"""
This animation example shows how perform a radar sweep animation.
If Python and Arcade are installed, this example can be run from the command line with:
python -m arcade.examples.radar_sweep
"""
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
class Radar:
def __init__(self):
self.angle = 0
def update(self):
# Move the angle of the sweep.
self.angle += RADIANS_PER_FRAME
def draw(self):
""" Use this function to draw everything to the screen. """
# Calculate the end point of our radar sweep. Using math.
x = SWEEP_LENGTH * math.sin(self.angle) + CENTER_X
y = SWEEP_LENGTH * math.cos(self.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,
border_width=10,
num_segments=60)
class MyGame(arcade.Window):
""" Main application class. """
def __init__(self, width, height, title):
super().__init__(width, height, title)
# Create our rectangle
self.radar = Radar()
# Set background color
arcade.set_background_color(arcade.color.BLACK)
def on_update(self, delta_time):
# Move the rectangle
self.radar.update()
def on_draw(self):
""" Render the screen. """
# Clear screen
self.clear()
# Draw the rectangle
self.radar.draw()
def main():
""" Main function """
MyGame(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
arcade.run()
if __name__ == "__main__":
main()