---
name: "lua-oocairo-scaledfont"
section: "3"
platform: "linux"
package: "liblua5.1-oocairo0"
version: "1.4-1.2"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/lua-oocairo-scaledfont"
---

# lua-oocairo-scaledfont(3)

Scaled font face object

## Name

lua-oocairo-scaledfont - Scaled font face object

## Introduction

Scaled font objects represent Cairo font faces which have been scaled to a particular point size.  They can be created from a font face object with the `"scaled_font_create"` function in the main module table (see [*lua-oocairo*(3)](/lua-oocairo/3.md)), or the `"get_scaled_font"` method on context objects (see [*lua-oocairo-context*(3)](/lua-oocairo-context/3.md)).

Scaled font objects can be compared with the `"=="` operator.  This will compare the identity of the objects, so different Lua objects which refer to the same `"cairo_font_face_t"` will compare as equal.

## Methods

Scaled font objects provide the following methods.

- font:extents ()

  Returns a table containing metrics information about the font.  The return value is in the same format as that of the `"font_extents"` method on context objects (see [*lua-oocairo-context*(3)](/lua-oocairo-context/3.md)).

- font:get\_ctm ()

  Returns the coordinate transformation matrix (CTM) associated with the font.  This maps user coordinates into device coordinates on the surface with which the font is used. See [*lua-oocairo-matrix*(3)](/lua-oocairo-matrix/3.md) for details of the return value type.

- font:get\_font\_face ()

  Returns an object representing the unscaled font face used to create this font.  See [*lua-oocairo-fontface*(3)](/lua-oocairo-fontface/3.md) for details of its methods.

- font:get\_font\_matrix ()

  Returns the matrix representing the scaling of the font into user coordinates. See [*lua-oocairo-matrix*(3)](/lua-oocairo-matrix/3.md) for details of the return value type.

- cr:get\_font\_options ()

  Returns a font options object (see [*lua-oocairo-fontopt*(3)](/lua-oocairo-fontopt/3.md)) containing the rendering options that were supplied when creating this font.

- font:get\_scale\_matrix ()

  Returns a matrix table representing the scaling of the font to the coordinate space of the surface it is used on.  This is the matrix obtained by multiplying the font matrix by the surface CTM.  See [*lua-oocairo-matrix*(3)](/lua-oocairo-matrix/3.md) for details of the return value type. Only available with Cairo 1.8 or better.

- font:get\_type ()

  Returns a string indicating which back-end library provides the font face information.  The return value will be one of the same strings returned by the `"get_type"` method on a font face object (see [*lua-oocairo-fontface*(3)](/lua-oocairo-fontface/3.md)).

- font:glyph\_extents (glyphs)

  Same as `"font:text_extents()"`, but instead of a string, the *glyphs* value should be table in the format accepted by the `"show_glyphs()"` method on context objects (see [*lua-oocairo-context*(3)](/lua-oocairo-context/3.md)).

- font:text\_extents (text)

  Returns a table containing measurements of the given UTF-8 text as it would be rendered in this font.  The return value is in the same format as that of the `"text_extents"` method on context objects (see [*lua-oocairo-context*(3)](/lua-oocairo-context/3.md)).

- font:text\_to\_glyphs (x, y, text)

  Given some UTF-8 text in the string *text*, and starting coordinates of *x* and *y*, this works out which glyphs need to be drawn to represent the text, and which glyphs correspond to the bytes in *text*.  The method returns two tables, the first an array of glyphs suitable for supplying to methods like `"show_glyphs"` and `"glyph_extents"`, and the second is a table of text clusters suitable for supplying to the `"show_text_glyphs"` method on a context object.

  Only available with Cairo 1.8 or better.