package textmeasure

Import Path
	github.com/pancsta/d2/lib/textmeasure (on go.dev)

Dependency Relation
	imports 29 packages, and imported by 9 packages

Involved Source Files

	    atlas.go
	    atlas_metrics.go
	    fontface.go
	    links.go
	    markdown.go
	    markdown_svg.go
	    rect.go
	    substitutions.go
	    textmeasure.go
Package-Level Type Names (total 9)

	/* sort by: alphabet | popularity */
	 type MarkdownColorRole string (basic type)
		MarkdownColorRole is a semantic Markdown color. It mirrors the roles used by
		github-markdown.css without coupling text measurement to a D2 theme.

		As Types Of (total 11)
			const MarkdownColorAccent
			const MarkdownColorBorder
			const MarkdownColorBorderMuted
			const MarkdownColorCanvas
			const MarkdownColorCanvasSubtle
			const MarkdownColorForeground
			const MarkdownColorForegroundStroke
			const MarkdownColorMuted
			const MarkdownColorMutedStroke
			const MarkdownColorNeutralMuted
			const MarkdownColorNone

	 type MarkdownFontRole string (basic type)
		MarkdownFontRole lets an SVG renderer select the correct embedded D2 font.
		Font sizes are kept separately on each primitive.

		As Types Of (total 8)
			const MarkdownFontBold
			const MarkdownFontItalic
			const MarkdownFontMono
			const MarkdownFontMonoBold
			const MarkdownFontMonoItalic
			const MarkdownFontMonoSemibold
			const MarkdownFontRegular
			const MarkdownFontSemibold

	 type MarkdownLayout (struct)
		MarkdownLayout contains the exact dimensions used by D2 layout and the
		positioned primitives used to paint those dimensions. MeasureMarkdown calls
		LayoutMarkdown, ensuring measurement and rendering share one code path.

		Fields (total 4)
			Corpus string
				Corpus contains the visible source text used by the primitives. Renderers
				embedding subset fonts should include it.

			Height int
			Primitives []MarkdownPrimitive
			Width int
		Methods (only one)
			(*MarkdownLayout) SVG(opts MarkdownSVGOptions) string
				SVG serializes a MarkdownLayout as native SVG elements. It deliberately
				emits a fragment rather than an <svg> document so d2svg can translate and
				theme it inside a diagram.

		As Outputs Of (at least one exported)
			func LayoutMarkdown(mdText string, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily, fontSize int) (*MarkdownLayout, error)

	 type MarkdownPrimitive (struct)
		MarkdownPrimitive is a serializer-neutral native SVG drawing operation.
		
		Text uses X/Y as the baseline origin and Width/Height as its measured box.
		Rect uses X/Y/Width/Height/Radius. Line uses X/Y and X2/Y2. FillRole and
		StrokeRole are semantic so light/dark themes can serialize the same layout.

		Fields (total 20)
			Decoration MarkdownTextDecoration
			FillRole MarkdownColorRole
			Font MarkdownFontRole
			FontSize float64
			Height float64
			Kind MarkdownPrimitiveKind
			Link string
			LinkTitle string
			Radius float64
			StrokeRole MarkdownColorRole
			StrokeWidth float64
			SyntheticBold bool
				SyntheticBold/SyntheticItalic preserve inherited CSS axes when the
				innermost Markdown element selects a different concrete D2 font family.
				For example, em > strong uses the bold face with a synthetic slant, while
				strong > em uses the italic face with synthetic weight.

			SyntheticItalic bool
			Text string
			TextLength bool
				TextLength fits the glyphs to Width. CSS paints a discretionary soft
				hyphen at one third of an em even inside D2's monospace code face.

			Width float64
			X float64
			X2 float64
			Y float64
			Y2 float64

	 type MarkdownPrimitiveKind string (basic type)
		MarkdownPrimitiveKind identifies the kind of native SVG primitive in a
		MarkdownLayout. The layout package intentionally does not choose concrete
		colors so that renderers can map the semantic roles to their active theme.

		As Types Of (total 3)
			const MarkdownLinePrimitive
			const MarkdownRectPrimitive
			const MarkdownTextPrimitive

	 type MarkdownSVGOptions (struct)
		MarkdownSVGOptions controls native SVG serialization without affecting
		layout. A renderer can override role paints and font classes to match its
		theme/font embedding scheme.

		Fields (total 5)
			Class string
			DisableLinks bool
				DisableLinks emits linked text without inner <a> elements. d2svg uses
				this when a Markdown label is already wrapped by a shape/connection link.

			FontClasses map[MarkdownFontRole]string
			RolePaint map[MarkdownColorRole]MarkdownSVGPaint
			Underline bool
				Underline applies D2's style.underline to every Markdown text primitive.

