cairoGetCurrentPoint(cr, x, y)cr is in an
error status, x and y will both be set to 0.0. It is possible to
check this in advance with cairoHasCurrentPoint.
Most path construction functions alter the current point. See the
following for details on how they affect the current point:
cairoNewPath, cairoNewSubPath,
cairoAppendPath, cairoClosePath,
cairoMoveTo, cairoLineTo, cairoCurveTo,
cairoRelMoveTo, cairoRelLineTo, cairoRelCurveTo,
cairoArc, cairoArcNegative, cairoRectangle,
cairoTextPath, cairoGlyphPath, cairoStrokeToPath()
Some functions use and alter the current point but do not otherwise
change current path:
cairoShowText, cairoShowGlyphs.
Some functions unset the current path and as a result, current point:
cairoFill, cairoStroke.