text

type Alignment ¶

type Alignment uint8

const (
	Start Alignment = iota
	End
	Middle
)

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(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 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
)