emulator: support a refresh rate

emulator.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 """
@@ -32,6 +32,7 @@
 __email__ = '[email protected]'
 __status__ = 'Development'
 
+import select
 import sys
 import socket
 
@@ -60,6 +61,7 @@ def __init__(self, width=40, height=16, ip='127.0.0.1', port=1337, dotsize=10):
             self.matrix.append(0)
 
         self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        self.sock.setblocking(0)
         self.sock.bind((ip, port))
         # size is width * height * 3 (rgb) + 4 (checksum)
         self.packetsize = self.width * self.height * 3 + 4
@@ -68,10 +70,14 @@ def recv_data(self):
         """
         Grab the next frame and put it on the matrix.
         """
-        data, addr = self.sock.recvfrom(self.packetsize)
-        matrix = map(ord, data.strip())
-        if len(matrix) == self.packetsize:
-            self.matrix = matrix[:-4]
+        select.select([], [self.sock], [])
+        try:
+            data, addr = self.sock.recvfrom(self.packetsize)
+        except socket.error:
+            pass
+        else:
+            self.matrix = list(data.strip())[:self.packetsize-4]
+
 
     def update(self):
         """
@@ -81,8 +87,7 @@ def update(self):
         for x in range(self.width):
             for y in range(self.height):
                 pixel = y * self.width * 3 + x * 3
-                #TODO: sometimes the matrix is not as big as it should
-                if pixel < pixels:
+                if pixel < pixels - 2:
                     pygame.draw.circle(self.screen,
                                        (self.matrix[pixel], self.matrix[pixel + 1], self.matrix[pixel + 2]),
                                        (x * self.dotsize + self.dotsize / 2, y * self.dotsize + self.dotsize / 2), self.dotsize / 2, 0)
@@ -93,6 +98,7 @@ def render(self):
         """
         pygame.display.update()
         pygame.display.flip()
+        self.clock.tick(60)
 
     def gameloop(self):
         """