Question

我是python和pygame的新手，我正在尝试学习矢量和类的基础知识，并且在这个过程中我设法搞砸了，我正在努力理解和修复标题中的错误信息。

这是我的Vector类的代码：

import math

class Vector(object):

    #defaults are set at 0.0 for x and y
    def __init__(self, x=0.0, y=0.0):
        self.x = x
        self.y = y

    #allows us to return a string for print
    def __str__(self):
        return "(%s, %s)"%(self.x, self.y)

    # from_points generates a vector between 2 pairs of (x,y) coordinates
    @classmethod
    def from_points(cls, P1, P2):
        return cls(P2[0] - P1[0], P2[1] - P1[1])

    #calculate magnitude(distance of the line from points a to points b
    def get_magnitude(self):
        return math.sqrt(self.x**2+self.y**2)

    #normalizes the vector (divides it by a magnitude and finds the direction)
    def normalize(self):
        magnitude = self.get_magnitude()
        self.x/= magnitude
        self.y/= magnitude

    #adds two vectors and returns the results(a new line from start of line ab to end of line bc)
    def __add__(self, rhs):
        return Vector(self.x +rhs.x, self.y+rhs.y)

    #subtracts two vectors
    def __sub__(self, rhs):
        return Vector(self.x - rhs.x, self.y-rhs.y)

    #negates or returns a vector back in the opposite direction
    def __neg__(self):
        return vector(-self.x, -self.y)

    #multiply the vector (scales its size) multiplying by negative reverses the direction
    def __mul__(self, scalar):
        return Vector(self.x*scalar, self.y*scalar)

    #divides the vector (scales its size down)
    def __div__(self, scalar):
        return Vector(self.x/scalar, self.y/scalar)

这是我程序的代码：

#The simple mouse move game by Ramon Cabral


#imports
import pygame, sys, Vector
from pygame.locals import *

#game init
pygame.init()

#screen
screen = pygame.display.set_mode((800,600),0,32)

#images
mouse_file = 'mouse.png'
MOUSE = pygame.image.load(mouse_file).convert_alpha()


#variables
bgcolor = (255,255,255)
position = (100.0,100.0)
heading = Vector.vector()

#clock and speed
clock = pygame.time.Clock()
speed = 250.0


#main game function
while True:

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

        if event.type == MOUSEBUTTONDOWN:
            destination = pygame.mouse.get_pos()
            heading = Vector.vector.from_points(position, destination)
            heading.normalize()

    screen.fill(bgcolor)
    screen.blit(MOUSE, position)

    time_passed = clock.tick(30.)
    time_passed_seconds = time_passed/1000.0

    distance_moved = time_passed_seconds*speed
    position += heading * distance_moved

    pygame.display.update()

Answer 1

为您的班级提供tuple方法：

class Vector(object):
    ...

    def tuple(self):
        return (self.x, self.y)

变化：

position = (100.0,100.0)

要：

position = Vector.vector(100.0,100.0)

和

screen.blit(MOUSE, position)

要：

screen.blit(MOUSE, position.tuple())

您正在添加不兼容的类型。

TypeError：只能将元组（不是“vector”）连接到元组

1 个答案: