clean up prototype

getting_started/prototype_opencv.py

@@ -3,7 +3,7 @@
 
 Install dependencies:
 
-    pip install numpy opencv-python
+    pip install opencv-python
 """
 import numpy as np
 import cv2
@@ -13,37 +13,41 @@
 SCREEN_SIZE_X, SCREEN_SIZE_Y = 640, 640
 TILE_SIZE = 64
 
-size2x = lambda a: np.kron(a, np.ones((2, 2, 1), dtype=a.dtype))
 
-# load image and extract square tiles from it
-wall = size2x(cv2.imread('tiles/wall.png'))
-player = size2x(cv2.imread('tiles/deep_elf_high_priest.png'))
+def draw_player(background, player, x, y):
+    """draws the player image on the screen"""
+    frame = background.copy()
+    xpos, ypos = x * TILE_SIZE, y * TILE_SIZE
+    frame[ypos : ypos + TILE_SIZE, xpos : xpos + TILE_SIZE] = player
+    cv2.imshow("frame", frame)
+
+
+def double_size(img):
+    """returns an image twice as big"""
+    return np.kron(img, np.ones((2, 2, 1), dtype=img.dtype))
 
-# define boundaries of the 2D grid
-min_x, max_x = 0, SCREEN_SIZE_X // TILE_SIZE
-min_y, max_y = 0, SCREEN_SIZE_Y // TILE_SIZE
 
-# NumPy array used as background (BGR color channels)
+# load image
+player = double_size(cv2.imread("tiles/deep_elf_high_priest.png"))
+
+# create black background image with BGR color channels
 background = np.zeros((SCREEN_SIZE_Y, SCREEN_SIZE_X, 3), np.uint8)
 
-# starting position of the player
+# starting position of the player in dungeon
 x, y = 4, 4
 
-while True:
+exit_pressed = False
 
-    # draw
-    frame = background.copy()
-    xpos, ypos = x * TILE_SIZE, y * TILE_SIZE
-    frame[ypos:ypos + TILE_SIZE, xpos:xpos + TILE_SIZE] = player
-    cv2.imshow('frame', frame)
+while not exit_pressed:
+    draw_player(background, player, x, y)
 
     # handle keyboard input
     key = chr(cv2.waitKey(1) & 0xFF)
-    if key == 'q':
-        break
-    elif key == 'd':
+    if key == "d":
         x += 1
-    elif key == 'a':
+    elif key == "a":
         x -= 1
+    elif key == "q":
+        exit_pressed = True
 
 cv2.destroyAllWindows()