Contour labels obscured for data with NaNs

[haakon-e]

Certain fields that contain NaNs result in rendering errors for contours with labels=true

Code setup

using CairoMakie
function f_ex(x,y, set_nans=true)
    # Define coefficients
    a = 1000  # Overall scale
    b = 4     # Controls the "peak" location
    c = 0.3   # Controls the rate of decrease for large x and y
    
    # Create a surface that rises and then falls
    z = a * (1 - (x - 0.5)^2 - (y - 0.3)^2 - c * (x * y))
    
    # Adjust to ensure positive values and add base level
    z = max(z, 0) + 200

	set_nans && y > 2x + 0.4 && return NaN
    
    return z
end
function make_contour_plot(; set_nans, levels = 900:50:1100)
    x,y = 0:0.01:0.5, 0:0.01:0.8
    z = f_ex.(x,y',true)
    f,a,c = contourf(x,y,z)
    contour!(a,x,y,z; labels=true, color=:black, levels)
    f
end

Case 1: The field has no NaNs

In this case, labels show as expected

make_contour_plot(set_nans=false)

Case 2: Set some values to NaN

In this case, the contour strikes through some of the labels

make_contour_plot(set_nans=true)

Case 3: Show fewer contours

If none of the contours intersect the NaNs, labels show as expected:

make_contour_plot(set_nans=true, levels = 1000:50:1100)

---

• what version of Makie are you running? (]st -m Makie) Makie v0.21.11
• can you reproduce the bug with a fresh environment ? (]activate --temp; add Makie)
• What platform + GPU are you on? Mac M1