pygame Pong - how to attribute my scoring system and collision detection - pygame

Question

Hey I'm working on pong and regardless of how hard I try, I keep facing the same problem; the scoring system doesn't appear on the window when I run the code.
I was told I need to initialize attributes such as scoring system, ball and paddles and I guess I did so for the ball and paddle even though I don't really get what that means since this course is the farthest thing from being kind to students who are new to python. But I guess I didn't do so for the scoring system since it's not appearing on the screen.
I've been struggling with these past few weeks and still haven't found a way to fix this and I need to hand in this next week which is making me freak out.
I would appreciate it if you can explain me what did I do wrong and what initializing attribute means and also check my codes for collision detection!
Thank you all SO MUCH!! (By the way, this always happens and confuses me a lot since I get no error message but the scoring system is just not working as I expected)
# Pong V2
# Pong game needs two players and players try to prevent the ball from hitting
# the edge of the screen of their side. If the ball hits the edge of the window,
# the counterpart of the player who couldn't defence the wall gains a point.
# When one of the players reach 11 points, game ends and the player with higher
# points win the game. Players and move the paddles of their own by pressing
# some keys and ball bounces off when the ball has hit the front part of the
# paddle but passes through when they hit the back part of the paddle.
# wall, game continuing until the player presses 'x' button to close the window,
# paddles on the screen but cannot be moved.
# Version 2 of Pong implies the scoring system and game ending when someone hits
# 11 scores. Also, now collision detection for the paddles and the ball has been
# added as a new feature even though still player cannot move the paddles.
import pygame
from random import randint
def main():
# initialize all pygame modules (some need initialization)
pygame.init()
# create a pygame display window
pygame.display.set_mode((500, 400))
# set the title of the display window
pygame.display.set_caption('Pong')
# get the display surface
w_surface = pygame.display.get_surface()
# create a game object
game = Game(w_surface)
# start the main game loop by calling the play method on the game object
game.play()
# quit pygame and clean up the pygame window
pygame.quit()
class Game:
def __init__(self, surface):
# Initialize a Game.
self.surface = surface
self.bg_color = pygame.Color('black')
self.FPS = 60
self.game_Clock = pygame.time.Clock()
self.close_clicked = False
self.continue_game = True
#iniotialize the ball
self.ball = Ball('white', 5, [250, 200], [1, 2], self.surface)
self.max_frames = 150
self.frame_counter = 0
# initialize paddles
self.paddleA = pygame.Rect((70, 170), (10, 60))
self.paddleB = pygame.Rect((415, 170), (10, 60))
# initialize paddles
self.scoreA = 0
self.scoreB = 0
def draw_score_A(self):
# this method draws the player's score in the top-left corner of the
# game window.
strscoreA = str(self.scoreA)
font_color = pygame.Color('white')
font_bg = pygame.Color('black')
font = pygame.font.SysFont("arial", 72)
text_img = font.render(strscoreA, True, font_color, font_bg)
text_pos = (0, 0)
self.surface.blit(text_img, text_pos)
def draw_score_B(self):
# this method draws the player's score in the top-right corner of the
# game window.
strscoreB = str(self.scoreB)
font_color = pygame.Color('white')
font_bg = pygame.Color('black')
font = pygame.font.SysFont("arial", 72)
text_img = font.render(strscoreB, True, font_color, font_bg)
text_pos = (425,0)
self.surface.blit(text_img, text_pos)
def update_score(self):
# check if the ball has hit the left or right side edge and update score
# if the ball hit left side, scoreB goes up by 1 and if the ball hit the right
# side the scoreA goes up by 1.
if self.ball.center[0] < self.ball.radius:
self.scoreB += 1
if self.ball.center[0] + self.ball.radius > self.surface.get_width():
self.scoreA += 1
return self.scoreA, self.scoreB
def play(self):
# Play the game until the player presses the close box.
# - self is the Game that should be continued or not.
while not self.close_clicked: # until player clicks close box
# play frame
self.handle_events()
self.draw()
self.update_score()
self.draw_score_A()
self.draw_score_B()
if self.continue_game:
self.update()
self.decide_continue()
self.game_Clock.tick(self.FPS) # run at most with FPS Frames Per Second
def handle_events(self):
