Julia: Affine Transformations with Compose module

Question

Is it possible to transform images (as shown below) via matrices with Compose.jl? If so, could you please provide a simple example?

I'm aware of the rotation keyword argument in the Compose.context method, but I was wondering if there was something similar for general affine transformations. Thanks!

Answer 1

You can use Shear. For example, you can transform

from the tutorials (code below)

julia> composition = compose(context(),
               (context(units=UnitBox(0, 0, 1000, 1000)),
                polygon([(0, 1000), (500, 1000), (500, 0)]),
                fill("tomato")),
               (context(),
                polygon([(1, 1), (0.5, 1), (0.5, 0)]),
                fill("bisque")))

and shear it with

julia> composition_sheared = compose(context(shear=Shear(0.3,0.0,0.5,1.0)),
               (context(units=UnitBox(0, 0, 1000, 1000)),
                polygon([(0, 1000), (500, 1000), (500, 0)]),
                fill("tomato")),
               (context(),
                polygon([(1, 1), (0.5, 1), (0.5, 0)]),
                fill("bisque")))

to obtain