Links added with one of the functions ps_add_weblink(), ps_add_pdflink(), etc. will be displayed with a surounded rectangle when the postscript document is converted to pdf and viewed in a pdf viewer. This rectangle is not visible in the postscript document. This function sets the length of the black and white portion of a dashed border line.
psdoc
Resource identifier of the postscript file as returned by ps_new().
black
The length of the dash.
white
The length of the gap between dashes.