Python坐标函数

Question

我已经把木乃伊编程到我的游戏中，我想让他们跟着我的玩家。我想做一个函数，我可以用它来应用于我选择创建的所有敌人，但我有一个不是很有效。木乃伊会产卵，但他们不会跟着玩家。如何更改函数以使其工作？在

import random
import pygame
import sys
import time
from pygame import mixer

screenx = 800
screeny = 600

clock = pygame.time.Clock()

#PICTURES
#name = pygame.display.set_caption('Brutal Survival')
#win = pygame.display.set_mode((screenx,screeny))
#player_right = pygame.image.load('maincharright.png')
#player_left = pygame.image.load('maincharleft.png')
#player_up = pygame.image.load('maincharup.png')
#player_down = pygame.image.load('mainchardown.png')
#background = pygame.image.load('background.jpg')
#mummychar = pygame.image.load('mummychar.png')

randomspawnabove = (random.randint(0, screenx), -100)
randomspawnbelow = (random.randint(0, screenx), (screeny + 100))
randomspawnleft = (-100, random.randint(0, screeny))
randomspawnright = ((screenx + 100), random.randint(0, screeny))

enemyalive = True
multiplier = 2
level = 1
nextlevel = True
spawn = True
up = True
down = False
left = False
right = False
run = True


class player():
    def __init__(self, x, y, width, height):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.alive = True
        self.vel = 5

class enemy():
    def __init__(self, x, y, width, height):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.alive = False
        self.vel = 2

def enemyfollow(self):
    if self.alive == True and self.x > mainChar.x:
        self.x = self.x - self.vel
    if self.alive == True and self.x < mainChar.x:
        self.x = self.x + self.vel
    if self.alive == True and self.y > mainChar.y:
        self.y = self.y - self.vel
    if self.alive == True and self.y < mainChar.y:
        self.y = self.y + self.vel


def redrawScreen():
    pygame.display.update()
    if run == True:
        win.blit(background, (0,0))
    if up == True and left == False and right == False and down == False:
        win.blit(player_up, (mainChar.x, mainChar.y))
    if up == False and left == False and right == False and down == True:
        win.blit(player_down, (mainChar.x, mainChar.y))
    if up == False and left == False and right == True and down == False:
        win.blit(player_right, (mainChar.x, mainChar.y))
    if up == False and left == True and right == False and down == False:
        win.blit(player_left, (mainChar.x, mainChar.y))
    if enemyalive == True:
        win.blit(mummychar, (mummy1.x, mummy1.y))
        enemyfollow(mummy1)


mainChar = player(screenx/2 - 30, screeny/2, 60, 60)
maxenemies = (level * multiplier)
mummy_Spawn = [randomspawnleft, randomspawnright, randomspawnabove, randomspawnbelow]
mummy1 = enemy(*random.choice(mummy_Spawn), 50, 50)

while run:
    clock.tick(60)

    keys = pygame.key.get_pressed()
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False
            pygame.quit()

    for x in range(maxenemies):
        Enemies.append(enemy(*random.choice(mummy_Spawn), 50, 50))

    if nextlevel == True:
        if level >= 1:
            enemyalive = True

    if keys[pygame.K_ESCAPE]:
        run = False
        pygame.quit()
    if keys[pygame.K_UP]:
        mainChar.y = mainChar.y - mainChar.vel
        up = True
        down = False
        left = False
        right = False
    if keys[pygame.K_DOWN]:
        mainChar.y = mainChar.y + mainChar.vel
        down = True
        left = False
        up = False
        right = False
    if keys[pygame.K_RIGHT]:
        mainChar.x = mainChar.x + mainChar.vel
        right = True
        left = False
        up = False
        down = False
    if keys[pygame.K_LEFT]:
        mainChar.x = mainChar.x - mainChar.vel
        left = True
        right = False
        down = False
        up = False
    if (mainChar.y + mainChar.height) > screeny:
        mainChar.y = mainChar.y - 5
    if mainChar.y < 0:
        mainChar.y = mainChar.y + 5
    if mainChar.x < 0:
        mainChar.x = mainChar.x + 5
    if (mainChar.x + mainChar.width) > screenx:
        mainChar.x = mainChar.x - 5

    redrawScreen()

