我如何让汽车朝着它指向的方向移动（使用 pygame.translation.rotate 之后）

Question

好的，所以我正在为制作赛车游戏进行测试... 我希望汽车朝着它所指的方向移动。 这是我的代码。

import pygame, sys
from pygame.locals import *
pygame.init()
mainClock = pygame.time.Clock()
degree = 0
WHITE = 250,250,250
rect2 = pygame.rect = (100,100,50,50)
WINDOWWIDTH = 1200
WINDOWHEIGHT = 750
thing = pygame.image.load('car.png')
screen = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT), 0, 32)
pygame.display.set_caption('Teh test')
left = False
right = False
while True:
    rect2 = pygame.rect = (100,100,50,50)
    if right == True:
        degree -= 2
    if left == True:
        degree += 2
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type == KEYDOWN:
            if event.key == ord('a'):
                left = True
            if event.key == ord('d'):
                right = True
        if event.type == KEYUP:
            if event.key == ord('a'):
                left = False
            if event.key == ord('d'):
                right = False
    pygame.draw.rect(screen,WHITE,rect2)
    screen.fill((40, 40, 40))
    thing2 = pygame.transform.rotate(thing,degree)
    screen.blit(thing2,(100,100))
    pygame.display.update()
    mainClock.tick(60)

就像我说的，我想知道如何让汽车朝它指向的方向移动。 我试着想办法，但我什么也想不出来。所以真的没有什么可以纠正的。 （如果有任何问题，我会编辑我的问题来回答。）在回答之前，请确保您了解 pygame。

Answer 1

您需要使用三角函数来计算您想在 x 和 y 方向上移动多少，以便汽车最终朝正确的方向移动。要计算这个，你可以这样做：

dx = math.cos(math.radians(degree))
dy = math.sin(math.radians(degree))
position = (position[0] + dx * SPEED, position[1] - dy * SPEED)

请注意，您还需要在代码开头的某处初始化一个位置变量，如下所示：

position = (100, 100)

然后，您必须更改 blit 代码行，以便在位置变量处绘制，而不是一直在 (100, 100) 处绘制：

screen.blit(thing2, position)

编辑：工作示例

import pygame, sys
from pygame.locals import *
import math
pygame.init()
mainClock = pygame.time.Clock()
degree = 0
WHITE = 250,250,250
rect2 = pygame.rect = (100,100,50,50)
WINDOWWIDTH = 1200
WINDOWHEIGHT = 750
thing = pygame.image.load('car.png')
screen = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT), 0, 32)
pygame.display.set_caption('Teh test')
left = False
right = False
position = (100, 100)
while True:
    rect2 = pygame.rect = (100,100,50,50)
    if right == True:
        degree -= 2
    if left == True:
        degree += 2
    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type == KEYDOWN:
            if event.key == ord('a'):
                left = True
            if event.key == ord('d'):
                right = True
        if event.type == KEYUP:
            if event.key == ord('a'):
                left = False
            if event.key == ord('d'):
                right = False
    pygame.draw.rect(screen,WHITE,rect2)
    screen.fill((40, 40, 40))
    thing2 = pygame.transform.rotate(thing,degree)
    dx = math.cos(math.radians(degree))
    dy = math.sin(math.radians(degree))
    position = (position[0] + dx, position[1] - dy)
    screen.blit(thing2, position)
    pygame.display.update()
    mainClock.tick(60)

Answer 2

kabb 答案的工作示例

import pygame, sys
from pygame.locals import *

import math # math library

pygame.init()
mainClock = pygame.time.Clock()
degree = 0
WHITE = 250,250,250
rect2 = pygame.rect = (100,100,50,50)
WINDOWWIDTH = 1200
WINDOWHEIGHT = 750
thing = pygame.image.load('car.png')
screen = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT), 0, 32)
pygame.display.set_caption('Teh test')
left = False
right = False


forward = False
backward = False

thing2_x = 100
thing2_y = 100
speed = 20


while True:
    rect2 = pygame.rect = (100,100,50,50)

    if right: # don't need == True
        degree -= 2
        while degree < 0:
            degree += 360
    elif left: # don't need == True
        degree += 2
        while degree > 359:
            degree -= 360

    dx = math.cos(math.radians(degree))
    dy = math.sin(math.radians(degree))

    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()

        if event.type == KEYDOWN:
            if event.key == K_ESCAPE:
                pygame.quit()
                sys.exit()
            elif event.key == K_a: # use constants K_a
                left = True
            elif event.key == K_d: # use constants K_d
                right = True
            elif event.key == K_w: # use constants K_w
                forward = True
            elif event.key == K_s: # use constants K_s
                backward = True

        if event.type == KEYUP:
            if event.key == K_a: # use constants K_a
                left = False
            elif event.key == K_d: # use constants K_d
                right = False
            elif event.key == K_w: # use constants K_w
                forward = False
            elif event.key == K_s: # use constants K_s
                backward = False

    if forward:
        thing2_y -= int(speed * dx)
        thing2_x -= int(speed * dy)
    elif backward:
        thing2_y += int(speed * dx)
        thing2_x += int(speed * dy)

    pygame.draw.rect(screen,WHITE,rect2)
    screen.fill((40, 40, 40))

    thing2 = pygame.transform.rotate(thing,degree)
    screen.blit(thing2,(thing2_x,thing2_y))

    pygame.display.update()
    mainClock.tick(60)