Tuttle: A simple ComputerCraft turtle pathfinding API.

tuttle.lua

-- A simple turtle pathfinding API for ComputerCraft.
--[[
Copyright 2023 Marcus Wenzel

Permission is hereby granted, free of charge, to any person obtaining a copy of 
this software and associated documentation files (the "Software"), to deal in 
the Software without restriction, including without limitation the rights to 
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies 
of the Software, and to permit persons to whom the Software is furnished to 
do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all 
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 
SOFTWARE.
]]

local api = {}

api.PICKAXE = "minecraft:diamond_pickaxe"
api.BLOCK_SCANNER = "plethora:module_scanner"
api.ENTITY_SENSOR = "plethora:module_sensor"
api.heading = nil

local function doTimes(f, times)
  for i = 1, times do
    f()
  end
end

--- Equips an item
-- @tparam item string The item to add to equip. Some constants are defined in this API, see lines 3-5.
function api.equip(item)
  for i = 1, 16 do
    if turtle.getItemDetail(i) and turtle.getItemDetail(i).name == item then
      turtle.select(i)
      turtle.equipLeft()
      return true
    end
  end

  return false
end

--- Selects an item
-- @tparam item string The item ID to select.
function api.select(item)
  for i = 1, 16 do
    if turtle.getItemDetail(i) and turtle.getItemDetail(i).name == item then
      turtle.select(i)
      return true, i
    end
  end

  return false
end

--- Scans for blocks
-- @returns table A table containing all scanned blocks.
function api.scan()
  api.equip(api.BLOCK_SCANNER)
  return peripheral.call("left", "scan")
end

--- Sense for entities
-- @returns table A table containing all scanned entities.
function api.sense()
  api.equip(api.ENTITY_SENSOR)
  return peripheral.call("left", "sense")
end

--- Digs in a direction
-- @tparam string direction Down, up, or a cardinal direction, this defines what direction the turtle will move in.
-- @tparam[opt] int times The amount of blocks to dig
function api.dig(direction, times)
  api.equip(api.PICKAXE)
  if direction == "down" then
    doTimes(turtle.digDown, times or 1)
    return
  elseif direction == "up" then
    doTimes(turtle.digUp, times or 1)
    return
  end
  doTimes(turtle.dig, times or 1)
end

--- Gets the turtle's current heading
-- @returns string A cardinal direction defining the direction the turtle is currently heading in.
function api.getHeading()
  if api.heading then return api.heading end
  local blocks = api.scan()

  for i, v in pairs(blocks) do
    if v.x == 0 and v.y == 0 and v.z == 0 then
      api.heading = v.state.facing
      return v.state.facing
    end
  end
end

local headingVariables = {north = 1, east = 2, south = 3, west = 4}

--- Set the turtle's heading
-- @tparam to string The direction to set heading to.
-- @tparam[opt] loose boolean If set to true, `true` will be returned if the target direction is opposite the current direction, signaling to move backwards
function api.setHeading(to, loose)
  local currentHeading = api.getHeading()

  if currentHeading == to then return end

  local headingDifference = headingVariables[currentHeading] - headingVariables[to]

  -- Same heading
  if headingDifference == 0 then return
  -- Opposite heading
  elseif math.abs(headingDifference) == 2 then
    if loose then return true end
    turtle.turnRight()
    turtle.turnRight()
  -- left heading
  elseif headingDifference == 1 or headingDifference == -3 then
    turtle.turnLeft()
  -- Right heading
  elseif headingDifference == -1 or headingDifference == 3 then
    turtle.turnRight()
  end

  api.heading = to
end

--- Gets directions relative to the turtle's position.
-- @tparam tX number The target X position
-- @tparam tY number The target Y position
-- @tparam tZ number The target Z position
function api.getDirectionsRelative(tX, tY, tZ)
  local x, y, z = nil, nil, nil

  if tX < 0 then
    x = "west"
  elseif tX > 0 then
    x = "east"
  end

  if tY > 0 then
    y = "up"
  elseif tY < 0 then
    y = "down"
  end

  if tZ < 0 then
    z = "north"
  elseif tZ > 0 then
    z = "south"
  end

  return x, y, z
end

--- Gets directions to a world position from the turtle's position.
-- @tparam tX number The target X position
-- @tparam tY number The target Y position
-- @tparam tZ number The target Z position
function api.getDirections(tX, tY, tZ)
  local cX, cY, cZ = gps.locate()
  return api.getDirectionsRelative(tX - cX, tY - cY, tZ - cZ)
end

--- Move in a direction
-- @tparam dir string The direction to move in.
-- @tparam[opt] times int The amount of times to move.
-- @tparam[opt] loose boolean If not set, turtles will always face the direction they are moving in.
function api.move(dir, times, loose)
  if dir == "up" then
    for i = 1, math.abs(times) do
      api.dig("up")
      turtle.up()
    end
    return
  elseif dir == "down" then
    for i = 1, math.abs(times) do
      api.dig("down")
      turtle.down()
    end
    return
  end

  local useBack = api.setHeading(dir, loose)

  if loose and useBack then
    for i = 1, math.abs(times) do
      turtle.back()
    end
  else
    for i = 1, math.abs(times) do
      api.dig()
      turtle.forward()
    end
  end
end

--- Goes to absolute coordinates in the world.
-- @tparam tX number The target X position
-- @tparam tY number The target Y position
-- @tparam tZ number The target Z position
function api.goToCoordinates(tX, tY, tZ, loose)
  local cX, cY, cZ = gps.locate()

  local dX, dY, dZ = tX - cX, tY - cY, tZ - cZ
  local hX, hY, hZ = api.getDirections(tX, tY, tZ)

  if hX then
    api.move(hX, math.abs(dX), loose)
  end

  if hZ then
    api.move(hZ, math.abs(dZ), loose)
  end

  if hY then
    api.move(hY, math.abs(dY), loose)
  end
end

return api