Answer 1

此版本的代码可以工作。我认为主要的问题是enemy.alive默认为False的组合，我不确定重新绘制的顺序。在

因为我必须用我自己的一些位图来替换位图，所以我对常量大小的参数做了进一步的修改——尤其是50x50的大小，但是还有其他一些参数。在

我花了不少时间才对我有用，而且我有点迷路了。在

import random
import pygame
import sys
import time
from pygame import mixer

screenx = 800
screeny = 600

clock = pygame.time.Clock()

#PICTURES
name = pygame.display.set_caption('Brutal Survival')
win = pygame.display.set_mode((screenx,screeny))
player_right = pygame.image.load('maincharright.png')
player_left = pygame.image.load('maincharleft.png')
player_up = pygame.image.load('maincharup.png')
player_down = pygame.image.load('mainchardown.png')
background = pygame.image.load('background.jpg')
mummychar = pygame.image.load('mummychar.png')

# stretch background to fit window
background = pygame.transform.smoothscale( background, ( screenx, screeny) )

randomspawnabove = (random.randint(0, screenx), -100)
randomspawnbelow = (random.randint(0, screenx), (screeny + 100))
randomspawnleft = (-100, random.randint(0, screeny))
randomspawnright = ((screenx + 100), random.randint(0, screeny))

enemyalive = True
multiplier = 2
level = 1
nextlevel = True
spawn = True
up = True
down = False
left = False
right = False
run = True


class player():
    def __init__(self, x, y, width, height):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.alive = True
        self.vel = 5

class enemy():
    def __init__(self, x, y, width, height):
        self.x      = x
        self.y      = y
        self.width  = width
        self.height = height
        self.alive  = True
        self.vel    = 2

    def enemyfollow(self, player_pos):
        play_x, play_y = player_pos
        if self.alive == True and self.x > play_x:
            self.x = self.x - self.vel
        elif self.alive == True and self.x < play_x:
            self.x = self.x + self.vel
        if self.alive == True and self.y > play_y:
            self.y = self.y - self.vel
        elif self.alive == True and self.y < play_y:
            self.y = self.y + self.vel


def redrawScreen( player_image, Enemies ):
    win.blit(background, (0,0))
    win.blit(player_image, (mainChar.x, mainChar.y))
    for e in Enemies:
        if e.alive == True:
            win.blit(mummychar, (e.x, e.y))
    pygame.display.update()


mainChar     = player(screenx/2 - 30, screeny/2, 60, 60)
maxenemies   = (level * multiplier)
mummy_Spawn  = [randomspawnleft, randomspawnright, randomspawnabove, randomspawnbelow]
player_image = player_left

# Create some enemies:
Enemies = []
for x in range(maxenemies):
    Enemies.append(enemy(random.randrange(0, screenx), random.randrange(0, screeny), mummychar.get_rect().width, mummychar.get_rect().height))

while run:
    clock.tick(60)

    keys = pygame.key.get_pressed()
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    for i in range(maxenemies):
        Enemies[i].enemyfollow( (mainChar.x, mainChar.y) )

    if nextlevel == True:
        if level >= 1:
            enemyalive = True

    if keys[pygame.K_ESCAPE]:
        run = False
    if keys[pygame.K_UP]:
        mainChar.y = mainChar.y - mainChar.vel
        player_image = player_up
    if keys[pygame.K_DOWN]:
        mainChar.y = mainChar.y + mainChar.vel
        player_image = player_down
    if keys[pygame.K_RIGHT]:
        mainChar.x = mainChar.x + mainChar.vel
        player_image = player_right
    if keys[pygame.K_LEFT]:
        mainChar.x = mainChar.x - mainChar.vel
        player_image = player_left

    if (mainChar.y + mainChar.height) > screeny:
        mainChar.y = mainChar.y - 5
    if mainChar.y < 0:
        mainChar.y = mainChar.y + 5
    if mainChar.x < 0:
        mainChar.x = mainChar.x + 5
    if (mainChar.x + mainChar.width) > screenx:
        mainChar.x = mainChar.x - 5

    redrawScreen( player_image, Enemies )

pygame.quit()

Answer 2

if语句的一部分是if self == True，但是{}是False

Answer 3

所以木乃伊需要跟随玩家的目标。进一步完善此问题描述：

Every time a Mummy moves, it should be in the direction of the Player.

