From 1569546ada9cdb0ff776908b008335dc95d853ab Mon Sep 17 00:00:00 2001
From: Florian Jung <flo@windfisch.org>
Date: Tue, 18 Aug 2015 03:03:49 +0200
Subject: pathfinding works \o/

it's still horribly slow (2 seconds calculation time), and atm it only
weighs every cell with a really large cost (so it avoids basically
everything). BUT HEY IT F***ING WORKS \o/
---
 pathfinding.py | 115 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 pathfinding.py

(limited to 'pathfinding.py')

diff --git a/pathfinding.py b/pathfinding.py
new file mode 100644
index 0000000..72de22d
--- /dev/null
+++ b/pathfinding.py
@@ -0,0 +1,115 @@
+from gui import marker, marker_updated
+import gui
+
+
+# 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
+        # assert that siblings are only in horizontal or vertical directions. otherwise
+        #        someone must replace the number "1" by appropriate distances
+        return manhattan(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,y - 1),(x,y + 1),(x+1,y)]]
+    return [link for link in links if link.value != None]
+
+def manhattan(point,point2):
+    return abs(point.point[0] - point2.point[0]) + abs(point.point[1]-point2.point[1])
+
+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 = manhattan(node, goal)
+                
+                node.parent = current
+                openset.add(node)
+    
+    raise ValueError('No Path Found')
+
+path = None
+grid_radius=1200
+grid_density=20
+
+class PathfindingTesterStrategy:
+    def __init__(self, c):
+        self.c = c
+
+    def process_frame(self):
+        global path
+
+        if marker_updated[0]:
+            marker_updated[0]=False
+
+            goalx = int((marker[0][0] - self.c.player.center[0] + grid_radius)/grid_density)
+            goaly = int((marker[0][1] - self.c.player.center[1] + grid_radius)/grid_density)
+            
+            grid = []
+            for x in range(-grid_radius,grid_radius+1,grid_density):
+                gridline = []
+                for y in range(-grid_radius,grid_radius+1,grid_density):
+                    val = 0
+
+                    for cell in self.c.player.world.cells.values():
+                        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:
+                            val += 100000000
+
+                    gridline.append(Node(None if (x in [-grid_radius,grid_radius] or y in [-grid_radius,grid_radius]) else val, (self.c.player.center[0]+x,self.c.player.center[1]+y), (int((x+grid_radius)/grid_density), int((y+grid_radius)/grid_density))))
+                grid.append(gridline)
+
+            path = aStar(grid[int(grid_radius/grid_density)][int(grid_radius/grid_density)], grid[goalx][goaly], grid)
+            for node in path:
+                print (node.point_in_grid)
+            print("="*10)
+
+
+        for (node1,node2) in zip(path,path[1:]):
+            gui.draw_line(node1.point, node2.point, (0,0,0))
+        return marker[0]
-- 
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