def _render_indicators()

in gym/envs/box2d/car_racing.py [0:0]


    def _render_indicators(self, W, H):
        s = W / 40.0
        h = H / 40.0
        color = (0, 0, 0)
        polygon = [(W, H), (W, H - 5 * h), (0, H - 5 * h), (0, H)]
        pygame.draw.polygon(self.surf, color=color, points=polygon)

        def vertical_ind(place, val):
            return [
                (place * s, H - (h + h * val)),
                ((place + 1) * s, H - (h + h * val)),
                ((place + 1) * s, H - h),
                ((place + 0) * s, H - h),
            ]

        def horiz_ind(place, val):
            return [
                ((place + 0) * s, H - 4 * h),
                ((place + val) * s, H - 4 * h),
                ((place + val) * s, H - 2 * h),
                ((place + 0) * s, H - 2 * h),
            ]

        assert self.car is not None
        true_speed = np.sqrt(
            np.square(self.car.hull.linearVelocity[0])
            + np.square(self.car.hull.linearVelocity[1])
        )

        # simple wrapper to render if the indicator value is above a threshold
        def render_if_min(value, points, color):
            if abs(value) > 1e-4:
                pygame.draw.polygon(self.surf, points=points, color=color)

        render_if_min(true_speed, vertical_ind(5, 0.02 * true_speed), (255, 255, 255))
        # ABS sensors
        render_if_min(
            self.car.wheels[0].omega,
            vertical_ind(7, 0.01 * self.car.wheels[0].omega),
            (0, 0, 255),
        )
        render_if_min(
            self.car.wheels[1].omega,
            vertical_ind(8, 0.01 * self.car.wheels[1].omega),
            (0, 0, 255),
        )
        render_if_min(
            self.car.wheels[2].omega,
            vertical_ind(9, 0.01 * self.car.wheels[2].omega),
            (51, 0, 255),
        )
        render_if_min(
            self.car.wheels[3].omega,
            vertical_ind(10, 0.01 * self.car.wheels[3].omega),
            (51, 0, 255),
        )

        render_if_min(
            self.car.wheels[0].joint.angle,
            horiz_ind(20, -10.0 * self.car.wheels[0].joint.angle),
            (0, 255, 0),
        )
        render_if_min(
            self.car.hull.angularVelocity,
            horiz_ind(30, -0.8 * self.car.hull.angularVelocity),
            (255, 0, 0),
        )