sync with current state

apps/fading_pixels.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import numpy as np
+import pygame
+
+Nx = int(sys.argv[1])
+Ny = int(sys.argv[2])
+try:
+    fps = float(sys.argv[3])
+except (IndexError, ValueError):
+    fps = 1.0
+
+
+def point2idx(x,y):
+    return 3*(x+Nx*y)
+
+def set_pixel_max(buffer, x, y):
+    idx = point2idx(x,y)
+    for i in range(3):
+        buffer[idx+i] = max(0x00, buffer[idx+i]-1)
+
+def set_pixel_rand(buffer, x, y):
+    idx = point2idx(x,y)
+    for i in range(3):
+        buffer[idx+i] = np.random.randint(0x00, 0xff)
+
+clock = pygame.time.Clock()
+buffer = bytearray(b"\x00"*(3*Nx*Ny))
+
+i = 0
+while True:
+    i = i + 1
+    for px in range(Nx):
+        for py in range(Ny):
+            set_pixel_max(buffer, px, py)
+    for j in range(10):
+        set_pixel_rand(buffer, np.random.randint(0, Nx), np.random.randint(0, Ny))
+        if i > 100:
+            os.write(1, buffer)
+            clock.tick_busy_loop(fps)