cairoShowText
if the cairo graphics state were set to the same font_face,
font_matrix, ctm, and font_options as scaled.font
). Additionally,
the x_advance and y_advance values indicate the amount by which the
current point would be advanced by cairoShowText
.cairoScaledFontTextExtents(scaled.font, utf8)
scaled.font
utf8
extents
CairoTextExtents
] a CairoTextExtents
which to store the retrieved extents.