Multiple Contexts about cimgui.jl HOT 5 CLOSED

UPDATE:

Now the master branch supports multi-viewport and this multiple contexts support is being removed since it's not recommended to use Dear ImGui in this way. Also, see #52.

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These global GLFW/OpenGL states are holding temporarily only for rendering purpose. They're not ImGui states. Almost all of them are refreshed in every rendering loop when calling:

ImGui_ImplOpenGL3_NewFrame()
ImGui_ImplGlfw_NewFrame()

except g_Window and g_FontTexture. So the hot-fix would be to remove the optimization trick g_FontTexture == 0 used in this line:

and make ImGui_ImplGlfw_NewFrame() aware of current GLFW window context:

function ImGui_ImplGlfw_NewFrame(window)
    global g_Time
    global g_Window = window

then this modified example will work: https://gist.github.com/Gnimuc/b9308bb8ed0a81b4fe1e76d706837f3d

from cimgui.jl.

Thank you for the example!

except g_Window and g_FontTexture

nice.

I am still experiencing some issues with that fix, that seem to be related to the event handling: for example, in your code multicontext.jl I sometimes cannot close window1 and only window2 and sometimes the other way around.

Also it seems that currently there is no possiblity to manage the callbacks manually via

ImGui_ImplGlfw_MouseButtonCallback
ImGui_ImplGlfw_ScrollCallback
ImGui_ImplGlfw_KeyCallback
ImGui_ImplGlfw_KeyCallback

which might be of interest also for single multiple contexts.

regards,

from cimgui.jl.

That's because the script didn't destory GLFW windows instance in the rendering loop: https://gist.github.com/Gnimuc/b9308bb8ed0a81b4fe1e76d706837f3d#file-multicontext-jl-L118-L123
This can be fixed by something like:

# in rendering loop
GLFW.PollEvents()
if GLFW.WindowShouldClose(window1)
    CImGui.DestroyContext(ctx1)
    GLFW.DestroyWindow(window1)
end

As for the callbacks, I didn't implement that because I thought they were not very useful in that one can always overload these callbacks before GLFW initialization. But this feature is very simple to implement by following:
https://github.com/ocornut/imgui/blob/d9568c717de8ec53445bad00be73133f1a110317/examples/imgui_impl_glfw.cpp#L82-L83

so feel free to submit a PR. Or I'll fix it this weekend.

from cimgui.jl.

Indeed, I got it working in the way you proposed; the "issues" were just in my implementation. Could resolve them now

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