LineAxis: add arbitrary {x,y}labelrotation

[t-bltg]

Fix #1187.
Fix #2222.

Description

As discussed with @jkrumbiegel on discord, add the ability to rotate axis labels:

julia> using CairoMakie
julia> fap = lines(0..2π, sin; axis = (; xlabel = "x", ylabel = "y", ylabelrotation = 0))
julia> save("sin.png", fap)

Any comments on adding docs about this (where should this go ?) or tests (do you want static tests or new ref images maybe ?) would be appreciated.

TODO:

• handle alignements

Type of change

Delete options that do not apply:

• New feature (non-breaking change which adds functionality)

Checklist

• Added an entry in NEWS.md (for new features and breaking changes)
• Added or changed relevant sections in the documentation
• Added unit tests for new algorithms, conversion methods, etc.
• Added reference image tests for new plotting functions, recipes, visual options, etc.

[jkrumbiegel]

A good reference test would have two steps

• an Axis with long x and y labels in default position (so you can really see the effect of rotation and alignment, and the visual differ picks up changes)
• the same axis, now with ax.xlabelrotation = ...; ax.ylabelrotation = ... to check if the observables update correctly and if the layout adjusts accordingly.
  You can use a stepper for this like in this example https://github.com/MakieOrg/Makie.jl/blob/master/ReferenceTests/src/tests/examples2d.jl#L237-L272

[fatteneder]

Closes #2222

[jkrumbiegel]

And it seems the LineAxis attributes also need a labelrotation default if I look at the failing Makie CI. Maybe you were talking about that on discord and I misunderstood what you meant.

[t-bltg]

Yeah, I think I need to add a labelrotation to the @Block Colorbar.

[t-bltg]

For the alignements, I've reused (and renamed) the calculate_real_ticklabel_align routine, but it was implemented for discrete rotation values, so it's not very suited to arbitrary rotation values.

Would it be acceptable to use sin(rot) and cos(rot) instead ?

[jkrumbiegel]

Those functions are just meant for ticklabels which have to be aligned sensibly relative to the tick marks, and this behavior should be reasonably automatic given the rotation angle.

For the axis labels, an alignment of (:center, :center) should always work, only the distance from the axis must be computed accordingly (using the text's boundingbox).

[t-bltg]

So I've got this simple example.

julia> N = 18  # number of rotations
julia> fig, ax, _ = scatter(0:1; axis = (; xlabel = "a nice and long x label for this axis", ylabel = "a nice and long y label for this axis"))
julia> record(fig, "rot.gif") do io
        for rot in LinRange(0, 2π, N)
            ax.xlabelrotation[] = rot
            ax.ylabelrotation[] = rot
            recordframe!(io)
        end
    end

Regarding the test I have a few questions:

• what is a Stepper and how is it used in the tests ? why a single Makie.step!(st) ?
• what do we really want in terms of alignment ?

[jkrumbiegel]

Ok you can see in your example how the layout does not react to the different space taken up by the rotating labels. I would make the alignment behave like Label does when you set rotation on it, treat the whole thing like it takes up a rectangular box around the center of which it rotates. That's why I said align = (:center, :center) and that the anchor position has to be adjusted given the boundingbox width (for y label) or height (for x label).

[t-bltg]

How do I draw text bounding boxes again ?
I have an earlier snippet here but it does not work in this case:

foreach(Any, fig.layout) do l
  wireframe!(fig.scene, l.layoutobservables.suggestedbbox[])
end

[t-bltg]

If the alignment is set to (:center, :center), where is the code that deals with anchoring ?

[jkrumbiegel]

By anchor I just mean the point at which the text is plotted. This is not the same anymore as it was before your PR, it must be shifted outwards by half the boundingbox.

And I think it's something like wireframe!(scene, boundingbox(textobject))

[t-bltg]

How can I access the axis decorations (for accessing labeltext) ? I mean the decorations dict is filled, but doesn't seem stored somewhere.

[jkrumbiegel]

Could be that this dict is just a remnant at this point, do you need it? The LineAxis just needs to communicate its protrusion value outwards, so at least the Axis shouldn't need access. Or is this just for debugging?

[t-bltg]

I though so:

Makie.jl/src/makielayout/lineaxis.jl

Line 257 in 5de2b6b

decorations = Dict{Symbol, Any}()

, just for debugging bounding boxes. I will move forward without it then.

[jkrumbiegel]

I was mostly using it for debugging as well at the time, must have dropped out of use without me noticing.

[t-bltg]

I doesn't seem possible to know the textlabel boundingbox beforehand right ?
I think I have to first create the textlabel, and then shift it according to the given rotation ?

[t-bltg]

Probably more effort needed (how can we trigger viewport update ? notify(...what ?...), but it starts to work:

EDIT: how can I lower the gif fps using record ? ==> more frames for now.

[t-bltg]

I've minimized the changes and removed unrelated modifications, but the WGLMakie ci error still persists.
The error is related to the Colorbar block, but I fail to see the link with the camera.

I am a bit clueless here ...

