widget_gallery example crash on Windows [scroll, resize]

[Eteokles]

On Windows (works well on Linux)

error: process didn't exit successfully: '...\druid-master\target\debug\examples\widget_gallery.exe' (exit code: 0xc000041d)

To reproduce the issue, just scroll down to the end then try to resize the window. I reproduced the error on two different computer.

[raphlinus]

Confirm. Looking at the crash, it's in the draw_bitmap method. The bitmap argument is not a null pointer, but I wasn't able to validate it beyond that. The error code maps to STATUS_FATAL_USER_CALLBACK_EXCEPTION, which is also odd, because I don't see a user callback of any kind here.

This is somewhat mysterious. I haven't dug deeper, but wanted to post my results.

It's possible this is caused by creating the image resource in a DXGI DeviceContext, but switching to a hwnd render context during resize. If so, I can think of ways to fix this, but we should confirm.

[Eteokles]

Didn't know if it's can help but in debug, i got this:

D2D DEBUG ERROR - An operation failed because a device-dependent resource is associated with the wrong ID2D1Device (resource domain).
ERROR [druid_shell::platform::windows::window] EndDraw error: hresult 88990015
D2D DEBUG WARNING - A Draw call by a render target failed [88990015]. Tags [0x0, 0x0].

last function called in druid is : paint in widget/image.rs

[derekdreery]

I shall have a look at this. Edit: I'm not a super expert on D2D so it might be best looked at by someone else.

[raphlinus]

The simpler_d2d branch appears to fix this, so I think the approach is to get that landed.