Bug Report - The transparent display flag isn't reliably supported

[PycraftDeveloper]

Describe the bug
Since the switch from OpenGL to BGFX and the already flakey support for transparent displays with GLFW this feature either needs attention or removal as it does not behave reliably.

To Reproduce

import pmma

display = pmma.Display()
display.create((1280, 720), transparent=True)

while True:
    display.clear()

    display.continuous_refresh()

Expected behavior
A transparent window should appear showing the contents that would otherwise be behind it. Instead the window appears black, obscuring the content behind it.

Screenshots

Platform Information:

• What Operating System are you using? Windows
• What version of that Operating System is it? 11 25H2
• What GPU do you have? AMD RX 7700 XT
• Does your CPU support AVX in any way? AVX-2
• Did you use a pre-compiled version of PMMA or a custom build? Both
• Which version of PMMA are you using? PMMA 5.2

Do you have any thoughts on what could be causing the issue?
I believe the issue to be because of flaky window backend support, although more research is needed.

Additional context

PMMA (Info) - 20/10/2025 at 21:46:01.371 - PMMA logging initialized, log files are named: 'DD-MM-YYYY at HH-MM-SS.txt'.
PMMA (Info) - 20/10/2025 at 21:46:01.371 - Welcome to Python Multi-Media API (PMMA) version: 5.0.16
PMMA (Info) - 20/10/2025 at 21:46:01.371 - Please note that PMMA is currently in a developmental state, meaning that the API is subject to change - we are hoping to remove this warning and improve backwards compatibility in PMMA 6.
PMMA (Info) - 20/10/2025 at 21:46:01.371 - Your device is not running in power saving mode.
PMMA (Info) - 20/10/2025 at 21:46:01.371 - PMMA has detected that your system has AVX2 support and will automatically use it where applicable. AVX2 allows for up to 8 operations to be performed simultaneously on the CPU.
PMMA (Info) - 20/10/2025 at 21:46:01.372 - PMMA has been built with compatibility for the Python programming language!
You have specified that this window should be transparent. Please note that this isn't guaranteed and relies on the Operating System, GPU/drivers and device settings to be set correctly in order to work.
PMMA (Info) - 20/10/2025 at 21:46:01.751 - You are running on the Operating System: 'Windows'.
PMMA (Info) - 20/10/2025 at 21:46:01.751 - PMMA is using the 'Direct3D 11.0' backend for graphics.

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What happens next?
After you submit a bug report to us, we will react to the message to indicate we are reviewing your input. Then we will try and get back to you as soon as possible with an idea of when this issue might be resolved. We may also ask for more specific information before being able to fix the issue, we will respond to the issue with any questions and close the issue when it is resolved.

Urgency
There is no need to specify an urgency when it comes to bugs, we will prioritize bug fixes over anything else.

[PycraftDeveloper]

After reviewing this feature it does seem likely that the issue is related to Windows' Desktop Window Manager (DWM). There are DirectX and some API specific solutions, but none that wouldn't require significant or messy changes to PMMA's display logic. Ideally we don't want to remove this feature for those applications that do use it, so instead we will look into 'emulating the effect' and if that's not possible we will have no choice but to remove the feature.

[PycraftDeveloper]

OK, after reviewing this closer and understanding that not only is it a Windows issue, but also related to the GPU vendor, driver support and display backend (X11 and Wayland for example) it simply isn't possible to get this feature to work reliably and likely attempting to 'emulate the effect' would be just as much work to set-up, more reliable, but potentially less secure. We will remove support for transparent displays in PMMA 5.1 - sorry! We shall continually review this to see if we can re-add this mechanic in at a later date.