pangoMacros {RGtk2} | R Documentation |
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