Fallback renderer

[SubZ69]

Hello,

I'm using slint = "1.13.1" in my Cargo.toml, which should enable both renderer-femtovg and renderer-software by default.?

However, on Windows 11 without OpenGL support, my application crashes with "Failed to initialize OpenGL Driver" instead of falling back to the software renderer.

Is this expected behavior, or am I missing something?

Setting SLINT_BACKEND=winit-software manually works fine.

[tronical]

Hi! At the moment that’s the expected behavior when the OpenGL driver is insufficient. Unfortunately we can’t do a gentle fallback. See also #8708 . We plan on changing defaults in a future release. Meanwhile you can activate the renderer-femtovg-wgpu feature to address your issue, as long as you don’t need to support running on machines that only support GLES.

[SubZ69]

Thanks for the quick response!

I tested renderer-femtovg-wgpu, but it panics on some Intel HD Graphics systems. Since my app needs to work reliably in production, I'm going with renderer-skia for now, which works well on all machines I've tested.

Thanks for your hard work on Slint! :)

[tronical]

Oh, what’s the panic message you received?

[SubZ69]

renderer-femtovg-wgpu works well with an Intel Iris Xe, but on a laptop with an Intel HD 530 GPU, I get this panic:

thread 'main' panicked at C:\Users\subzz.cargo\registry\src\index.crates.io-1949cf8c6b5b557f\ash-0.38.0+1.3.281\src\extensions_generated.rs:2361:29:
Unable to load cmd_begin_debug_utils_label_ext
stack backtrace:
0: 0x7ff6cc9e3412 -
1: 0x7ff6cc9fabbb -
2: 0x7ff6cc9dff77 -
3: 0x7ff6cc9e3255 -
4: 0x7ff6cc9e5e3c -
5: 0x7ff6cc9e5bd2 -
6: 0x7ff6cc9e6a1f -
7: 0x7ff6cc9e6782 -
8: 0x7ff6cc9e3b1f -
9: 0x7ff6cc9e63be -
10: 0x7ff6cca7bc01 -
11: 0x7ff6cca420b4 -
12: 0x7ff6cc4eff1d -
13: 0x7ff6cc4eef30 -
14: 0x7ff6cc37330c -
15: 0x7ff6cc39be38 -
16: 0x7ff6cc39ae59 -
17: 0x7ff6cc3851a4 -
18: 0x7ff6cc3a1968 -
19: 0x7ff6cc3c755e -
20: 0x7ff6cc290bc4 -
21: 0x7ff6cc05b937 -
22: 0x7ff6cc058943 -
23: 0x7ff6cbfc6ec2 -
24: 0x7ff6cbfc47f8 -
25: 0x7ff6cbfc63dc -
26: 0x7ff6cc013beb -
27: 0x7ff6cc0140ed -
28: 0x7ff6cbfe3514 -
29: 0x7ff6cc0305d2 -
30: 0x7ff6cc016aea -
31: 0x7ff6cbfebab8 -
32: 0x7ff6cc096cc0 -
33: 0x7ff6cc083f9c -
34: 0x7ff6cc0989ff -
35: 0x7ff6cc0965f8 -
36: 0x7ff6cc083af5 -
37: 0x7ff6cc07ea53 -
38: 0x7ff83cb921e4 - CallWindowProcW
39: 0x7ff83cb91d7b - CallWindowProcW
40: 0x7ff82a76a85e - glDebugEntry
41: 0x7ff83cb921e4 - CallWindowProcW
42: 0x7ff83cb91ed7 - CallWindowProcW
43: 0x7ff83cba2a53 - MapWindowPoints
44: 0x7ff83f149c34 - KiUserCallbackDispatcher
45: 0x7ff83b531764 - NtUserDispatchMessage
46: 0x7ff83cb91baf - DispatchMessageW
47: 0x7ff6cbfe082c -
48: 0x7ff6cbfe0703 -
49: 0x7ff6cc0196f6 -
50: 0x7ff6cbff553e -
51: 0x7ff6cbfbfe73 -
52: 0x7ff6cbfc1263 -
53: 0x7ff6cbd55009 -
54: 0x7ff6cbf578c0 -
55: 0x7ff6cbdd1b46 -
56: 0x7ff6cbbfbee0 -
57: 0x7ff6cc9d8bfc -
58: 0x7ff6cbf57e4c -
59: 0x7ff6cca02ad0 -
60: 0x7ff83ed784d4 - BaseThreadInitThunk
61: 0x7ff83f0f1a11 - RtlUserThreadStart

