From bbf582e64a08ff1bf52b92045e3a51a9406ed156 Mon Sep 17 00:00:00 2001
From: hagrid67 <jdhwatson@gmail.com>
Date: Sun, 5 May 2019 15:55:41 +0100
Subject: [PATCH] add remove_deadends flag to set_transition in
Grid4Transition. Add has_deadend and remove_deadends() in RailEnvTransitions.
(should they be in RailEnv or Grid4...?)
---
flatland/core/transitions.py | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/flatland/core/transitions.py b/flatland/core/transitions.py
index 4b1874a8..a862c6a8 100644
--- a/flatland/core/transitions.py
+++ b/flatland/core/transitions.py
@@ -253,8 +253,7 @@ class Grid4Transitions(Transitions):
"""
return ((cell_transition >> ((4 - 1 - orientation) * 4)) >> (4 - 1 - direction)) & 1
- def set_transition(self, cell_transition, orientation, direction,
- new_transition):
+ def set_transition(self, cell_transition, orientation, direction, new_transition, remove_deadends=False):
"""
Set the transition bit (1 value) that determines whether an agent
oriented in direction `orientation' and inside a cell with transitions
@@ -271,7 +270,8 @@ class Grid4Transitions(Transitions):
Direction of movement whose validity is to be tested.
new_transition : int
Validity of the requested transition: 0/1 allowed/not allowed.
-
+ remove_deadends -- boolean, default False
+ remove all deadend transitions.
Returns
-------
int
@@ -285,6 +285,9 @@ class Grid4Transitions(Transitions):
else:
cell_transition &= ~(1 << ((4 - 1 - orientation) * 4 + (4 - 1 - direction)))
+ if remove_deadends:
+ cell_transition = self.remove_deadends(cell_transition)
+
return cell_transition
def rotate_transition(self, cell_transition, rotation=0):
@@ -548,6 +551,10 @@ class RailEnvTransitions(Grid4Transitions):
super(RailEnvTransitions, self).__init__(
transitions=self.transition_list
)
+
+ # These bits represent all the possible dead ends
+ self.maskDeadEnds = 0b0010000110000100
+
# create this to make validation faster
self.transitions_all = []
for index, trans in enumerate(self.transitions):
@@ -621,11 +628,11 @@ class RailEnvTransitions(Grid4Transitions):
return False
def has_deadend(self, cell_transition):
- binDeadends = 0b0010000110000100
- if cell_transition & binDeadends > 0:
+ if cell_transition & self.maskDeadEnds > 0:
return True
else:
return False
- # def remove_deadends(self, cell_transition)
-
\ No newline at end of file
+ def remove_deadends(self, cell_transition):
+ cell_transition &= cell_transition & (~self.maskDeadEnds) & 0xffff
+ return cell_transition
--
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