Rotating Cube

-- Rotating Cube Demo - Auto Monitor Detection + Safe Text Scale
-- Uses Advanced Monitor on the right if available, otherwise falls back to primary terminal

local mon = peripheral.wrap("right")
local isMonitor = false

if mon then
    isMonitor = true
    print("Using Advanced Monitor on the right")
else
    mon = term
    print("No monitor on right - using primary terminal")
end

-- Auto-set text scale ONLY if it's a real monitor
local function autoSetScale(display)
    if not isMonitor then
        return  -- terminal does not support setTextScale
    end

    local w, h = display.getSize()

    -- Choose a good text scale based on monitor size
    if w >= 80 and h >= 40 then
        display.setTextScale(3)
    elseif w >= 51 and h >= 26 then
        display.setTextScale(2)
    elseif w >= 30 and h >= 16 then
        display.setTextScale(1.5)
    else
        display.setTextScale(1)
    end
end

autoSetScale(mon)

local width, height = mon.getSize()

-- Cube vertices
local vertices = {
    {-1,-1,-1}, {1,-1,-1}, {1,1,-1}, {-1,1,-1},   -- back face
    {-1,-1, 1}, {1,-1, 1}, {1,1, 1}, {-1,1, 1}    -- front face
}

-- Cube edges
local edges = {
    {1,2},{2,3},{3,4},{4,1},   -- back
    {5,6},{6,7},{7,8},{8,5},   -- front
    {1,5},{2,6},{3,7},{4,8}    -- sides
}

local function rotateY(p, angle)
    local c, s = math.cos(angle), math.sin(angle)
    return {p[1]*c - p[3]*s, p[2], p[1]*s + p[3]*c}
end

local function rotateX(p, angle)
    local c, s = math.cos(angle), math.sin(angle)
    return {p[1], p[2]*c - p[3]*s, p[2]*s + p[3]*c}
end

local function project(point)
    local scale = math.min(width, height) / 4.8   -- tuned for good fit
    local x = math.floor(width / 2 + point[1] * scale)
    local y = math.floor(height / 2 - point[2] * scale)
    return x, y
end

-- Main loop
local angle = 0
local speed = 0.06

while true do
    mon.clear()

    mon.setCursorPos(2, 1)
    mon.setTextColor(colors.white)
    mon.write("Rotating Cube")

    -- Rotate points
    local rotated = {}
    for i, v in ipairs(vertices) do
        local p = rotateY(v, angle)
        p = rotateX(p, angle * 0.75)
        rotated[i] = p
    end

    -- Draw wireframe
    mon.setTextColor(colors.lime)
    for _, edge in ipairs(edges) do
        local p1 = rotated[edge[1]]
        local p2 = rotated[edge[2]]

        local x1, y1 = project(p1)
        local x2, y2 = project(p2)

        local dx = x2 - x1
        local dy = y2 - y1
        local steps = math.max(math.abs(dx), math.abs(dy)) + 1

        for i = 0, steps do
            local x = math.floor(x1 + dx * i / steps)
            local y = math.floor(y1 + dy * i / steps)
            if x >= 1 and x <= width and y >= 1 and y <= height then
                mon.setCursorPos(x, y)
                mon.write("#")
            end
        end
    end

    -- Center point
    mon.setCursorPos(math.floor(width/2), math.floor(height/2))
    mon.write("+")

    -- Footer
    mon.setCursorPos(2, height)
    mon.setTextColor(colors.lightGray)
    mon.write("Ctrl + T to stop")

    angle = angle + speed
    sleep(0.05)
end