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muthuveera
02-21-2015, 05:08 AM
Hi guys,
I need some kind of information about layering. Is there any relationship b/w layering and how many textures supported by open gl versions??

Alfonse Reinheart
02-21-2015, 08:02 AM
Layering? That word has a very great many meanings in different contexts. So what exactly are you trying to do?

muthuveera
02-23-2015, 08:54 PM
I am trying to create 8 windows. each will independent of each other. I need to refresh the all windows independently. How can i do this?? Thanks in advance.

mhagain
02-24-2015, 12:31 AM
No, it's "what are you trying to do?", not "how are you trying to do it?"

So, what's your intended end result? What are you trying to achieve by drawing 8 windows? Because there may be a way to do it that doesn't involve drawing 8 windows.

muthuveera
02-24-2015, 03:17 AM
In one window i need to put weather radar display, another window i need to draw a grid on top of it. Window transparency also i need to do. I hav tried sequential rendering. It takes more time to update the weather radar display, so i need to render all windows parallely. Is there any way to do this??

The Little Body
02-26-2015, 04:17 PM
In one window i need to put weather radar display, another window i need to draw a grid on top of it. Window transparency also i need to do. I hav tried sequential rendering. It takes more time to update the weather radar display, so i need to render all windows parallely. Is there any way to do this??

You can display your weather radar data into a texture on a thread A and use this texture on a thread B that display it

When the display of your weather radar data is finish on the thread A, then you can bind this texture
=> the thread B now display this refreshed texture instead the previous version of this texture

With this, thread A and thread B can to be asynchronous : the thread B always display the last wheater radar picture computed and the thread A can now spend more time than the thread B for to compute it
(the texture content used by the thread B is always the same until the thread A hasn't bind the texture for to refresh the content of the texture see by the thread B)

What is the format of your weather radar data and how is it displayed ?
(this can perhaps to be optimised for to be make in real-time , cf. without the need to be make in a asynchronous thread)

muthuveera
04-18-2015, 01:14 AM
Yes, this weather radar display will update in separate thread at the same time i need to draw some other things also like grids updation of other parameters.. Can i use two draw calls at a same time.. Updation of weather radar pattern in one thread.. Displaying weather radar pattern in separate thread.. And then some other parameter displays in seperate thread.. Finally i am creating two threads for displays one thread for weather radar pattern updation.. But two display threads giving segmentation fault.. How can i achieve this?? Because that Weather radar display and other display has different viewports...

The Little Body
04-23-2015, 04:43 PM
Finally i am creating two threads for displays one thread for weather radar pattern updation.. But two display threads giving segmentation fault.. How can i achieve this?? Because that Weather radar display and other display has different viewports...

You say that you use **differents viewports** for each display, use you two distincts windows or only one window that is splitted in two ?

If you use two windows, I think that it"s better to create the two windows, cf. the two windows creations and mouse/keyboard/display functions registering, **before** to begin the threads separation

On other side, I see at http://stackoverflow.com/questions/2177038/call-opengl-functions-from-another-thread that GL don't seem to always be thread safe

Markr Crossbones+ seem to say the same thing at http://www.gamedev.net/topic/475265-multithreading-opengl/ (http://www.gamedev.net/topic/475265-multithreading-opengl/)


=> the better solution seem to handle the OpenGL window(s) creation(s)/handling in **only** one thread
(but you can handle the majority of computations on others threads, the only limit is that you can't use OpenGL's calls on them)

http://www.equalizergraphics.com/documentation/parallelOpenGLFAQ.html#one contain a compilation of questions/responses that can perhaps help you about this

Note that I have never test to use multiples thread with OpenGL ... but it's perhaps the time to begin :)