mckie@nas.nasa.gov (William McKie) (11/18/90)
We're currently using the SunPHIGS locator logical input device to select 2 points with a rubber band line connecting them (device=1, pet=-4), and we get a nice rubberband line which changes colour to contrast with whatever pixel colour it crosses. When we are done selecting points with request locator, the rubberband line disappears and the original pixels which it crossed are restored. This all works great. What we're looking for now is a SunPHIGS mechanism which will allow us to draw a polyline-like curve on top of an existing frame, which behaves similarly to the rubberband locator input line described above. I.e. we have a set of 2-D world coordinates which we would like the curve to pass through (typically 2 pts), and we would like to make this curve visible "on top" of the existing frame, and after an arbitrary time for viewing, then turn the curve off and recover the pixels which were originally "under it". As in the locator rubberband line, we'd like the colour of the curve to contrast with the original pixels (most of our frames are completely area-shaded with a variety of colours). Can someone suggest how this might be done? Thanks, -Bill McKie NASA Ames Research Center mckie@sky.arc.nasa.gov