		As Inputs Of (at least one exported)
			func (*MarkdownLayout).SVG(opts MarkdownSVGOptions) string

	 type MarkdownSVGPaint (struct)
		MarkdownSVGPaint controls how a semantic role is emitted by SVG. Class is
		optional; Color is an SVG paint value such as "currentColor", "#fff", or a
		CSS variable.

		Fields (total 2)
			Class string
			Color string

	 type MarkdownTextDecoration string (basic type)

		As Types Of (total 2)
			const MarkdownTextDecorationLineThrough
			const MarkdownTextDecorationNone

	 type Ruler (struct)
		Ruler allows for effiecient and convenient text drawing.
		
		To create a Ruler object, use the New constructor:
		
			txt := text.New(pixel.ZV, text.NewAtlas(face, text.ASCII))
		
		As suggested by the constructor, a Ruler object is always associated with one font face and a
		fixed set of runes. For example, the Ruler we created above can draw text using the font face
		contained in the face variable and is capable of drawing ASCII characters.
		
		Here we create a Ruler object which can draw ASCII and Katakana characters:
		
			txt := text.New(0, text.NewAtlas(face, text.ASCII, text.RangeTable(unicode.Katakana)))
		
		Similarly to IMDraw, Ruler functions as a buffer. It implements io.Writer interface, so writing
		text to it is really simple:
		
			fmt.Print(txt, "Hello, world!")
		
		Newlines, tabs and carriage returns are supported.
		
		Finally, if we want the written text to show up on some other Target, we can draw it:
		
			txt.Draw(target)
		
		Ruler exports two important fields: Orig and Dot. Dot is the position where the next character
		will be written. Dot is automatically moved when writing to a Ruler object, but you can also
		manipulate it manually. Orig specifies the text origin, usually the top-left dot position. Dot is
		always aligned to Orig when writing newlines. The Clear method resets the Dot to Orig.

		Fields (total 3)
			Dot *geo.Point
				Dot is the position where the next character will be written. Dot is automatically moved
				when writing to a Ruler object, but you can also manipulate it manually

			LineHeightFactor float64
				lineHeight is the vertical distance between two lines of text.
				
				Example:
				  txt.lineHeight = 1.5 * txt.atlas.lineHeight

			Orig *geo.Point
				Orig specifies the text origin, usually the top-left dot position. Dot is always aligned
				to Orig when writing newlines.

		Methods (total 4)
			(*Ruler) HasFontFamilyLoaded(fontFamily *d2fonts.FontFamily) bool
			(*Ruler) Measure(font d2fonts.Font, s string) (width, height int)
			(*Ruler) MeasureMono(font d2fonts.Font, s string) (width, height int)
			(*Ruler) MeasurePrecise(font d2fonts.Font, s string) (width, height float64)
		As Outputs Of (at least one exported)
			func NewRuler() (*Ruler, error)
		As Inputs Of (at least 7)
			func LayoutMarkdown(mdText string, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily, fontSize int) (*MarkdownLayout, error)
			func MeasureMarkdown(mdText string, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily, fontSize int) (width, height int, err error)
			func github.com/pancsta/d2/d2graph.GetTextDimensions(mtexts []*d2target.MText, ruler *Ruler, t *d2target.MText, fontFamily *d2fonts.FontFamily) *d2target.TextDimensions
			func github.com/pancsta/d2/d2graph.GetTextDimensionsWithMono(mtexts []*d2target.MText, ruler *Ruler, t *d2target.MText, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily) *d2target.TextDimensions
			func github.com/pancsta/d2/d2graph.(*Graph).SetDimensions(mtexts []*d2target.MText, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily) error
			func github.com/pancsta/d2/d2graph.(*Object).GetDefaultSize(mtexts []*d2target.MText, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily, labelDims d2target.TextDimensions, withLabelPadding bool) (*d2target.TextDimensions, error)
			func github.com/pancsta/d2/d2graph.(*Object).GetLabelSize(mtexts []*d2target.MText, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily) (*d2target.TextDimensions, error)


Package-Level Functions (total 11)

	 func HeaderToFontScale(header string) float64
		HeaderToFontScale returns github-markdown.css's exact heading size. The
		legacy measurement path keeps HeaderToFontSize's integer truncation so graph
		dimensions remain stable, while native SVG painting uses this scale and can
		reproduce fractional CSS sizes such as h6's 13.6px at a 16px base.

	 func HeaderToFontSize(baseFontSize int, header string) int
	 func IsDangerousLink(link string) bool
		IsDangerousLink reports whether link uses a URL scheme that must not be
		exposed as interactive metadata. It intentionally shares Goldmark's
		dangerous-URL policy with Markdown links while preserving relative URLs,
		board targets, and opaque application schemes.

	 func LayoutMarkdown(mdText string, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily, fontSize int) (*MarkdownLayout, error)
		LayoutMarkdown parses Markdown once, measures it with D2's existing box
		model, and paints that same box model into native SVG primitives.

	 func MeasureMarkdown(mdText string, ruler *Ruler, fontFamily *d2fonts.FontFamily, monoFontFamily *d2fonts.FontFamily, fontSize int) (width, height int, err error)
	 func NewAtlas(face font.Face, runeSets ...[]rune) *atlas
		NewAtlas creates a new atlas containing glyphs of the union of the given sets of runes (plus
		unicode.ReplacementChar) from the given font face.
		
