latex_tree: Inspect the parsed layout of a LaTeX expression

In gridmicrotex: Native 'LaTeX' Math Rendering for Grid Graphics

Inspect the parsed layout of a LaTeX expression

Description

Returns the raw draw-record table produced by MicroTeX's layout pass together with the bounding-box metadata. Useful for debugging alignment issues, building custom grobs on top of the layout, or counting glyphs/paths/rules in a formula.

Usage

latex_tree(
  tex,
  math_font = "",
  max_width = 0,
  tex_style = "",
  input_mode = c("mixed", "math"),
  render_mode = c("typeface", "path"),
  gp = grid::gpar()
)

Arguments

tex	Character string of LaTeX math code.
math_font	Name of the math font to use (e.g., "stix"). Use "" (default) for Lete Sans Math, which pairs with R's default sans-serif text font. See available_math_fonts for loaded fonts.
max_width	Numeric maximum width in big points for automatic line wrapping. Use 0 (default) for no wrapping.
tex_style	Character: TeX style override. One of "" (default; let the parser decide), "display", "text", "script", or "scriptscript". See latex_grob for the semantics of each value.
input_mode	How tex is interpreted before being parsed. "mixed" wraps the input in \text{...} so the string reads as ordinary text and $...$ (or \(...\)) opens math mode, matching document-level LaTeX semantics. Useful for labels that arrive from external sources mixing prose and math without explicit \text{} markers. "math" (default) is the standard MicroTeX behaviour — the whole string is treated as math, so unwrapped prose renders as spaced math italics. The default can be changed globally via latex_options(input_mode = "mixed"). See latex_wrap for details on the wrapping process.
render_mode	Character string: "typeface" (default) renders glyphs as native text using the math font, producing selectable/accessible text in PDF and SVG output. Bundled math fonts and any registered via load_font are read directly from their OTF files — no system-wide font install is required. Falls back to path mode automatically on devices that lack the R \geq 4.3 glyph engine (e.g., the base pdf() device). For selectable PDF output, prefer cairo_pdf. "path" renders math symbols as filled vector paths (works on all devices but text is not selectable in PDF/SVG).
gp	Graphical parameters (see gpar). Common entries: col (formula foreground), fontfamily / fontface (text font), fontsize / cex (formula size), and lineheight (multi-line spacing). See latex_grob for how each of these flows through MicroTeX.

Value

A list with class "latex_tree" containing:

records

Data frame of draw records (one row per glyph, path, line, rect, or text block). Columns include type, x, y, glyph, font_size, color, text, codepoint, font_file.

bbox

Named numeric vector with width, height, depth, baseline (all in big points).

tex

The (macro-expanded) input string.

render_mode

Rendering mode used for the layout.

See Also

latex_grob, latex_dims

Examples

  tree <- latex_tree("\\frac{a}{b}")
  print(tree)
  head(tree$records)

gridmicrotex documentation built on May 16, 2026, 5:06 p.m.