Pygame zero version

Pgzero/README.md

@@ -0,0 +1,12 @@
+
+Install with
+
+``
+pip install pgzero
+``
+
+Run with
+
+``
+pgzrun bugrace.py
+``

Pgzero/bugrace.py

@@ -0,0 +1,87 @@
+import math
+
+bug = Actor("bug")
+bug.pos = 170, 80
+bug.outside = False
+
+WIDTH = 480
+HEIGHT = 360
+GREEN = (0, 255, 0)
+
+
+def draw():
+    screen.clear()
+    screen.fill(GREEN)
+    screen.blit("track", (0, 0))
+    bug.draw()
+
+
+def update():
+    move(bug, 1)
+    stop_at_edge(bug)
+    if touching_color(bug, GREEN):
+        if not bug.outside:
+            print("Outside")
+        bug.outside = True
+    else:
+        if bug.outside:
+            print("Inside")
+        bug.outside = False
+
+
+def on_key_down(key):
+    if key == keys.LEFT:
+        bug.angle += 15
+    elif key == keys.RIGHT:
+        bug.angle -= 15
+
+
+def move(sprite, steps):
+    radians = math.pi / 180.0 * sprite.angle
+    dx = steps * math.cos(radians)
+    dy = steps * math.sin(radians)
+    sprite.left += dx
+    sprite.top -= dy
+
+
+def stop_at_edge(sprite):
+    if sprite.right >= WIDTH:
+        sprite.right = WIDTH
+    elif sprite.left <= 0:
+        sprite.left = 0
+    if sprite.bottom >= HEIGHT:
+        sprite.bottom = HEIGHT
+    elif sprite.top <= 0:
+        sprite.top = 0
+
+
+def touching_color(sprite, color):
+    def _scan_y(dx):
+        # Scan the contour of the sprite from top to middle
+        for y in range(ymin, halfheight + 1):
+            if sprite._surf.get_at((x, y))[3] == 0:  # If transparent
+                continue
+            worldx = int(sprite.left + x - dx)
+            worldy = int(sprite.top + y - 1)
+            return screen.surface.get_at((worldx, worldy)) == color
+        # Scan the contour of the sprite from bottom to middle
+        for y in range(ymax, halfheight - 1, -1):
+            if sprite._surf.get_at((x, y))[3] == 0:
+                continue
+            worldx = int(sprite.left + x - dx)
+            worldy = int(sprite.top + y + 1)
+            return screen.surface.get_at((worldx, worldy)) == color
+        return False
+
+    xmin, ymin, xmax, ymax = sprite._surf.get_bounding_rect()
+    halfwidth = int(0.5 * (xmax - xmin))
+    halfheight = int(0.5 * (xmax - xmin))
+    # Scan the contour of the sprite from left to middle
+    for x in range(xmin, halfwidth + 1):
+        if _scan_y(dx=-1):
+            return True
+    # Scan the contour of the sprite from right to middle
+    for x in range(xmax, halfwidth - 1, -1):
+        if _scan_y(dx=+1):
+            return True
+    return False