Spinning cubes for ComputerCraft

-- Constants
local width = 51  -- Adjusted width for ComputerCraft monitor
local height = 19  -- Adjusted height for ComputerCraft monitor
local backgroundASCIICode = '.'
local distanceFromCam = 50  -- Adjusted distance for better visibility
local K1 = 20  -- Adjusted perspective constant
local incrementSpeed = 0.2  -- Reduced increment speed for finer control

-- Variables
local A, B, C = 0, 0, 0
local cubeWidth = 5  -- Reduced width for the cubes
local horizontalOffset
local zBuffer = {}
local buffer = {}

-- Initialize buffers
for i = 1, width * height do
    zBuffer[i] = 0
    buffer[i] = backgroundASCIICode
end

-- Calculate X, Y, Z coordinates
local function calculateX(i, j, k)
    return j * math.sin(A) * math.sin(B) * math.cos(C) - k * math.cos(A) * math.sin(B) * math.cos(C) +
           j * math.cos(A) * math.sin(C) + k * math.sin(A) * math.sin(C) + i * math.cos(B) * math.cos(C)
end

local function calculateY(i, j, k)
    return j * math.cos(A) * math.cos(C) + k * math.sin(A) * math.cos(C) -
           j * math.sin(A) * math.sin(B) * math.sin(C) + k * math.cos(A) * math.sin(B) * math.sin(C) -
           i * math.cos(B) * math.sin(C)
end

local function calculateZ(i, j, k)
    return k * math.cos(A) * math.cos(B) - j * math.sin(A) * math.cos(B) + i * math.sin(B)
end

-- Calculate for surface
local function calculateForSurface(cubeX, cubeY, cubeZ, ch)
    local x = calculateX(cubeX, cubeY, cubeZ)
    local y = calculateY(cubeX, cubeY, cubeZ)
    local z = calculateZ(cubeX, cubeY, cubeZ) + distanceFromCam

    local ooz = 1 / z
    local xp = math.floor(width / 2 + horizontalOffset + K1 * ooz * x * 2)
    local yp = math.floor(height / 2 + K1 * ooz * y)

    local idx = xp + yp * width
    if idx >= 1 and idx <= width * height then
        if ooz > zBuffer[idx] then
            zBuffer[idx] = ooz
            buffer[idx] = ch
        end
    end
end

-- Main loop
while true do
    -- Clear buffers
    for i = 1, width * height do
        zBuffer[i] = 0
        buffer[i] = backgroundASCIICode
    end

    -- Draw cubes
    local cubeSizes = {5, 3, 2}  -- Adjusted sizes for the cubes
    local offsets = {-2, 1, 4}

    for index, size in ipairs(cubeSizes) do
        horizontalOffset = offsets[index] * size
        for cubeX = -size, size, incrementSpeed do
            for cubeY = -size, size, incrementSpeed do
                calculateForSurface(cubeX, cubeY, -size, '@')
                calculateForSurface(size, cubeY, cubeX, '$')
                calculateForSurface(-size, cubeY, -cubeX, '~')
                calculateForSurface(-cubeX, cubeY, size, '#')
                calculateForSurface(cubeX, -size, -cubeY, ';')
                calculateForSurface(cubeX, size, cubeY, '+')
            end
        end
    end

    -- Display the buffer
    term.clear()
    term.setCursorPos(1, 1)
    for k = 1, width * height do
        if k % width == 1 and k > 1 then
            print() -- New line
        end
        write(buffer[k])
    end

    -- Update angles
    A = A + 0.05
    B = B + 0.05
    C = C + 0.01

    os.sleep(0.08) -- Sleep for a bit to control speed
end