arcade.draw_lines() draws random data when passed an empty list when a camera is activated

[daynebatten]

Pretty much what it says on the tin. If you have a camera active, draw some points, and then call draw_lines() with an empty list, you'll get lines between the points, as if Arcade is re-using some kind of memory buffer or something.

Minimal example:

import arcade

# Set up the constants
WINDOW_WIDTH = 800
WINDOW_HEIGHT = 600
WINDOW_TITLE = "draw_lines bug"


class GameView(arcade.View):
    def __init__(self):
        super().__init__()
        self.background_color = arcade.color.BLACK
        self.camera = arcade.camera.Camera2D(position=(WINDOW_WIDTH / 2, WINDOW_HEIGHT / 2))

    def on_draw(self):
        self.clear()

        with self.camera.activate():
            # Draw some points
            arcade.draw_points([(100, 100), (200, 200), (300, 300), (400, 400)], arcade.color.RED, 5)

            # Draw an empty list of lines
            arcade.draw_lines([], arcade.color.RED, 3)

def main():
    window = arcade.Window(WINDOW_WIDTH, WINDOW_HEIGHT, WINDOW_TITLE)
    game = GameView()
    window.show_view(game)
    arcade.run()

if __name__ == "__main__":
    main()

Here's what Arcade shows for this code:

Correct output would obviously just be to show the 4 points.

[einarf]

Thanks. That shouldn't be too difficult to fix.

[einarf]

https://github.com/pythonarcade/arcade/pull/2737