OpenGL Coverflow

[maxprod]

Right, if I comment-out calls to both drawForeground and drawBackground it works beautifully (very smooth)

Cool. That's a first point and we know where is the problem now. Take a look about the other point when you will have 5 minutes (color mode).

[Dub]

//A little test by inverting BGR to RGB & BGRA to RGBA will probably resolve your problem. //
I didn't quite understand that reverse RGB to GBR - (Quick Google) Where do I find the defines for those?

[maxprod]

http://www.opengl.org/resources/features/OGLextensions/
http://lists.apple.com/archives/mac-opengl/2005/Apr/msg00146.html
http://lists.apple.com/archives/mac-opengl//2009/Jun/msg00078.html

Good reading

Edit:

Look at this post too, to understand the Color problematic : http://www.rawmaterialsoftware.com/viewtopic.php?t=&f=&p=20259

The right name about this question to search : Pixel Format.

[maxprod]

I've send a HD Video on YouTube. The problem is that it's first time i recorded my screen in HD, so there's sometimes little blocking due to my hard-drive and the 8000Kps bitrate used to record the video. Need to defrag my drive and/or use another drive. Next time.

http://www.youtube.com/watch?v=x0CD2ahtjyA

[zamrate]

removing drawBackground() and drawForeground() also helps for me (I can use the .exe now, and there's no white rectangle anymore).
but still got problems: some of the covers are just white. I'm not sure if this has something to do with it, but I remember vaguely that in my code I had to use some kind of OpenGL context lock for uploading the textures, i.e. you cannot load up textures to the GPU while the same OpenGL context is being used to draw. Otherwise I also got this white areas.. Not sure if this hint helps, haven't checked your code much at the moment..

Edit: The white covers were due to JPG's my JUCE version (147) couldn't read (for instance Chic - Le Freak.jpg). I removed them from the XML and it was ok.

Still, I do face the problem that whenever I move the scrollbar, the animation "hangs" until I release it. I suppose this is not normal?

[maxprod]

removing drawBackground() and drawForeground() also helps for me (I can use the .exe now, and there's no white rectangle anymore).
but still got problems: some of the covers are just white. I'm not sure if this has something to do with it, but I remember vaguely that in my code I had to use some kind of OpenGL context lock for uploading the textures, i.e. you cannot load up textures to the GPU while the same OpenGL context is being used to draw. Otherwise I also got this white areas.. Not sure if this hint helps, haven't checked your code much at the moment..

You're surely right. The two methods are Thread safe (CriticalSection) but at the Juce UI level. Maybe there's a method to lock the OpenGL drawing until the texture loading is finish. I'm not a OpenGL expert. I will see that as soon as possible.

Edit: The white covers were due to JPG's my JUCE version (147) couldn't read (for instance Chic - Le Freak.jpg). I removed them from the XML and it was ok.

Juce 1.47 don't like disco-funk music ?

Still, I do face the problem that whenever I move the scrollbar, the animation "hangs" until I release it. I suppose this is not normal?

I've the same reaction when I resize the window in full screen on my laptop. It's not normal. Maybe it's the same problem because scrollBarMoved () just change the "current" selected item in the CoverFlowContext and call delayedUpdate () that change the 2D foreground, send it and call a repaint() to OpenGL. So, maybe the solution is to lock the OpenGL drawing during the access to the GPU (texture loading). Now the question is how do?

[Dub]

Juce 1.47 don't like disco-funk music ?

{Checks Juce Demo Table Components page which seems to confirm with this }

[zamrate]

So, maybe the solution is to lock the OpenGL drawing during the access to the GPU (texture loading). Now the question is how do?

i think you have to use OpenGlCompoent::getContextLock( ) when transfering textures. the problem with transfering textures to the GPU is that you have to do it in portions, because if it takes to long your drawing will obviously be stalled.

[maxprod]

i think you have to use OpenGlCompoent::getContextLock( ) when transfering textures.

I will check that when I'll find minutes. Thanks for replying. If it's the solution, i will rewrite the component more proper, especially CoverFlowComponent is badly written.

[maxprod]

{Checks Juce Demo Table Components page which seems to confirm with this }

[alimjan]

Hi, maxprod! Here is my problem with coverflow, this is about high CPU usage


?

[Bruce Wheaton]

i think you have to use OpenGlCompoent::getContextLock( ) when transfering textures.

I will check that when I'll find minutes. Thanks for replying. If it's the solution, i will rewrite the component more proper, especially CoverFlowComponent is badly written.

Just found this thread, super work Max! And it looks like you're learning OpenGL as you go along too? Cool.

So yes, OpenGL is fussy about threads. You should ideally:
- only use each context on one thread
- create and destroy the context on the same thread

There are two things you may want to look at as well:
- shared contexts, where each context can access the textures, lists etc. of the other (you can use one thread/context just to upload)
- PBOs, where you can 'start' a texture upload, then go off and do other things in that thread - the GPU will use DMA to transfer, as long as you don't try to access the texture right away.

Keep it up, great stuff.

Bruce

[Dub]

http://www.opengl.org/resources/features/OGLextensions/
http://lists.apple.com/archives/mac-opengl/2005/Apr/msg00146.html
http://lists.apple.com/archives/mac-opengl//2009/Jun/msg00078.html

Good reading

Edit:

Look at this post too, to understand the Color problematic : http://www.rawmaterialsoftware.com/viewtopic.php?t=&f=&p=20259

The right name about this question to search : Pixel Format.

Eek! When I get a chance, I'd love to

[rolnxyz]

I would like to see that cool VU Meter you mentioned in the original post.

[maxprod]

Yes : http://www.rawmaterialsoftware.com/viewtopic.php?f=6&t=4917