NAME
        OpenFont -- Get a pointer to a system font.

   SYNOPSIS
        font = OpenFont(textAttr)
        D0              A0

        struct textfont *openfont(struct textattr *);

   FUNCTION
        This function searches the system font space for the graphics
        text font that best matches the attributes specified.  The
        pointer to the font returned can be used in subsequent
        setfont and closefont calls.  it is important to match this
        call with a corresponding closefont call for effective
        management of ram fonts.

   INPUTS
        textAttr - a textattr or ttextattr structure that describes the
                   text font attributes desired.

   RESULT
        font is zero if the desired font cannot be found.  If the named
        font is found, but the size and style specified are not
        available, a font with the nearest attributes is returned.

   BUGS
        Prior to V39 this function would return a textfont pointer
        for any font which matched exactly in Y size, regardless of
        differences in DPI, or DotSize.

        As part of fixing this bug it is REQUIRED that you use pass the
        same textattr (or ttextattr) to this function that was used when
        opendiskfont() was called.

        OpenFont(), and opendiskfont() use weightamatch() to measure
        how well two fonts match.  WeightTAMatch() was a public function
        in graphics.library V36-V37; it is now a system PRIVATE function
        as of V39.

   SEE ALSO
        closefont()  setfont()
        diskfont.library/opendiskfont  graphics/text.h
        intuition/intuition.h