class Cairo::FontExtents
- Cairo::FontExtents
- Reference
- Object
Overview
The FontExtents structure stores metric information for a font.
Values are given in the current user-space coordinate system.
Because font metrics are in user-space coordinates, they are mostly,
but not entirely, independent of the current transformation matrix.
If you call context.scale(2.0, 2.0), text will be drawn twice as big,
but the reported text extents will not be doubled. They will change slightly due
to hinting (so you can't assume that metrics are independent of the transformation matrix),
but otherwise will remain unchanged.
Defined in:
cairo/font_extents.crConstructors
- .new(ascent : Float64, descent : Float64, height : Float64, max_x_advance : Float64, max_y_advance : Float64)
- .new(font_extents : LibCairo::FontExtentsT)
- .new
Instance Method Summary
-
#ascent : Float64
The distance that the font extends above the baseline.
- #ascent=(ascent : Float64)
-
#descent : Float64
The distance that the font extends below the baseline.
- #descent=(descent : Float64)
-
#height : Float64
The recommended vertical distance between baselines when setting consecutive lines of text with the font.
- #height=(height : Float64)
-
#max_x_advance : Float64
The maximum distance in the X direction that the origin is advanced for any glyph in the font.
- #max_x_advance=(max_x_advance : Float64)
-
#max_y_advance : Float64
The maximum distance in the Y direction that the origin is advanced for any glyph in the font.
- #max_y_advance=(max_y_advance : Float64)
- #to_cairo_font_extents : LibCairo::FontExtentsT
- #to_unsafe : LibCairo::PFontExtentsT
Constructor Detail
Instance Method Detail
The distance that the font extends above the baseline.
NOTE that this is not always exactly equal to the maximum of the extents of all the glyphs in the font, but rather is picked to express the font designer's intent as to how the font should align with elements above it.
The distance that the font extends below the baseline.
This value is positive for typical fonts that include portions below the baseline.
NOTE that this is not always exactly equal to the maximum of the extents of all the glyphs in the font, but rather is picked to express the font designer's intent as to how the font should align with elements below it.
The recommended vertical distance between baselines when setting consecutive lines of text with the font.
This is greater than ascent+descent by a quantity known as the line spacing or external leading. When space is at a premium, most fonts can be set with only a distance of ascent+descent between lines.
The maximum distance in the X direction that the origin is advanced for any glyph in the font.
The maximum distance in the Y direction that the origin is advanced for any glyph in the font.
This will be zero for normal fonts used for horizontal writing. (The scripts of East Asia are sometimes written vertically.)