#! /usr/bin/python

import Image, random, sys

# Size of background
(BGX, BGY) = (18000, 11000)
# Put a border around it for pictures to extend into
# It will be removed later.
border = 2000

# resize all images
RESIZE = 0.5

bg = Image.new('RGB', (BGX + 2*border, BGY + 2*border))

files = sys.argv[1:]
random.shuffle(files)

for infile in files:
    img = Image.open(infile).convert('RGBA')
    (oldx,oldy) = img.size
    img = img.resize((int(oldx*RESIZE), int(oldy*RESIZE)))
    img = img.rotate(random.uniform(0,360), expand=1)
    (x,y) = img.size
    (xmid,ymid) = (border + random.randrange(BGX),
                   border + random.randrange(BGY))
    # Must be inside the whole box
    xmid = max(xmid, x/2)
    xmid = min(xmid, BGX + 2*border - x/2)
    ymid = max(ymid, y/2)
    ymid = min(ymid, BGY + 2*border - y/2)
    bg.paste(img, (xmid-x/2, ymid-y/2), img)

bg = bg.crop((border, border, BGX+border, BGY+border))
bg.save('collage.jpg')