Gradient filled background

Sharjith Naramparambath's picture
Sharjith Naramp...
Thu, 09/26/2002 - 18:06
Forums: 
Other usage issues

Hi,
How can the Open Cascade viewer be made gradient filled like the ones the modern packages like Pro/E , Catia and PowerShape etc. have?

Patrik Mueller's picture
Patrik Mueller
Fri, 09/27/2002 - 08:53

Hi,

I want to test it but at the moment I don't have the time:

Try to load a bitmap as background for your window. Create the bitmap 1 px width and 256 px height. Do a gradient with a paint programm in it.

Perhaps it works....

Best regards,

Patrik Müller

Nair Sharjith's picture
Nair Sharjith (not verified)
Fri, 09/27/2002 - 09:22

Hi Pat,
Thanks for the idea! But can u please help me more by giving some idea --some code fragment-- about how to load a bitmap in the background?

Thanks!

Patrik Mueller's picture
Patrik Mueller
Fri, 09/27/2002 - 09:40

Hi,

here's an extract from Xw_window.cdl:

Load ( me ; aFilename : CString from Standard) returns Boolean
---Level: Advanced
---Purpose: Loads the XWD file to this Window.
-- Returns TRUE if the loading occurs normaly.
---Warning: Note that the Window is enlarged automatically
--when the image size is too large for this window.
---Category: Methods to modify the class definition
---Trigger: Raises if Window is not defined properly
raises WindowError from Aspect is virtual;

The same routine exists in WNT_Window.
As I've written it's just an idea. If you get it to work please post it to the forum. I think we aren't alone wanting such a background.
I personally would prefer it creating a gradient bitmap as AlienImage in mem and send it to the window - but I haven't found a solution for that at the moment. With this idea the user could change the gradient.

PS:
There would be similar result when doing a textured plane as a billboard to the scene - but more work :-))

Regards,

Patrik Müller

DU's picture
DU
Fri, 09/27/2002 - 19:03

Hi,

I have tried Patrik's mentioned method, but the return boolean value is "True", but It dosen't display the image. by the way, I think the textured plane is not a good solution for the issue.
Kindly regards,
Shangjian Du

Patrik Mueller's picture
Patrik Mueller
Sat, 09/28/2002 - 07:16

Hi all,

as I said these are untestested ideas. But why should OCC implement methods without functionality? Perhaps you can post me the lines and I can look if there's a logical problem or it doesn't work.

On the other hand - it would be easier if it would be possible clearing the background with different vertex colors (the OpenGL gradient fill).

Regards,

Patrik Müller