# Set `mat` at the uniform rotation matrix
	fun rotation=(mat: Matrix)
	do
		var i = 0
		for r in [rotation_row0, rotation_row1, rotation_row2, rotation_row3] do
			if r.is_active then
				glDisableVertexAttribArray r.location
				r.uniform(mat[0, i], mat[1, i], mat[2, i], mat[3, i])
			end
			i += 1
		end
		var gl_error = glGetError
		assert gl_error == gl_NO_ERROR else print_error gl_error
	end