relative-gps coord system

sys/autorun/gps.lua

@@ -12,21 +12,16 @@ if turtle and device.wireless_modem then
       }
       Config.load('gps', config)
 
-      local GPS = require('gps')
-      local pt
-      for i = 1, 3 do
-        pt = GPS.getPointAndHeading(2)
-        if pt then
-          break
-        end
+      local s = turtle.enableGPS(2)
+      if not s then
+        s = turtle.enableGPS(2)
       end
-
-      if not pt and config.destructive then
+      if not s and config.destructive then
         turtle.setPolicy('turtleSafe')
-        pt = GPS.getPointAndHeading(2)
+        s = turtle.enableGPS(2)
       end
 
-      if not pt then
+      if not s then
         error('Unable to get GPS position')
       end
 
@@ -34,18 +29,12 @@ if turtle and device.wireless_modem then
         turtle.setPolicy('turtleSafe')
       end
 
-      Util.print('Setting turtle point to %d %d %d', pt.x, pt.y, pt.z)
-      turtle.setPoint(pt)
-      turtle.getState().coordSystem = 'GPS'
-
       if not turtle.pathfind(homePt) then
         error('Failed to return home')
       end
     end
   end)
 
-  turtle.setPolicy('none')
-
   if not s and m then
     error(m)
   end