A State Variable

Part of the Game Rules section of Coddy's Pygame journey. Lesson 1 of 29.

Right now a hit closes the window. A game should stop and show what happened instead. The program needs to remember which part of the game it is in: playing, or over.

Keep that in one variable, a state, holding a short string:

state = "play"
...
if state == "play":
    # move the player and the rock
    if rock.colliderect(player):
        state = "over"

Only the code under if state == "play": moves things, so when the state becomes "over" everything freezes. The loop keeps running: it still reads events, draws and ticks the clock, so the window stays open and can show a message.

A string reads well in the code. A test like state == "over" says what it means, and the next lessons add more states the same way.

Challenge

Easy

Before the loop, add state = "play".
Put the keys, the player and the rock code under if state == "play":.
When the rock hits the player, set state = "over" instead of running = False.
After drawing the score, when state == "over", show Game over centred at (240, 160).

Try it yourself

import random
import pygame

pygame.init()
screen = pygame.display.set_mode((480, 360))
pygame.display.set_caption("Meteor Dodge")
clock = pygame.time.Clock()
font = pygame.font.Font(None, 32)

player = pygame.Rect(220, 300, 40, 40)
rock = pygame.Rect(random.randint(0, 456), -24, 24, 24)
score = 0

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        player.x -= 6
    if keys[pygame.K_RIGHT]:
        player.x += 6
    player.clamp_ip(screen.get_rect())

    rock.y += 4
    if rock.top > 360:
        rock.y = -24
        rock.x = random.randint(0, 456)
        score += 1
    if rock.colliderect(player):
        running = False

    screen.fill((30, 30, 46))
    pygame.draw.rect(screen, (255, 196, 0), player)
    pygame.draw.rect(screen, (235, 80, 80), rock)
    score_text = font.render(f"Score: {score}", True, (240, 240, 240))
    screen.blit(score_text, (10, 10))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()