RWS@ZERMATT.LCS.MIT.EDU (Robert Scheifler) (04/11/88)
Date: 22 Mar 88 10:42:08 GMT From: srinivas@sally.utexas.edu (Srini Sankaran) The following code doesn't work viewport = XtCreateManagedWidget("viewport", viewportWidgetClass, toplevel, arglist, XtNumber(arglist)); win = XtWindow(viewport); XDrawArc(dpy, win, gc, XSIZE >> 1, YSIZE >> 1, i * (XSIZE >> 5) , i * (YSIZE >> 5), 0, 64*360); The viewport widget contains a "clip" widget as a child. The clip widget's window completely obscures the viewport widget's window. As a result, when you try to draw into the viewport widget's window, you get no output. You aren't expected to do graphics directly into the viewport widget; instead you should be creating another widget to place inside the viewport (it will get reparented inside the clip widget). By the way, your code is making the canonical mistake of hardcoding pixel values 0 and 1. This is not X10; using 0 and 1 is guaranteed to get you inverse colors on lots of monochrome displays, and garbage on lots of color displays.