问题描述
我对 Pygame 2(实际上是一般的 Python)很陌生,我想为学校制作一个小游戏。我使用了 this 中的代码,但是当我按下 SPACE 时,我无法让它移向光标。我不希望它在 x/y 轴上移动... 这是代码顺便说一句
import sys,pygame,math
from pygame.locals import *
spaceship = ('spaceship.png')
mouse_c = ('cursor.png')
backg = ('background.jpg')
lazer = pygame.mixer.sound("pew.WAV")
pygame.init()
display_width = 1280
display_height = 720
screen = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption("Space Survival")
bk = pygame.image.load(backg).convert_alpha()
space_ship = pygame.image.load(spaceship).convert_alpha()
mousec = pygame.image.load(mouse_c).convert_alpha()
clock = pygame.time.Clock()
pygame.mouse.set_visible(False)
Ammo = 20
Fuel = 200
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
elif event.type == MOUSEBUTTONDOWN and event.button == 1 and Ammo <= 20:
print("Pew")
pygame.mixer.sound.play(lazer)
elif event.type == MOUSEBUTTONDOWN and event.button == 3 and Fuel <= 200:
print("Boost")
screen.blit(bk,(0,0))
pos = pygame.mouse.get_pos()
angle = 270-math.atan2(pos[1]-(display_height/2),pos[0]-(display_width/2))*180/math.pi
rotimage = pygame.transform.rotate(space_ship,angle)
rect = rotimage.get_rect(center=((display_width/2),(display_height/2)))
screen.blit(rotimage,rect) #I need space_ship to rotate towards my cursor
screen.blit(mousec,(pos))
pygame.display.update()
clock.tick(60) #FPS
在 Python 3.8 上运行 Pygame 2.0。 任何提示将不胜感激:)
解决方法
编写一个“跟随目标”的函数:
def FollowMe(pops,fpos,step):
# [...]
我建议计算飞船和鼠标之间的距离以及从 (fpos
) 到 (pops
) 的单位方向向量。
距离可以通过计算Euclidean distance得到。 Pygame 为此提供了 distance_to()
。单位方向向量可以通过将方向向量除以距离或通过归一化(normalize()
)方向向量来计算:
target_vector = pygame.math.Vector2(pops)
follower_vector = pygame.math.Vector2(fpos)
distance = follower_vector.distance_to(target_vector)
direction_vector = target_vector - follower_vector
if distance > 0:
direction_vector /= distance
现在您可以定义一个精确的 step_distance
并沿着精灵的方向移动到跟随者:
if distance > 0:
new_follower_vector = follower_vector + direction_vector * step_distance.
定义一个 step
并确保步距不大于步距:
step_distance = min(distance,step)
最大步距为
max_step = distance - minimum_distance
把它们放在一起:
def FollowMe(pops,step):
target_vector = pygame.math.Vector2(pops)
follower_vector = pygame.math.Vector2(fpos)
new_follower_vector = pygame.math.Vector2(fpos)
distance = follower_vector.distance_to(target_vector)
if distance > 0:
direction_vector = (target_vector - follower_vector) / distance
step_distance = min(distance,step)
new_follower_vector = follower_vector + direction_vector * step_distance
return (new_follower_vector.x,new_follower_vector.y)
另见How to make smooth movement in pygame。
当按下SPACE时,使用该函数沿鼠标方向移动飞船,使用pygame.key.get_pressed()
移动飞船。 pygame.key.get_pressed()
返回一个包含每个键状态的列表。如果某个键被按下,则该键的状态为 True
,否则为 False
。使用 pygame.key.get_pressed()
评估按钮的当前状态并获得连续移动:
ship_pos = display_width // 2,display_height // 2
while True:
# [...]
keys = pygame.key.get_pressed()
if keys[pygame.K_SPACE]:
ship_pos = FollowMe(pos,ship_pos,3)
angle = 270-math.atan2(pos[1]-ship_pos[1],pos[0]-ship_pos[0])*180/math.pi
rotimage = pygame.transform.rotate(space_ship,angle)
rect = rotimage.get_rect(center=ship_pos)
有关图像的旋转,请参阅 How to rotate an image(player) to the mouse direction? 和 How do I rotate an image around its center using PyGame?
另见Rotate towards target or mouse各自的Move towards target和问题的答案How do I rotate a sprite towards the mouse and move it?
不使用任何外部资源(声音和图像)的最小示例:
import sys,pygame,math
from pygame.locals import *
pygame.init()
def FollowMe(pops,new_follower_vector.y)
display_width = 1280
display_height = 720
screen = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption("Space Survival")
clock = pygame.time.Clock()
bk = pygame.Surface(screen.get_size())
space_ship = pygame.Surface((20,50),pygame.SRCALPHA)
space_ship.fill((0,255,0))
mousec = pygame.Surface((20,20),pygame.SRCALPHA)
mousec.fill((255,0))
ship_pos = display_width // 2,display_height // 2
while True:
clock.tick(60)
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
pos = pygame.mouse.get_pos()
keys = pygame.key.get_pressed()
if keys[pygame.K_SPACE]:
ship_pos = FollowMe(pos,angle)
rect = rotimage.get_rect(center=ship_pos)
screen.blit(bk,(0,0))
screen.blit(rotimage,rect)
screen.blit(mousec,pos)
pygame.display.update()