CODEWITHSUNDEEP
pythonpygame
Hi There
Hi There

Reputation: 1966

What is the difference between pygame.draw.rect and screen_surface.blit()?

I am trying to make a red rectangle move to the right and by using pygame.move.rect or .blit, I Am able to accomplish the same thing. I am able to display the red rectangle and move it to the right by pressing the right arrow. However, is there any difference between these 2 functions that I should know? Why are there 2 functions that basically do the same thing.

Code with pygame.move.rect

import pygame
import sys

pygame.init()
#obtain the surface and rect for screen
screen_surface = pygame.display.set_mode((1200,800))
pygame.display.set_caption("Hi")

#Obtain Surface and rect for the rectangle 
red_rectangle = pygame.Surface((600,400))
red_rectangle_rect = red_rectangle.get_rect()

#make the rectangle surface red
red_rectangle.fill((255,0,0))

move_right = False

while True:
   #event loop
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
                move_right = True
            print(event.type)
            print(event.key)

        elif event.type == pygame.KEYUP:
            if event.key == pygame.K_RIGHT:
                move_right = False
          

    #rectangle move to right when right arrow is pressed 
    if move_right:
        red_rectangle_rect.x += 10
        print(red_rectangle_rect.x)
        
                
 


    screen_surface.fill((255,255,255))
    
    # the difference between this function and the .blit
    pygame.draw.rect(screen_surface,(255,0,0),red_rectangle_rect)
   

    pygame.display.flip()

Code with .blit

import pygame
import sys

pygame.init()
#obtain the surface and rect for screen
screen_surface = pygame.display.set_mode((1200,800))
pygame.display.set_caption("Hi")

#Obtain Surface and rect for the rectangle 
red_rectangle = pygame.Surface((600,400))
red_rectangle_rect = red_rectangle.get_rect()

#make the rectangle surface red
red_rectangle.fill((255,0,0))

move_right = False

while True:
   #event loop
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
                move_right = True
            print(event.type)
            print(event.key)

        elif event.type == pygame.KEYUP:
            if event.key == pygame.K_RIGHT:
                move_right = False
          

    #rectangle move to right when right arrow is pressed 
    if move_right: then 
        red_rectangle_rect.x += 10
        print(red_rectangle_rect.x)
        
                
 


    screen_surface.fill((255,255,255))

 
    #Difference between this and the draw function
    screen_surface.blit(red_rectangle,red_rectangle_rect)

    pygame.display.flip()

Upvotes: 3

Views: 5113

Answers (3)

Rabbid76
Rabbid76

Reputation: 211176

Why are there 2 functions that basically do the same thing.

No, they do not the same thing. While pygame.draw.rect draw uniform colored rectangles, pygame.Surface.blit is a method of pygame.Surface and is used to draw bitmap images.

See pygame.draw.rect:

rect(surface, color, rect) -> Rect
Draws a rectangle on the given surface.

See pygame.Surface.blit

blit(source, dest, area=None, special_flags=0) -> Rect
Draws a source Surface onto this Surface

In your case, it looks like they're doing the same thing because your Surface object is evenly filled with one color.
The behavior changes completely when you load a bitmap image with pygame.image.load. You cannot draw an image using pygame.draw.rect, but you can use blit.

When to use pygame.draw.rect, see:

Pygame Drawing a Rectangle

When to use blit, see:

What is a good way to draw images using pygame?

Upvotes: 5

Hi There
Hi There

Reputation: 1966

So just to clarify,

Use blit for image and rect for rectangle with 1 colour.

Upvotes: 0

Ashish M J
Ashish M J

Reputation: 700

blit(image, (left, top)) - Draws image to the screen at the given position.The function accepts either a Surface or a string as its image parameter. If image is a str then the named image will be loaded from the images/ directory.

draw.rect(rect, (r, g, b)) - Draws the outline of a rectangle. Takes a rectangle.

Upvotes: 2

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