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)), or the "get_scaled_font" method on context
objects (see
lua-oocairo-context(3)).
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)).
- 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) 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) 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) for details of the
return value type.
- cr:get_font_options ()
- Returns a font options object (see
lua-oocairo-fontopt(3)) 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) 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)).
- 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)).
- 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)).
- 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.
