Modals backgrounds are transparent

[bertrandboudaud]

Dear ImGui team,

When running ShowDemoWindow, the modal dialog boxes background is transparent.

While the window on the background should be "transparent", and the modal opaque, like previously:

I tried different commits in the master, and it seems the difference comes from this commit:
23ef6c149ea14d8a5981cfec02994dcd7d21d09e

(I detected first the issue on the Docking branch)

Dear ImGui 1.86 WIP (18514)
--------------------------------
sizeof(size_t): 8, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=199711
define: _WIN32
define: _WIN64
define: _MSC_VER=1929
define: _MSVC_LANG=201703
--------------------------------
io.BackendPlatformName: imgui_impl_sdl
io.BackendRendererName: imgui_impl_opengl2
io.ConfigFlags: 0x00000000
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigMemoryCompactTimer = 60.0
io.BackendFlags: 0x00000006
 HasMouseCursors
 HasSetMousePos
--------------------------------
io.Fonts: 1 fonts, Flags: 0x00000000, TexSize: 512,64
io.DisplaySize: 1280.00,720.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 8.00,8.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 0.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00

[ocornut]

Hello,
I think this was already already?
Only WIP versions from that commit (4 days ago) to ~yesterday should be affected.
At least I cannot repro on neither branches now.

[bertrandboudaud]

Hello,

I am still getting the problem with the latest commit on master.

So if you cannot reproduce it, could be a setup issue on our side (I am running the demo inside our application, which I had however made as much as possible empty, but still there can be some code from us that leads to that defect).

We can close that and I will come back if I can identify something that would need your feedback.
thanks,

[ocornut]

We touched this code only a few days ago so it is likely we added a bug. One of the thing it does may have effects on some / not all backends, i’ll be testing this with your backend.

[ocornut]

Interestingly, this was a bug in the OpenGL2 backend: c80e8b9
The bug never had any visible impact before the change we just made to dimming code.
You can update or cherry-pick that commit to get the fix!