New arrows for ER models + associative entities

["Georg Lothar Thimm (Asst Prof)" <MGEORG ntu edu sg>]

Dear All,

Lars asked me - for good reasons - the post my additions for ER models to this place, and do it in the form of a diff to the latest CVS version. Thus, if you did not yet add the files I sent earlier to dia, and you are desperate to use the arrows as used in "Modern Database Management" by McFadden, Hoffer & Prescott, use this diff to get there.

I added sort of dummy-cases in calculate_arrow_point() - as, despite Lars' explanations, I did not quite get it. And - helas - the graphs look ok to me.

Cheers,
  Georg

Georg Thimm, Dr (Assistant Prof.)      Nanyang Technological University 
Email: mgeorg@ntu.edu.sg               School of MPE, 50 Nanyang Ave.
Tel: +65 6790 4415                     Singapore 639798
WWW: www.drc.ntu.edu.sg/users/mgeorg

ADD_ER_ARROWS_ENTITY.diff