		Creating an atlas is rather expensive, do not create a new atlas each frame.
		
		Do not destroy or close the font.Face after creating the atlas. atlas still uses it.

	 func NewRuler() (*Ruler, error)
		New creates a new Ruler capable of drawing runes contained in the provided atlas. Orig and Dot
		will be initially set to orig.
		
		Here we create a Ruler capable of drawing ASCII characters using the Go Regular font.
		
			ttf, err := parseFont(goregular.TTF)
			if err != nil {
			    panic(err)
			}
			face := ttf.newFace(14)
			txt := text.New(orig, text.NewAtlas(face, text.ASCII))

	 func RenderMarkdown(m string) (string, error)
	 func ReplaceSubstitutionsMarkdown(mdText string, variables map[string]string) string
	 func ReplaceSubstitutionsMarkdownBounded(ctx context.Context, mdText string, variables map[string]string, maxExpansion int64) (string, int64, error)
		ReplaceSubstitutionsMarkdownBounded replaces variables outside Markdown code
		spans and blocks while bounding candidate-match work and bytes inserted by
		replacements. It checks the bound before each allocating replacement.

	 func SafeMarkdownLink(link string) string
		SafeMarkdownLink returns link when it is safe to expose as interactive
		metadata and an empty string for unsafe Markdown URL schemes. PDF and PPTX
		annotations use the same policy.


Package-Level Variables (only one)

	  var Runes []rune
		Runes encompasses ASCII, Latin-1, and geometric shapes like black square


Package-Level Constants (total 52)

	const BorderBottom_h1_h2 = 1
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const BorderLeft_blockquote_em = 0.25
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const CODE_LINE_HEIGHT = 1.3
	const FontSize_pre_code_em = 0.85
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const Height_hr_em = 0.25
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const LineHeight_h = 1.25
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const LineHeight_pre = 1.45
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginBottom_blockquote = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginBottom_h = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginBottom_p = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginBottom_pre = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginBottom_table = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginBottom_ul = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginTop_h = 24
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginTop_li_em = 0.25
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginTop_li_p = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarginTopBottom_hr = 24
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarkdownColorAccent MarkdownColorRole = "accent"
	const MarkdownColorBorder MarkdownColorRole = "border"
	const MarkdownColorBorderMuted MarkdownColorRole = "border-muted"
	const MarkdownColorCanvas MarkdownColorRole = "canvas"
	const MarkdownColorCanvasSubtle MarkdownColorRole = "canvas-subtle"
	const MarkdownColorForeground MarkdownColorRole = "foreground"
	const MarkdownColorForegroundStroke MarkdownColorRole = "foreground-stroke"
	const MarkdownColorMuted MarkdownColorRole = "muted"
	const MarkdownColorMutedStroke MarkdownColorRole = "muted-stroke"
	const MarkdownColorNeutralMuted MarkdownColorRole = "neutral-muted"
	const MarkdownColorNone MarkdownColorRole = ""
	const MarkdownFontBold MarkdownFontRole = "bold"
	const MarkdownFontItalic MarkdownFontRole = "italic"
	const MarkdownFontMono MarkdownFontRole = "mono"
	const MarkdownFontMonoBold MarkdownFontRole = "mono-bold"
	const MarkdownFontMonoItalic MarkdownFontRole = "mono-italic"
	const MarkdownFontMonoSemibold MarkdownFontRole = "mono-semibold"
	const MarkdownFontRegular MarkdownFontRole = "regular"
	const MarkdownFontSemibold MarkdownFontRole = "semibold"
	const MarkdownFontSize = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarkdownLineHeight = 1.5
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const MarkdownLinePrimitive MarkdownPrimitiveKind = "line"
	const MarkdownRectPrimitive MarkdownPrimitiveKind = "rect"
	const MarkdownTextDecorationLineThrough MarkdownTextDecoration = "line-through"
	const MarkdownTextDecorationNone MarkdownTextDecoration = ""
	const MarkdownTextPrimitive MarkdownPrimitiveKind = "text"
	const Padding_pre = 16
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const PaddingBottom_h1_h2_em = 0.3
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const PaddingLeft_ul_ol_em = 2
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const PaddingLeftRight_code_em = 0.4
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const PaddingLeftRight_heading_code_em = 0.2
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const PaddingLR_blockquote_em = 1
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const PaddingTopBottom_code_em = 0.2
		these are css values from github-markdown.css so we can accurately compute the rendered dimensions

	const SIZELESS_FONT_SIZE = 0
	const TAB_SIZE = 4

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