Rotating a rectangle (not image) in pygame

Keatinge picture Keatinge · Apr 9, 2016 · Viewed 19.3k times · Source

In pygame I use pygame.draw.rect(screen, color, rectangle) for all the rectangles in my program. I want to be able to rotate these rectangles to any angle. I have seen the following code to rotate IMAGES but my question is with RECTANGLES.

pygame.transform.rotate(image, angle)

But I am working with rectangles, I don't have an image or "surface" that I can rotate. When I try to rotate a rectangle with

rect = pygame.draw.rect(screen, self.color, self.get_rectang())
rotatedRect = pygame.transform.rotate(rect, self.rotation)
screen.blit(rotatedRect)

This gives TypeError: must be pygame.Surface, not pygame.Rect on the line with .rotate()

My question is, how can I rotate a and display a RECTANGLE(x,y,w,h), not an image, in pygame.

The linked post that this is a "potential duplicate" of is not a duplicate. One answer explains about the consequences of rotating a rectangle and the other uses code for rotating an image.

Answer

Ashish kumar picture Ashish kumar · Jul 17, 2018
import pygame as py  

# define constants  
WIDTH = 500  
HEIGHT = 500  
FPS = 30  

# define colors  
BLACK = (0 , 0 , 0)  
GREEN = (0 , 255 , 0)  

# initialize pygame and create screen  
py.init()  
screen = py.display.set_mode((WIDTH , HEIGHT))  
# for setting FPS  
clock = py.time.Clock()  

rot = 0  
rot_speed = 2  

# define a surface (RECTANGLE)  
image_orig = py.Surface((100 , 100))  
# for making transparent background while rotating an image  
image_orig.set_colorkey(BLACK)  
# fill the rectangle / surface with green color  
image_orig.fill(GREEN)  
# creating a copy of orignal image for smooth rotation  
image = image_orig.copy()  
image.set_colorkey(BLACK)  
# define rect for placing the rectangle at the desired position  
rect = image.get_rect()  
rect.center = (WIDTH // 2 , HEIGHT // 2)  
# keep rotating the rectangle until running is set to False  
running = True  
while running:  
    # set FPS  
    clock.tick(FPS)  
    # clear the screen every time before drawing new objects  
    screen.fill(BLACK)  
    # check for the exit  
    for event in py.event.get():  
        if event.type == py.QUIT:  
            running = False  

    # making a copy of the old center of the rectangle  
    old_center = rect.center  
    # defining angle of the rotation  
    rot = (rot + rot_speed) % 360  
    # rotating the orignal image  
    new_image = py.transform.rotate(image_orig , rot)  
    rect = new_image.get_rect()  
    # set the rotated rectangle to the old center  
    rect.center = old_center  
    # drawing the rotated rectangle to the screen  
    screen.blit(new_image , rect)  
    # flipping the display after drawing everything  
    py.display.flip()  

py.quit()