Excavation program for turtles in minecraft.

excavate.lua

-- run by calling: f=fs.open("/startup", "w");f.write(http.get("https://gist.github.com/raw/4246007").readAll());f.close();dofile("/startup")


-- orientation: 0 = N, 1 = E, 2 = S, 3 = W

function save_state()
    f = fs.open("/excavate_state", "w")
    f.write("state = ")
    f.write(textutils.serialize(state))
    f.close()
end


function load_state()
    dofile("/excavate_state")
end


function dig()
    if turtle.detect() then
        turtle.dig()
    end
end


function dig_down()
    if turtle.detectDown() then
        turtle.digDown()
    end
end


function dig_up()
    if turtle.detectUp() then
        turtle.digUp()
    end
end


function orient_to(target_orientation)
    delta_orientation = ((target_orientation % 4) - state["orientation"]) % 4

    state["orientation"] = target_orientation
    save_state()

    if delta_orientation == 3 then
        delta_orientation = -1
    end

    if delta_orientation == -3 then
        delta_orientation = 1
    end

    while delta_orientation > 0 do
        turtle.turnRight()
        delta_orientation = delta_orientation - 1
    end

    while delta_orientation < 0 do
        turtle.turnLeft()
        delta_orientation = delta_orientation + 1
    end
end


function move_up()
    dig_up()
    turtle.attackUp()
    turtle.suckUp()

    state["y_pos"] = state["y_pos"] + 1
    save_state()

    r = turtle.up()
    if not r then
        state["y_pos"] = state["y_pos"] - 1
        save_state()
    end

    return r
end


function move_down()
    dig_down()
    turtle.attackDown()
    turtle.suckDown()

    state["y_pos"] = state["y_pos"] - 1
    save_state()

    r = turtle.down()
    if not r then
        state["y_pos"] = state["y_pos"] + 1
        save_state()
    end

    return r
end


function move_forward()
    dig()
    turtle.attack()
    turtle.suck()

    if state["orientation"] == 0 then
        state["z_pos"] = state["z_pos"] + 1
    elseif state["orientation"] == 1 then
        state["x_pos"] = state["x_pos"] + 1
    elseif state["orientation"] == 2 then
        state["z_pos"] = state["z_pos"] - 1
    elseif state["orientation"] == 3 then
        state["x_pos"] = state["x_pos"] - 1
    end

    save_state()

    r = turtle.forward()
    if not r then
        if state["orientation"] == 0 then
            state["z_pos"] = state["z_pos"] - 1
        elseif state["orientation"] == 1 then
            state["x_pos"] = state["x_pos"] - 1
        elseif state["orientation"] == 2 then
            state["z_pos"] = state["z_pos"] + 1
        elseif state["orientation"] == 3 then
            state["x_pos"] = state["x_pos"] + 1
        end

        save_state()
    end

    return r
end


function move_to_pos_step(target_x, target_z, target_y)
    -- prioritize x over z over y

    -- we're to the west of the target point
    if state["x_pos"] < target_x then
        orient_to(1)
        move_forward()

    -- we're to the east of the target point
    elseif state["x_pos"] > target_x then
        orient_to(3)
        move_forward()

    -- we're to the south of the target point
    elseif state["z_pos"] < target_z then
        orient_to(0)
        move_forward()

    -- we're to the north of the target point
    elseif state["z_pos"] > target_z then
        orient_to(2)
        move_forward()
    
    -- we're under the target point
    elseif state["y_pos"] < target_y then
        move_up()

    -- we're above the target point
    elseif state["y_pos"] > target_y then
        move_down()
    end

    if state["x_pos"] == target_x and state["y_pos"] == target_y and state["z_pos"] == target_z then
        return true
    else
        return false
    end
end


function move_to_pos(target_x, target_y, target_z)
    while not move_to_pos_step(target_x, target_y, target_z) do
    end
end


function inventory_has_empty_slot()
    for i = 1, 16 do
        if turtle.getItemCount(i) == 0 then
            return true
        end
    end

    return false
end


function drop_inventory()
    for i = 1, 16 do
        turtle.select(i)
        while turtle.getItemCount(i) > 0 do turtle.drop() end
    end
end


function excavate()
    if state["done"] then
        return
    end

    while true do
        if state["start"] then
            move_to_pos(0, 0, starting_height)

            if state["bottom_to_top"] then
                dig_up()
                move_up()
                dig_up()
            else
                dig_down()
                move_down()
                dig_down()
            end

            if state["width"] < 0 then
                orient_to(3)
            else
                orient_to(1)
            end

            while not move_forward() do end
            dig_up()
            dig_down()

            state["start"] = false
            save_state()

        elseif state["dropping"] then
            move_to_pos(0, 0, 0)

