stripmine.lua

--[[ This program strip mines 1 wide x 3 high tunnels, 3 blocks apart
     Shafts are connected at both ends to simplify return to base logic
     Torches are placed on the floor of the shafts
     Two chests needed for setup, one to receive output, one to supply torches

     Assumes a robot with a generator, inventory manager, diamond pick equipped
     Torches in slot 16, Fuel in slot 15

     The robot tries to make the tunnels safe to walk.  Cobble in slot 1 is used for this.

     Author: ArchReplicator

     Invocation

     stripmine length numstrips [left | right]

     length is how far to mine, default 100
     numstrips is how many tunnels, default 5
     left/right is direction to work, default left

     Setup

     T=tunnel I=input chest O=output chest R=robot

     We start with an 8 meter pre-dug tunnel to ensure lave doesn't eat the chests

        T
        T
        T
        T
        T
        T
        T
        T
        RI
        O
         ]]

 local component = require("component")
 local shell = require("shell")
 local generator, ic

 -- check required equipment

 if not component.isAvailable("robot") then
   io.stderr:write("This program must run on a robot.")
   return
end

if not component.isAvailable("generator") then
    io.stderr:write("The robot needs a generator.")
    return
else
  generator = component.getPrimary("generator")
end

if not component.isAvailable("inventory_controller") then
    io.stderr:write("The robot needs an inventory controller.")
    return
else
   ic = component.getPrimary("inventory_controller")
end

local robot = require("robot")

-- get arguments

local args, options = shell.parse(...)

-- "global" variables (defined as local to this file which contains the whole thing)

local minedir = 1 -- valid values are 1(->chest),2(left),3(away),4(right)
local dx = 0      -- start at 0 x,y,z displacement
local dy = 0
local dz = 0

local savedx, savedy, savedz, savedir

local diglen, numtun, direct

-- function definitions
--[[
movement functions
keeps track of direction and movement in the dx,dy,dz variables
direction vectors x,z,y
1 vector -1,0,0
2 vector 0,-1,0
3 vector 1,0,0
4 vector 0,1,0
up vector 0,0,-1
down vector 0,0,1
]]

local deltas = { -- entries are X, Z, Y (note order!!!)
    {-1, 0, 0},
    {0, -1, 0},
    {1, 0, 0},
    {0, 1, 0},
    {0, 0, -1}, -- up
    {0, 0, 1}  -- down
    }

function movefwd()
    local ok, reason = robot.forward()
    if ok then
        dx = dx + deltas[minedir][1]
        dz = dz + deltas[minedir][2]
        dy = dy + deltas[minedir][3]
    else
        io.stderr:write("Can't move forward: " .. reason)
    end
    return ok, reason
end

function moveup()
    local ok, reason = robot.up()
    if ok then
        dx = dx + deltas[5][1]
        dz = dz + deltas[5][2]
        dy = dy + deltas[5][3]
    else
        io.stderr:write("Can't move up: " .. reason)
    end
    return ok,reason
end

function movedown()
    local ok, reason = robot.down()
    if ok then
        dx = dx + deltas[6][1]
        dz = dz + deltas[6][2]
        dy = dy + deltas[6][3]
    else
        io.stderr:write("Can't move down: " .. reason)
    end
    return ok,reason
end

function turnleft()
    robot.turnLeft()
    if minedir == 1 then
        minedir = 4
    else
        minedir = minedir - 1
    end
end

function turnright()
    robot.turnRight()
    if minedir == 4 then
        minedir = 1
    else
        minedir = minedir + 1
    end
end

function turnaround()
    turnleft()
    turnleft()
end

function turnto(tgtdir)
    if tgtdir == minedir then
        return
    elseif tgtdir < minedir then
    do
        local num = minedir - tgtdir
        for i = 1,num do turnleft() end
    end
    else do
        local num = tgtdir - minedir
        for i = 1,num do turnright() end
    end
    end
end

function printpos()
    io.stdout:write(dx, " ", dz, " ", dy, " ", minedir, "\n")
end

function xmoveto(tgtx)

    local done = false
    local lsavedir = minedir
    if tgtx == dx then
        return
    end
    if tgtx < dx then
        turnto(1)
    else
        turnto(3)
    end
    while not done do
        if tgtx == dx then
            done = true
        else
            movefwd()
        end
    end
    turnto(lsavedir)
end

function zmoveto(tgtz)

    local done = false
    local lsavedir = minedir
    if tgtz == dz then
        return
    end

    if tgtz < dz then
        turnto(2)
    else
        turnto(4)
    end
    while not done do
        if tgtz == dz then
            done = true
        else
            movefwd()
        end
    end
    turnto(lsavedir)
end

function ymoveto(tgty)

    local done = false
    while not done do
        if dy == tgty then
            done = true
        elseif dy > tgty then
            moveup()
        else
            movedown()
        end
    end -- while
end

function rtb() -- return to base

    savedx = dx; savedy = dy; savedz = dz; savedir = minedir
    -- get Y to zero
    ymoveto(0)

    -- go to a cross tunnel
    local tgtx
    if (minedir == 1) or (minedir == 3) then
        if minedir == 1 then    -- current direction toward chest
            tgtx = diglen + 8   -- go back to far end of current tunnel
        else                    -- away from chest
            tgtx = 8            -- go to near end of current tunnel
        end

        turnaround()
        xmoveto(tgtx)

    end -- done moving to end of tunnel

    -- go to the initial tunnel
    zmoveto(0)

    -- go to start pos
    turnto(1)
    xmoveto(0)

end -- rtb

function resumedig() -- back to digging after a return to base

    -- go to the side tunnel needed to reach old position
    turnto(3) -- away
    if (savedir == 1) or (savedx == diglen+8) then  -- old direction toward, or in far side tunnel
        xmoveto(diglen+8)
    else                                            -- old direction away, or in near side tunnel
        xmoveto(8)
    end

    -- go to the old z location (which mining tunnel or side tunnel depth)

    zmoveto(savedz)

    -- go to the mining location within the tunnel

    turnto(savedir)
    xmoveto(savedx)
    ymoveto(savedy)

end -- resumedig


-- mainline code

diglen = args[1] or 100
numtun = args[2] or 5
direct = args[3] or "left"

if (direct ~= "left") and (direct ~= "right") then
    io.stderr:write("Invalid direction, left assumed")
    direct = "left"
end

-- put main call here

-- 1st test: directions

--printpos()
--turnaround()
--printpos()
--for i=1,5 do movefwd() end
--turnleft()
--for i=1,3 do movefwd() end
--for i=1,2 do moveup() end
--printpos()
--rtb()
--printpos()
--resumedig()
--printpos()