LabVIEW
Issue with Custom Needle Image Rotation on Speedometer Gauge
When I import my custom image (originally 12x150 px) onto the needle part in the Control Editor, the needle moves along the gauge arc but stays vertically static—it doesn’t rotate to point at the numbers.
I followed the common advice of placing the needle on a transparent square canvas (300x300 px) with the base of the needle positioned at the exact center (150, 150) to create a pivot point.
I want the custom image to behave like a standard vector needle where the base stays fixed at the gauge center and the tip rotates to indicate the values.
Hi Abhishek,
@Abhishek_Dass wrote:
So if you have any suggestion for this problem it will be helpful for me.
Do what tst suggested to you…
Once I had a similar problem and I ended up using a XYgraph:
- I placed the image of a (car) speedometer as background image
- I used a plot with a thick line as needle.
- I adjusted the XY scales so the needle was moving in the correct positions.
(You can hide all the functionality inside a XControl…)
@Abhishek_Dass wrote:
Hi tst,
Thank you for the suggestion. I have one more question: is it possible to create a customized line-type PICC for needle that I want ? I am relatively new to LabVIEW and still gaining experience, so my current knowledge is limited. I am learning primarily through hands-on project work.
Not really. The PICC format is LabVIEW proprietary. It is similar to the Macintosh PICT format but not the same, since NI had to create their own routines anyhow for non MacOS versions of LabVIEW. There is AFAIK no editor outside of NI that could create the necessary resource format and I found never enough motivation to try to reverse engineer such an archaic feature.
It is also quite unlikely that NI would even spend any effort to create new PICCs nowadays. The software routines to handle them are there, but they were developed 35 years ago at a time when the LabVIEW developers were fighting for virtually every byte that could be saved. That code is accordingly arcane, difficult to maintain and almost impossible to modify by modern software developers who are used to very different architectural and structural designs. The Custom Control Editor to manipulate these controls is quirky and has strange artefacts when dealing with such PICC (and other) resources.
And yes, LabVIEW also supports WMF and EMF formats which are the Windows equivalent of PICT. However WMF is highly limited and has many quirks that were interpreted differently by different software packages and even between different Windows versions. EMF was an attempt to standardize it and extend the format to allow for coordinates beyond 16 bit size but still had quite some quirks and there were only very few applications supporting the use of that format. The Windows GDI still supports it, but due to its rare use I would not be surprised if it has bitrotted since. I don't believe that LabVIEW tries to convert EMF to PICC in any way, so if you use EMF resources in your controls or frontpanel they usually end up as empty rectangles on non-Windows systems. And you have similar quirks in the Control Editor with EMF resources as you have with PICC or PICT resources when trying to manipulate them in any way.
@rolfk wrote:
@Abhishek_Dass wrote:
Hi tst,
Thank you for the suggestion. I have one more question: is it possible to create a customized line-type PICC for needle that I want ? I am relatively new to LabVIEW and still gaining experience, so my current knowledge is limited. I am learning primarily through hands-on project work.Not really. The PICC format is LabVIEW proprietary. It is similar to the Macintosh PICT format but not the same, since NI had to create their own routines anyhow for non MacOS versions of LabVIEW. There is AFAIK no editor outside of NI that could create the necessary resource format and I found never enough motivation to try to reverse engineer such an archaic feature.
It is also quite unlikely that NI would even spend any effort to create new PICCs nowadays. The software routines to handle them are there, but they were developed 35 years ago at a time when the LabVIEW developers were fighting for virtually every byte that could be saved. That code is accordingly arcane, difficult to maintain and almost impossible to modify by modern software developers who are used to very different architectural and structural designs. The Custom Control Editor to manipulate these controls is quirky and has strange artefacts when dealing with such PICC (and other) resources.
And yes, LabVIEW also supports WMF and EMF formats which are the Windows equivalent of PICT. However WMF is highly limited and has many quirks that were interpreted differently by different software packages and even between different Windows versions. EMF was an attempt to standardize it and extend the format to allow for coordinates beyond 16 bit size but still had quite some quirks and there were only very few applications supporting the use of that format. The Windows GDI still supports it, but due to its rare use I would not be surprised if it has bitrotted since. I don't believe that LabVIEW tries to convert EMF to PICC in any way, so if you use EMF resources in your controls or frontpanel they usually end up as empty rectangles on non-Windows systems. And you have similar quirks in the Control Editor with EMF resources as you have with PICC or PICT resources when trying to manipulate them in any way.
You are such a wealth of knowledge. Never EVER leave this forum!
