问题描述
在我正在创建的基于图块的rpg中,我试图实现一个使播放器在图块之间平滑移动的功能。我已经在播放器更新和getkeys函数中应用了此功能。当玩家在四个方向中的任意一个方向上移动时,程序应计算玩家应降落的下一个图块,直到它们降落在该图块上为止,玩家应在两个图块之间平滑移动。
但是,我创建的功能无法正确定位播放器。该功能不足以应对下一个图块应位于的位置,从而导致播放器移出网格,从而导致碰撞错误。
import sys
vec = pg.math.Vector2
WHITE = ( 255,255,255)
BLACK = ( 0,0)
RED = ( 255,0)
YELLOW = ( 255,0)
BLUE = ( 0,255)
WIDTH = 512 # 32 by 24 tiles
HEIGHT = 384
FPS = 60
TILESIZE = 32
PLAYER_SPEED = 3 * TILESIZE
MAP = ["1111111111111111","1..............1","1...........P..1","1..1111........1","1..1..1........1","1........11111.1","1........1...1.1","1111111111111111"]
def collide_hit_rect(one,two):
return one.hit_rect.colliderect(two.rect)
def player_collisions(sprite,group):
hits_walls = pg.sprite.spritecollide(sprite,group,False,collide_hit_rect)
if hits_walls:
sprite.pos -= sprite.vel * TILESIZE
class Player(pg.sprite.Sprite):
def __init__(self,game,x,y):
self.groups = game.all_sprites
pg.sprite.Sprite.__init__(self,self.groups)
self.game = game
self.walk_buffer = 200
self.vel = vec(0,0)
self.pos = vec(x,y) *TILESIZE
self.dirvec = vec(0,0)
self.last_pos = self.pos
self.next_pos = vec(0,0)
self.current_frame = 0
self.last_update = pg.time.get_ticks()
self.walking = True
self.between_tiles = False
self.walking_sprites = [pg.Surface((TILESIZE,TILESIZE))]
self.walking_sprites[0].fill(YELLOW)
self.image = self.walking_sprites[0]
self.rect = self.image.get_rect()
self.hit_rect = self.rect
self.hit_rect.bottom = self.rect.bottom
def update(self):
self.get_keys()
self.rect = self.image.get_rect()
self.rect.topleft = self.pos
if self.pos == self.next_pos:
self.between_tiles = False
if self.between_tiles:
self.pos += self.vel * self.game.dt
self.hit_rect.topleft = self.pos
player_collisions(self,self.game.walls) # may change postion
self.hit_rect.topleft = self.pos # reset rectangle
self.rect.midbottom = self.hit_rect.midbottom
def get_keys(self):
self.dirvec = vec(0,0)
Now = pg.time.get_ticks()
keys = pg.key.get_pressed()
if Now - self.last_update > self.walk_buffer:
self.vel = vec(0,0)
self.last_update = Now
if keys[pg.K_LEFT] or keys[pg.K_a]:
self.dirvec.x = -1
self.vel.x = -PLAYER_SPEED
elif keys[pg.K_RIGHT] or keys[pg.K_d]:
self.dirvec.x = 1
self.vel.x = PLAYER_SPEED
elif keys[pg.K_UP] or keys[pg.K_w]:
self.dirvec.y = -1
self.vel.y = -PLAYER_SPEED
elif keys[pg.K_DOWN] or keys[pg.K_s]:
self.dirvec.y = 1
self.vel.y = PLAYER_SPEED
if self.dirvec != vec(0,0):
self.between_tiles = True
self.walking = True
## self.offset = self.vel * self.game.dt
self.last_pos = self.pos
self.next_pos = self.pos + self.dirvec * TILESIZE
else:
self.between_tiles = False
self.walking = False
class Obstacle(pg.sprite.Sprite):
def __init__(self,y):
self.groups = game.walls
pg.sprite.Sprite.__init__(self,self.groups)
self.x = x * TILESIZE
self.y = y * TILESIZE
self.w = TILESIZE
self.h = TILESIZE
self.game = game
self.image = pg.Surface((self.w,self.h))
self.image.fill(BLACK)
self.rect = self.image.get_rect()
self.hit_rect = self.rect
self.rect.x = self.x
self.rect.y = self.y
class Game:
def __init__(self):
pg.init()
self.screen = pg.display.set_mode((WIDTH,HEIGHT))
pg.display.set_caption("Hello Stack Overflow")
self.clock = pg.time.Clock()
pg.key.set_repeat(500,100)
def new(self):
self.all_sprites = pg.sprite.Group()
self.walls = pg.sprite.Group()
for row,tiles in enumerate(MAP):
for col,tile in enumerate(tiles):
if tile == "1":
Obstacle(self,col,row)
elif tile == "P":
print("banana!")
