Re: [GtkGLExt] gtkglext or goocanvas?

[Mitchell Laks <mlaks post harvard edu>]

On 17:47 Wed 30 Apr     , z pekar gmail com wrote:
> No, I meant what I said - draw an ellipse upon an image and have the

LOL! 

http://en.wikipedia.org/wiki/Ellipsis

ellipsis (plural ellipses; from Greek 'omission') in printing and writing refers to a mark or series of marks that usually indicate an intentional omission of a word or a phrase from the original text. An ellipsis can also be used to indicate a pause in speech, an unfinished thought or, at the end of a sentence, a trailing off into silence (aposiopesis).

ellipses is the plural of ellipsis.


> ability to trace mouseclicks on this ellipse (like a normal button
> widget drawn upon an image just ellipse instead). As far as I know
> goocanvas can do it, my question is: can gtkglext do it?


I have no idea what you mean. And I speak both hebrew and english fairly
fluently.

I  think what you mean to say is 
"I meant WHAT I MEANT," 
NOT 
"what I (or you) said"!


Certainly you can draw an ellipse in OpenGL. There are even glut 
functions for conics.

The more important question is:

What in the world do you mean by:  'trace mouseclicks on this ellipse'??

What is this word 'trace'?

Do you mean count? 

Do you mean count the  number of clicks "within the area subtended by
the ellipse" or clicks "on the ellipse itself".

(Recall in mathematics, an ellipse is the locus of points in a 
plane such that the sum of the distances to two fixed points is a constant.)

To count clicks you are asking a basic gtk question on low level events.
Ie at the gdk level - see the Pennington gtk/gdk book.

Ie: you will have to enable low level mouse click events and then
capture them if they meet  your perimeter critera.

to enable events if you use a 
drawing_area
then you use the drawing_area set_events method
to include button-press-mask etc.

I have been using gtkglext with perl lately,
and here is a typical gtk2 perl tutorial

http://www.perlmonks.org/?node_id=583578

it does not use gtkglext but it could.

I use gtkglext with perl for similar stuff to display medical images
and draw on them. While I don't count mouseclicks - I need to be aware
of them :).

If you  want code for gtkglextmm or gtkglext and mouse events
just combine drawingarea and standard gtk code for mouse click events.
drawingarea is the simplest interface to low level gtk events. look
up scribble tutorials for gtk.

Meshulum Laks



 





> 
> On Wed, Apr 30, 2008 at 4:35 PM, Mitchell Laks <mlaks post harvard edu> wrote:
> > On 22:22 Sat 26 Apr     , z pekar gmail com wrote:
> >  > Hi, I need to upload an image to my app and place clickable ellipses
> >  > on it (and connect a signal handler to them) - I was told I should use
> >  > goocanvas to do it.
> >
> >  I am not sure what you mean by clickable ellipses ...
> >  :)
> >
> >  I guess you want to display a composite of the picture and '...' next to it.
> >
> >  You can certainly use gtkglext to display your image in any gtk widget,
> >  which can then be placed  in a HBox next to a button or widget which displays
> >  the ...-.
> >
> >  I guess you have to see if it looks nice to you :).
> >
> >  Mitchell
> >
> >
> >  >I already use gtkglext in my program, so the
> >  > question is whether gtkglext can do the job or I anyway have to take
> >  > goocanvas? (I just don't want to have a new unnecessary dependence).
> >  >
> >  > thank you in advance
> >  > Zeev Pekar
> >  > _______________________________________________
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