[t-bltg]

I tried to reproduce locally using WGLMakie, and got a slightly different error, but still occurring when setting the Colorbar :

using JSServe, Markdown, WGLMakie
Page(exportable=true, offline=true)
WGLMakie.activate!()
fig, ax, plot = scatter(0:1)
Colorbar(fig[1, 2]; label = "vertical cbar")
display(fig)

ERROR: TypeError: scene is undefined
Stacktrace:
  [1] error(s::String)
    @ Base ./error.jl:35
  [2] evaljs_value(session::Session, js::JSServe.JSCode; error_on_closed::Bool, time_out::Float64)
    @ JSServe ~/.julia/packages/JSServe/kIK9q/src/session.jl:238
  [3] evaljs_value
    @ ~/.julia/packages/JSServe/kIK9q/src/session.jl:206 [inlined]
  [4] insert!(td::WGLMakie.ThreeDisplay, scene::Scene, plot::Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ WGLMakie ~/.julia/packages/WGLMakie/L5URO/src/three_plot.jl:24
  [5] insert!(td::WGLMakie.Screen, scene::Scene, plot::Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ WGLMakie ~/.julia/packages/WGLMakie/L5URO/src/display.jl:173
  [6] push!(scene::Scene, plot::Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ Makie [...]/Makie.jl/src/scenes.jl:409
  [7] plot!(scene::Scene, P::Type{Poly{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}}}, attributes::Attributes, input::Tuple{Observable{Vector{GeometryBasics.HyperRectangle{2, Float32}}}}, args::Observable{Tuple{Vector{GeometryBasics.HyperRectangle{2, Float32}}}})
    @ Makie [...]/Makie.jl/src/interfaces.jl:422
  [8] plot!(scene::Scene, P::Type{Poly}, attributes::Attributes, args::Observable{Vector{GeometryBasics.HyperRectangle{2, Float32}}}; kw_attributes::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Makie [...]/Makie.jl/src/interfaces.jl:336
  [9] plot!
    @ [...]/Makie.jl/src/interfaces.jl:303 [inlined]
 [10] #plot!#165
    @ [...]/Makie.jl/src/interfaces.jl:287 [inlined]
 [11] poly!(::Scene, ::Vararg{Any}; attributes::Base.Pairs{Symbol, Any, Tuple{Symbol, Symbol, Symbol}, NamedTuple{(:color, :visible, :inspectable), Tuple{Observable{Vector{ColorTypes.RGBA{Float64}}}, Observable{Bool}, Bool}}})
    @ MakieCore [...]/Makie.jl/MakieCore/src/recipes.jl:38
 [12] initialize_block!(cb::Colorbar)
    @ Makie [...]/Makie.jl/src/makielayout/blocks/colorbar.jl:197
 [13] _block(::Type{Colorbar}, ::Figure; bbox::Nothing, kwargs::Base.Pairs{Symbol, Any, Tuple{Symbol, Symbol}, NamedTuple{(:label, :labelrotation), Tuple{String, Int64}}})
    @ Makie [...]/Makie.jl/src/makielayout/blocks.jl:408
 [14] _block(::Type{Colorbar}, ::GridPosition; kwargs::Base.Pairs{Symbol, Any, Tuple{Symbol, Symbol}, NamedTuple{(:label, :labelrotation), Tuple{String, Int64}}})
    @ Makie [...]/Makie.jl/src/makielayout/blocks.jl:294
 [15] #_#1077
    @ [...]/Makie.jl/src/makielayout/blocks.jl:279 [inlined]
 [16] top-level scope
    @ REPL[21]:1
 [17] eval
    @ ./boot.jl:368 [inlined]
 [18] eval_user_input(ast::Any, backend::REPL.REPLBackend)
    @ REPL ~/share/julia/stdlib/v1.8/REPL/src/REPL.jl:151
 [19] repl_backend_loop(backend::REPL.REPLBackend)
    @ REPL ~/share/julia/stdlib/v1.8/REPL/src/REPL.jl:247
 [20] start_repl_backend(backend::REPL.REPLBackend, consumer::Any)
    @ REPL ~/share/julia/stdlib/v1.8/REPL/src/REPL.jl:232
 [21] run_repl(repl::REPL.AbstractREPL, consumer::Any; backend_on_current_task::Bool)
    @ REPL ~/share/julia/stdlib/v1.8/REPL/src/REPL.jl:369
 [22] run_repl(repl::REPL.AbstractREPL, consumer::Any)
    @ REPL ~/share/julia/stdlib/v1.8/REPL/src/REPL.jl:355
 [23] (::Base.var"#967#969"{Bool, Bool, Bool})(REPL::Module)
    @ Base ./client.jl:419
 [24] #invokelatest#2
    @ ./essentials.jl:729 [inlined]
 [25] invokelatest
    @ ./essentials.jl:726 [inlined]
 [26] run_main_repl(interactive::Bool, quiet::Bool, banner::Bool, history_file::Bool, color_set::Bool)
    @ Base ./client.jl:404
 [27] top-level scope
    @ none:40

[t-bltg]

I've tried this PR against #2428, same error.
The previous example with the colorbar also fails in WGLMakie on the latest Makie release.
I'm going to open a new issue.

[t-bltg]

Dropping a note to say that this PR is ready, and only needs new reference images merged.

[jkrumbiegel]

Thank you, @t-bltg!

[t-bltg]

Thanks for the help and the constructive comments made on this PR, I couldn't have done without (or would have written sloppy code for sure :)) !

[github-actions]

Missing reference images

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