how to make sprite move upwards and downwards with joystick in pygame

问题

I am trying to create a project that I have made before but apart from this time I am going to be using a play-station one remote I was given for free from my school. The problem that when I move the joystick upwards and downwards it shows the same coordinates.(If you do not understand what I mean then look at the picture below). Then also I am not sure what I wold need to put into the if statement so that it checks if the joystick is upwards or downwards. I am also having trouble thinking on how you would check if the joystick is going in no direction.

I have already tried using an if statement where if the joystick is more than one number and less than another one (the first number being in the top half of the joystick and the other number meaning that it is in the bottom half of the joystick it will move downwards. The current if statement does not give off any errors but does not work. I have tried an if statement to check if it is in the middle but I am not too sure about it.

    joystick_count = pygame.joystick.get_count()
if joystick_count == 0:
    # No joysticks!
    print("Error, I didn't find any joysticks.")
else:
    # Use joystick #0 and initialize it
    joystick = pygame.joystick.Joystick(0)
    joystick.init()

if pygame.joystick.Joystick(0).get_axis(0) >= -0.0 and pygame.joystick.Joystick(0).get_axis(0) <= 0.0:
      player_one.speed_y = 5

elif pygame.joystick.Joystick(0).get_axis(0) > -0.1 and pygame.joystick.Joystick(0).get_axis(0) < -0.9:
    player_one.speed_y = -5

elif pygame.joystick(0).get_axis(0) == 0.0:
    player_one.speed_y = -5



#The first if statement checks if the joystick is up and the second one
#checks if the joystick is downwards
# the middle one checks if the if statement is in the middle (not too sure)
#player one and two speed is what gets added on each time

The actual results that are that the sprite does not move when the joystick is moved downwards.

Joystick axis

回答1:

First ensure that you have a joystick, by getting the number of joysticks by pygame.joystick.get_count(). Initialize the joystick by pygame.joystick.Joystick.init:

joystick = None
if pygame.joystick.get_count() > 0:
    joystick = pygame.joystick.Joystick(0)
    joystick.init()

Once a joystick is initialized, ist axis value can be get by pygame.joystick.Joystick.get_axis. The value returned by this function is in range [-1, 1]. -1 for the maximum negative tilt and +1 for the maximum positive tilt.
Note, each analog stick of a gamepad or joystick has 2 axis, one for the horizontal direction and 1 for the vertical direction. Since the amount of the value returned by get_axis() depends on the tilting of the analog stick you should multiply the speed by the value.
Further you should ignore values near 0 for the dead center, because of the inaccuracy of the hardware. This can be don by a simple check using the built in function abs(x) e.g. abs(axisval) > 0.1:

if joystick:
    axis_x, axis_y = (joystick.get_axis(0), joystick.get_axis(1))
    if abs(axis_x) > 0.1:
        player_one.speed_x = 5 * axis_x
    if abs(axis_y) > 0.1:
        player_one.speed_y = 5 * axis_y

See the following simple demo app:

import pygame
pygame.init()

size = (800,600)
screen = pygame.display.set_mode(size)
clock = pygame.time.Clock()
pos = [size[0]/2, size[1]/2]
speed = 5
joystick = None

done = False
while not done:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
        elif event.type == pygame.KEYDOWN:
            if event.key==pygame.K_RETURN:
                done = True

    if joystick:
        axis_x, axis_y = (joystick.get_axis(0), joystick.get_axis(1))
        if abs(axis_x) > 0.1:
            pos[0] += speed * axis_x
        if abs(axis_y) > 0.1:
            pos[1] += speed * axis_y
    else:
        if pygame.joystick.get_count() > 0:
            joystick = pygame.joystick.Joystick(0)
            joystick.init()
            print("joystick initialized")

    screen.fill((0, 0, 255))
    pygame.draw.rect(screen, (255,255,255), (*pos, 10, 10))
    pygame.display.flip()

来源：https://stackoverflow.com/questions/54677539/how-to-make-sprite-move-upwards-and-downwards-with-joystick-in-pygame

标签

python

pygame

joystick