無法使敵人向玩家移動

Question

我很難讓這個工作。 基本上，我希望我的敵人精靈追逐我的玩家精靈。 此刻，它會斜向移動到屏幕的右下邊緣。

我正在學習python我正在制作游戲而且還是新游戲所以我很抱歉這是一個非常簡單的事情，我遇到了問題。

相關代碼：

class Enemy(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)

        self.bitmap = pygame.image.load("ball.bmp")
        self.enemy_rect = self.bitmap.get_rect()
        self.enemy_rect.topleft = [100, 200]
        self.speed = 2

    def move_to_player(self, Player):
        dx, dy = self.enemy_rect.x - player.player_rect.x, self.enemy_rect.y - player.player_rect.y
        dist = math.hypot(dx, dy)
        if dist == 0:
            dist = 1
        else:
            dx, dy = dx / dist, dy / dist

        self.enemy_rect.x += dx * self.speed
        self.enemy_rect.y += dx * self.speed

while 1:  # main game loop
enemy.move_to_player(player) 

以及所有代碼，用於上下文：

import pygame
import sys
import pygame.locals
import math

pygame.init() 

size = width, height = 800, 500
colour = 100, 20, 30  # colour for background

screen = pygame.display.set_mode(size)
pygame.display.set_caption('Test')

class Player(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)

        self.bitmap = pygame.image.load("ball.bmp")
        self.player_rect = self.bitmap.get_rect(
        self.player_rect.topleft = [100, 200]

    def move(self, x, y):
        self.player_rect.centerx += x
        self.player_rect.centery += y

    def render(self):
        screen.blit(self.bitmap, (self.shipRect))

class Enemy(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)

        self.bitmap = pygame.image.load("ball.bmp")
        self.enemy_rect = self.bitmap.get_rect()
        self.enemy_rect.topleft = [100, 200]
        self.speed = 2

    def move_to_player(self, Player):
        dx, dy = self.enemy_rect.x - player.player_rect.x, self.enemy_rect.y - player.player_rect.y
        dist = math.hypot(dx, dy)
        if dist == 0:
            dist = 1
        else:
            dx, dy = dx / dist, dy / dist

        self.enemy_rect.x += dx * self.speed
        self.enemy_rect.y += dx * self.speed

player = Player()
enemy = Enemy()

player.player_rect.x = 50
player.player_rect.y = 50

enemy.enemy_rect.x = 500
enemy.enemy_rect.y = 300

while 1:  # main game loop
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_DOWN:
                player.move(0, 5)
            if event.key == pygame.K_UP:
                player.move(0, -5)
            if event.key == pygame.K_LEFT:
                player.move(-5, 0)
            if event.key == pygame.K_RIGHT:
                player.move(5, 0)

        if player.player_rect.colliderect(enemy.enemy_rect):
            pygame.display.set_caption('Hit!')

    screen.fill(colour)
    screen.blit(player.bitmap, player.player_rect)
    screen.blit(enemy.bitmap, enemy.enemy_rect)
    enemy.move_to_player(player)
    pygame.display.flip()

Answer 1

首先， self.enemy_rect.y += dx * self.speed可能應該是self.enemy_rect.y += dy * self.speed

其次，我認為你的數學是向后的，這樣你的敵人就會逃跑。 我們來試試一個簡單的例子：

Player at 0,0; enemy at 2,0.  
Expected result if speed = 2: both at 0,0
dx = 2, dy = 0 (before normalizing by hypot)
dx = 1, dy = 0 (after)
New result: player still at 0,0; enemy at 4,0

Answer 2

這就是我用於此...

if PlayerX > AI_X:
    AI_X += 3
if PlayerX < AI_X:
    AI_X -= 3
if PlayerY > AI_Y:
    AI_Y += 3
if PlayerY < AI_Y:
    AI_Y -= 3

希望這可以幫助！