[comp.windows.x] Need help with arcs in R4

gened@gssc.UUCP (Gene Daniel) (08/16/90)

It appears that the arc drawing code in R4 mi has changed drasticly.
When I run the xbench arc tests there appears to be some start/path 
combinations that don't draw at all and others that may be drawing in 
the wrong direction. The server I'm using uses only mi code for drawing 
arcs so I'm assuming that the problem is in miPolyArc(). Does anyone know 
of any fixes to miarc.c? Has anyone got miPolyArc() to work in their server?

Thanks!!!!

-- 
Gene Daniel			   | gened@gssc.gss.com
Graphic Software Systems, Inc.     |       or
P.O. Box 4900                      | ..!tektronix!sequent!gssc!gened
Beaverton, Oregon 97005-7161       |

keith@EXPO.LCS.MIT.EDU (Keith Packard) (08/16/90)

> It appears that the arc drawing code in R4 mi has changed drasticly.
> When I run the xbench arc tests there appears to be some start/path 
> combinations that don't draw at all and others that may be drawing in 
> the wrong direction. The server I'm using uses only mi code for drawing 
> arcs so I'm assuming that the problem is in miPolyArc(). Does anyone know 
> of any fixes to miarc.c? Has anyone got miPolyArc() to work in their server?

Yes, the R4 arc code had a wide range of bug fixes, but the basic algorithms
have remained the same since R3.  Certainly the interpretation of the protocol
values hasn't changed.

I have never seen the troubles you are having, and that code has seen some
rough testing.  If you can put together a sample program which draws incorrect
arcs, please send it to xbugs@expo.lcs.mit.edu and we'll have a closer look.

Keith Packard
MIT X Consortium