pangoMacros: Pango Convenience Macros
In RGtk2: R Bindings for Gtk 2.8.0 and Above

Description Usage Arguments Details Value Author(s)

These macros and constants help you layout text with Pango.

pangoAscent(x)
pangoDescent(x)
pangoLbearing(x)
pangoRbearing(x)
PANGO_SCALE
pangoPixels(size)
PANGO_SCALE_LARGE
PANGO_SCALE_MEDIUM
PANGO_SCALE_SMALL
PANGO_SCALE_X_LARGE
PANGO_SCALE_X_SMALL
PANGO_SCALE_XX_LARGE
PANGO_SCALE_XX_SMALL

`x`	A rectangle describing the glyph extents
`size`	A size on the Pango scale

When positioning text, it is beneficial to know the extents of the glyphs being drawn. The macros pangoAscent, pangoDescent, pangoLbearing, and pangoRbearing perform simple math on the given rectangle (representing the glyph extents) to determine the corresponding properties. The "ascent" and "descent" are how high the glyph extends above and below the baseline, respectively. The "lbearing" and "rbearing" describe the left-most and right-most extents of the glyph.

The rest are merely constants for scaling. PANGO_SCALE is the factor by which device units are scaled to Pango units. To return to device units, use the pangoPixels. The rest are pre-fab factors for scaling by different degrees.

The requested quantity in the units of the provided rectangle.

Michael Lawrence

RGtk2 documentation built on Oct. 14, 2021, 5:08 p.m.