Add animation example

Author: sfe-SparkFro

opencv-examples/ex07_animation.py

@@ -0,0 +1,61 @@
+#-------------------------------------------------------------------------------
+# SPDX-License-Identifier: MIT
+# 
+# Copyright (c) 2025 SparkFun Electronics
+#-------------------------------------------------------------------------------
+# ex07_animation.py
+# 
+# This example demonstrates how to play an animation using a series of frames
+# stored in a single image file. It assumes full 320x240 frames are stacked
+# vertically in the image, and the animation plays by displaying each frame in
+# sequence. This can be the basis for things like sprite sheets, where smaller
+# icons or characters are stored in a single image and displayed as needed.
+#-------------------------------------------------------------------------------
+
+# Import OpenCV and hardware initialization module
+import cv2 as cv
+from cv2_hardware_init import *
+
+# Load an animation sheet image that contains multiple frames of an animation
+animation_sheet = cv.imread("opencv-examples/images/animation_sheet.png")
+
+# This example assumes the image has full 320x240 frames stacked vertically
+frame_height = 240
+
+# Calculate the number of frames in the sheet by dividing the sheet height by
+# the frame height
+frame_num = animation_sheet.shape[0] // frame_height
+
+# Initialize variables to keep track of the current row in the sheet and the
+# direction of animation playback (up or down)
+row_index = 0
+direction = 1
+
+# Prompt the user to press a key to continue
+print("Press any key to continue")
+
+# Loop to continuously play the animation
+while True:
+    # Calculate the starting and ending pixel row for the current frame
+    row_start_px = row_index * frame_height
+    row_end_px = row_start_px + frame_height
+    cv.imshow(display, animation_sheet[row_start_px:row_end_px, :])
+
+    # Update the row index based on the direction of playback
+    row_index += direction
+
+    # If we reach the end of the sheet, reverse the direction
+    if row_index == frame_num-1:
+        direction = -1
+    elif row_index == 0:
+        direction = 1
+
+    # Check for key presses. If you want the animation to play at a specific
+    # frame rate, you can change the wait time to slow it down. This example
+    # plays the animation as fast as possible, which is often needed to look
+    # smooth in MicroPython
+    key = cv.waitKey(1)
+
+    # If any key is pressed, exit the loop
+    if key != -1:
+        break