[PyGame] How to rotate images

[metulburr]

When you rotate an image you need to make sure that you make an original of the image, and use that to rotate, otherwise it gets distorted if you keep rotating the image from a rotated image, etc. 

Whatever you rotate, whether it be an image or text, both are going to be a surface and rotated the same way. 

You are going to use pygame.transform.rotate

Here is an example of a surface rotated based on mouse position

import pygame as pg
import math

class Rotator:
    def __init__(self, screen_rect):
        self.orig_image = pg.Surface([10,100]).convert_alpha() #
        self.image = self.orig_image
        self.image.fill((255,255,255))
        self.rect = self.image.get_rect(center=screen_rect.center)
        self.angle = 0
        self.distance = 0
        self.angle_offset = 0

    def render(self, screen):
        screen.blit(self.image, self.rect)
        
    def get_angle(self):
        mouse = pg.mouse.get_pos()
        offset = (self.rect.centerx-mouse[0],self.rect.centery-mouse[1])
        self.angle = math.degrees(math.atan2(*offset)) - self.angle_offset
        old_center = self.rect.center
        self.image = pg.transform.rotate(self.orig_image, self.angle)
        self.rect = self.image.get_rect(center=old_center)
        self.distance = math.sqrt((offset[0] * offset[0]) + (offset[1] * offset[1]))
        
    def update(self):
        self.get_angle()
        self.display = 'angle:{:.2f} disatance:{:.2f}'.format(self.angle, self.distance)

if __name__ == '__main__':
    running = True
    pg.init()
    screen = pg.display.set_mode((600,400))
    screen_rect = screen.get_rect()
    rotator = Rotator(screen_rect)
    clock = pg.time.Clock()

    while running:
        screen.fill((0,0,0))
        for event in pg.event.get():
            if event.type == pg.QUIT:
                running = False
        rotator.update()
        rotator.render(screen)
        pg.display.set_caption(rotator.display)
        pg.display.update()
        clock.tick(60)

here the surface is just a generic rectangle, but you can plug in an image or text surface. The lines you would need to change to do that is

        #self.orig_image = pg.Surface([10,100]).convert_alpha() #
        self.orig_image = pg.image.load("your_image.png").convert()
        self.image = self.orig_image
        #self.image.fill((255,255,255))

where you load your image as the original instead and comment out the image fill

another example, a non-interactive example a constant turning object. Again you can plugin your image/text surface instead of a generic surface

import pygame as pg

screen = pg.display.set_mode((800,600))
screen_rect = screen.get_rect()
clock = pg.time.Clock()
done = False

class Rotator:
    def __init__(self, screen_rect):
        self.screen_rect = screen_rect
        self.master_image = pg.Surface([100,100]).convert_alpha()
        self.master_image.fill((255,0,0))
        self.image = self.master_image.copy()
        self.rect = self.image.get_rect(center=self.screen_rect.center)
        self.delay = 10
        self.timer = 0.0
        self.angle = 0

    def new_angle(self):
        self.angle += 1
        self.angle %= 360

    def rotate(self):
        self.new_angle()
        self.image = pg.transform.rotate(self.master_image, self.angle)
        self.rect = self.image.get_rect(center=self.screen_rect.center)

    def update(self):
        if pg.time.get_ticks()- self.timer > self.delay:
            self.timer = pg.time.get_ticks()
            self.rotate()

    def draw(self, surf):
        surf.blit(self.image, self.rect)

rotator = Rotator(screen_rect)

while not done:
    for event in pg.event.get():
        if event.type == pg.QUIT:
            done = True
    screen.fill((0,0,0))
    rotator.update()
    rotator.draw(screen)
    pg.display.update()