import arcade

import math

# Set up the constants

SCREEN_WIDTH = 800

SCREEN_HEIGHT = 600

SCREEN_TITLE = "Radar Sweep Example"

# These constants control the particulars about the radar

CENTER_X = SCREEN_WIDTH // 2

CENTER_Y = SCREEN_HEIGHT // 2

RADIANS_PER_FRAME = 0.02

SWEEP_LENGTH = 250

def on_draw(_delta_time):

""" Use this function to draw everything to the screen. """

# Move the angle of the sweep.

on_draw.angle += RADIANS_PER_FRAME

# Calculate the end point of our radar sweep. Using math.

x = SWEEP_LENGTH * math.sin(on_draw.angle) + CENTER_X

y = SWEEP_LENGTH * math.cos(on_draw.angle) + CENTER_Y

# Start the render. This must happen before any drawing

# commands. We do NOT need an stop render command.

arcade.start_render()

# Draw the radar line

arcade.draw_line(CENTER_X, CENTER_Y, x, y, arcade.color.OLIVE, 4)

# Draw the outline of the radar

arcade.draw_circle_outline(CENTER_X, CENTER_Y, SWEEP_LENGTH,

arcade.color.DARK_GREEN, 10)

# This is a function-specific variable. Before we

# use them in our function, we need to give them initial

# values.

on_draw.angle = 0 # type: ignore # dynamic attribute on function obj

def main():

# Open up our window

arcade.open_window(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)

arcade.set_background_color(arcade.color.BLACK)

# Tell the computer to call the draw command at the specified interval.

arcade.schedule(on_draw, 1 / 80)

# Run the program

arcade.run()

# When done running the program, close the window.

arcade.close_window()

if __name__ == "__main__":

main()