pyscript · tildebyte · Jul 4, 2022
diff --git a/examples/bouncy-bubbles-p5js/bouncy_bubbles.py b/examples/bouncy-bubbles-p5js/bouncy_bubbles.py
@@ -0,0 +1,96 @@
+# Bouncy Bubbles
+# based on code from Keith Peters. Multiple-object collision.
+# Adapted from https://p5js.org/examples/motion-bouncy-bubbles.html
+# Port to pyscript by Ben Alkov, 2022-07
+
+# We could also use p5.js' math functions, but might as well use Python's
+import math
+
+# Not strictly necessary, but seeing naked e.g. `document`, `window`, etc. really bothers me
+import js
+
+from pyodide import create_proxy
+
+NUM_BALLS = 13
+SPRING = 0.05
+GRAVITY = 0.03
+FRICTION = -0.9
+BALLS = []
+HEIGHT = 400
+WIDTH = 720
+
+# Convenience
+p5js = js.window
+
+
+class Ball():
+    def __init__(self, x, y, dia):
+        self.x = x
+        self.y = y
+        self.diameter = dia
+        self.vx = 0
+        self.vy = 0
+
+    def collide(self):
+        for other_ball in BALLS:
+            dx = other_ball.x - self.x
+            dy = other_ball.y - self.y
+            distance = math.sqrt(dx * dx + dy * dy)
+            min_dist = other_ball.diameter / 2 + self.diameter / 2
+            if (distance < min_dist):
+                angle = math.atan2(dy, dx)
+                targetX = self.x + math.cos(angle) * min_dist
+                targetY = self.y + math.sin(angle) * min_dist
+                ax = (targetX - other_ball.x) * SPRING
+                ay = (targetY - other_ball.y) * SPRING
+                self.vx -= ax
+                self.vy -= ay
+                other_ball.vx += ax
+                other_ball.vy += ay
+
+    def move(self):
+        self.vy += GRAVITY
+        self.x += self.vx
+        self.y += self.vy
+        if self.x + self.diameter / 2 > WIDTH:
+            self.x = WIDTH - self.diameter / 2
+            self.vx *= FRICTION
+        elif self.x - self.diameter / 2 < 0:
+            self.x = self.diameter / 2
+            self.vx *= FRICTION
+
+        if self.y + self.diameter / 2 > HEIGHT:
+            self.y = HEIGHT - self.diameter / 2
+            self.vy *= FRICTION
+        elif (self.y - self.diameter / 2 < 0):
+            self.y = self.diameter / 2
+            self.vy *= FRICTION
+
+    def display(self):
+        p5js.ellipse(self.x, self.y, self.diameter, self.diameter)
+
+
+# These functions are named per convention: p5.js doesn't know anything about them
+
+def setup():
+    global BALLS
+
+    p5js.createCanvas(WIDTH, HEIGHT)
+    BALLS = [Ball(p5js.random(WIDTH), p5js.random(HEIGHT), p5js.random(30, 70))
+             for _ in range(NUM_BALLS)]
+    p5js.noStroke()
+    p5js.fill(255, 204)
+    p5js.background(0)
+
+
+def draw(*args):
+    p5js.background(0)
+    for ball in BALLS:
+        ball.collide()
+        ball.move()
+        ball.display()
+    p5js.requestAnimationFrame(create_proxy(draw))
+
+
+setup()
+js.window.requestAnimationFrame(create_proxy(draw))
diff --git a/examples/bouncy-bubbles-p5js/index.html b/examples/bouncy-bubbles-p5js/index.html
@@ -0,0 +1,24 @@
+<!--
+  contributor: ben.alkov@gmail.com
+  tags: p5js, external-libs, graphics, animation
+-->
+
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <title>Bouncy Bubbles</title>
+  <link rel="stylesheet" href="https://pyscript.net/alpha/pyscript.css" />
+  <script defer src="https://pyscript.net/alpha/pyscript.js"></script>
+  <py-config>
+    - autoclose_loader: true
+  </py-config>
+</head>
+  <body>
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.4.1/p5.js"></script>
+    <script>
+      function setup() {}
+    </script>
+    <py-script src="bouncy_bubbles.py"></py-script>
+  </body>
+</html>
diff --git a/tests/test_examples.py b/tests/test_examples.py
@@ -33,7 +33,8 @@
 ]
 
 EXAMPLES = [
-    "hello_world"
+    "hello_world",
+    "bouncy-bubbles-p5js",
 ]
 
 TEST_PARAMS = {
@@ -42,6 +43,11 @@
         "pattern": "\\d+:\\d+:\\d+",
         "title": "PyScript Hello World",
     },
+    "bouncy-bubbles-p5js": {
+        "file": "bouncy-bubbles-p5js/index.html",
+        "pattern": "false",
+        "title": "Bouncy Bubbles",
+    },
 }
 
 
@@ -87,16 +93,17 @@ def test_examples(example, http_server):
         # DOM from within the timing loop for a string that is not present in the
         # initial markup but should appear by way of rendering
 
-        re_sub_content = re.compile(TEST_PARAMS[example]["pattern"])
-        py_rendered = False  # Flag to be set to True when condition met
+        if TEST_PARAMS[example]["pattern"] != "false":
+            re_sub_content = re.compile(TEST_PARAMS[example]["pattern"])
+            py_rendered = False  # Flag to be set to True when condition met
 
-        for _ in range(TEST_ITERATIONS):
-            time.sleep(TEST_TIME_INCREMENT)
-            content = page.inner_html("*")
-            if re_sub_content.search(content):
-                py_rendered = True
-                break
+            for _ in range(TEST_ITERATIONS):
+                time.sleep(TEST_TIME_INCREMENT)
+                content = page.inner_html("*")
+                if re_sub_content.search(content):
+                    py_rendered = True
+                    break
 
-        assert py_rendered  # nosec
+            assert py_rendered  # nosec
 
         browser.close()