Getter function API instability

[wsphillips]

Getter functions aren't working correctly across all platforms using the current (implot ~v0.8) binaries (see #18), due to a bug with the wrapper function prototype in cimplot, which has already been fixed upstream. This means getter functions currently work only on Linux and segfault on other platforms. It should be resolved with the upgrade to the binaries in cimguipack_jll which uses the fixed wrappers.

[sairus7]

By the way, I've tried it on Ubuntu 20.04.1 LTS and had the same problem.

signal (11): Segmentation fault
in expression starting at none:0
unsafe_store! at ./pointer.jl:118 [inlined]
unsafe_store! at ./pointer.jl:118 [inlined]
SineWave at /home/gvg/.julia/dev/ImPlot/demo/implot_demo.jl:44
unknown function (ip: 0x7f6df168db41)
_Z7WrapperPvi at /home/gvg/.julia/artifacts/5b2b61e1b0721d0f69fa855d20f464a98f4df73f/lib/libcimplot.so (unknown line)
_ZN6ImPlot9PlotLineGEPKcPF11ImPlotPointPviES3_ii at /home/gvg/.julia/artifacts/5b2b61e1b0721d0f69fa855d20f464a98f4df73f/lib/libcimplot.so (unknown line)
PlotLineG at /home/gvg/.julia/dev/ImPlot/src/libcimplot.jl:1590
PlotLineG at /home/gvg/.julia/dev/ImPlot/src/libcimplot.jl:1590
unknown function (ip: 0x7f6df169f1c5)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2237 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2419
ShowDemoWindow at /home/gvg/.julia/dev/ImPlot/demo/implot_demo.jl:1203
#3 at /home/gvg/.julia/dev/ImPlot/demo/implot_demo.jl:1952 [inlined]
renderloop at /home/gvg/.julia/dev/ImPlot/demo/Renderer.jl:70
#4 at ./task.jl:411
unknown function (ip: 0x7f6df169d4bc)
_jl_invoke at /buildworker/worker/package_linux64/build/src/gf.c:2237 [inlined]
jl_apply_generic at /buildworker/worker/package_linux64/build/src/gf.c:2419
jl_apply at /buildworker/worker/package_linux64/build/src/julia.h:1703 [inlined]
start_task at /buildworker/worker/package_linux64/build/src/task.c:839
unknown function (ip: (nil))
Allocations: 20839517 (Pool: 20828136; Big: 11381); GC: 27
Segmentation fault (core dumped)

[wsphillips]

That's because in the last commit before merging #18 to main I revised it to how it "should be", based on what we found out (which does indeed segfault on Linux with that error) If you're curious, try checking out v0.20 from the registry and see if it still segfaults (there the demo should be the original and was working for me)

See: 071a29c

That usage (or very close to it) should work as expected using the binaries currently provided by LibCImGui.jl (once we make things compatible as intended)