How to add score tracker in PyGame Snake game?

Question

I've been working on a Snake game in python 3.8 with PyGame as a side project. I've got all of the basics down, the only thing I am having trouble with is adding a score tracker.

def main():
    global width, rows, s, snack
    title()
    width = 500
    rows = 20
    win = pygame.display.set_mode((width, width)) # Creates the screen, sets resolution
    s = snake((0,255,0), (10,10))    # Sets snake colour to green and starting position
    snack = cube(randomSnack(rows, s), colour=(255,0,0))
    score = 0
    flag = True

    white = (255, 255, 255)

    message = score
    font = pygame.font.Font('Fonts/PressStart2P-vaV7.ttf', 30)
    text = font.render(str(message), True, (255, 255, 255))
    win.blit(text, (120,30))
    pygame.display.flip()

    clock = pygame.time.Clock()    # Creates clock object that can change refresh rate

    while flag:
        pygame.time.delay(50)    # Delays by 50 ms, makes it so snake cannot move 10 blocks a second
        clock.tick(10)    # Sets max refresh rate
        s.move()
        if s.body[0].position == snack.position:
            s.addCube()
            score += 1
            print(score)
            snack = cube(randomSnack(rows, s), colour=(255,0,0))    # Randomizes snack position and sets colour as red

        for x in range(len(s.body)):    
            if s.body[x].position in list(map(lambda z:z.position,s.body[x+1:])):   # This checks if you die
                print('Score: ', len(s.body))
                s.reset((10,10))
                break

The score is in the while flag part, It pops up for a brief moment at the start then disappears. Spacing is a bit messed up on the question but the actual code works fine. The score just flashes and goes away

Your code to display the score is outside the while loop - `text = font.render(str(message), True, (255, 255, 255)); win.blit(text, (120,30))`. It needs to be called both before and inside the while loop, perhaps my putting it into a separate function and calling it from both places. Alternatively adjust the other parts of your code that show the snake so that they also show the updated score. — Stuart, Jan 17 '20 at 22:57
inside `while` loop you have to draw/blit all elements - snake, snack, score - and later send buffer on screen using `pygame.display.flip()` — furas, Jan 17 '20 at 23:18

score 0 · Answer 1 · answered Jan 18 '20 at 09:25

You have to do the drawing in the main application loop. The main application loop continuously redraws the entire scene. The main application loop has to do the following:

handle the events and change game sates dependent on the events and time
clear the display
draw the scene
update the display

Create the initial score Surface before the main application loop. Create a new score Surface when the score has changed. Draw the sore in the main application loop:

def main():
    global width, rows, s, snack
    title()
    width = 500
    rows = 20
    win = pygame.display.set_mode((width, width)) # Creates the screen, sets resolution
    s = snake((0,255,0), (10,10))    # Sets snake colour to green and starting position
    snack = cube(randomSnack(rows, s), colour=(255,0,0))
    score = 0
    flag = True
    white = (255, 255, 255)

    # create score surface
    message = score
    font = pygame.font.Font('Fonts/PressStart2P-vaV7.ttf', 30)
    text = font.render(str(message), True, (255, 255, 255))

    clock = pygame.time.Clock()    # Creates clock object that can change refresh rate

    while flag:
        pygame.time.delay(50)    # Delays by 50 ms, makes it so snake cannot move 10 blocks a second
        clock.tick(10)    # Sets max refresh rate

        # handle the events
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                flag = False

        s.move()
        if s.body[0].position == snack.position:
            s.addCube()
            score += 1

            # update score surface
            message = score
            text = font.render(str(message), True, (255, 255, 255))

            print(score)
            snack = cube(randomSnack(rows, s), colour=(255,0,0))    # Randomizes snack position and sets colour as red

        for x in range(len(s.body)):    
            if s.body[x].position in list(map(lambda z:z.position,s.body[x+1:])):   # This checks if you die
                print('Score: ', len(s.body))
                s.reset((10,10))
                break

        # clear the display
        # [...]

        # draw the score
        win.blit(text, (120,30))

        # draw the snake etc.
        # [...]

        pygame.display.flip()

How to add score tracker in PyGame Snake game?

1 Answers1