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108 | """
Simple Snow
Based primarily on:
https://api.arcade.academy/en/latest/examples/sprite_collect_coins_move_down.html
Contributed to Python Arcade Library by Nicholas Hartunian
If Python and Arcade are installed, this example can be run from the command line with:
python -m arcade.examples.snow
"""
import random
import math
import arcade
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
SCREEN_TITLE = "Snow"
class Snowflake:
"""
Each instance of this class represents a single snowflake.
Based on drawing filled-circles.
"""
def __init__(self):
self.x = 0
self.y = 0
def reset_pos(self):
# Reset flake to random position above screen
self.y = random.randrange(SCREEN_HEIGHT, SCREEN_HEIGHT + 100)
self.x = random.randrange(SCREEN_WIDTH)
class MyGame(arcade.Window):
""" Main application class. """
def __init__(self, width, height, title):
""" Initializer """
# Calls "__init__" of parent class (arcade.Window) to setup screen
super().__init__(width, height, title)
# Sprite lists
self.snowflake_list = None
def start_snowfall(self):
""" Set up snowfall and initialize variables. """
self.snowflake_list = []
for i in range(50):
# Create snowflake instance
snowflake = Snowflake()
# Randomly position snowflake
snowflake.x = random.randrange(SCREEN_WIDTH)
snowflake.y = random.randrange(SCREEN_HEIGHT + 200)
# Set other variables for the snowflake
snowflake.size = random.randrange(4)
snowflake.speed = random.randrange(20, 40)
snowflake.angle = random.uniform(math.pi, math.pi * 2)
# Add snowflake to snowflake list
self.snowflake_list.append(snowflake)
# Don't show the mouse pointer
self.set_mouse_visible(False)
# Set the background color
arcade.set_background_color(arcade.color.BLACK)
def on_draw(self):
""" Render the screen. """
# This command is necessary before drawing
self.clear()
# Draw the current position of each snowflake
for snowflake in self.snowflake_list:
arcade.draw_circle_filled(snowflake.x, snowflake.y,
snowflake.size, arcade.color.WHITE)
def on_update(self, delta_time):
""" All the logic to move, and the game logic goes here. """
# Animate all the snowflakes falling
for snowflake in self.snowflake_list:
snowflake.y -= snowflake.speed * delta_time
# Check if snowflake has fallen below screen
if snowflake.y < 0:
snowflake.reset_pos()
# Some math to make the snowflakes move side to side
snowflake.x += snowflake.speed * math.cos(snowflake.angle) * delta_time
snowflake.angle += 1 * delta_time
def main():
window = MyGame(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
window.start_snowfall()
arcade.run()
if __name__ == "__main__":
main()
|