-- Localized math functions for faster access
local mathfloor = math.floor
local mathsqrt = math.sqrt
local mathsin = math.sin

-- Globals
screen1 = {}
screen2 = {}
screen3 = {}
screenlist = {}
screencount = 0
pallet = {}
plasma = {}
w = platform.window:width()
h = platform.window:height()
tsize = 5

function on.arrowDown()
    if tsize > 1 then tsize = tsize - 1 end
end
function on.arrowUp()
    if tsize < 15 then tsize = tsize + 1 end
end

function on.resize(ww,hh)
    timer.stop()
    w,h = ww,hh
    init()
end

function on.paint(gc)
    local time = timer.getMilliSecCounter() / 10
    local x,y = 0,0
    while (x < w) do
        while (y < h) do
            local color = pallet[mathfloor((plasma[x][y] + time) % 256)]
            gc:setColorRGB(color.r, color.g, color.b)
            gc:fillRect(x, y, tsize, tsize)
            y = y + tsize
        end
        x = x + tsize
        y = 0
    end
    screencount = (screencount + 1) % 3
    timer.start(0.01)
end


function dist(a, b, c, d)
    return mathsqrt(((a - c) * (a - c) + (b - d) * (b - d)))
end

function on.timer()
    timer.stop()
    platform.window:invalidate()
end

function init()
    pallet = {}
    plasma = {}

    local r,g,b = 0,0,0
    for i = 0, 256 do
        pallet[i] = { r = mathfloor(128.0 + 128 * mathsin(3.1416 * i / 16.0)),
                      g = mathfloor(128.0 + 128 * mathsin(3.1416 * i / 128.0)),
                      b = 0 }
    end

    for a = 0, w do
        plasma[a] = {}
        for b = 0, h do
            plasma[a][b] = mathfloor(128.0 + (128.0 * mathsin(a / 16.0)) + 128.0 + (128.0 * mathsin(b / 16.0))) / 2
        end
    end

    timer.start(0.01)
end

init()