Add initial touch screen example

Author: sfe-SparkFro

examples/ex04_touch_screen.py

@@ -0,0 +1,55 @@
+# Import OpenCV and hardware initialization module
+import cv2
+from cv2_hardware_init import *
+
+# Import NumPy
+from ulab import numpy as np
+
+# Initialize an image to draw on
+img = np.zeros((240, 320, 3), dtype=np.uint8)
+
+# Prompt the user to draw on the screen
+img = cv2.putText(img, "Touch to draw!", (10, 30), cv2.FONT_HERSHEY_SIMPLEX, 1, (255, 255, 255), 2)
+
+# Prompt the user to press a key to continue
+print("Press any key to continue")
+
+# Create variables to store touch coordinates and state
+x0, y0, x1, y1 = 0, 0, 0, 0
+touching = False
+
+# Loop to continuously read touch input and draw on the image
+while True:
+    # Read touch input
+    x, y, touch_num = touch_screen.get_touch()
+
+    # Update the touch coordinates and state
+    if touch_num > 0:
+        if not touching:
+            x0 = x
+            y0 = y
+            x1 = x
+            y1 = y
+            touching = True
+        else:
+            x0 = x1
+            y0 = y1
+            x1 = x
+            y1 = y
+    else:
+        if touching:
+            touching = False
+
+    # Draw a line if touching
+    if touching:
+        img = cv2.line(img, (x0, y0), (x1, y1), (255, 255, 255), 2)
+
+    # Display the frame
+    display.imshow(img)
+
+    # Check for key presses
+    key = cv2.waitKey(1)
+
+    # If any key is pressed, exit the loop
+    if key != -1:
+        break