Jaga Kamera Tetap di Dalam Batas

Termasuk bagian Dunia Game dalam perjalanan Pygame di Coddy. Pelajaran 22 dari 35.

Kamera yang selalu memusatkan pemain akan menampilkan langit di sebelah kiri level saat mulai, dan hal yang sama setelah melewati ujungnya. Jaga agar kamera tetap berada di antara tepi level.

Posisi kamera paling kecil adalah 0: jendela dimulai dari tepi kiri level. Posisi paling besar adalah level_width - WIDTH: tepi kanan jendela berada di tepi kanan level. Batasi posisinya setelah mengikuti pemain:

camera_x = player.centerx - WIDTH // 2
camera_x = max(0, min(camera_x, level_width - WIDTH))

min menurunkan posisi kamera yang terlalu jauh ke kanan; max menaikkan posisi kamera yang terlalu jauh ke kiri. Di tengah level, keduanya tidak mengubah apa pun dan kamera tetap mengikuti pemain seperti sebelumnya. Di dekat ujung level, kamera berhenti dan pemain berjalan menuju tepi jendela. Begitulah perilaku kebanyakan game dengan tampilan gulir samping.

Tantangan

Mudah

Setelah camera_x = player.centerx - WIDTH // 2, batasi nilainya: camera_x = max(0, min(camera_x, level_width - WIDTH)).

Coba sendiri

import pygame

TILE = 36
WIDTH = 576
SPEED = 4
GRAVITY = 1
JUMP = -15
MAX_FALL = 12

LEVEL = [
    "................................................",
    "................................................",
    "#...........###..........####..........###.....#",
    "#..............................................#",
    "#.....####.........###.........###.............#",
    "#..............................................#",
    "#.P........#####.........######.........####...#",
    "#..............................................#",
    "#..............................................#",
    "################################################",
]

pygame.init()
screen = pygame.display.set_mode((WIDTH, 360))
pygame.display.set_caption("Camera")
clock = pygame.time.Clock()

block_img = pygame.image.load("assets/images/block.png").convert_alpha()
player_img = pygame.image.load("assets/images/player.png").convert_alpha()

walls = []
for row, line in enumerate(LEVEL):
    for col, char in enumerate(line):
        if char == "#":
            walls.append(pygame.Rect(col * TILE, row * TILE, TILE, TILE))
        elif char == "P":
            start = (col * TILE + TILE // 2, row * TILE + TILE)

level_width = len(LEVEL[0]) * TILE
player = player_img.get_rect(midbottom=start)
vel_y = 0
on_ground = False
camera_x = 0

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN and event.key in (pygame.K_SPACE, pygame.K_UP):
            if on_ground:
                vel_y = JUMP
        elif event.type == pygame.KEYUP and event.key in (pygame.K_SPACE, pygame.K_UP):
            if vel_y < -4:
                vel_y = -4

    keys = pygame.key.get_pressed()
    dx = 0
    if keys[pygame.K_LEFT]:
        dx -= SPEED
    if keys[pygame.K_RIGHT]:
        dx += SPEED

    player.x += dx
    for wall in walls:
        if player.colliderect(wall):
            if dx > 0:
                player.right = wall.left
            elif dx < 0:
                player.left = wall.right

    vel_y = min(vel_y + GRAVITY, MAX_FALL)
    player.y += vel_y
    on_ground = False
    for wall in walls:
        if player.colliderect(wall):
            if vel_y > 0:
                player.bottom = wall.top
                on_ground = True
            elif vel_y < 0:
                player.top = wall.bottom
            vel_y = 0

    camera_x = player.centerx - WIDTH // 2

    screen.fill((140, 200, 240))
    for wall in walls:
        screen.blit(block_img, (wall.x - camera_x, wall.y))
    screen.blit(player_img, (player.x - camera_x, player.y))
    pygame.display.flip()
    clock.tick(60)

pygame.quit()