Display snowflakes falling using arcade library in Python

arcade library is a Python library for creating 2D arcade style video games and simulations. If you want to use the arcade library to create a snowing effect, you can first create a new arcade window and set a dark blue background color to represent the night sky.

Using the arcade library in Python

The arcade library is a Python library used for developing 2D games and applications. It provides a simple interface to create interactive graphics and animations. In this article, we'll use the arcade library to create a simple snowfall animation.

To get started, we need to install the arcade library. You can do this by running the following command in your terminal or command prompt −

pip install arcade

Once the installation is completed, we can start writing our code. Here's a simple program that displays snowfall −

import arcade
import random

SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
SNOWFLAKE_SIZE = 64

class Snowflake:
   def __init__(self):
      self.x = random.randrange(SCREEN_WIDTH)
      self.y = SCREEN_HEIGHT + SNOWFLAKE_SIZE
      self.speed = random.randrange(5, 20)
      self.angle = random.uniform(0, 2 * 3.1415)
        
   def update(self):
      self.x += self.speed * math.sin(self.angle)
      self.y -= self.speed * math.cos(self.angle)
      if self.y < -SNOWFLAKE_SIZE:
         self.y = SCREEN_HEIGHT + SNOWFLAKE_SIZE
         self.x = random.randrange(SCREEN_WIDTH)
        
   def draw(self):
      arcade.draw_circle_filled(self.x, self.y, SNOWFLAKE_SIZE, arcade.color.WHITE)
        
class Snowfall(arcade.Window):
   def __init__(self, width, height):
      super().__init__(width, height, "Snowfall")
      arcade.set_background_color(arcade.color.BLUE_GRAY)
      self.snowflakes = []
      for i in range(100):
         self.snowflakes.append(Snowflake())
            
   def on_draw(self):
      arcade.start_render()
      for snowflake in self.snowflakes:
         snowflake.draw()
            
   def on_update(self, delta_time):
      for snowflake in self.snowflakes:
         snowflake.update()

if __name__ == "__main__":
   window = Snowfall(SCREEN_WIDTH, SCREEN_HEIGHT)
   arcade.run()

Output

Next, you can create a list of snowflakes, where each snowflake is represented as a tuple of (x, y, size) values. The x and y values ​​represent the snowflake's position on the screen, and the size value represents the snowflake's size.

On each frame of the game loop, you update the position of each snowflake by adding a small random amount to its y-value. You can also check if the snowflake has fallen from the bottom of the screen, and if so, reset its position to a random x value at the top of the screen.

Finally, you can draw each snowflake on the screen using the arcade.draw_circle_filled() function, which accepts (x, y) position and size values ​​as parameters.

Let's go over the code step-by-step.

First, we import the arcade library and the random module, which we'll use to generate random values ​​for the snowflakes. We also define some constants: SCREEN_WIDTH and SCREEN_HEIGHT, which define the size of our window, and SNOWFLAKE_SIZE, which defines the size of our snowflakes.

Next, we define a Snowflake class. This class represents a single snowflake. In the constructor, we generate random values ​​for the snowflake's position, speed, and angle. The update() method updates the snowflake's position based on its speed and angle. If the snowflake falls off the bottom of the screen, we reset its position to the top of the screen. The draw() method draws the snowflake on the screen using the arcade.draw_circle_filled() function.

After that, we define a Snowfall class. This class represents our main application window. In the constructor, we set the background color to blue-gray and create a list of 100 snowflakes. In the on_draw() method, we iterate over the list of snowflakes and call each snowflake's draw() method. In the on_update() method, we iterate over the list of snowflakes and call each snowflake's update() method.

Finally, we create an instance of the Snowfall class and call arcade.run() to start the application.

This code creates a Snowflake class to represent each snowflake, and a SnowfallGame class to manage the game loop and draw the snowflakes on the screen. The on_draw() method is called each frame to draw the snowflakes, and the on_update() method is called each frame to update the position of the snowflakes. The arcade.run() function starts the game loop and keeps the window open until the user closes it.

That's it! When you run the program, you should see a window with snowflakes falling on the screen.

In addition, Python provides a turtle drawing function, and we can use turtle drawing to achieve the snowflake effect shown below.

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