The character only moves when mouse is moving

Question

I'm new in this world of programming, so I'm having some trouble making my first game. The character just moves when mouse is moving in the screen of the game, and I saw that I need to update the code inside the function, but I actually don't know how to do that, so I reorganized the code sometimes to see what happens, but I'm still having the problem. The game is not ready yet.

import pygame
from random import randrange


def eat(c1, c2):
    return c1[0] == c2[0] and c1[1] == c2[1]


UP = 0
RIGHT = 1
DOWN = 2
LEFT = 3

pygame.init()
SCREEN = pygame.display.set_mode((500, 500))
pygame.display.set_caption('Jogo da Cobrinha')
icon = pygame.image.load('snake_icon_game.png')
pygame.display.set_icon(icon)

snake = [(230, 250), (240, 250), (250, 250)]
snake_skin = pygame.Surface((10, 10))
snake_skin.fill((255, 255, 255))
current_direction = RIGHT

apple_position = (randrange(0, 500, 10), randrange(0, 500, 10))
apple_skin = pygame.image.load('apple_skin_game.png').convert_alpha()

score = 0

clock = pygame.time.Clock()
game_over = False

while not game_over:
    clock.tick(10)
    SCREEN.fill((0, 0, 0))

    for x in range(0, 500, 10):
        pygame.draw.line(SCREEN, (40, 40, 40), (x, 0), (x, 600))

    for y in range(0, 500, 10):
        pygame.draw.line(SCREEN, (40, 40, 40), (0, y), (600, y))

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP and current_direction != DOWN:
                current_direction = UP
            if event.key == pygame.K_RIGHT and current_direction != LEFT:
                current_direction = RIGHT
            if event.key == pygame.K_DOWN and current_direction != UP:
                current_direction = DOWN
            if event.key == pygame.K_LEFT and current_direction != RIGHT:
                current_direction = LEFT

        if current_direction == UP:
            snake[0] = (snake[0][0], snake[0][1] - 10)
        if current_direction == RIGHT:
            snake[0] = (snake[0][0] + 10, snake[0][1])
        if current_direction == DOWN:
            snake[0] = (snake[0][0], snake[0][1] + 10)
        if current_direction == LEFT:
            snake[0] = (snake[0][0] - 10, snake[0][1])

        for i in range(len(snake) - 1, 0, -1):
            snake[i] = (snake[i - 1][0], snake[i - 1][1])

        if eat(snake[0], apple_position):
            apple_position = (randrange(0, 500, 10), randrange(0, 500, 10))
            snake.append((0, 0))
            score += 10

        if snake[0][0] == 500 or snake[0][1] == 500 or snake[0][0] < 0 or snake[0][1] < 0:
            game_over = True

    SCREEN.blit(apple_skin, apple_position)

    for position in snake:
        SCREEN.blit(snake_skin, position)

    pygame.display.update()

Answer 1

Maybe it's just a paste-error, but your processing logic in the main loop is indented such that it only gets handled when events come though. This correlates with things stopping when the mouse is not moving inside the window (mouse movements generate events).

Note the difference:

while not game_over:
    clock.tick(10)
    SCREEN.fill((0, 0, 0))

    for x in range(0, 500, 10):
        pygame.draw.line(SCREEN, (40, 40, 40), (x, 0), (x, 600))

    for y in range(0, 500, 10):
        pygame.draw.line(SCREEN, (40, 40, 40), (0, y), (600, y))

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            exit()

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP and current_direction != DOWN:
                current_direction = UP
            if event.key == pygame.K_RIGHT and current_direction != LEFT:
                current_direction = RIGHT
            if event.key == pygame.K_DOWN and current_direction != UP:
                current_direction = DOWN
            if event.key == pygame.K_LEFT and current_direction != RIGHT:
                current_direction = LEFT

    # STARTING HERE -- INDENTATION FIX
    if current_direction == UP:
        snake[0] = (snake[0][0], snake[0][1] - 10)
    if current_direction == RIGHT:
        snake[0] = (snake[0][0] + 10, snake[0][1])
    if current_direction == DOWN:
        snake[0] = (snake[0][0], snake[0][1] + 10)
    if current_direction == LEFT:
        snake[0] = (snake[0][0] - 10, snake[0][1])

    for i in range(len(snake) - 1, 0, -1):
        snake[i] = (snake[i - 1][0], snake[i - 1][1])

    if eat(snake[0], apple_position):
        apple_position = (randrange(0, 500, 10), randrange(0, 500, 10))
        snake.append((0, 0))
        score += 10

    if snake[0][0] == 500 or snake[0][1] == 500 or snake[0][0] < 0 or snake[0][1] < 0:
        game_over = True

    SCREEN.blit(apple_skin, apple_position)

    for position in snake:
        SCREEN.blit(snake_skin, position)

    pygame.display.update()