Pico-8 – Lines Screensaver

Okay, so it’s not really a screensaver in this instance, but it’s the art from inside one. You recognize it. You’ve seen it before. But here it is… much lower res than usual. 😉

Source: https://gist.github.com/Fortyseven/a4e2d5d3105ed86e0916d162a1a4d466

pico-8 cartridge // http://www.pico-8.com
version 16
__lua__
-- lines (classic)
-- by fortyseven

SPACING = 4
SPEED = 1

function buildPolyVerts()
    local verts = {
        x=rnd(128),
        y=rnd(128),
        xvel= SPEED,
        yvel= SPEED
    };
    if (rnd(1) > 0.5)  verts.xvel = -verts.xvel
    if (rnd(1) > 0.5)  verts.yvel = -verts.yvel
    return verts;
end;

-------------------------------------------------------------
poly = {}

function poly:init(i, color)
    self.color = color
    self.verts = {}

    -- ensure we use the same seed for each poly object, so it will always
    -- create the same intial x/y/velocity directions

    for i = 1, 4 do
        verts = buildPolyVerts()
        add(self.verts,verts)
    end

    -- run the update a couple times to space them out

    for i = 1, i*SPACING do self:update() end
end

function poly:update()
    foreach(self.verts, function(vert)
        vert.x += vert.xvel
        if ((vert.x >= 128) or (vert.x <= 0)) vert.xvel = -vert.xvel
        vert.y += vert.yvel
        if ((vert.y >= 128) or (vert.y <= 0)) vert.yvel = -vert.yvel
    end)
end

function poly:draw()
    for i = 1, 3 do
        color(self.color);
        line(self.verts[i].x, self.verts[i].y, self.verts[i+1].x, self.verts[i+1].y)
    end
    line(self.verts[4].x, self.verts[4].y, self.verts[1].x, self.verts[1].y)
end

function poly:new(o)
    self.__index = self
    return setmetatable(o or {}, self)
end

-------------------------------------------------------------
polyCluster = {}

function polyCluster:init(col_array)
    self.objects = {}
    seed = flr(rnd(1000))

    -- generate three unique polys
    for i = 1, 3 do
        srand(seed)
        local o = poly:new()
        o:init(i, col_array[i])
        add(self.objects, o )
    end
end

function polyCluster:update()
    foreach(self.objects, function(obj)
        obj:update()
    end)
end

function polyCluster:draw()
    foreach(self.objects, function(obj)
        obj:draw()
    end)
end

function polyCluster:new(o)
    self.__index = self
    return setmetatable(o or {}, self)
end

-------------------------------------------------------------
clusters = {}

function _init()
    local c = polyCluster:new()
    c:init({2,8,14})
    add(clusters, c)

    c = polyCluster:new()
    c:init({1,6,12})
    add(clusters, c)

    c = polyCluster:new()
    c:init({13,6,7})
    add(clusters, c)
end

function _draw()
    foreach(clusters, function(c)
        c:update()
    end)
end

function _update()
    cls()
    foreach(clusters, function(c)
        c:draw()
    end)
end