# Handle each user event by changing the game state appropriately.
# - self is the Game whose events will be handled
events = pygame.event.get()
for event in events:
if event.type == pygame.QUIT:
self.close_clicked = True
def draw(self):
# Draw all game objects.
self.surface.fill(self.bg_color) # clear the display surface first
# draw ball on the surface
self.ball.draw()
# draw both paddles on the surface
paddleA = pygame.Rect((70, 170), (10, 60))
self.paddleA = pygame.draw.rect(self.surface, (255, 255, 255), paddleA)
paddleB = pygame.Rect((415, 170), (10, 60))
self.paddleB = pygame.draw.rect(self.surface, (255, 255, 255), paddleB)
pygame.display.update() # make the updated surface appear on the display
def collision_detection(self):
# figure out if the paddle and the ball has collide or not.
# If the ball has hit the front of the paddle, it is recognizes as
# a collision and bounces off to the opposite direction. However
# if the ball has hit the backside of the paddle, this is not
# considered as a collision and this will not make the ball bounce of but
# go through the paddle.We need to check if the center of the ball has passed
# the center of the paddle or not and for this we will use rect.collidepoint
if self.paddleA.collidepoint(self.center) and self.velocity[index] > 0 is True:
self.velocity[index] = self.velocity[index]
elif self.paddleA.collidepoint(self.center) and self.velocity[index] < 0 is True:
self.velocity[index] = - self.velocity[index]
elif self.paddleB.collidepoint(self.center) and self.velocity[index] > 0 is True:
self.velocity[index] = - self.velocity[index]
elif self.paddleB.collidepoint(self.center) and self.velocity[index] < 0 is True:
self.velocity[index] = self.velocity[index]
def update(self):
# Update the game objects for the next frame.
self.ball.move()
self.frame_counter += self.frame_counter
def decide_continue(self):
# Check and remember if the game should continue
# if the score of one of the players reaches 11, the game should end.
# thus we need to check if anyone's score has reached 11 or not and
# decide if we'll continue the game or not.
if self.scoreA == 11 or self.scoreB == 11 :
self.continue_game = False
class Ball:
# An object in this class represents a ball that moves
def __init__(self, ball_color, ball_radius, ball_center, ball_velocity,
surface):
# Initialize a ball.
# - self is the ball to initialize
# - color is the pygame.Color of the ball
# - center is a list containing the x and y int
# coords of the center of the dot
# - radius is the int pixel radius of the ball
# - velocity is a list containing the x and y components
# - surface is the window's pygame.Surface object
self.color = pygame.Color(ball_color)
self.radius = ball_radius
self.center = ball_center
self.velocity = ball_velocity
self.surface = surface
def move(self):
# Change the location of the ball by adding the corresponding
# speed values to the x and y coordinate of its center
# we need the height and width of the screen to determine when ball
# should change their direction of motion (bounce)
screen_width = self.surface.get_width()
screen_height = self.surface.get_height()
# updates the ball's position based on its velocity and also bounces the
# ball off a wall if it gets too close
screen_size = (screen_width, screen_height)
for index in range(0, len(self.center)):
self.center[index] += self.velocity[index]
if (self.center[index] <= 0 + self.radius or self.center[index] >=
screen_size[index] - self.radius):
self.velocity[index] = -self.velocity[index]
def draw(self):
# Draw the ball on the surface
pygame.draw.circle(self.surface, self.color, self.center, self.radius)
main()

Answer 1

The code is calling draw() (to repaint and flush the screen), and then calling draw_score_A() and draw_score_B() without flushing. So the changes made by the draw_score_ functions are never seen by the user.
If you have a function draw() - make it draw everything. This keeps all the drawing and flushing operations in a single place. Sure the draw() function calls other functions to do the painting, but it's all starts from one place.
def draw( self ):
# Draw all game objects.
# clear the display surface first
self.surface.fill( self.bg_color )
# draw ball on the surface
self.ball.draw()
# draw both paddles on the surface
pygame.draw.rect( self.surface, ( 255, 255, 255 ), self.paddleA )
pygame.draw.rect( self.surface, ( 255, 255, 255 ), self.paddleB )
# Paint the scores
self.draw_score_A()
self.draw_score_B()
# make the updated surface appear on the display
pygame.display.update()
Also, your draw() function seems to be re-defining paddleA and paddleB as part of the drawing. I corrected this in the version above.