colors = {{1, 0, 0, 1}, {1, 0.5, 0, 1}, {1, 1, 0, 1}, {0.5, 1, 0, 1}, {0, 1, 0, 1}, {0, 1, 0.5, 1}, {0, 1, 1, 1}, {0, 0.5, 1, 1}, {0, 0, 1, 1}, {0.5, 0, 1, 1}, {1, 0, 1, 1}, {1, 0, 0.5, 1}}

function love.load()
    ex, ey = 10, 10
    step = 100
    love.window.setMode(800, 600, {resizable = true})
end
--
function love.update(dt)
    if (love.keyboard.isDown("w")) then
        ey = ey - step * dt
    end
    if (love.keyboard.isDown("s")) then
        ey = ey + step * dt
    end
    if (love.keyboard.isDown("a")) then
        ex = ex - step * dt
    end
    if (love.keyboard.isDown("d")) then
        ex = ex + step * dt
    end
end
--
function rect(t, l, w, h)
    love.graphics.rectangle("fill", l, t, w, h)
end

function drawRecursiveRect(s, t, l, w, h, d)
    --create the stencil that draws d rectangles,
    love.graphics.stencil(s, "increment", 1)
    --set the stencil test so that it only draws where all d rectangles overlap.
    love.graphics.setStencilTest("gequal", d)
    --draw an extremely large rectangle. Only the parts in the stencil will be drawn.
    love.graphics.setColor(colors[(d-1) % #colors + 1])
    rect(0, 0, 2000, 2000)
    --end the stencil test.
    love.graphics.setStencilTest()

    if (d < 20) then
        --create the stencil function for the next iteration,
        t2, l2, w2, h2 = t + ey, l + ex, 9*w/10, 9*h/10
        s2 = function()
            s(t, l, w, h)
            rect(t2, l2, w2, h2)
        end
        --draw the next rectangle.
        drawRecursiveRect(s2, t2, l2, w2, h2, d + 1)
    end

end
--
function love.draw()

    ----[[
    t, l, w, h = 0, 0, 800, 600
    s = function()
        rect(t, l, w, h)
    end
    drawRecursiveRect(s, t, l, w, h, 1)
    --]]

    --[[
    --the following works:
    s = function()
        rect(0, 0, 400, 300)
    end
    s2 = function()
        s()
        rect(200, 150, 400, 300)
    end
    love.graphics.stencil(s2, "increment", 1)
    love.graphics.setStencilTest("gequal", 2)
    love.graphics.setColor(1, 1, 1, 1)
    rect(0, 0, 2000, 2000)
    love.graphics.setStencilTest()
    ]]

end