grid.lua

term = require("term")
comp = require("component")
w = comp.debug.getWorld()

function quit(msg)
  print(msg)
  os.exit()
end

function getNumber(msg)
  while (not value) do
    print("Enter a number: " .. msg)
    value = tonumber(term.read())
  end
  return math.floor(value)
end

function getYesNo(msg)
  while (value == nil) do
    print("Yes or no: " .. msg)
    v = string.lower(io.read())
    if (v == "yes" or v == "y" or v == "true" or v == "t" or v == "1") then value = true
    elseif (v == "no" or v == "n" or v == "false" or v == "f" or v == "0") then value = false end
  end
  return value
end

-- Find starting coordinate
sx = getNumber("X-coordinate of grid origin.")
sy = getNumber("Y-coordinate of grid origin.")
sz = getNumber("Z-coordinate of grid origin.")

-- Find grid size
print("For the following three numbers, enter the number of points, not the number of blocks.")
print("Use a negative number to go the opposite direction. Use 0 to not extend the grid this way.")
print("Note that the program will exit if you enter zero for all three numbers.")
gx = getNumber("Length to extend grid east.")
gy = getNumber("Length to extend grid up.")
gz = getNumber("Length to extend grid south.")
if (gx == 0 and gy == 0 and gz == 0) then os.exit() end

-- Find blocks and grid lengths
print("Now enter the block ID *number* and data *byte* to set the blocks at the points to.")
bld = {id = getNumber("Block ID"), data = getNumber("Block data")}
blx = {}
bly = {}
blz = {}
dx = 0
dy = 0
dz = 0
if gx ~= 0 then
  print("Now enter the id and data for blocks along lines on the X axis.")
  blx = {id = getNumber("Block ID"), data = getNumber("Block data")}
  print("Now the distance between block centers of two consecutive intersecting points. It can't be 0 or negative.")
  while dx < 1 do dx = getNumber("X distance") end
end
if gy ~= 0 then
  print("Now enter the id and data for blocks along lines on the Y axis.")
  bly = {id = getNumber("Block ID"), data = getNumber("Block data")}
  print("Now the distance between block centers of two consecutive intersecting points. It can't be 0 or negative.")
  while dy < 1 do dy = getNumber("Y distance") end
end
if gz ~= 0 then
  print("Now enter the id and data for blocks along lines on the Z axis.")
  blz = {id = getNumber("Block ID"), data = getNumber("Block data")}
  print("Now the distance between block centers of two consecutive intersecting points. It can't be 0 or negative.")
  while dz < 1 do dz = getNumber("Z distance") end
end

-- Find total grid lengths
lx = gx * dx
ly = gy * dy
lz = gz * dz

-- Start on the bottom northwest corner regardless of input values
if (gx < 0) then
  sx = sx + lx
  gx = -gx
  lx = -lx
end
if (gy < 0) then
  sy = sy + ly
  gy = -gy
  ly = -ly
end
if (gz < 0) then
  sz = sz + lz
  gz = -gz
  lz = -lz
end

-- Draw x gridlines
if (gx ~= 0) then
  for cy = 0, gy do
    y = sy + cy * dy
    for cz = 0, gz do
      z = sz + cz * dz
      for cx = 0, gx-1 do
        for x = sx + cx * dx, sx + (cx + 1) * dx - 1 do
          w.setBlock(x, y, z, blx.id, blx.data)
        end
      end
    end
  end
end

-- Draw y gridlines
if (gy ~= 0) then
  for cx = 0, gx do
    x = sx + cx * dx
    for cz = 0, gz do
      z = sz + cz * dz
      for cy = 0, gy-1 do
        for y = sy + cy * dy, sy + (cy + 1) * dy - 1 do
          w.setBlock(x, y, z, bly.id, bly.data)
        end
      end
    end
  end
end

-- Draw z gridlines
if (gz ~= 0) then
  for cy = 0, gy do
    y = sy + cy * dy
    for cx = 0, gx do
      x = sx + cx * dx
      for cz = 0, gz-1 do
        for z = sz + cz * dz, sz + (cz + 1) * dz - 1 do
          w.setBlock(x, y, z, blz.id, blz.data)
        end
      end
    end
  end
end

-- Draw grid intersections
for cx = 0, gx do
  x = sx + cx * dx
  for cy = 0, gy do
    y = sy + cy * dy
    for cz = 0, gz do
      z = sz + cz * dz
      w.setBlock(x, y, z, bld.id, bld.data)
    end
  end
end