self.player = Player(self,row)
def quit(self):
pg.quit()
sys.exit()
def run(self):
# game loop - set self.playing = False to end the game
self.playing = True
while self.playing:
self.dt = self.clock.tick(FPS) / 1000
self.events()
self.update()
self.draw()
def events(self):
# catch all events here
for event in pg.event.get():
if event.type == pg.QUIT:
self.quit()
def update(self):
self.player.update()
def draw(self):
self.screen.fill(WHITE)
for wall in self.walls:
self.screen.blit(wall.image,wall.rect)
for sprite in self.all_sprites:
self.screen.blit(sprite.image,sprite.rect)
pg.display.flip()
# create the game object
g = Game()
while True:
g.new()
g.run()
pg.quit()
TL; DR更新和getkeys函数错误地计算了玩家也应该移动的下一个图块的位置,从而导致它们从图块网格上掉下来并产生了碰撞错误
解决方法
有一些问题。
确保仅在按键时更改运动状态属性。按下键时,设置变量new_dir_vec
。根据新的运动方向更改运动方向和状态变量。
new_dir_vec = vec(0,0)
if keys[pg.K_LEFT] or keys[pg.K_a]:
new_dir_vec = vec(-1,0)
# [...]
if new_dir_vec != vec(0,0):
self.dirvec = new_dir_vec
# [...]
目标位置(next_pos
)必须与网格对齐。计算当前单元格的索引和目标位置:
current_index = self.rect.centerx // TILESIZE,self.rect.centery // TILESIZE
self.last_pos = vec(current_index) * TILESIZE
self.next_pos = self.last_pos + self.dirvec * TILESIZE
完整方法get_keys
:
class Player(pg.sprite.Sprite):
# [...]
def get_keys(self):
now = pg.time.get_ticks()
keys = pg.key.get_pressed()
if now - self.last_update > self.walk_buffer:
self.last_update = now
new_dir_vec = vec(0,0)
if self.dirvec.y == 0:
if keys[pg.K_LEFT] or keys[pg.K_a]:
new_dir_vec = vec(-1,0)
elif keys[pg.K_RIGHT] or keys[pg.K_d]:
new_dir_vec = vec(1,0)
if self.dirvec.x == 0:
if keys[pg.K_UP] or keys[pg.K_w]:
new_dir_vec = vec(0,-1)
elif keys[pg.K_DOWN] or keys[pg.K_s]:
new_dir_vec = vec(0,1)
if new_dir_vec != vec(0,0):
self.dirvec = new_dir_vec
self.vel = self.dirvec * PLAYER_SPEED
self.between_tiles = True
self.walking = True
current_index = self.rect.centerx // TILESIZE,self.rect.centery // TILESIZE
self.last_pos = vec(current_index) * TILESIZE
self.next_pos = self.last_pos + self.dirvec * TILESIZE
确保玩家没有越过目标。计算到目标的距离(delta = self.next_pos - self.pos
)。如果下一步大于到目标的距离,请使用目标位置来确定位置(self.pos = self.next_pos
):
delta = self.next_pos - self.pos
if delta.length() > (self.vel * self.game.dt).length():
self.pos += self.vel * self.game.dt
else:
self.pos = self.next_pos
self.vel = vec(0,0)
# [...]
完整方法update
:
class Player(pg.sprite.Sprite):
