White Boxes

[Drostan]

Hello!

First some specs:
Version: Java 6 Update 15 Operating System: Windows XP 5.1 Architecture: x86

Downloaded Alchemy, started in for the first time and started drawing. Every few strokes I get a white box over my parts of my canvas. The box covers everything under it so I can't see it. It also repositions a part of the drawing to another place on the canvas. So really, what I'm guessing it's doing is that it takes a rectangular piece of my drawing and moves it to another place. The problem can happen with short strokes but is more common with long strokes towards the edges of my canvas. It really looks like a drawing problem (graphics glitch) or something but I have not experienced anything similar or any problems in any other programs.

To get the image right again I can just resize my window slightly and everything goes back to normal... that is until I make another stroke.

Read around and couldn't find anyone that had seen anything like it.

Pictures:

Working image:

http://img12.imageshack.us/i/workingm.jpg/

White box has appeared:

http://img256.imageshack.us/i/whitebox.jpg/

White box plus some elements that are drawn in too places (marked in photoshop)

http://img29.imageshack.us/i/repositioned.jpg/

Any takers?

UPDATE:

After writing the initial post I've experimented for a bit.

- The problem does not appear until letting go of a stroke. As soon as I does release a stroke the problem has a (quite large) chance of occurring. This makes me believe it has something to do with the redrawing in java (be it java or the hardware or anything inbetween that doesn't work as it should).

- The problem is never visible whilst drawing. If I start drawing (or resize my window) the problem disappears until I let go of the stroke again.

- The area of the white box(es) that appears are smaller the smaller i make my Alchemy Window.

- I do not get this problem in other Java applications.

- I do not get this problem in other graphical applications (not even vector apps like Illustrator).

What I have done:
Cleaned my java runtime installation and made sure I have the latest version.
Cleaned my graphics drivers and made sure I have the latest version.
My cards is a nVidia 8800GT and I the 190.38 drivers for it.

My best bet still is still that the redrawing isn't working as it should. Skipping patches of info or displacing them to another place of the canvas/alchemy program.

[Karl DD]

This sounds like a glitch of some sort with how Java draws the screen.
To keep things quick in Alchemy shapes are added to an image buffer when the pen/mouse is lifted/released.
That way Java only needs to draw an image to the screen rather than draw a whole bunch of shape forms.
So it sounds like there is some problem drawing that image buffer to the screen.

I am guessing if you try out Alchemy Alpha 002, which did not use the image buffer, this problem will not occur.
Give it a try and let me know.
The problem with these issues is that it is super hard to debug because it is specific to the hardware

[Drostan]

Kind of what I suspected then.

You are absolutely right about Alpha 002 working splendidly. If only it had the same functionality as the latest build

Is there anything I can do to help? Any specs you want to know or anything I should try out? Just tell me and I'll try it!

As I've said, I've already reinstalled the latest version of Java and made sure my graphics drivers are the latest ver.

Is there any nvidia settings you think I should tweak on an per application basis to see if we can nail down the problem for you to fix in Alchemy?

[Zafio]

Thanks for pointing me your thread.
After reading what Karl said, I found a workaround, just disable hardware acceleration like this:


Karl: Should we give feedback to Nvidia about this here?

[Karl DD]

Thanks for that!
It sounds more like a Java bug to be honest.
They plug-in the support for hardware acceleration, so something could be going wrong in that process.

Does the performance suffer without acceleration?
It must be a pain to toggle that on and off I imagine

[Drostan]

That workaround works for me as well. Of course it's not an acceptable way of working (especially not when you want to switch between different programs, some of which really wants hardware acceleration on!) but at least I can play around a bit with alchemy now.

Again Karl, just tell us if there's any debugging we should do. At least we're starting to nail down the problem somewhat.

Do you think it may be (not any critique! just trying to find the solution!) your code for using the image buffer? That there might be a better way of writing it to minimize possible glitches? Or do we just have to wait for Nvidia/Java to (hopefully!) solve the issue?

Thanks for all your hard work!

[longhornxtreme]

http://forums.nvidia.com/lofiversion/in ... 10141.html

This fix worked for me.