def getGradVicinity(self, gameState):
'''
Returns a number indicating if we are moving
away from the body of the snake or towards it.
We calculate the negated inverse of the Manhattan
distance of all points we are moving towards
'''
if self.X_MAX is None:
self.X_MAX = gameState.numXCell - 1
self.Y_MAX = gameState.numYCell - 1
XY_MAX = (self.X_MAX, self.Y_MAX)
direction = gameState.getCurrentDirection()
snakePos = gameState.getSnakeHeadCordinate()
allPos = gameState.getSnakeCordinates()
allPos.remove(snakePos)
ret = 0.0
sX, sY = snakePos
for pos in allPos:
x, y = pos
if direction == GameState.ACTION_RIGHT:
if x > sX:
md = manhattanDistance((x, y), (sX, sY))
ret += 1 / md
else:
md = circularManhattanDistance(snakePos, pos, XY_MAX,
GameState.ACTION_RIGHT)
ret += 1 / md
elif direction == GameState.ACTION_LEFT:
if x < sX:
md = manhattanDistance((x, y), (sX, sY))
ret += 1 / md
else:
md = circularManhattanDistance(snakePos, pos, XY_MAX,
GameState.ACTION_LEFT)
ret += 1 / md
elif direction == GameState.ACTION_UP:
if y < sY:
md = manhattanDistance((x, y), (sX, sY))
ret += 1 / md
else:
md = circularManhattanDistance(snakePos, pos, XY_MAX,
GameState.ACTION_UP)
ret += 1 / md
else:
if y > sY:
md = manhattanDistance((x, y), (sX, sY))
ret += 1 / md
else:
md = circularManhattanDistance(snakePos, pos, XY_MAX,
GameState.ACTION_DOWN)
ret += 1 / md
return ret
def getMinCircularManhattanDistance(self, gameState):
'''
Returns the minimum circular manhattan distance.
Where circular is defined as a motion through the
ends of the grid (borders of the gird)
'''
md = []
foodPos = gameState.getFoodCordinate()
if None in foodPos:
return None
snakePos = gameState.getSnakeHeadCordinate()
temp = manhattanDistance(snakePos, foodPos)
md.append(temp)
if self.X_MAX is None:
self.X_MAX = gameState.numXCell - 1
self.Y_MAX = gameState.numYCell - 1
XY_MAX = (self.X_MAX, self.Y_MAX)
# Moving Up
md.append(
circularManhattanDistance(snakePos, foodPos, XY_MAX,
GameState.ACTION_UP))
# Moving into lower border
md.append(
circularManhattanDistance(snakePos, foodPos, XY_MAX,
GameState.ACTION_DOWN))
# Moving into left border
md.append(
circularManhattanDistance(snakePos, foodPos, XY_MAX,
GameState.ACTION_LEFT))
# Moving into right border
md.append(
circularManhattanDistance(snakePos, foodPos, XY_MAX,
GameState.ACTION_RIGHT))
return min(md)
def getFeatures(self, gameState, action):
# We don't want new food as we want to detect
# if the snake ate the food
successorGameState = gameState.generateSuccessor(action, newFood=False)
foodPos = successorGameState.getFoodCordinate()
if None in foodPos:
return {self.FOOD_VICINITY: 2.0}
snakePos = successorGameState.getSnakeHeadCordinate()
from dlsnake.base.util import manhattanDistance
foodVicinityFactor = manhattanDistance(foodPos, snakePos)
foodVicinityFactor = 1 / foodVicinityFactor
return {self.FOOD_VICINITY: foodVicinityFactor}
def getNextFoodCordinates(self, gameState):
'''
Returns None if no food is possible
'''
msg = 'FoodAgent.getNextFoodCordinates called even when '
msg += 'food is already present!'