thread 'main' panicked at library\core\src\panicking.rs:226:5:
panic in a function that cannot unwind
stack backtrace:
0: 0x7ff6cc9e3412 -
1: 0x7ff6cc9fabbb -
2: 0x7ff6cc9dff77 -
3: 0x7ff6cc9e3255 -
4: 0x7ff6cc9e5e3c -
5: 0x7ff6cc9e5bd2 -
6: 0x7ff6cc9e6a1f -
7: 0x7ff6cc9e6782 -
8: 0x7ff6cc9e3b1f -
9: 0x7ff6cc9e63be -
10: 0x7ff6cca7bc55 -
11: 0x7ff6cca7bd03 -
12: 0x7ff6cca7be8b -
13: 0x7ff6cca420d3 -
14: 0x7ff82be11030 -
15: 0x7ff82be14388 - is_exception_typeof
16: 0x7ff83f14a173 - RtlCaptureContext
17: 0x7ff6cca420b4 -
18: 0x7ff6cc4eff1d -
19: 0x7ff6cc4eef30 -
20: 0x7ff6cc37330c -
21: 0x7ff6cc39be38 -
22: 0x7ff6cc39ae59 -
23: 0x7ff6cc3851a4 -
24: 0x7ff6cc3a1968 -
25: 0x7ff6cc3c755e -
26: 0x7ff6cc290bc4 -
27: 0x7ff6cc05b937 -
28: 0x7ff6cc058943 -
29: 0x7ff6cbfc6ec2 -
30: 0x7ff6cbfc47f8 -
31: 0x7ff6cbfc63dc -
32: 0x7ff6cc013beb -
33: 0x7ff6cc0140ed -
34: 0x7ff6cbfe3514 -
35: 0x7ff6cc0305d2 -
36: 0x7ff6cc016aea -
37: 0x7ff6cbfebab8 -
38: 0x7ff6cc096cc0 -
39: 0x7ff6cc083f9c -
40: 0x7ff6cc0989ff -
41: 0x7ff6cc0965f8 -
42: 0x7ff6cc083af5 -
43: 0x7ff6cc07ea53 -
44: 0x7ff83cb921e4 - CallWindowProcW
45: 0x7ff83cb91d7b - CallWindowProcW
46: 0x7ff82a76a85e - glDebugEntry
47: 0x7ff83cb921e4 - CallWindowProcW
48: 0x7ff83cb91ed7 - CallWindowProcW
49: 0x7ff83cba2a53 - MapWindowPoints
50: 0x7ff83f149c34 - KiUserCallbackDispatcher
51: 0x7ff83b531764 - NtUserDispatchMessage
52: 0x7ff83cb91baf - DispatchMessageW
53: 0x7ff6cbfe082c -
54: 0x7ff6cbfe0703 -
55: 0x7ff6cc0196f6 -
56: 0x7ff6cbff553e -
57: 0x7ff6cbfbfe73 -
58: 0x7ff6cbfc1263 -
59: 0x7ff6cbd55009 -
60: 0x7ff6cbf578c0 -
61: 0x7ff6cbdd1b46 -
62: 0x7ff6cbbfbee0 -
63: 0x7ff6cc9d8bfc -
64: 0x7ff6cbf57e4c -
65: 0x7ff6cca02ad0 -
66: 0x7ff83ed784d4 - BaseThreadInitThunk
67: 0x7ff83f0f1a11 - RtlUserThreadStart
thread caused non-unwinding panic. aborting.

When I force WGPU_BACKEND=dx12 no panic and everything works fine.

[tronical]

Ah, I've heard about this before. I think that problem doesn't happen in release builds though. Disabling the Vulkan backend on Windows is indeed a valid workaround.