text

Documentation

Index

• type Alignment
  • func (a Alignment) String() string
• type Cache
  • func NewCache(collection []FontFace) *Cache
  • func (s *Cache) Layout(font Font, size fixed.Int26_6, maxWidth int, txt io.Reader) ([]Line, error)
  • func (s *Cache) LayoutString(font Font, size fixed.Int26_6, maxWidth int, str string) []Line
  • func (s *Cache) Shape(font Font, size fixed.Int26_6, layout Layout) op.CallOp
• type Face
• type Font
• type FontFace
• type Layout
• type Line
• type Shaper
• type Style
• type Typeface
• type Variant
• type Weight

Types

type Alignment

type Alignment uint8

const (
	Start Alignment = iota
	End
	Middle
)

func (Alignment) String

func (a Alignment) String() string

type Cache

type Cache struct {
	// contains filtered or unexported fields
}

Cache implements cached layout and shaping of text from a set of registered fonts.

If a font matches no registered shape, Cache falls back to the first registered face.

The LayoutString and ShapeString results are cached and re-used if possible.

func NewCache

func NewCache(collection []FontFace) *Cache

func (*Cache) Layout

func (s *Cache) Layout(
	font Font, size fixed.Int26_6, maxWidth int,
	txt io.Reader,
) ([]Line, error)

Layout implements the Shaper interface.

func (*Cache) LayoutString

func (s *Cache) LayoutString(
	font Font, size fixed.Int26_6, maxWidth int,
	str string,
) []Line

LayoutString is a caching implementation of the Shaper interface.

func (*Cache) Shape

func (s *Cache) Shape(font Font, size fixed.Int26_6, layout Layout) op.CallOp

Shape is a caching implementation of the Shaper interface. Shape assumes that the layout argument is unchanged from a call to Layout or LayoutString.

type Face

type Face interface {
	Layout(ppem fixed.Int26_6, maxWidth int, txt io.Reader) ([]Line, error)
	Shape(ppem fixed.Int26_6, str Layout) op.CallOp
}

Face implements text layout and shaping for a particular font. All methods must be safe for concurrent use.

type Font

type Font struct {
	Typeface Typeface
	Variant  Variant
	Style    Style
	// Weight is the text weight. If zero, Normal is used instead.
	Weight Weight
}

Font specify a particular typeface variant, style and weight.

type FontFace

type FontFace struct {
	Font Font
	Face Face
}

A FontFace is a Font and a matching Face.

type Layout

type Layout struct {
	Text     string
	Advances []fixed.Int26_6
}

type Line

type Line struct {
	Layout Layout
	// Width is the width of the line.
	Width fixed.Int26_6
	// Ascent is the height above the baseline.
	Ascent fixed.Int26_6
	// Descent is the height below the baseline, including
	// the line gap.
	Descent fixed.Int26_6
	// Bounds is the visible bounds of the line.
	Bounds fixed.Rectangle26_6
}

A Line contains the measurements of a line of text.

type Shaper

type Shaper interface {
	// Layout a text according to a set of options.
	Layout(font Font, size fixed.Int26_6, maxWidth int, txt io.Reader) (
		[]Line,
		error,
	)
	// LayoutString is Layout for strings.
	LayoutString(font Font, size fixed.Int26_6, maxWidth int, str string) []Line
	// Shape a line of text and return a clipping operation for its outline.
	Shape(font Font, size fixed.Int26_6, layout Layout) op.CallOp
}

Shaper implements layout and shaping of text.

type Style

type Style int

Style is the font style.

const (
	Regular Style = iota
	Italic
)

type Typeface

type Typeface string

Typeface identifies a particular typeface design. The empty string denotes the default typeface.

type Variant

type Variant string

Variant denotes a typeface variant such as "Mono" or "Smallcaps".

type Weight

type Weight int

Weight is a font weight, in CSS units subtracted 400 so the zero value is normal text weight.

const (
	Normal Weight = 400 - 400
	Medium Weight = 500 - 400
	Bold   Weight = 600 - 400
)