Ye can’t be rotating yer images with alpha

Nick Post mentioned in a comment that he's had problems trying to get images in the 2D panels that have an alpha channel to rotate.  An astute observation!  I had to try this out myself with an XML gauge to see why it doesn't work, and sure enough, this code path simply isn't implemented.  In a debug build of flight sim (which I run most of the time) I get an assert which alerts me to this fact.  Note that you can successfully shift an image element that has alpha; the code paths diverge significantly for shifts vs. rotations.  Unfortunately, I don't see any way to work around this issue in FS9, but a bug has been logged for future reference.

I haven't tried using an image with alpha in a C-style gauge yet, but based on the code I see, it looks it shouldn't work either.

Thanks for pointing this out, Nick.

Comments (3)

  1. Lefteris Kalamaras, PMDG says:

    Hey Susan-

    you say you’re running a debug build of flight sim most of the time… Can you give us a comparison of frame rates, between release and debug builds on your PC? (I’m always interested, as when I run debug builds of our app, it’s not that much different)…

  2. Nick Pike says:

    He, he, this blog could become a full time job.

    1) An explanation of Formatted text would be really useful, again not covered in the SDK’s. This is a very useful feature.

    2) In the Spirit of St Louis panel, the periscope gauge has the line,

    <CustomDraw Name="fs9view:view" X="84" Y="77" Zoom="1.0" Pitch="0" Bank="0" Heading="0" OffsetUp="1" OffsetForward="1"> The pitch, bank and heading do not work. Also the periscope view does not work in VC view.

    3) I have written 3 tutorials on XML programming. I thought you might like to take a look. On the Tutorials page at I intended to write more but it’s finding the time. I’d like to write one on Formatted text, but I have a lot to learn here.

    4) I’m not being funny, and please do not take this the wrong way, but I am interested in knowing why the SDK’s are a bit ‘thin’ on information. We can achieve so much with FS, and it’s a terrific piece of software, yet the SDK’s only cover a proportion of the possibilities. It’s also interesting that the default aicraft are somewhat ‘simple’, again considering the features available.

    5) …and finally (you’ll be glad to hear) the effects SDK could be more forthcoming. Again, a feature set that can bring FS to life, yet fx files are still a mystery to most.

    Hope I haven’t taken up too much of your time,



  3. susan says:

    Nice work on the tutorials, Nick. To be honest, I haven’t read through all 5 million pages of .pdf’s that you’ve written… yet. It looks like I’ll have something to read on my bus ride home!

    Yes, you are right about the pitch/bank/heading not being implemented. And yes, the VC version is a bit of a hoax, really, because we can’t use the periscope from the 2D panel in the VC. But it does let you experience the limited view capabilities that Lindberg had to some extent at least!

    Yes, the SDK is thin (downright anorexic, really) on the documentation of XML gauge development stuff. I’ll see if I can’t help rectify that in the future.

    I have nothing to do with the effects system whatsoever, so, um, I’ll pass the message along to those guys. 🙂

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