| Re: Dilating a point [message #31176] |
Thu, 20 June 2002 19:26  |
Mark Hadfield
Messages: 783
Registered: May 1995
|
Senior Member |
|
|
"Akhila" <idlfreak@yahoo.com> wrote in message
news:b1ad7b05.0206201342.3e9de643@posting.google.com...
> "Dick Jackson" <dick@d-jackson.com> wrote in message
> news:<i34Q8.38238$s82.3100417@news1.calgary.shaw.ca>...
>> "Akhila" <idlfreak@yahoo.com> wrote in message
>> news:b1ad7b05.0206191006.3ef24d3c@posting.google.com...
>>> I have a blank screen. Using CURSOR and PLOTS command i mark a
>>> point >>> in that screen with a value of 255B. I want to dilate
>>> that point. Can >>> anybody tell me how to do that.....Please
>>> help me.
>> How about this:
>> [direct graphics example code]
> I guess this works only for direct graphics. I need to get it
> working in Object Graphics. I used the Widget_Draw event.x and
> event.y to obtain the cursor point. I tried the 'DLgrPlot' to plot
> it, but it didn't work. Please tell me how to plot that point, in
> the current object graphics window.
(I think I've got the quoting right.)
Your original query specifically mentioned a couple of Direct Graphics
commands, leading everyone to assume you wanted a Direct Graphics
solution. How does Object Graphics come into it? Have you tried and
succeeded with DG and now want to try with OG? Or were you looking for
an OG solution all along?
Be that as it may, you will need to give more information before
anyone can help you effectively. But first, go to David Fanning's page
and check out his OG example programs. Several of these support cursor
interaction, In particular, look at his zoombox program, which uses
the cursor to mark out a box on an image and then displays the
contents of the box in a separate window. (This is probably more
elaborate than what you want.)
The basic idea is to trap your event structure in an event handler,
pass [event.x, event.y] to your window's PickData method to locate the
cursor event relative to one of the atoms in the graphics tree, then
either modify that atom or add another atom to achieve the visual
effect you want. Oh, and make sure you clean up after yourself!
--
Mark Hadfield "Ka puwaha te tai nei, Hoea tatou"
m.hadfield@niwa.co.nz
National Institute for Water and Atmospheric Research (NIWA)
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
