An event loop repeatedly checks for new input, dispatches responses, and continues until an exit event occurs. In a Pygame robot controller, it initializes the display, polls events, prints them, handles pygame.QUIT, and limits processing to a configured frame rate. section 7.4.1
def main():
pygame.init()
screen = pygame.display.set_mode(WINDOW_SIZE)
clock = pygame.time.Clock()
while True:
for event in pygame.event.get():
print('event detected:', event)
if event.type == pygame.QUIT:
pygame.quit()
return
clock.tick(FRAME_RATE)
Use this compact loop to initialize Pygame, fetch every available event, handle window closure, and maintain 60 checks per second. section 7.4.1
Processing a live camera stream
A camera loop captures one frame per iteration, checks for Q or Esc, runs face detection, displays the marked frame, and releases the capture device when exiting. section 9.4.4
def main():
cap = cv2.VideoCapture(0)
assert cap.isOpened(), 'Cannot open camera'
while cv2.waitKey(1) not in [ord('q'), ESC_KEY]:
ret, frame = cap.read()
assert ret, 'Cannot read frame from camera'
detect_face(frame)
cv2.imshow('preview', frame)
cap.release()
Adapt this OpenCV loop when the repeated work is reading camera frames and showing detection results rather than processing joystick or window events. section 9.4.4
