richmon@astrovax.UUCP (Michael Richmond) (11/09/85)
When I try to draw polylines with the v_pline() function from GSS_Drivers,
if one of the points is outside of NDC space my machine just sits and
does nothing. When I interrupt the program at this point, I find myself in
some routine called '_msgsys', but it seems to get caught there. Does
this happen with other people? If so, it makes the graphics package
somewhat useless, since I would have to do my own clipping; have I missed
something?
--
Michael Richmond Princeton University, Astrophysics
{allegra,akgua,burl,cbosgd,decvax,ihnp4,noao,princeton,vax135}!astrovax!richmonacy@milo.UUCP (Adnan Yaqub) (11/19/85)
> When I try to draw polylines with the v_pline() function from GSS_Drivers, > if one of the points is outside of NDC space my machine just sits and > does nothing. When I interrupt the program at this point, I find myself in > some routine called '_msgsys', but it seems to get caught there. Does > this happen with other people? If so, it makes the graphics package > somewhat useless, since I would have to do my own clipping; have I missed > something? > > -- > Michael Richmond Princeton University, Astrophysics The GSS package is a Virtual Device Interface (VDI) package. The VDI packages are not supposed to do clipping. That, as well as other "higher level" functions, is handled be packages following the Graphics Kernel System (GKS) standard. By the time things get to VDI, they are supposed to be in NDC. I agree that it is bad that the package just hangs, but I guess we can't expect it to do clipping. Packages from GSS that will do clipping (I think) include GSS-Chart and GSS-Terminal. According to their documantation, these packages provide a GKS interface to the user. Adnan Yaqub @Allen-Bradley Co. ...!decvax!cwruecmp!milo!acy