effect = nil

function _create()
    local fxSrc = [[in vec2 vPosition;

        void main() {
            vec2 uv = vPosition * 0.5 + 0.5;
            FragColor = vec4(uv, 0.5 + 0.5 * sin(uTime), 1.0);
        }
    ]]
    effect = Effect.new(fxSrc)
end

function _update(dt)

end

function _render()
    gl.Clear(0, 0, 0, 1.0)
    effect:Render()
end