How to generate the food for a snake game

Question

I can not figure out how to generate the food for the snake to eat. I know the position of the snake at line 97 and 98, I have created a class to generate a pixel where I want to draw a peace of food at line 22 (EDIT: should probably be a function, commented #def (?) in the code). All I have to do is add 15 pixels at the x and y coordinates from the position that is randomly allocated and print it to get a block.

The problem is to check if I eat it or not. It should be something like:

if x >= x_food && x <= x_food + 15 || y >= y_food && y <= y_food + 15:
    ...add a point and make snake longer...

The problem is putting it all together for some reason.. Can some one give me a hint or solve how I should write this class so I can continue with other problems? Thank you!

import pygame
import random

#Global variables
#Color
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)

#Start length of snake
snake_length = 3

#Set the width of the segments of the snake
segment_width = 15
segment_height = 15
# Margin within each segment
segment_margin = 3

#Set initial speed
x_change = segment_width + segment_margin
y_change = 0

#def (?)
class Food():
    #Class to print food
    x_food = random.randint(0, 785)
    y_food = random.randint(0, 585)


class Segment(pygame.sprite.Sprite):
    """ Class to represent the segment of the snake. """
    # Methods
    # Constructer function
    def __init__(self, x, y):
        #Call the parents constructor
        super().__init__()

        #Set height, width
        self.image = pygame.Surface([segment_width, segment_height])
        self.image.fill(WHITE)

        #Make our top-left corner the passed-in location.
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y

#Call this function so the Pygame library can initialize itself
pygame.init()

#Create an 800x600 size screen
screen = pygame.display.set_mode([800, 600])

#Set the title of the window
pygame.display.set_caption("Snake")

allspriteslist = pygame.sprite.Group()

#Create an initial snake
snake_segments = []
for i in range(snake_length):
    x = 250 - (segment_width + segment_margin) * i
    y = 30
    segment = Segment(x, y)
    snake_segments.append(segment)
    allspriteslist.add(segment)

clock = pygame.time.Clock()
done = False

while not done:

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

        #Set the speed based on the key pressed
        #We want the speed to be enough that we move a full
        #Segment, plus the margin
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                x_change = (segment_width + segment_margin) * -1
                y_change = 0
            if event.key == pygame.K_RIGHT:
                x_change = (segment_width + segment_margin)
                y_change = 0
            if event.key == pygame.K_UP:
                x_change = 0
                y_change = (segment_height + segment_margin) * -1
            if event.key == pygame.K_DOWN:
                x_change = 0
                y_change = (segment_width + segment_margin)

    #Get rid of last segment of the snake
    #.pop() command removes last item in list
    old_segment = snake_segments.pop()
    allspriteslist.remove(old_segment)

    #Figure out where new segment will be
    x = snake_segments[0].rect.x + x_change
    y = snake_segments[0].rect.y + y_change
    segment = Segment(x, y)

    #Insert new segment to the list
    snake_segments.insert(0, segment)
    allspriteslist.add(segment)

    #Draw
    #Clear screen
    screen.fill(BLACK)

    allspriteslist.draw(screen)

    #Flip screen
    pygame.display.flip()

    #Pause
    clock.tick(5)

pygame.quit()

Answer 1

i took your code and i think i work something out, pls note that this only monitors when the snake goes over the block, then it prints: yummy, so you will have to add the detail, also note that i dont use your class to generate the food:

import pygame
import random

#Global variables
#Color
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)

#Start length of snake
snake_length = 3

#Set the width of the segments of the snake
segment_width = 15
segment_height = 15
# Margin within each segment
segment_margin = 3

#Set initial speed
x_change = segment_width + segment_margin
y_change = 0

#def (?)
class Food():
    #Class to print food
    x_food = random.randint(0, 785)
    y_food = random.randint(0, 585)


class Segment(pygame.sprite.Sprite):
    """ Class to represent the segment of the snake. """
    # Methods
    # Constructer function
    def __init__(self, x, y):
        #Call the parents constructor
        super().__init__()

        #Set height, width
        self.image = pygame.Surface([segment_width, segment_height])
        self.image.fill(WHITE)

        #Make our top-left corner the passed-in location.
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y

#Call this function so the Pygame library can initialize itself
pygame.init()

#Create an 800x600 size screen
screen = pygame.display.set_mode([800, 600])

#Set the title of the window
pygame.display.set_caption("Snake")

allspriteslist = pygame.sprite.Group()

#Create an initial snake
snake_segments = []
for i in range(snake_length):
    x = 250 - (segment_width + segment_margin) * i
    y = 30
    segment = Segment(x, y)
    snake_segments.append(segment)
    allspriteslist.add(segment)

clock = pygame.time.Clock()
done = False
x_food = random.randint(0, 785)
y_food = random.randint(0, 585)

while not done:

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

        #Set the speed based on the key pressed
        #We want the speed to be enough that we move a full
        #Segment, plus the margin
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                x_change = (segment_width + segment_margin) * -1
                y_change = 0
            if event.key == pygame.K_RIGHT:
                x_change = (segment_width + segment_margin)
                y_change = 0
            if event.key == pygame.K_UP:
                x_change = 0
                y_change = (segment_height + segment_margin) * -1
            if event.key == pygame.K_DOWN:
                x_change = 0
                y_change = (segment_width + segment_margin)

            if y < y_food+30:
                if x > x_food and x < x_food+30 or x+20 > x_food and x+20<x_food+30:
                    print('yummy')



    #Get rid of last segment of the snake
    #.pop() command removes last item in list
    old_segment = snake_segments.pop()
    allspriteslist.remove(old_segment)

    #Figure out where new segment will be
    x = snake_segments[0].rect.x + x_change
    y = snake_segments[0].rect.y + y_change
    segment = Segment(x, y)

    #Insert new segment to the list
    snake_segments.insert(0, segment)
    allspriteslist.add(segment)

    #Draw
    #Clear screen
    screen.fill(BLACK)
    pygame.draw.rect(screen, WHITE, [x_food, y_food, 30, 30])

    allspriteslist.draw(screen)

    #Flip screen
    pygame.display.flip()

    #Pause
    clock.tick(5)

pygame.quit()

hope this helped, thanks!

Answer 2

if x >= x_food && x <= x_food + 15 || y >= y_food && y <= y_food + 15:

Why do you OR these pairs of conditions? Don't all 4 tests have to be true at the same time?

if x >= x_food && x <= x_food + 15 && y >= y_food && y <= y_food + 15: