freetypy.Size_Metrics

class freetypy.Size_Metrics

The metrics of a size object.

The scaling values, if relevant, are determined first during a size changing operation. The remaining fields are then set by the driver. For scalable formats, they are usually set to scaled values of the corresponding fields in Face.

Note that due to glyph hinting, these values might not be exact for certain fonts. Thus they must be treated as unreliable with an error margin of at least one pixel!

Indeed, the only way to get the exact metrics is to render all glyphs. As this would be a definite performance hit, it is up to client applications to perform such computations.

The Size_Metrics object is valid for bitmap fonts also.

Attributes

ascender	The ascender in fractional pixels.
descender	The descender in fractional pixels.
height	The height in fractional pixels.
max_advance	The maximum advance width in fractional pixels.
x_ppem	The width of the scaled EM square in pixels.
x_scale	A fractional scaling value used to convert horizontal metrics from font units to 26.6 fractional pixels.
y_ppem	The height of the scaled EM square in pixels.
y_scale	A fractional scaling value used to convert horizontal metrics from font units to 26.6 fractional pixels.