1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 """ This animation example shows how perform a radar sweep animation. """ import arcade import math # Set up the constants SCREEN_WIDTH = 800 SCREEN_HEIGHT = 600 # 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) # These are function-specific variables. Before we # use them in our function, we need to give them initial # values. on_draw.angle = 0 # Open up our window arcade.open_window(SCREEN_WIDTH, SCREEN_HEIGHT, "Radar Sweep Example") 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()