pygame_image_rotate_5_scale_function.py

# pygame.transform module
# https://www.pygame.org/docs/ref/transform.html
#
# How to rotate an image around its center while its scale is getting larger(in Pygame)
# https://stackoverflow.com/questions/54462645/how-to-rotate-an-image-around-its-center-while-its-scale-is-getting-largerin-py/54713639#54713639
#
# GitHub - PyGameExamplesAndAnswers - Collision and Intersection - Circle and circle
# https://github.com/Rabbid76/PyGameExamplesAndAnswers/blob/master/documentation/pygame/pygame_surface_rotate.md
#
# https://replit.com/@Rabbid76/PyGame-RotateAroundPivotAndZoom#main.py

import pygame
import os
os.chdir(os.path.join(os.path.dirname(os.path.abspath(__file__)), '../../resource'))

pygame.init()
screen = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()

def blitRotate(surf, image, pos, originPos, angle, zoom):

    # calcaulate the axis aligned bounding box of the rotated image
    w, h       = image.get_size()
    box        = [pygame.math.Vector2(p) for p in [(0, 0), (w, 0), (w, -h), (0, -h)]]
    box_rotate = [p.rotate(angle) for p in box]
    min_box    = (min(box_rotate, key=lambda p: p[0])[0], min(box_rotate, key=lambda p: p[1])[1])
    max_box    = (max(box_rotate, key=lambda p: p[0])[0], max(box_rotate, key=lambda p: p[1])[1])

    # calculate the translation of the pivot 
    pivot        = pygame.math.Vector2(originPos[0], -originPos[1])
    pivot_rotate = pivot.rotate(angle)
    pivot_move   = pivot_rotate - pivot

    # calculate the upper left origin of the rotated image
    move   = (-originPos[0] + min_box[0] - pivot_move[0], -originPos[1] - max_box[1] + pivot_move[1])
    origin = (pos[0] + zoom * move[0], pos[1] + zoom * move[1])

    # get a rotated image
    rotozoom_image = pygame.transform.rotozoom(image, angle, zoom)
  
    # rotate and blit the image
    surf.blit(rotozoom_image, origin)

    # draw rectangle around the image
    pygame.draw.rect (surf, (255, 0, 0), (*origin, *rotozoom_image.get_size()),2)

try:
    image = pygame.image.load('icon/AirPlaneFront1-128.png')
except:
    text = pygame.font.SysFont('Times New Roman', 50).render('image', False, (255, 255, 0))
    image = pygame.Surface((text.get_width()+1, text.get_height()+1))
    pygame.draw.rect(image, (0, 0, 255), (1, 1, *text.get_size()))
    image.blit(text, (1, 1))
w, h = image.get_size()

start = False
angle, zoom = 0, 1
done = False
while not done:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
        elif event.type == pygame.KEYDOWN or event.type == pygame.MOUSEBUTTONDOWN:
            start = True

    pos = (screen.get_width()/2, screen.get_height()/2)
    
    screen.fill(0)
    blitRotate(screen, image, pos, (w/2, h/2), angle, zoom)
    if start:
        angle += 1
        zoom += 0.01
        if zoom > 5:
            zoom = 1

    pygame.draw.line(screen, (0, 255, 0), (pos[0]-20, pos[1]), (pos[0]+20, pos[1]), 3)
    pygame.draw.line(screen, (0, 255, 0), (pos[0], pos[1]-20), (pos[0], pos[1]+20), 3)
    pygame.draw.circle(screen, (0, 255, 0), pos, 7, 0)

    pygame.display.flip()
    
pygame.quit()
exit()