python - 关于动画的Python pygame noob问题

Question

你能帮我解决我遇到的问题吗？我是编程方面的新手，为了指导我，我正在使用这本书：如何像计算机科学家一样思考第 3 版。并且它无法解决第 17 章的练习 2。这表示单击精灵右侧的任何帧时都会发生错误，这会导致动画开始，理论上它应该只做动画，如果它是你直接点击精灵，我试过很多方法都解决不了，你能帮帮我吗？，我认为错误发生在这部分

 return ( x >= my_x and x + my_width and y >= my_y and y < my_y + my_height)

但我不确定，我给你留下我所有的代码

import pygame
gravity = 0.025
my_clock = pygame.time.Clock()
class QueenSprite:

    def __init__(self, img, target_posn):
        self.image = img
        self.target_posn = target_posn
        (x, y) = target_posn
        self.posn = (x, 0)     # Start ball at top of its column
        self.y_velocity = 0    #    with zero initial velocity

    def update(self):
        self.y_velocity += gravity
        (x, y) = self.posn
        new_y_pos = y + self.y_velocity
        (target_x, target_y) = self.target_posn   # Unpack the position
        dist_to_go = target_y - new_y_pos         # How far to our floor?
        if dist_to_go < 0:                        # Are we under floor?
            self.y_velocity = -0.65 * self.y_velocity     # Bounce
            new_y_pos = target_y + dist_to_go     # Move back above floor
        self.posn = (x, new_y_pos)                # Set our new position.

    def draw(self, target_surface):      # Same as before.
        target_surface.blit(self.image, self.posn)
    def contains_point(self, pt):
      """ Return True if my sprite rectangle contains point pt """
      (my_x, my_y) = self.posn
      my_width = self.image.get_width()
      my_height = self.image.get_height()
      (x, y) = pt
      return ( x >= my_x and x < my_x + my_width and
               y >= my_y and y < my_y + my_height)   
    def handle_click(self):
        self.y_velocity += -2   # Kick it up
        
class DukeSprite:

    def __init__(self, img, target_posn):
        self.image = img
        self.posn = target_posn
        self.anim_frame_count = 0
        self.curr_patch_num = 0

    def update(self):
        if self.anim_frame_count > 0:
           self.anim_frame_count = (self.anim_frame_count + 1 ) % 60
           self.curr_patch_num = self.anim_frame_count // 6

    def draw(self, target_surface):
        patch_rect = (self.curr_patch_num * 50, 0,
                       50, self.image.get_width())
        target_surface.blit(self.image, self.posn, patch_rect)

    def contains_point(self, pt):
         """ Return True if my sprite rectangle contains  pt """
         (my_x, my_y) = self.posn
         my_width = self.image.get_width()
         my_height = self.image.get_height()
         (x, y) = pt
         return ( x >= my_x and x + my_width and y >= my_y and y < my_y + my_height)

    def handle_click(self):
         if self.anim_frame_count == 0:
            self.anim_frame_count = 5

def draw_board(the_board):
    """ Draw a chess board with queens, as determined by the the_board. """

    pygame.init()
    colors = [(255,0,0), (0,0,0)]    # Set up colors [red, black]

    n = len(the_board)         # This is an NxN chess board.
    surface_sz = 480           # Proposed physical surface size.
    sq_sz = surface_sz // n    # sq_sz is length of a square.
    surface_sz = n * sq_sz     # Adjust to exactly fit n squares.

    # Create the surface of (width, height), and its window.
    surface = pygame.display.set_mode((surface_sz, surface_sz))

    ball = pygame.image.load("ball.png")

    # Use an extra offset to centre the ball in its square.
    # If the square is too small, offset becomes negative,
    #   but it will still be centered :-)
    ball_offset = (sq_sz-ball.get_width()) // 2
    all_sprites = []      # Keep a list of all sprites in the game

    # Create a sprite object for each queen, and populate our list.
    for (col, row) in enumerate(the_board):
        a_queen = QueenSprite(ball,
                   (col*sq_sz+ball_offset, row*sq_sz+ball_offset))
        all_sprites.append(a_queen)
    # Load the sprite sheet
    duke_sprite_sheet = pygame.image.load("duke_spritesheet.png")
    
    # Instantiate two duke instances, put them on the chessboard
    duke1 = DukeSprite(duke_sprite_sheet,(sq_sz*2, 0))
    duke2 = DukeSprite(duke_sprite_sheet,(sq_sz*5, sq_sz))
    
    # Add them to the list of sprites which our game loop manages
    all_sprites.append(duke1)
    all_sprites.append(duke2)
    while True:

    # Look for an event from keyboard, mouse, etc.
        ev = pygame.event.poll()
        if ev.type == pygame.QUIT:
            break;
        if ev.type == pygame.KEYDOWN:
            key = ev.dict["key"]
            if key == 27:                  # On Escape key ...
                break                      #   leave the game loop.
            if key == ord("r"):
                colors[0] = (255, 0, 0)    # Change to red + black.
            elif key == ord("g"):
                colors[0] = (0, 255, 0)    # Change to green + black.
            elif key == ord("b"):
                colors[0] = (0, 0, 255)    # Change to blue + black.
        if ev.type == pygame.MOUSEBUTTONDOWN: # Mouse gone down?
            posn_of_click = ev.dict["pos"]    # Get the coordinates.
            for sprite in all_sprites:
                if sprite.contains_point(posn_of_click):
                    sprite.handle_click()
                    break    
        
        for sprite in all_sprites:
            sprite.update()
          
        # Draw a fresh background (a blank chess board)
        for row in range(n):           # Draw each row of the board.
            c_indx = row % 2           # Alternate starting color
            for col in range(n):       # Run through cols drawing squares
                the_square = (col*sq_sz, row*sq_sz, sq_sz, sq_sz)
                surface.fill(colors[c_indx], the_square)
                # Now flip the color index for the next square
                c_indx = (c_indx + 1) % 2
          
        # Ask every sprite to draw itself.
        for sprite in all_sprites:
            sprite.draw(surface)
        my_clock.tick(60)  # Waste time so that frame rate becomes 60 fps
   
        pygame.display.flip()
    
    pygame.quit()

if __name__ == "__main__":
    draw_board([0, 5, 3, 1, 6, 4, 2])    # 7 x 7 to test window size

标签： pythonpygame

Answer 1

类方法中的比较表达式中< my_x缺少：contains_pointDukeSprite

return ( x >= my_x and x + my_width and y >= my_y and y < my_y + my_height)

return ( x >= my_x and x < my_x + my_width and y >= my_y and y < my_y + my_height)

无论如何，在 python 中你应该使用链式比较：

return my_x <= x < my_x + my_width and my_y <= y < my_y + my_height

在 pygame 中，您应该使用pygame.Rectand collidepoint()。您可以pygame.Surface使用该方法获得的对象的矩形get_rect和位置可以通过关键字参数设置：

def contains_point(self, pt):
    """ Return True if my sprite rectangle contains  pt """
    my_rect = self.image.get_rect(topleft = self.posn)
    return my_rect.collidepoint(pt)