoundBytes returns the bounding box of s, drawn at the drawer dot, as well as
				the advance.
				
				It is equivalent to BoundBytes(string(s)) but may be more efficient.

			
				BoundString returns the bounding box of s, drawn at the drawer dot, as well
				as the advance.

			
				DrawBytes draws s at the dot and advances the dot's location.
				
				It is equivalent to DrawString(string(s)) but may be more efficient.

			
				DrawString draws s at the dot and advances the dot's location.

			
				MeasureBytes returns how far dot would advance by drawing s.
				
				It is equivalent to MeasureString(string(s)) but may be more efficient.

			
				MeasureString returns how far dot would advance by drawing s.



	
		Face is a font face. Its glyphs are often derived from a font file, such as
		"Comic_Sans_MS.ttf", but a face has a specific size, style, weight and
		hinting. For example, the 12pt and 18pt versions of Comic Sans are two
		different faces, even if derived from the same font file.
		
		A Face is not safe for concurrent use by multiple goroutines, as its methods
		may re-use implementation-specific caches and mask image buffers.
		
		To create a Face, look to other packages that implement specific font file
		formats.

		
			( Face) Close() error
			
				Glyph returns the draw.DrawMask parameters (dr, mask, maskp) to draw r's
				glyph at the sub-pixel destination location dot, and that glyph's
				advance width.
				
				It returns !ok if the face does not contain a glyph for r. This includes
				returning !ok for a fallback glyph (such as substituting a U+FFFD glyph
				or OpenType's .notdef glyph), in which case the other return values may
				still be non-zero.
				
				The contents of the mask image returned by one Glyph call may change
				after the next Glyph call. Callers that want to cache the mask must make
				a copy.

			
				GlyphAdvance returns the advance width of r's glyph.
				
				It returns !ok if the face does not contain a glyph for r. This includes
				returning !ok for a fallback glyph (such as substituting a U+FFFD glyph
				or OpenType's .notdef glyph), in which case the other return values may
				still be non-zero.

			
				GlyphBounds returns the bounding box of r's glyph, drawn at a dot equal
				to the origin, and that glyph's advance width.
				
				It returns !ok if the face does not contain a glyph for r. This includes
				returning !ok for a fallback glyph (such as substituting a U+FFFD glyph
				or OpenType's .notdef glyph), in which case the other return values may
				still be non-zero.
				
				The glyph's ascent and descent are equal to -bounds.Min.Y and
				+bounds.Max.Y. The glyph's left-side and right-side bearings are equal
				to bounds.Min.X and advance-bounds.Max.X. A visual depiction of what
				these metrics are is at
				https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyphterms_2x.png

			
				Kern returns the horizontal adjustment for the kerning pair (r0, r1). A
				positive kern means to move the glyphs further apart.

			
				Metrics returns the metrics for this Face.

		
			 Face : github.com/prometheus/common/expfmt.Closer
			 Face : io.Closer
		
			func github.com/golang/freetype/truetype.NewFace(f *truetype.Font, opts *truetype.Options) Face
		
			func BoundBytes(f Face, s []byte) (bounds fixed.Rectangle26_6, advance fixed.Int26_6)
			func BoundString(f Face, s string) (bounds fixed.Rectangle26_6, advance fixed.Int26_6)
			func MeasureBytes(f Face, s []byte) (advance fixed.Int26_6)
			func MeasureString(f Face, s string) (advance fixed.Int26_6)
			func oss.terrastruct.com/d2/lib/textmeasure.NewAtlas(face Face, runeSets ...[]rune) *textmeasure.atlas


	
		Hinting selects how to quantize a vector font's glyph nodes.
		
		Not all fonts support hinting.

		
			func github.com/golang/freetype/truetype.(*GlyphBuf).Load(f *truetype.Font, scale fixed.Int26_6, i truetype.Index, h Hinting) error
		
			const HintingFull
			const HintingNone
			const HintingVertical


	
		Metrics holds the metrics for a Face. A visual depiction is at
		https://developer.apple.com/library/mac/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png

		
			
				Ascent is the distance from the top of a line to its baseline.

			
				CapHeight is the distance from the top of uppercase letters to the
				baseline.

			
				CaretSlope is the slope of a caret as a vector with the Y axis pointing up.
				The slope {0, 1} is the vertical caret.

			
				Descent is the distance from the bottom of a line to its baseline. The
				value is typically positive, even though a descender goes below the
				baseline.

			
				Height is the recommended amount of vertical space between two lines of
				text.

			
				XHeight is the distance from the top of non-ascending lowercase letters
				to the baseline.

		
			func Face.Metrics() Metrics


	
		Stretch selects a normal, condensed, or expanded face.
		
		Not all fonts support stretches.

		
			const StretchCondensed
			const StretchExpanded
			const StretchExtraCondensed
			const StretchExtraExpanded
			const StretchNormal
			const StretchSemiCondensed
			const StretchSemiExpanded
			const StretchUltraCondensed
			const StretchUltraExpanded


	
		Style selects a normal, italic, or oblique face.
		
		Not all fonts support styles.

		
			const StyleItalic
			const StyleNormal
			const StyleOblique


	
		Weight selects a normal, light or bold face.
		
		Not all fonts support weights.
		
		The named Weight constants (e.g. WeightBold) correspond to CSS' common
		weight names (e.g. "Bold"), but the numerical values differ, so that in Go,
		the zero value means to use a normal weight. For the CSS names and values,
		see https://developer.mozilla.org/en/docs/Web/CSS/font-weight

		
			const WeightBlack
			const WeightBold
			const WeightExtraBold
			const WeightExtraLight
			const WeightLight
			const WeightMedium
			const WeightNormal
			const WeightSemiBold
			const WeightThin




Package-Level Functions (total 4)


	
		BoundBytes returns the bounding box of s with f, drawn at a dot equal to the
		origin, as well as the advance.
		
		It is equivalent to BoundString(string(s)) but may be more efficient.


	
		BoundString returns the bounding box of s with f, drawn at a dot equal to the
		origin, as well as the advance.


	
		MeasureBytes returns how far dot would advance by drawing s with f.
		
		It is equivalent to MeasureString(string(s)) but may be more efficient.


	
		MeasureString returns how far dot would advance by drawing s with f.




Package-Level Constants (total 24)


	const HintingFull Hinting = 2
	const HintingNone Hinting = 0
	const StyleItalic Style = 1
	const StyleNormal Style = 0
	const StyleOblique Style = 2
	const WeightBlack Weight = 5 // CSS font-weight value 900.
	const WeightBold Weight = 3 // CSS font-weight value 700.
	const WeightExtraBold Weight = 4 // CSS font-weight value 800.
	const WeightExtraLight Weight = -2 // CSS font-weight value 200.
	const WeightLight Weight = -1 // CSS font-weight value 300.
	const WeightMedium Weight = 1 // CSS font-weight value 500.
	const WeightNormal Weight = 0 // CSS font-weight value 400.
	const WeightSemiBold Weight = 2 // CSS font-weight value 600.
	const WeightThin Weight = -3 // CSS font-weight value 100.