#!/usr/bin/python

import cairo
import os
import sys

# Auxilliary function to draw some crap inside a surface
def draw_stuff(ctx, it):
    for l in range(0, 8):
        for i in range(0, 8):
            for j in range(0, 8):
                ctx.set_source_rgb(i / 10., j / 10., 0.3 * it / 500.)
                ctx.move_to(i * 72 + j * (72 / 8), l * 72 - it / 50.)
                ctx.line_to((i + 1) * 72 + j * (72 / 8), (l + 1) * 72 + it / 50.)
                ctx.set_line_width(4)
                ctx.stroke()

# Draw some crap inside a surface.
def draw_my_complex_stuff(ctx, complexity):
    ctx.set_source_rgb (0.3, 0.3, 0.3)
    ctx.paint()

    for i in range(0, complexity):
        draw_stuff(ctx, i)

if len(sys.argv) != 2:
    print "error: need complexity as argument"
    sys.exit(1)

complexity = int(sys.argv[1])

# First step: draw a single PDF file with the random crap on a (8*72)
# x (8*72) PDF surface
orig = cairo.PDFSurface("original.pdf", 8 * 72, 8 * 72)
ctx = cairo.Context(orig)
draw_my_complex_stuff(ctx, complexity)
orig.finish()

orig_size = os.stat("original.pdf")[6]

# Now, redraw the same thing in an anonymous PDF surface
orig = cairo.PDFSurface(None, 8 * 72, 8 * 72)
ctx = cairo.Context(orig)
draw_my_complex_stuff(ctx, complexity)

# Create a new surface whose width and height are a quarter of the
# original PDF surface. The goal is to display 1/16th of the original
# PDF surface into each page of the new surface.

new = cairo.PDFSurface("splitted.pdf", 2 * 72, 2 * 72)
ctx = cairo.Context(new)

for i in range(0, 4):
    for j in range(0, 4):
        # Each page is a part of the original PDF surface
        x_in_orig = - (i * 2 * 72)
        y_in_orig = - (j * 2 * 72)
        ctx.set_source_surface(orig, x_in_orig, y_in_orig)
        ctx.rectangle(0, 0, 2 * 72, 2 * 72)
        ctx.fill()
        ctx.show_page()

new.finish()

splitted_size = os.stat("splitted.pdf")[6]

# Show the size of the original file
print "Orig surface size once rendered in PDF is : %d bytes" % \
    orig_size

# Show the size of the 'splitted' file
print "Splitted surface size once rendered in PDF is : %d bytes" % \
    splitted_size

print "Size ratio: %f" % (float(splitted_size) / float(orig_size))