examples: Update conwaylife to work with new LCD API.

examples/pyb.py

@@ -6,8 +6,44 @@ def delay(n):
     pass
 
 rand_seed = 1
-def rand():
+def rng():
     global rand_seed
     # for these choice of numbers, see P L'Ecuyer, "Tables of linear congruential generators of different sizes and good lattice structure"
     rand_seed = (rand_seed * 653276) % 8388593
     return rand_seed
+
+# LCD testing object for PC
+# uses double buffering
+class LCD:
+    def __init__(self, port):
+        self.width = 128
+        self.height = 32
+        self.buf1 = [[0 for x in range(self.width)] for y in range(self.height)]
+        self.buf2 = [[0 for x in range(self.width)] for y in range(self.height)]
+
+    def light(self, value):
+        pass
+
+    def fill(self, value):
+        for y in range(self.height):
+            for x in range(self.width):
+                self.buf1[y][x] = self.buf2[y][x] = value
+
+    def show(self):
+        print('') # blank line to separate frames
+        for y in range(self.height):
+            for x in range(self.width):
+                self.buf1[y][x] = self.buf2[y][x]
+        for y in range(self.height):
+            row = ''.join(['*' if self.buf1[y][x] else ' ' for x in range(self.width)])
+            print(row)
+
+    def get(self, x, y):
+        if 0 <= x < self.width and 0 <= y < self.height:
+            return self.buf1[y][x]
+        else:
+            return 0
+
+    def pixel(self, x, y, value):
+        if 0 <= x < self.width and 0 <= y < self.height:
+            self.buf2[y][x] = value