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From: frisk@rhi.hi.is (Fridrik Skulason)
Newsgroups: comp.os.msdos.programmer
Subject: Bug in MSC 6.0 ?
Message-ID: <2161@krafla.rhi.hi.is>
Date: 12 Sep 90 12:06:42 GMT
Reply-To: frisk@rhi.hi.is (Fridrik Skulason)
Organization: University of Iceland (RHI)
Lines: 30

I have noticed what I believe is a minor error in the MSC 6.0 graphics
library - something which would normally not be noticed, but almost ruins
one application I'm writing.

The problem is that I cannot draw ellipses where the height is an even number.

See the following example - which was written to demonstrate the problem:

#include <graph.h>
main()
{
    _setvideomode(_ERESCOLOR);
    _ellipse(_GBORDER,10,10,15,13);    /* draw ellipse of height 4 */
    _ellipse(_GBORDER,20,10,25,14);    /* draw ellipse of height 5 */
    _ellipse(_GBORDER,30,10,35,15);    /* draw ellipse of height 6 */
    _ellipse(_GBORDER,40,10,45,16);    /* draw ellipse of height 7 */
    getch();
    _setvideomode(_TEXTC80);
}

The second and third ellipse should be of different sizes - but they are not.
It is possible to get the ellipse of height 6 by writing something like

    _arc(50,10,55,14,55,12,50,12);
    _arc(50,11,55,15,50,13,55,13);  

but what I wanted to ask is - what about other compilers, Watcom for example
do they have the same problem ?

-frisk