那我们怎么做呢？在

想象一下，我们从木乃伊的位置画一支箭给玩家。这将确定木乃伊应该移动的方向。在形式（数学）术语中，这是一个方向向量。为了求出方向向量，我们求出两点之间的直线，然后用它的长度除以直线的长度使之正规化。在

结果我们得到了一个简单的x和y单位向量，它们的分量可以乘以物体的速度来获得它的下一个位置。在

在下面的例子中，有3个精灵将向鼠标的位置移动。重要的部分是MySprite.update()函数。这将获取鼠标位置（在您的例子中，这是玩家）和精灵的位置（木乃伊位置），使用这两点来计算向量。一旦确定了矢量，分量将与精灵的速度一起用于计算下一个位置。我把位置保持在内部作为一个浮动，这样可以更好地处理小角度的变化和低速。在

import pygame
import random
import math

# Window size
WINDOW_WIDTH=400
WINDOW_HEIGHT=400

BLACK = (50,50,50)


class MySprite( pygame.sprite.Sprite ):
    def __init__( self, filename ):
        pygame.sprite.Sprite.__init__(self)
        self.image  = pygame.image.load(filename).convert_alpha()
        self.rect   = self.image.get_rect()
        self.speed  = random.randrange( 1, 3 )
        self.xfloat = random.randrange( 0, WINDOW_WIDTH )
        self.yfloat = random.randrange( 0, WINDOW_HEIGHT )
        self.rect.center = ( int( self.xfloat ), int( self.yfloat ) )

    def update( self ):
        # Re-compute our new movement vector based on the mouse every update
        # so we always move towards the mouse
        mouse_pos = pygame.mouse.get_pos()
        if ( mouse_pos != (0, 0) ):
            my_pos    = [ self.rect.centerx, self.rect.centery ]
            dir_vector= self.normalisedMovementVector( my_pos, mouse_pos )
            x_delta = self.speed * dir_vector[0]
            y_delta = self.speed * dir_vector[1]
            self.xfloat += x_delta
            self.yfloat += y_delta
            self.rect.center = ( int(self.xfloat), int(self.yfloat) )

    def lineLength( self, pointa, pointb ):
        """ Return the length of a line between the two points, in pixels """
        x1,y1 = pointa
        x2,y2 = pointb
        # length = sqrt((x2 - x1)^2 + (y2 - y1)^2)
        x_squared = (x2 - x1) * (x2 - x1)
        y_squared = (y2 - y1) * (y2 - y1)
        length = math.sqrt( x_squared + y_squared )
        return length

    def normalisedMovementVector( self, pointa, pointb ):
        """ Return a normalised vector between to points """
        # offset it from (0,0) to make calculations simpler
        # since it's a *direction* the actual positions don't matter
        pointb = (pointb[0]-pointa[0], pointb[1]-pointa[1])
        length = self.lineLength( (0,0), pointb )
        # normalise it (divide by it's own length)
        if ( length > 0 ):
            x = pointb[0] / length
            y = pointb[1] / length
            move_vector = ( x , y )
        else:
            # catch division by zero
            move_vector = ( 0, 0 )
        return move_vector




### MAIN
# Initialise the window
pygame.init()
SURFACE_TYPE = pygame.HWSURFACE|pygame.DOUBLEBUF|pygame.RESIZABLE
WINDOW  = pygame.display.set_mode( ( WINDOW_WIDTH, WINDOW_HEIGHT ), SURFACE_TYPE )
pygame.display.set_caption("Follow Mouse")

# Add some sprites
SPRITES = pygame.sprite.Group()
for i in range(3):
    s = MySprite( 'tiny_alien.png' )
    SPRITES.add( s ) # Put in sprites group

# tick tick tick
clock = pygame.time.Clock()

# Main loop
done = False
while not done:

    # Move the sprites (nd checks for collisions)
    SPRITES.update()

    # Handle user input
    for event in pygame.event.get():
        if ( event.type == pygame.QUIT ):
            done = True
        elif ( event.type == pygame.VIDEORESIZE ):
            WINDOW_WIDTH  = event.w
            WINDOW_HEIGHT = event.h
            WINDOW  = pygame.display.set_mode( ( WINDOW_WIDTH, WINDOW_HEIGHT ), SURFACE_TYPE )

    # Paint the screen
    WINDOW.fill( BLACK )
    SPRITES.draw( WINDOW )
    pygame.display.flip()
    clock.tick_busy_loop( 60 )

# Bye
pygame.quit()

任何PNG图像都可以替换tiny_alien.png。在

gif的画面有点不自然，但有点不自然