Merge pull request 'astar implementation' (#3) from astar into master

Reviewed-on: #3

astar_search.py

@@ -0,0 +1,110 @@
+class Node:
+    def __init__(self, state, parent='', action='', distance=0):
+        self.state = state
+        self.parent = parent
+        self.action = action
+        self.distance = distance
+
+class Search:
+    def __init__(self, cell_size, cell_number):
+        self.cell_size = cell_size
+        self.cell_number = cell_number
+
+    def succ(self, state):
+        x = state[0]
+        y = state[1]
+        angle = state[2]
+        match(angle):
+            case 'UP':
+                possible = [['left', x, y, 'LEFT'], ['right', x, y, 'RIGHT']]
+                if y != 0: possible.append(['move', x, y - self.cell_size, 'UP'])
+                return possible
+            case 'RIGHT':
+                possible = [['left', x, y, 'UP'], ['right', x, y, 'DOWN']]
+                if x != self.cell_size*(self.cell_number-1): possible.append(['move', x + self.cell_size, y, 'RIGHT'])
+                return possible
+            case 'DOWN':
+                possible = [['left', x, y, 'RIGHT'], ['right', x, y, 'LEFT']]
+                if y != self.cell_size*(self.cell_number-1): possible.append(['move', x, y + self.cell_size, 'DOWN'])
+                return possible
+            case 'LEFT':
+                possible = [['left', x, y, 'DOWN'], ['right', x, y, 'UP']]
+                if x != 0: possible.append(['move', x - self.cell_size, y, 'LEFT'])
+                return possible
+
+    def cost(self, node, stones, goal, flowers):
+        # cost = node.distance
+        cost = 0
+        # cost += 10 if stones[node.state[0], node.state[1]] == 1 else 1
+        cost += 1000000 if (node.state[0], node.state[1]) in stones else 1
+        cost += 30 if (node.state[0], node.state[1]) in flowers else 1
+
+        if node.parent:
+            node = node.parent
+            cost += node.distance  # should return only elem.action in prod
+        return cost
+
+    def heuristic(self, node, goal):
+        return abs(node.state[0] - goal[0]) + abs(node.state[1] - goal[1])
+
+    #bandaid to know about stones
+    def astarsearch(self, istate, goaltest, stones, flowers):
+        
+        #to be expanded
+        def cost_old(x, y):
+            if (x, y) in stones:
+                return 10
+            else:
+                return 1
+
+        
+        x = istate[0]
+        y = istate[1]
+        angle = istate[2]
+
+        # fringe = [(Node([x, y, angle]), cost_old(x, y))]  # queue (moves/states to check)
+        fringe = [(Node([x, y, angle]))]  # queue (moves/states to check)
+        fringe[0].distance = self.cost(fringe[0], stones, goaltest, flowers)
+        fringe.append((Node([x, y, angle]), self.cost(fringe[0], stones, goaltest, flowers)))
+        fringe.pop(0)
+
+        explored = []
+
+        while True:
+            if len(fringe) == 0:
+                return False
+
+            fringe.sort(key=lambda x: x[1])
+            elem = fringe.pop(0)[0]
+
+            # if goal_test(elem.state):
+            #     return
+            # print(elem.state[0], elem.state[1], elem.state[2])
+            if elem.state[0] == goaltest[0] and elem.state[1] == goaltest[1]:  # checks if we reached the given point
+                steps = []
+                while elem.parent: 
+                    steps.append([elem.action, elem.state[0], elem.state[1]])  # should return only elem.action in prod
+                    elem = elem.parent
+
+                steps.reverse()
+                print(steps)  # only for dev
+                return steps
+
+            explored.append(elem.state)
+
+            for (action, state_x, state_y, state_angle) in self.succ(elem.state):
+                x = Node([state_x, state_y, state_angle], elem, action)
+                x.parent = elem
+
+                priority = self.cost(elem, stones, goaltest, flowers) + self.heuristic(elem, goaltest)
+                elem.distance = priority
+                # priority = cost_old(x, y) + self.heuristic(elem, goaltest)
+                fringe_states = [node.state for (node, p) in fringe]
+
+                if x.state not in fringe_states and x.state not in explored:
+                    fringe.append((x, priority))
+                elif x.state in fringe_states:
+                    for i in range(len(fringe)):
+                        if fringe[i][0].state == x.state:
+                            if fringe[i][1] > priority:
+                                fringe[i] = (x, priority)

blocks.py

@@ -5,6 +5,7 @@ import soil
 
 
 class Blocks:
+
     def __init__(self, parent_screen,cell_size):
         self.parent_screen = parent_screen
         self.flower_image = pygame.image.load(r'resources/flower.png').convert_alpha()
@@ -28,6 +29,9 @@ class Blocks:
 
         self.soil = soil.Soil()
 
+        self.stones = set()
+        #bandaid to let astar know about stones
+
     def locate_blocks(self, blocks_number, cell_number, body):
         for i in range(blocks_number):
             self.x = random.randint(0, cell_number-1)
@@ -47,6 +51,8 @@ class Blocks:
                 self.parent_screen.blit(self.alive_leaf_image, (x, y))
             if color == 'stone':
                 self.parent_screen.blit(self.stone_image, (x, y))
+                #bandaid to let astar know about stones
+                self.stones.add((x, y))
             if color == 'flower':
                 self.parent_screen.blit(self.flower_image, (x, y))
             if color == 'fawn_seed':

main.py

@@ -4,7 +4,7 @@ import random
 import land
 import tractor
 import blocks
-import graph_search
+import astar_search
 from pygame.locals import *
 
 
@@ -69,7 +69,7 @@ class Game:
         move_tractor_event = pygame.USEREVENT + 1
         pygame.time.set_timer(move_tractor_event, 1000)  # tractor moves every 1000 ms
         tractor_next_moves = []
-        graph_search_object = graph_search.Search(self.cell_size, self.cell_number)
+        astar_search_object = astar_search.Search(self.cell_size, self.cell_number)
 
         while running:
             clock.tick(60)  # manual fps control not to overwork the computer
@@ -100,8 +100,9 @@ class Game:
                         print("Generated target: ",random_x, random_y)
                         # below line should be later moved into tractor.py
                         angles = {0: 'UP', 90: 'RIGHT', 270: 'LEFT', 180: 'DOWN'}
-                        tractor_next_moves = graph_search_object.graphsearch(
+                        #bandaid to know about stones
-                            [self.tractor.x, self.tractor.y, angles[self.tractor.angle]], [random_x, random_y])
+                        tractor_next_moves = astar_search_object.astarsearch(
+                            [self.tractor.x, self.tractor.y, angles[self.tractor.angle]], [random_x, random_y], self.blocks.stones, self.flower_body)
                     else:
                         self.tractor.move(tractor_next_moves.pop(0)[0], self.cell_size, self.cell_number)
                 elif event.type == QUIT: