1 files changed, 155 insertions, 0 deletions
diff --git a/pathfinding.py b/pathfinding.py
new file mode 100644
index 0000000..9386275
--- /dev/null
+++ b/pathfinding.py
@@ -0,0 +1,155 @@
+import math
+
+
+# A* code taken and adapted from https://gist.github.com/jamiees2/5531924
+
+class Node:
+    def __init__(self,value,point,point_in_grid):
+        self.value = value
+        self.point = point
+        self.point_in_grid = point_in_grid
+        self.parent = None
+        self.H = 0
+        self.G = 0
+
+    def move_cost(self,other):
+        # assert other in siblings(self,grid). otherwise this makes no sense
+        return distance(self, other) + (self.value + other.value)/2
+
+def siblings(point,grid):
+    x,y = point.point_in_grid
+    links = [grid[d[0]][d[1]] for d in [(x-1, y),(x-1,y-1),(x,y - 1),(x+1,y-1),(x+1,y),(x+1,y+1),(x,y + 1),(x-1,y+1)]]
+    return [link for link in links if link.value != None]
+
+def distance(point,point2):
+    return math.sqrt((point.point[0] - point2.point[0])**2 + (point.point[1]-point2.point[1])**2)
+
+def aStar(start, goal, grid):
+    print("aStar("+str(start.point)+"="+str(start.point_in_grid)+",  "+str(goal.point)+"="+str(goal.point_in_grid)+")")
+    openset = set()
+    closedset = set()
+    
+    current = start 
+    openset.add(current)
+   
+    while openset:
+        #Find the item in the open set with the lowest G + H score
+        current = min(openset, key=lambda o:o.G + o.H)
+        
+        #If it is the item we want, retrace the path and return it
+        if current == goal:
+            path = []
+            while current.parent:
+                path.append(current)
+                current = current.parent
+            path.append(current)
+            return path[::-1]
+        
+        openset.remove(current)
+        closedset.add(current)
+        
+        for node in siblings(current,grid):
+            if node in closedset:
+                continue
+            
+            if node in openset:
+                #Check if we beat the G score 
+                new_g = current.G + current.move_cost(node)
+                if node.G > new_g:
+                    #If so, update the node to have a new parent
+                    node.G = new_g
+                    node.parent = current
+            else:
+                #If it isn't in the open set, calculate the G and H score for the node
+                node.G = current.G + current.move_cost(node)
+                node.H = distance(node, goal)
+                
+                node.parent = current
+                openset.add(node)
+    
+    raise ValueError('No Path Found')
+
+grid_radius=int(1100/30)*30
+grid_density=30
+
+class PathfindingTesterStrategy:
+    def __init__(self, c, gui):
+        self.c = c
+        self.path = None
+        self.gui = gui
+
+    def build_grid(self):
+        grid = [[0 for x in range(int(2*grid_radius//grid_density+1))] for x in range(int(2*grid_radius//grid_density+1))]
+
+        interesting_cells = list(filter(lambda c : not (c.is_food or c in self.c.player.own_cells), self.c.player.world.cells.values()))
+
+        for cell in interesting_cells:
+            for x in range(-grid_radius,grid_radius+1,grid_density):
+                gridx = (x+grid_radius) // grid_density
+                for y in range(-grid_radius,grid_radius+1,grid_density):
+                    gridy = (y+grid_radius) // grid_density
+
+                    relpos = (cell.pos.x - (x+self.c.player.center.x), cell.pos.y - (y+self.c.player.center.y))
+                    dist_sq = relpos[0]**2 + relpos[1]**2
+                    if dist_sq < cell.size**2 *3:
+                        grid[gridx][gridy] += 100000000
+                
+        for x in range(-grid_radius,grid_radius+1,grid_density):
+            gridx = (x+grid_radius) // grid_density
+            for y in range(-grid_radius,grid_radius+1,grid_density):
+                gridy = (y+grid_radius) // grid_density
+                
+                if (gridx in [0,len(grid)-1] or gridy in [0, len(grid[gridx])-1]):
+                    val = None
+                else:
+                    val = grid[gridx][gridy]
+
+                grid[gridx][gridy] = Node(val, (self.c.player.center[0]+x,self.c.player.center[1]+y), (gridx, gridy))
+
+        return grid
+
+    def plan_path(self):
+        goalx = int((self.gui.marker[0][0] - self.c.player.center[0] + grid_radius)/grid_density)
+        goaly = int((self.gui.marker[0][1] - self.c.player.center[1] + grid_radius)/grid_density)
+        
+        grid = self.build_grid()
+
+        path = aStar(grid[int(grid_radius/grid_density)][int(grid_radius/grid_density)], grid[goalx][goaly], grid)
+        return path
+
+    def path_is_valid(self, path):
+        interesting_cells = list(filter(lambda c : not (c.is_food or c in self.c.player.own_cells), self.c.player.world.cells.values()))
+        for node in path:
+            for cell in interesting_cells:
+                relpos = (cell.pos.x - node.point[0], cell.pos.y - node.point[1])
+                dist_sq = relpos[0]**2 + relpos[1]**2
+                if dist_sq < cell.size**2 *2:
+                    return False
+
+        return True
+
+    def process_frame(self):
+        if self.gui.marker_updated[0]:
+            self.gui.marker_updated[0]=False
+            
+            self.path = self.plan_path()
+            for node in self.path:
+                print (node.point_in_grid)
+            print("="*10)
+
+
+        for (node1,node2) in zip(self.path,self.path[1:]):
+            self.gui.draw_line(node1.point, node2.point, (0,0,0))
+
+        if self.path:
+            relx, rely = self.path[0].point[0]-self.c.player.center.x, self.path[0].point[1]-self.c.player.center.y
+            if relx*relx + rely*rely < (2*grid_density)**2:
+                self.path=self.path[1:]
+
+        if self.path and not self.path_is_valid(self.path):
+            print("recalculating!")
+            self.path = self.plan_path()
+
+        if self.path:
+            return self.path[0].point
+        return self.gui.marker[0]