            -- drop to south
            orient_to(2)
            drop_inventory()

            move_to_pos(state["saved_x_pos"], state["saved_z_pos"], state["saved_y_pos"])
            orient_to(state["saved_orientation"])

            state["dropping"] = false
            save_state()

        else
            while inventory_has_empty_slot() do
                -- prioritize width over length over height
                if state["x_pos"] == 0 or state["x_pos"] == state["width"] then
                    if state["z_pos"] == (state["length"] - 1) then
                        if state["bottom_to_top"] then
                            if state["y_pos"] >= (state["height"] + state["starting_height"] - 2) then
                                -- we're done
                                state["done"] = true
                                save_state()
                                return true
                            end

                            -- move to the next level
                            move_to_pos(0, 0, state["y_pos"] + 3)
                            dig_down()                        
                            dig_up()
                        else
                            if state["y_pos"] <= (-state["height"] + state["starting_height"] + 2) then
                                -- we're done
                                state["done"] = true
                                save_state()
                                return true
                            end

                            -- move to the next level
                            move_to_pos(0, 0, state["y_pos"] - 3)
                            dig_down()                        
                            dig_up()
                        end
                        
                        if state["width"] < 0 then
                            orient_to(3)
                        else
                            orient_to(1)
                        end
                    else
                        -- move to next row
                        orient_to(0)
                        while not move_forward() do end
                        dig_up()
                        dig_down()

                        dir = 1
                        if state["x_pos"] == state["width"] then
                            dir = (dir + 2) % 4
                        end

                        if state["width"] < 0 then
                            dir = (dir + 2) % 4
                        end

                        orient_to(dir)
                    end
                end

                while not move_forward() do end
                dig_up()
                dig_down()
            end

            state["saved_x_pos"] = state["x_pos"]
            state["saved_y_pos"] = state["y_pos"]
            state["saved_z_pos"] = state["z_pos"]
            state["saved_orientation"] = state["orientation"]
            state["dropping"] = true
            save_state()
        end
    end
end


function main()
    if fs.exists("/excavate_state") then
        load_state()
    else
        term.clear()
        term.setCursorPos(1, 1)
        print("----- Excavate program -----")
        print("")
        print("What dimensions?")
        print("")

        term.write("Width (+right, -left): ")
        width = tonumber(io.read())

        term.write("Length (in front of the turtle): ")
        length = math.abs(tonumber(io.read()))

        term.write("Height (multiple of 3, +up, -down): ")
        height = tonumber(io.read())

        term.write("Starting height (relative, +/-): ")
        starting_height = tonumber(io.read())

        -- sanitize input
        if math.abs(height) < 3 then
            return
        end

        if height < 0 then
            bottom_to_top = false
            height = -height
        else
            bottom_to_top = true
        end

        if math.abs(width) < 2 then
            return
        end

        -- fix bug where the turtle wants to dig one too wide
        if width < 0 then
            width = width + 1
        else
            width = width - 1
        end

        state = {
            x_pos = 0,
            y_pos = 0,
            z_pos = 0,
            orientation = 0,

            width = width,
            length = length,
            height = height,
            starting_height = starting_height,
            bottom_to_top = bottom_to_top,

            start = true,
            done = false,
            dropping = false
        }

        save_state()
    end

    print("Excavating...")
    excavate()

    -- return to base and unload
    move_to_pos(0, 0, 0)
    orient_to(2)
    drop_inventory()
    orient_to(0)

    print("Done!")

    fs.delete("/excavate_state")
end

main()