Add support for saving the raw output to a file

diff --git a/pygame-vertical-scrolling-map.py b/pygame-vertical-scrolling-map.py
index 75227e1..90e1af0 100755 (executable)
--- a/pygame-vertical-scrolling-map.py
+++ b/pygame-vertical-scrolling-map.py
@@ -21,6 +21,8 @@
 # https://www.cs.ucsb.edu/~pconrad/cs5nm/topics/pygame/drawing/
 
 import pygame
+import sys
+import os
 
 IMAGE_PATH = 'road.png'
 SCREEN_WIDTH = 800
@@ -99,6 +101,14 @@ def main():
     except:
         joystick = None
 
+    if len(sys.argv) > 1:
+        if sys.argv[1] == '-':
+            outputfile = sys.stdout.fileno()
+        else:
+            outputfile = os.open(sys.argv[1], os.O_WRONLY)
+    else:
+        outputfile = None
+
     clock = pygame.time.Clock()
 
     fps = 30
@@ -129,6 +139,10 @@ def main():
         screen.blit(background.convert(), (0, 0))
         scrolling_map.draw(screen)
 
+        if outputfile:
+            buf = pygame.image.tostring(pygame.display.get_surface(), "RGB", False)
+            os.write(outputfile, buf)
+
         pygame.display.update()
 
     pygame.quit()