Example of using Makie.jl to pick points off of an image with the mouse/keyboard

description.md

Run the Julia code below, and it'll pop up a window with an image. Select the window. Move the mouse around, and hit the f key. A red marker should appear.

I used the keyboard with the mouse because my application had several different features I wanted to pick out. You could adapt this to use the mouse buttons.

example.jl

using Makie, FileIO, GeometryTypes, Colors, Images

scene = Scene(resolution = (500, 500), color = :black)

img = rand(RGB{N0f8}, 500, 500) 
mimg = image(img) 

scene[:keyboardbuttons] = lift_node(scene[:buttons_pressed]) do x
    map(Keyboard.Button, x)
end

scene[:markers] = to_node(GeometryTypes.Point{2,Float32}[])
sc = scatter(scene[:markers], marker = :+, markersize = 20, color = RGBA(1,0,0, 0.8))

cam = scene[:screen].cameras[:orthographic_pixel]

s = lift_node(scene[:keyboardbuttons]) do keyset
    # println(scene[:keyboardbuttons])
    if ispressed(scene, Keyboard.f)    # mark a point on the image
        mp = scene[:mouseposition]
        p = to_world(Point2f0(to_value(mp)), cam)
        println(p)
        scene[:markers] = push!(to_value(scene[:markers]), p)
    elseif ispressed(scene, Keyboard.x) # do other stuff here...
    end
    nothing
end