我的第一个Python程序遇到了障碍，我认为我不具备解决问题的知识。
它是2d表面上的可控太空船，我想增加动量/惯性 我有它所以当发动机停止时，船继续沿着它前面的矢量行驶。 但是我只能让它“快速”捕捉到它旋转的新矢量。
我想要发生的是惯性矢量与新的指向矢量缓慢对齐，因为它加速 - 如旋转加速度？ （我对数学不太热） - 我可以旋转惯性矢量，但是我需要以某种方式将它与新的指向矢量进行比较，并根据它们的差异对其进行修改？
如果有人可以建议我如何开始接近这个，那就太棒了 - 我怀疑我是从完全错误的方式来到这里的。 下面是一些代码（请温柔！）
使用的精灵是： - ship.png
import pygame
import sys
from math import sin, cos, pi, atan2
from pygame.locals import *
import random
from random import randint
from pygame.math import Vector2
import operator
"""solar system generator"""
"""set screen size and center and some global namespace colors for ease of use"""
globalalpha = 255
screenx = int(1200)
screeny = int(700)
centerx = int(screenx / 2)
centery = int(screeny / 2)
center = (centerx, centery)
black = ( 0, 0, 0)
white = (255, 255, 255)
red = (209, 2, 22)
TRANSPARENT = (255,0,255)
numstars = 150
DISPLAYSURF = pygame.display.set_mode((screenx, screeny), 0, 32)
clock = pygame.time.Clock()
globaltimefactor = 1
shipimage = pygame.image.load('ship.png').convert()
DISPLAYSURF.fill(black)
screen_rect = DISPLAYSURF.get_rect()
class Playership(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.imageorig = pygame.image.load('ship.png').convert_alpha()
self.startpos = (screen_rect.center)
self.image = self.imageorig.copy()
self.rect = self.imageorig.get_rect(center=self.startpos)
self.angle = 0
self.currentposx = 600
self.currentposy = 350
self.tuplepos = (self.currentposx, self.currentposy)
self.speed = 1
self.rotatespeed = 1.5
self.initialvec = (600, 0)
self.destination = 0
self.anglechange = 0
self.currentspeed = 0
self.maxspeed = 5
self.engineon = False
self.newvec = (600, 0)
self.newdestination = 0
self.acceleration = 0.015
self.inertiaspeed = 0
self.transitionalvec = self.initialvec
def get_angleafterstopping(self):
newvec = self.initialvec
self.newvec = newvec
def get_destinationafterstopping(self):
x_dist = self.newvec[0] - self.tuplepos[0]
y_dist = self.newvec[1] - self.tuplepos[1]
self.newdestination = atan2(-y_dist, x_dist) % (2 * pi)
def get_destination(self):
x_dist = self.initialvec[0] - self.tuplepos[0]
y_dist = self.initialvec[1] - self.tuplepos[1]
self.destination = atan2(-y_dist, x_dist) % (2 * pi)
def moveship(self):
if self.engineon is True:
self.currentspeed = self.currentspeed + self.acceleration
if self.currentspeed > self.maxspeed:
self.currentspeed = self.maxspeed
elif self.currentspeed < 0:
self.currentspeed = 0
self.inertiaspeed = self.currentspeed
elif self.engineon is False:
self.currentposx = self.currentposx + (cos(self.newdestination) * self.inertiaspeed * globaltimefactor)
self.currentposy = self.currentposy - (sin(self.newdestination) * self.inertiaspeed * globaltimefactor)
self.tuplepos = (self.currentposx, self.currentposy)
self.rect.center = self.tuplepos
return
self.get_destination()
self.currentposx = self.currentposx + (cos(self.destination) * self.currentspeed * globaltimefactor)
self.currentposy = self.currentposy - (sin(self.destination) * self.currentspeed * globaltimefactor)
self.tuplepos = (self.currentposx, self.currentposy)
self.rect.center = self.tuplepos
def rotateship(self, rotation):
self.anglechange = self.anglechange - (rotation * self.rotatespeed * globaltimefactor)
self.angle += (rotation * self.rotatespeed * globaltimefactor)
self.image = pygame.transform.rotate(self.imageorig, self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
initialvec = self.tuplepos + Vector2(0, -600).rotate(self.anglechange * globaltimefactor)
initialvec = int(initialvec.x), int(initialvec.y)
self.initialvec = initialvec
myship = Playership()
all_sprites_list = pygame.sprite.Group()
all_sprites_list.add(myship)
firsttimedone = False
def main():
done = False
while not done:
keys_pressed = pygame.key.get_pressed()
if keys_pressed[pygame.K_LEFT]:
myship.rotateship(1)
if keys_pressed[pygame.K_RIGHT]:
myship.rotateship(-1)
if keys_pressed[pygame.K_UP]:
myship.engineon = True
myship.moveship()
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit(); sys.exit();
if event.type == pygame.KEYUP:
if event.key == pygame.K_UP:
myship.engineon = False
myship.currentspeed = 0
myship.get_angleafterstopping()
myship.get_destinationafterstopping()
DISPLAYSURF.fill(black)
all_sprites_list.update()
all_sprites_list.draw(DISPLAYSURF)
pygame.draw.line(DISPLAYSURF, white, (myship.tuplepos), (myship.initialvec))
pygame.draw.line(DISPLAYSURF, red, (myship.tuplepos), (myship.newvec))
pygame.display.flip()
if myship.engineon is False:
myship.moveship()
clock.tick(50)
pygame.display.set_caption("fps: " + str(clock.get_fps()))
if __name__ == '__main__':
pygame.init()
main()
pygame.quit(); sys.exit();
编辑：
我修复了它：只需要更好地理解矢量 船开始时加速度和速度都表示为矢量。
self.position = vec(screenx / 2, screeny / 2)
self.vel = vec(0, 0)
self.acceleration = vec(0, -0.2) # The acceleration vec points upwards from the starting ship position
旋转船将该矢量旋转到位
self.acceleration.rotate_ip(self.angle_speed)
self.angle += self.angle_speed
self.image = pygame.transform.rotate(self.imageorig, -self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
正在加速：
self.vel += self.acceleration * self.enginepower * globaltimefactor
更新职位：
self.position += self.vel
self.rect.center = self.position
我使它变得比它需要的更难，速度需要保持不变，直到被旋转的加速度矢量作用。我不知道如何将矢量添加到一起等。
答案 0 :(得分：1)
我修复了它：只需要更好地理解矢量 船开始时加速度和速度都表示为矢量。
self.position = vec(screenx / 2, screeny / 2)
self.vel = vec(0, 0)
self.acceleration = vec(0, -0.2) # The acceleration vec points upwards from the starting ship position
旋转船将该矢量旋转到位
self.acceleration.rotate_ip(self.angle_speed)
self.angle += self.angle_speed
self.image = pygame.transform.rotate(self.imageorig, -self.angle)
self.rect = self.image.get_rect(center=self.rect.center)
正在加速：
self.vel += self.acceleration * self.enginepower * globaltimefactor
更新职位：
self.position += self.vel
self.rect.center = self.position
我使它变得比它需要的更难，速度需要保持不变，直到被旋转的加速度矢量作用。我不知道如何将矢量添加到一起等。