or 1.0 if matrix is null.
Matrix.getFontScaleFactor
double getFontScaleFactor()Returns the scale factor of a matrix on the height of the font.
That is, the scale factor in the direction perpendicular to the vector that the X coordinate is mapped to. If the scale in the X coordinate is needed as well, use [pango.matrix.Matrix.getFontScaleFactors].
Returns
the scale factor of matrix on the height of the font,