Zooming on small region can freeze the display

[OuaisBla]

If you Zoom (either X or Y) repeatedly on a small portion of the WaveForm graph, the visible range become smaller at each zoom. But, at some point, when the zoomed region is very small, the display freeze.

For having caught an issue like this in a proprietary product of our own, I guess that the error come from the floating inexact representation. I bet 10 bucks that the Tick drawing calculation loop is caught in an infinite loop with tick spacing or range value looking like -0.112e-17 (in fact 0, but not 0 binary).

Anyway, this bug is highly reproductible. Simply Zoom on 1 axis, until the display freeze.

[OuaisBla]

Is this bug fix in the 8.1.2 releases of Measurement Studio?

4D4BF0ZL

Fixed an issue where the horizontal gridlines are not aligned with the y-axis tick marks after panning or zooming.

Is this bug related to mine?

For info: Zoom on Y axis until the display freeze. On my system, after 10 iterations the probability of a freeze is more than 50%.

[JonathanN]

Hi OuaisBla,

It doesn't appear that anybody replied to your post the first time so I apologize for that.  Since nobody did reply, this meant that nobody tested out your behavior and could have caught your bug.

With that said, I quickly tested out your scenario and my application didn't freeze after zooming in 10 times or even more. Now, I just pulled up one of the example programs, PlotWaveforms and tried that. Do you see the same freeze behavior with our examples?

Does the UI still repaint or do you start seeing a large "white" section as if the UI can't refresh?

Best Regards,

[OuaisBla]

I tested of the sample program without any modifications and it does the same thing. Once, I'll upgrade to 8.1.2, I'll test it too.

To reproduce the bug, I simply click on a small portion of the graph for 10 times or roughly a little bit more. Then the CPU goes to 100% and the apps freeze totally.

Kind regards and thks for your reply.

Jean

[OuaisBla]

On the previous post, by "clicking" I mean by Zooming using the mouse and the shift key at the same time.

Jean

[JonathanN]

Hi Jean,

Well I was finally able to reproduce what you are seeing. The issue seems to revolve around the visible grid lines. If I make the grid lines invisible, I don't see the freeze.  Try that out and see if you still see the freeze behavior.

Thanks for reporting this issue.

Best Regards,