Makie embedding improvements

docs/src/_changelog.md

@@ -6,6 +6,14 @@ CurrentModule = CImGui
 This documents notable changes in CImGui.jl. The format is based on [Keep a
 Changelog](https://keepachangelog.com).
 
+## Unreleased
+
+### Changed
+- Modified [`MakieFigure`](@ref) to not rely on the `id` for its internal state
+  so that it's safe to call it on different figures with the same ID (not at
+  the same time of course). Also implemented [`delete_figure!()`](@ref) to allow
+  for cleaning up the internal state.
+
 ## [v6.2.0] - 2025-09-27
 
 ### Fixed

docs/src/api.md

@@ -17,5 +17,5 @@ imgui_version
 ```@autodocs
 Modules = [CImGui]
 Order   = [:constant, :function, :type]
-Filter  = t -> nameof(t) ∉ (:imgui_version, :render, :set_backend, :MakieFigure)
+Filter  = t -> nameof(t) ∉ (:imgui_version, :render, :set_backend, :MakieFigure, :delete_figure!)
 ```

docs/src/makie.md

@@ -39,4 +39,5 @@ None of this is thread-safe. Here's what you can and can't do:
 
 ```@docs
 MakieFigure
+delete_figure!
 ```

examples/makie_demo.jl

@@ -74,7 +74,13 @@ function makie_demo(; engine=nothing, spawn=1)
         @c ig.Checkbox("Stream data", &stream_data)
 
         if stream_data && isnothing(data_task)
-            data_task = errormonitor(Threads.@spawn live_data(data))
+            # We have to launch the task on the same thread because it modifies
+            # observables, which will end up modifying thread-unsafe OpenGL
+            # things. Hence we use @async instead of Threads.@spawn. If you're
+            # plotting live data being read from a different thread, consider
+            # putting all the updates into a channel that your render function
+            # empties within the render loop.
+            data_task = errormonitor(@async live_data(data))
         end
 
         ig.MakieFigure("plot", f; auto_resize_x, auto_resize_y, tooltip, stats)

ext/MakieIntegration.jl

@@ -6,6 +6,7 @@ import Statistics: mean, std
 import CImGui as ig
 import ModernGL as gl
 import GLFW
+
 import GLMakie
 import GLMakie.Makie as Makie
 
@@ -30,27 +31,27 @@ mutable struct ImMakieFigure
     end
 end
 
-const makie_context = Dict{ig.ImGuiID, ImMakieFigure}()
+const makie_context = IdDict{GLMakie.Figure, ImMakieFigure}()
 
 function destroy_context()
-    for imfigure in values(makie_context)
-        empty!(imfigure.figure)
+    for f in keys(makie_context)
+        empty!(f)
     end
 
     empty!(makie_context)
 end
 
 Base.isopen(window::ImMakieWindow) = isopen(window.glfw_window)
 GLMakie.framebuffer_size(window::ImMakieWindow) = GLMakie.framebuffer_size(window.glfw_window)
-GLMakie.scale_factor(window::ImMakieWindow) = GLMakie.scale_factor(window.glfw_window)
-GLMakie.was_destroyed(window::ImMakieWindow) = GLMakie.was_destroyed(window.glfw_window)
+GLMakie.scale_factor(window::ImMakieWindow)::Float32 = GLMakie.scale_factor(window.glfw_window)
+GLMakie.was_destroyed(window::ImMakieWindow)::Bool = GLMakie.was_destroyed(window.glfw_window)
 GLMakie.reopen!(x::GLMakie.Screen{ImMakieWindow}) = x
 GLMakie.destroy!(::ImMakieWindow) = nothing
 GLMakie.set_screen_visibility!(::GLMakie.Screen{ImMakieWindow}, ::Bool) = nothing
 
 # ShaderAbstractions support
 GLMakie.ShaderAbstractions.native_switch_context!(x::ImMakieWindow) = GLFW.MakeContextCurrent(x.glfw_window)
-GLMakie.ShaderAbstractions.native_context_alive(x::ImMakieWindow) = GLFW.is_initialized() && x.glfw_window != C_NULL
+GLMakie.ShaderAbstractions.native_context_alive(x::ImMakieWindow)::Bool = GLFW.is_initialized() && x.glfw_window != C_NULL
 
 # This is called by GLMakie.display() to set up connections to GLFW for
 # mouse/keyboard events etc. We disable it explicitly because we deliver the
@@ -129,24 +130,29 @@ function draw_popup(axis)
     end
 end
 
+function ig.delete_figure!(f::GLMakie.Figure)
+    delete!(makie_context, f)
+    return nothing
+end
+
 function ig.MakieFigure(title_id::String, f::GLMakie.Figure;
                         auto_resize_x=true, auto_resize_y=false,
                         tooltip=true, stats=false)
     ig.PushID(title_id)
     id = ig.GetID(title_id)
 
-    if !haskey(makie_context, id)
+    if !haskey(makie_context, f)
         window = ig.current_window()
         makie_window = ImMakieWindow(window)
         screen = GLMakie.Screen(; window=makie_window, start_renderloop=false)
 
-        makie_context[id] = ImMakieFigure(f, screen)
+        makie_context[f] = ImMakieFigure(f, screen)
         scene = Makie.get_scene(f)
         scene.events.window_open[] = true
         display(screen, f)
     end
 
-    imfigure = makie_context[id]
+    imfigure = makie_context[f]
     scene = Makie.get_scene(f)
 
     region_avail = ig.GetContentRegionAvail()

src/CImGui.jl

@@ -93,8 +93,8 @@ function pintask!(task::Task, tid::Integer)
     end
 end
 
-# This is implemented by the MakieIntegration extension but we document it here
-# so that we don't have to install GLMakie to build the docs.
+# The Makie functions are implemented by the MakieIntegration extension but we
+# document it here so that we don't have to install GLMakie to build the docs.
 """
     MakieFigure(id::String, f::GLMakie.Figure;
                 auto_resize_x=true, auto_resize_y=false,
@@ -137,6 +137,18 @@ Known issues:
 """
 function MakieFigure end
 
+"""
+    delete_figure!(f::GLMakie.Figure)
+
+Delete a figure from the internal CImGui state.
+
+When [`MakieFigure()`](@ref) is called it will create some internal state for
+the figure. If your application ever 'deletes' a figure (i.e. hiding it so it
+shouldn't be displayed again) then you should call this function to clear the
+internal state and allow the figure to be GC'd.
+"""
+function delete_figure! end
+
 ## Backends
 
 const _exit_handlers = Function[]
@@ -272,9 +284,10 @@ function __init__()
             if isempty(methods(exc.f))
                 print(io, "\nrender() cannot be called yet. You must load the packages for supported backends, e.g. `import ModernGL, GLFW` for the GLFW/OpenGL3 backend.")
             end
-        elseif exc.f === MakieFigure
+        elseif exc.f === MakieFigure || exc.f === delete_figure!
+            name = nameof(exc.f)
             if isempty(methods(exc.f))
-                print(io, "\nMakieFigure() cannot be called yet, you must load GLMakie with e.g. `import GLMakie`.")
+                print(io, "\n$(name)() cannot be called yet, you must load GLMakie with e.g. `import GLMakie`.")
             end
         end
     end