# [...]
def update(self):
self.get_keys()
self.rect = self.image.get_rect()
self.rect.topleft = self.pos
if self.pos != self.next_pos:
delta = self.next_pos - self.pos
if delta.length() > (self.vel * self.game.dt).length():
self.pos += self.vel * self.game.dt
else:
self.pos = self.next_pos
self.vel = vec(0,0)
self.dirvec = vec(0,0)
self.walking = False
self.between_tiles = False
self.hit_rect.topleft = self.pos
player_collisions(self,self.game.walls) # may change postion
self.hit_rect.topleft = self.pos # reset rectangle
self.rect.midbottom = self.hit_rect.midbottom
完整示例:
import pygame as pg
import sys
vec = pg.math.Vector2
WHITE = ( 255,255,255)
BLACK = ( 0,0)
RED = ( 255,0)
YELLOW = ( 255,0)
BLUE = ( 0,255)
WIDTH = 512 # 32 by 24 tiles
HEIGHT = 384
FPS = 60
TILESIZE = 32
PLAYER_SPEED = 3 * TILESIZE
MAP = ["1111111111111111","1..............1","1...........P..1","1..1111........1","1..1..1........1","1........11111.1","1........1...1.1","1111111111111111"]
def collide_hit_rect(one,two):
return one.hit_rect.colliderect(two.rect)
def player_collisions(sprite,group):
hits_walls = pg.sprite.spritecollide(sprite,group,False,collide_hit_rect)
if hits_walls:
sprite.pos -= sprite.vel * TILESIZE
class Player(pg.sprite.Sprite):
def __init__(self,game,x,y):
self.groups = game.all_sprites
pg.sprite.Sprite.__init__(self,self.groups)
self.game = game
self.walk_buffer = 200
self.vel = vec(0,0)
self.pos = vec(x,y) *TILESIZE
self.dirvec = vec(0,0)
self.last_pos = self.pos
self.next_pos = self.pos
self.current_frame = 0
self.last_update = pg.time.get_ticks()
self.walking = True
self.between_tiles = False
self.walking_sprites = [pg.Surface((TILESIZE,TILESIZE))]
self.walking_sprites[0].fill(RED)
self.image = self.walking_sprites[0]
self.rect = self.image.get_rect()
self.hit_rect = self.rect
self.hit_rect.bottom = self.rect.bottom
def update(self):
self.get_keys()
self.rect = self.image.get_rect()
self.rect.topleft = self.pos
if self.pos != self.next_pos:
delta = self.next_pos - self.pos
if delta.length() > (self.vel * self.game.dt).length():
self.pos += self.vel * self.game.dt
else:
self.pos = self.next_pos
self.vel = vec(0,self.game.walls) # may change postion
self.hit_rect.topleft = self.pos # reset rectangle
self.rect.midbottom = self.hit_rect.midbottom
def get_keys(self):
now = pg.time.get_ticks()
keys = pg.key.get_pressed()
if now - self.last_update > self.walk_buffer:
self.last_update = now
new_dir_vec = vec(0,self.rect.centery // TILESIZE
self.last_pos = vec(current_index) * TILESIZE
self.next_pos = self.last_pos + self.dirvec * TILESIZE
class Obstacle(pg.sprite.Sprite):
def __init__(self,y):
self.groups = game.walls
pg.sprite.Sprite.__init__(self,self.groups)
self.x = x * TILESIZE
self.y = y * TILESIZE
self.w = TILESIZE
self.h = TILESIZE
self.game = game
self.image = pg.Surface((self.w,self.h))
self.image.fill(BLACK)
self.rect = self.image.get_rect()
self.hit_rect = self.rect
self.rect.x = self.x
self.rect.y = self.y
class Game:
def __init__(self):
pg.init()
self.screen = pg.display.set_mode((WIDTH,HEIGHT))
pg.display.set_caption("Hello Stack Overflow")
self.clock = pg.time.Clock()
pg.key.set_repeat(500,100)
def new(self):
self.all_sprites = pg.sprite.Group()
self.walls = pg.sprite.Group()
for row,tiles in enumerate(MAP):
for col,tile in enumerate(tiles):
if tile == "1":
Obstacle(self,col,row)
elif tile == "P":
print("banana!")
self.player = Player(self,row)
def quit(self):
pg.quit()
sys.exit()
def run(self):
# game loop - set self.playing = False to end the game
self.playing = True
while self.playing:
self.dt = self.clock.tick(FPS) / 1000
self.events()
self.update()
self.draw()
def events(self):
# catch all events here
for event in pg.event.get():
if event.type == pg.QUIT:
self.quit()
def update(self):
self.player.update()
def draw(self):
self.screen.fill(WHITE)
for x in range (0,self.screen.get_width(),TILESIZE):
pg.draw.line(self.screen,(127,127,127),(x,0),self.screen.get_height()))
for y in range (0,self.screen.get_height(),(0,y),(self.screen.get_width(),y))
for wall in self.walls:
self.screen.blit(wall.image,wall.rect)
for sprite in self.all_sprites:
self.screen.blit(sprite.image,sprite.rect)
pg.display.flip()
# create the game object
g = Game()
while True:
g.new()
g.run()
pg.quit()