Posted December 16, 2023 by Kartik Agaram
When I first started messing with LÖVE, one of the first examples I gravitated towards was this Game of Life with colors. I just went back to it and ported it to Lua Carousel. Very fun. In the process I spent some time understanding its rules for assigning colors:
The link above also adds some randomness when cells are born, but I took it out to better see the interactions between "lineages" of cells.
math.randomseed(os.time()) N = 6 W, H = Safe_width/N, Safe_height/N curr, new = {}, {} for x=1,W do table.insert(curr, {}) table.insert(new, {}) for y=1,H do table.insert(curr[x], {v=0, c={0,0,0}}) table.insert(new[x], {v=0, c={0,0,0}}) end end -- R pentomino function set(x,y) curr[x][y].v = 1 curr[x][y].c = {rand()/2+0.25, rand()/2+0.25, rand()/2+0.25} end cx = math.floor(W/2) cy = math.floor(H/2) set(cx, cy) set(cx, cy+1) set(cx, cy+2) set(cx-1, cy) set(cx+1, cy+1) function car.draw() for x=1,W do for y=1,H do if curr[x][y].v > 0 then color(unpack(curr[x][y].c)) rect('fill', x*N, y*N, N-1,N-1) end end end end function car.update(dt) step() end function step() for x=2,W-1 do for y=2,H-1 do local n = nghs(x,y) if n < 2 or n > 3 then new[x][y].v = 0 elseif n == 2 then new[x][y].v = curr[x][y].v local c, oldc = new[x][y].c, curr[x][y].c c[1], c[2], c[3] = oldc[1], oldc[2], oldc[3] elseif n == 3 then new[x][y].v = 1 -- copy some random live neighbor's color over local oldc = random_color(x,y) local c = new[x][y].c c[1], c[2], c[3] = oldc[1], oldc[2], oldc[3] end end end curr, new = new, curr end function nghs(x,y) return curr[x-1][y-1].v + curr[x-1][y].v + curr[x-1][y+1].v + curr[x][y-1].v + curr[x][y+1].v + curr[x+1][y-1].v + curr[x+1][y].v + curr[x+1][y+1].v end function random_color(x,y) local rgbs = {} maybe_append_color(x-1, y-1, rgbs) maybe_append_color(x-1, y, rgbs) maybe_append_color(x-1, y+1, rgbs) maybe_append_color(x, y-1, rgbs) maybe_append_color(x, y+1, rgbs) maybe_append_color(x+1, y-1, rgbs) maybe_append_color(x+1, y, rgbs) maybe_append_color(x+1, y+1, rgbs) return rgbs[rand(#rgbs)] end function maybe_append_color(x,y, out) if curr[x][y].v > 0 then table.insert(out, curr[x][y].c) end end
If you try pasting this program into Lua Carousel, remember to first run the abbreviations on one of the example screens. Or if you've deleted that screen, here are the abbreviations this program uses:
g = love.graphics rect = g.rectangle color = g.setColor rand = math.random