MethodError: Cannot `convert` an object of type LibGEOS.GeometryCollection to an object of type LibGEOS.Polygon

[memeLordo]

Another error:

Error in callback:
MethodError: Cannot `convert` an object of type LibGEOS.GeometryCollection to an object of type LibGEOS.Polygon
The function `convert` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  convert(::Type{T}, ::T) where T
   @ Base Base.jl:126

Stacktrace:
  [1] setproperty!(x::Observable{LibGEOS.Polygon}, f::Symbol, v::LibGEOS.GeometryCollection)
    @ Base ./Base.jl:52
  [2] setindex!(observable::Observable, val::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:122
  [3] (::Observables.MapCallback)(value::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:436
  [4] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
  [5] invokelatest
    @ ./essentials.jl:1052 [inlined]
  [6] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
  [7] setindex!(observable::Observable, val::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123
  [8] (::Observables.MapCallback)(value::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:436
  [9] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
 [10] invokelatest
    @ ./essentials.jl:1052 [inlined]
 [11] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
 [12] setindex!(observable::Observable, val::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123
 [13] (::Observables.MapCallback)(value::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:436
 [14] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
 [15] invokelatest
    @ ./essentials.jl:1052 [inlined]
 [16] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
 [17] setindex!(observable::Observable, val::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123
 [18] (::Makie.var"#2024#2039"{Slider, Observable{Any}})(i::Int64, dragging::Bool)
    @ Makie ~/.julia/packages/Makie/ux0Te/src/makielayout/blocks/slider.jl:68
 [19] invokelatest(::Any, ::Any, ::Vararg{Any}; kwargs::@Kwargs{})
    @ Base ./essentials.jl:1055
 [20] invokelatest(::Any, ::Any, ::Vararg{Any})
    @ Base ./essentials.jl:1052
 [21] (::Observables.OnAny)(value::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:420
 [22] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
 [23] invokelatest
    @ ./essentials.jl:1052 [inlined]
 [24] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
 [25] setindex!(observable::Observable, val::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123
 [26] (::Makie.var"#2028#2043"{Slider, Observable{Float64}, Observable{Bool}, Observable{Int64}, Observable{Vector{Point{2, Float32}}}, Observable{Any}})(event::MouseEvent)
    @ Makie ~/.julia/packages/Makie/ux0Te/src/makielayout/blocks/slider.jl:116
 [27] (::Makie.var"#1501#1502"{Makie.var"#2028#2043"{Slider, Observable{Float64}, Observable{Bool}, Observable{Int64}, Observable{Vector{Point{2, Float32}}}, Observable{Any}}})(event::MouseEvent)
    @ Makie ~/.julia/packages/Makie/ux0Te/src/makielayout/mousestatemachine.jl:94
 [28] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
 [29] invokelatest
    @ ./essentials.jl:1052 [inlined]
 [30] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
 [31] setindex!
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123 [inlined]
 [32] (::Makie.var"#1543#1545"{Scene, Makie.var"#is_mouse_over_relevant_area#1542"{Scene, Observable{GeometryBasics.HyperRectangle{2, Float32}}}, Base.RefValue{Float64}, Base.RefValue{Bool}, Float64, Base.RefValue{Point{2, Float64}}, Base.RefValue{Bool}, Base.RefValue{Union{Nothing, Makie.Mouse.Button}}, Base.RefValue{Bool}, Base.RefValue{Point{2, Float32}}, Base.RefValue{Point{2, Float64}}, Base.RefValue{Makie.Mouse.Action}, Observable{MouseEvent}, Module})(mp::Tuple{Float64, Float64})
    @ Makie ~/.julia/packages/Makie/ux0Te/src/makielayout/mousestatemachine.jl:229
 [33] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
 [34] invokelatest
    @ ./essentials.jl:1052 [inlined]
 [35] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
 [36] setindex!(observable::Observable, val::Any)
    @ Observables ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123
 [37] (::GLMakie.MousePositionUpdater)(::Makie.TickState)
    @ GLMakie ~/.julia/packages/GLMakie/87u59/src/events.jl:6
 [38] #invokelatest#2
    @ ./essentials.jl:1055 [inlined]
 [39] invokelatest
    @ ./essentials.jl:1052 [inlined]
 [40] notify
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:206 [inlined]
 [41] setindex!
    @ ~/.julia/packages/Observables/YdEbO/src/Observables.jl:123 [inlined]
 [42] pollevents(screen::GLMakie.Screen{GLFW.Window}, frame_state::Makie.TickState)
    @ GLMakie ~/.julia/packages/GLMakie/87u59/src/screen.jl:547
 [43] on_demand_renderloop(screen::GLMakie.Screen{GLFW.Window})
    @ GLMakie ~/.julia/packages/GLMakie/87u59/src/screen.jl:1033
 [44] renderloop(screen::GLMakie.Screen{GLFW.Window})
    @ GLMakie ~/.julia/packages/GLMakie/87u59/src/screen.jl:1061
 [45] (::GLMakie.var"#79#80"{GLMakie.Screen{GLFW.Window}})()
    @ GLMakie ~/.julia/packages/GLMakie/87u59/src/screen.jl:922

[memeLordo]

Related to: #219

[memeLordo]

Somehow it bypasses error check:

∩(p1::LibGEOS.AbstractGeometry, p2::LibGEOS.AbstractGeometry) = let 
    if LibGEOS.intersects(p1, p2)
        try
            return LibGEOS.intersection(p1, p2)
        catch
            println("Error!")
        end
    end
    return LibGEOS.createEmptyPolygon()
end

polygon = lift(points) do points_
    points_::Vector{Vector{Float64}} = points_ 
    println(points_)
    points = [
        [0, 0],
        [0, max],
        [points_[1][1], max],
        points_[1],
        points_[2],
        [points_[2][1], 0],
        # [0, points_[2][2]],
        [0, 0]
    ]
    return LibGEOS.Polygon([points])
end

polygon2 = lift(polygon) do polygon_
    
    circle_ = let 
        points =[ 
            i + [5, 5] for i in [
                [0.0, 0.0],
                [0.0, 1.0],
                [1.0, 1.0],
                [1.0, 0.0],
                [0.0, 0.0]  # Close the ring (repeat first point)
                ]
            ]
        LibGEOS.Polygon([points])
    end
    
    return circle_ ∩ polygon_
end

scatter!(points, color = :red, markersize = 20, alpha=1)

limits!(ax, 0, 10, 0, 10)
poly!(ax, polygon)
poly!(ax, polygon2)

[memeLordo]

Already got it. There is only need to be used LibGEOS.getGeometries(...) function.
Example:

if res isa LibGEOS.Polygon
    # get polygon stuff goin'
elseif res isa LibGEOS.GeometryColection
    pol = LibGEOS.getGeometries(res)[1]
end

[memeLordo]

Needs a proper documentation for new incomers.