hexbin: the colorbar does not scale automatically.

[gjankowiak]

• [x] are you running newest version (version from docs) ? Makie v.0.20.7 and GLMakie v0.9.8
• [x] can you reproduce the bug with a fresh environment ? (]activate --temp; add Makie)

Platform: linux, GPU not relevant IMHO.

When changing the number of points passed to an hexbin plot with an attached Colorbar, the latter is not updated as it should be. Here is a MWE which create such a plot, increases the number of points (shown as a scatter) and write the corresponding animation.

Should it scale automatically, like with heatmap for example?

import GLMakie as M

start_n = 10

x = M.Observable(randn(start_n))
y = M.Observable(randn(start_n))

fig = M.Figure(size=(720, 480))
ax = M.Axis(fig[1, 1], aspect=1)
ax.title = "$start_n points"
M.limits!(ax, (-2, 2), (-2, 2))

h = M.hexbin!(ax, x, y; bins=10)
cb = M.Colorbar(fig[1, 2], h)

M.scatter!(ax, x, y, markersize=1)

display(fig)

function step_n(new_n)
  x.val = randn(new_n)
  y[] = randn(new_n)
  ax.title = "$new_n points"
end

M.record(step_n, fig, "test_hexbin.mp4", 1000:1000:10001, framerate=1)

[ffreyer]

Seems like hexbin generates its own color array rather than using value-colors with colorrange, which Colorbar checks

[asinghvi17]

I think there's a method that can be dispatched on to correct this for individual plot types, but forgot what it is...