# Make sure we are only called when there is no food
assert None in gameState.getFoodCordinate(), msg
if self.X_MAX is None:
self.X_MAX = gameState.numXCell
self.X_MIN = 0
self.Y_MAX = gameState.numYCell
self.Y_MIN = 0
self.__makeCornerCordinates()
# Make sure you can fetch a new food
totalCells = gameState.numXCell * gameState.numYCell
snakeCells = len(gameState.getSnakeCordinates())
if totalCells - snakeCells < 1:
return None, None
# find which corner the snake head is in
# and select the opposite corner
# if invalid:
# diagonally work for 5 moves
# if still invalid:
# select randomly and return
head = gameState.snake.getHead()
corners = self.corners
distances = [manhattanDistance(head, corner) for corner in corners]
maxIndex = distances.index(max(distances))
foodCords = corners[maxIndex]
validFood = self._FoodAgent__isValidFood(foodCords, gameState)
if validFood:
return foodCords
# The corner is occupied
fx, fy = foodCords
i = 0
while not validFood and i < 5:
fx, fy = self.__getDiagonallyNext(fx, fy)
validFood = self._FoodAgent__isValidFood((fx, fy), gameState)
i += 1
if validFood:
return fx, fy
while not validFood:
fx, fy = self._FoodAgent__randomFood()
validFood = self._FoodAgent__isValidFood((fx, fy), gameState)
return fx, fy
def getFeatures(self, gameState, action):
# We don't want new food as we want to detect
# if the snake ate the food
successorGameState = gameState.generateSuccessor(action, newFood=False)
foodPos = successorGameState.getFoodCordinate()
if None in foodPos:
foodVicinityFactor = 2.0
else:
snakePos = successorGameState.getSnakeHeadCordinate()
from dlsnake.base.util import manhattanDistance
foodVicinityFactor = manhattanDistance(foodPos, snakePos)
foodVicinityFactor = 1 / foodVicinityFactor
# Factor in the number of cells of the neighbor that
# are parts of the snake.
neighborCellCords = self.__getNeighborCellCords(successorGameState)
snakeCords = gameState.getSnakeCordinates()
oneNearestFactor = 0.0
newHead = successorGameState.getSnakeHeadCordinate()
# Detects if the new game state results in a crash
neighborCellCords.append(newHead)
for p in neighborCellCords:
if p in snakeCords:
oneNearestFactor -= 1.0
# How much score did we loose/gain (-1 to 1)
oldScore = gameState.score
newScore = successorGameState.score
scoreLostFactor = (newScore - oldScore)
# Can happen if gameOVer
if scoreLostFactor != 0:
scoreLostFactor = 1 / scoreLostFactor
# Length Factor
length = len(successorGameState.getSnakeCordinates())
length = 1 / length
comb = length * oneNearestFactor
return {
self.FOOD_VICINITY: foodVicinityFactor
# self.ONE_NEAREST_NEIGHBOURS: oneNearestFactor,
# self.SCORE_LOST: scoreLostFactor,
# self.LENGTH: length,
# self.COMB_LENGTH_NEIGHBOUR: comb
}
def evaluationFunction(self, gameState):
"""
A simple evaluation function
"""
msg = "No food in current game state! Did you call the evaluation "
msg += "function in the correct order?"
assert None not in gameState.getFoodCordinate(), msg
value = 0.0
foodCord = gameState.getFoodCordinate()
snakePos = gameState.getSnakeHeadCordinate()
from dlsnake.base.util import manhattanDistance
foodVicinityFactor = 0
if None not in foodCord:
foodVicinityFactor = manhattanDistance(snakePos, foodCord)
if foodVicinityFactor != 0:
value += 1.0 / foodVicinityFactor
else:
value += 1.0
scoreFactor = 0.1 * gameState.getScore()
value += scoreFactor
# We don't obviously want to die
if gameState.gameOver:
value -= 10
return value
def evaluationFunction(self, currentGameState, action):
"""
A simple evaluation function
"""
successorGameState = currentGameState.generateSuccessor(action)
value = 0.0
newFood = successorGameState.getFoodCordinate()
newPos = successorGameState.getSnakeHeadCordinate()
newScore = successorGameState.getScore()
oldScore = currentGameState.getScore()
from dlsnake.base.util import manhattanDistance
foodVicinityFactor = manhattanDistance(newPos, newFood)
scoreFactor = newScore - oldScore
if foodVicinityFactor != 0:
value += 1.0 / foodVicinityFactor
else:
value += 1.0
if scoreFactor != 0:
value += scoreFactor
# We don't obviously want to die
if successorGameState.gameOver:
value -= 10
return value
