#!/usr/bin/env python3.8
"""How to use pygame with no windowing system, like on headless servers.

Thumbnail generation with scaling is an example of what you can do with pygame.
NOTE: the pygame scale function uses mmx/sse if available, and can be run 
  in multiple threads.

"""
useage = """-scale inputimage outputimage new_width new_height
eg.  -scale in.png out.png 50 50

"""

import os, sys

# set SDL to use the dummy NULL video driver, 
#   so it doesn't need a windowing system.
os.environ["SDL_VIDEODRIVER"] = "dummy"


import pygame.transform


if 1:
    #some platforms need to init the display for some parts of pygame.
    import pygame.display
    pygame.display.init()
    screen = pygame.display.set_mode((1,1))



def scaleit(fin, fout, w, h):
    i = pygame.image.load(fin)

    if hasattr(pygame.transform, "smoothscale"):
        scaled_image = pygame.transform.smoothscale(i, (w,h))
    else:
        scaled_image = pygame.transform.scale(i, (w,h))
    pygame.image.save(scaled_image, fout)

def main(fin, fout, w, h):
    """smoothscale image file named fin as fout with new size (w,h)"""
    scaleit(fin, fout, w, h)

if __name__ == "__main__":
    if "-scale" in sys.argv:
        fin, fout, w, h = sys.argv[2:]
        w, h = map(int, [w,h])
        main(fin, fout, w,h)
    else:
        print (useage)




