This function is similar to ps_stringwidth but returns an array of dimensions containing the width, ascender, and descender of the text.
Resource identifier of the postscript file as returned by ps_new.
The text for which the geometry is to be calculated.
The identifier of the font to be used. If not font is specified the current font will be used.
The size of the font. If no size is specified the current size is used.
An array of the dimensions of a string. The element 'width' contains the width of the string as returned by ps_stringwidth. The element 'descender' contains the maximum descender and 'ascender' the maximum ascender of the string.