Mine: keep next shaft position

turtles/mine.lua

@@ -24,6 +24,10 @@ FUEL_LOW = 1000
 
 SHAFT_DEPTH = 100
 
+-- Start at this position to find the next shaft
+next_shaft_side = 0
+next_shaft_height = 0
+
 function distance_to_drop()
     return math.abs(depth - DROP_POINT_D)
     + math.abs(height - DROP_POINT_H)
@@ -178,7 +182,7 @@ function find_next_shaft()
         return is_shaft_pos() and turtle.detect()
     end
 
-    go_to(0, 0, 0)
+    go_to(next_shaft_height, 0, next_shaft_side)
 
     while true do
         for hei=1,MAX_HEIGHT-1 do
@@ -242,6 +246,8 @@ function main()
     while true do
         print("Finding shaft")
         find_next_shaft()
+        next_shaft_height = height
+        next_shaft_side = side
         print("Mining shaft at position:")
         _dump_pos()
         mine_shaft()