How to draw rectangle in Pygame?

Pygame is a popular Python library for game development and multimedia, built on top of the SDL library. One of the most basic graphical operations in Pygame is drawing shapes, such as rectangles. Rectangles are essential for making buttons, frames, game objects and more. It's key functions for drawing rectangles.

The basic syntax for drawing a rectangle is:

pygame.draw.rect(surface, color, rect, width=0)

Parameters:

• surface: The surface or screen where the rectangle will be drawn.
• color: The color of the rectangle in RGB format. For example, (255, 0, 0) is red.
• rect: A pygame.Rect object or a tuple specifying (x, y, width, height).
• width (optional): Thickness of the border. If width=0 (default), the rectangle is filled with color. If a positive number, only the border is drawn.

Examples

Example 1: Here, we draw a filled pink square at position (30, 30) with width and height of 60 pixels.

import pygame
pygame.init()  
surface = pygame.display.set_mode((400, 300))  # window
color = (255, 192, 203)  

pygame.draw.rect(surface, color, pygame.Rect(30, 30, 60, 60))  
pygame.display.flip() 
pygame.time.wait(3000)  # Pause for 3 seconds
pygame.quit()  

Output

Explanation:

• pygame.draw.rect(surface, color, pygame.Rect(30, 30, 60, 60)) draws a filled rectangle at position (30, 30) with width 60 and height 60.
• pygame.display.flip() updates the screen to display the drawn rectangle.
• pygame.time.wait(3000) keeps the window open for 3 seconds.

Example 2: Here, we draw a red rectangle with only a 2-pixel thick border and no fill inside.

import pygame
pygame.init()
surface = pygame.display.set_mode((400, 300)) # window
color = (255, 0, 0)

# Draw rectangle border (width=2)
pygame.draw.rect(surface, color, pygame.Rect(30, 30, 60, 60), 2)

pygame.display.flip()
pygame.time.wait(3000)
pygame.quit()

Output

Explanation:

• pygame.draw.rect(....) draws a rectangle border (not filled) at position (30, 30) with width 60 and height 60. The 2 specifies the border thickness in pixels.
• Updates the screen to show the rectangle, waits for 3 seconds and then closes the Pygame window.

Example 3: Here, we draw three rectangles: one filled red, one with a green 5-pixel border, and one with a blue 10-pixel border.

import pygame
pygame.init()
surface = pygame.display.set_mode((500, 400))

# colors
red = (255, 0, 0)
green = (0, 255, 0)
blue = (0, 0, 255)

pygame.draw.rect(surface, red, pygame.Rect(50, 50, 100, 80))
pygame.draw.rect(surface, green, pygame.Rect(200, 50, 100, 80), 5)
pygame.draw.rect(surface, blue, pygame.Rect(350, 50, 100, 80), 10)

pygame.display.flip()
pygame.time.wait(4000)
pygame.quit()

Output

Explanation:

• pygame.draw.rect(...) draws three rectangles at the top of the screen, a filled red rectangle, a green rectangle with 5px border and a blue rectangle with 10px border, each with position and size specified using pygame.Rect().
• Displays all rectangles on the window, keeps the window open for 4 seconds and then closes it.

Example 4: Here, we animate a blue rectangle moving from left to right across the screen in a loop.

import pygame
pygame.init() 
w, h = 600, 200  # size
s = pygame.display.set_mode((w, h)) 
c_white, c_blue = (255,255,255), (0,0,255)  # colors
x, y, rw, rh, spd = 0, 50, 60, 40, 5  # rect params
clk = pygame.time.Clock()  # clock

run = True  
while run:
    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            run = False 

    s.fill(c_white) 
    pygame.draw.rect(s, c_blue, (x, y, rw, rh))  
    x = (x + spd) % (w + rw) - rw 
    pygame.display.flip()  
    clk.tick(30)  

pygame.quit() 

Output

Explanation:

• while loop keeps the program active until the window is closed, handling events and updating the screen by clearing it and drawing the moving blue rectangle that wraps around horizontally.
• pygame.display.flip() refreshes the display each frame, while clk.tick(30) limits the frame rate to 30 FPS for smooth animation.