在 Pygame 中缩放窗口时出现不正确的图块编号问题

Question

您能否找出我的代码中的错误并解释为什么当我使用

int((mouse_x + scroll_x) // (tw / MAX_COL)), int((mouse_y // th / MAX_ROW))

并将鼠标悬停在某个图块上时，每次缩放窗口时它都会始终打印不正确的图块编号？例如，当引用图块(19, 0)时，打印的数字不正确，显示为(21, 0)，并且偏移量随着窗口比例的增大而增大或减小。仅当我首先滚动窗口时才会发生这种情况。我的代码：

import pygame as pg
import json

SCREEN_WIDTH = 1920
SCREEN_HEIGHT = 1080
ASPECT = SCREEN_WIDTH / SCREEN_HEIGHT
WIDTH = 640
HEIGHT = 360
TILE_SIZE = 32
MAX_COL = 20
MAX_ROW = 10

pg.init()

# 16:9 R
screen = pg.display.set_mode((WIDTH, HEIGHT), pg.RESIZABLE) # 0, 0
s = pg.Surface([WIDTH, HEIGHT])

pg.display.set_caption("Level editor")

scroll_x = 0

move_front = False
move_back = False

img = pg.image.load("rock.png") # .get_rect().colliderect() -> bool

world_data = []
for col in range(MAX_COL):
    world_data.append([-1 for i in range(MAX_ROW)])

def draw_world():
    for x, col in enumerate(world_data):
        for y, row in enumerate(col):
            if row >= 0:
                s.blit(img, (x * TILE_SIZE - scroll_x, y * TILE_SIZE))
    
    with open("data.json", "w") as file:
        json.dump(world_data, file)


def draw_grid():

    s.fill((255, 255, 255))

    for v in range(MAX_COL + 1):
        # vertical / col
        pg.draw.line(s, (0, 0, 0), (TILE_SIZE * v - scroll_x, 0), (TILE_SIZE * v - scroll_x, HEIGHT))
        # horizontal / row
    for h in range(MAX_ROW + 1):
        pg.draw.line(s, (0, 0, 0), (0 - scroll_x, TILE_SIZE * h), (MAX_COL * TILE_SIZE - scroll_x, TILE_SIZE * h))

def draw_bg():
    global tw, th
    sw = screen.get_width()
    sh = screen.get_height()
    tw = sw
    th = tw / ASPECT
    if th > sh:
        th = sh
        tw = th * ASPECT
    pad_x = sw / 2 - tw / 2
    pad_y = sh / 2 - th / 2

    f = pg.transform.scale(s, (tw ,th))
    screen.blit(f, (pad_x, pad_y))

while True:

    draw_grid()
    draw_world()
    draw_bg()

    if move_front: # move_right
        scroll_x += 1
    elif move_back:
        scroll_x -= 1

    mouse_x, mouse_y = pg.mouse.get_pos()

    grid_x = screen.get_width() / 2 - tw / 2
    grid_y = screen.get_height() / 2 - th / 2
    mouse_x -= grid_x
    mouse_y -= grid_y

    print(int((mouse_x + scroll_x) // (tw / MAX_COL)), int((mouse_y // th / MAX_ROW)))

    for event in pg.event.get():
        if event.type == pg.QUIT:
            pg.quit()
        if event.type == pg.KEYDOWN:
            if event.key == pg.K_d:
                move_front = True
            elif event.key == pg.K_a:
                move_back = True
        if event.type == pg.KEYUP:
            if event.key == pg.K_d:
                move_front = False
            elif event.key == pg.K_a:
                move_back = False
        if event.type == pg.MOUSEBUTTONDOWN:
            if mouse_x >= 0 and mouse_y >= 0:
                if mouse_x < tw and mouse_y < th:
                    pass

    pg.display.flip()

出现错误

我什么都试过了，但还是不行

Answer 1

问题在于您在计算列时缩放了

scroll_x

。但滚动是绝对的并且没有缩放：

print(int((mouse_x + scroll_x) // (tw / MAX_COL)), int((mouse_y // th / MAX_ROW)))

print(int(scroll_x / TILE_SIZE + mouse_x / (tw / MAX_COL)), int((mouse_y // (th / MAX_ROW))))