pngCanvas.py

#! -*- coding: utf-8 -*-

from __future__ import (
    absolute_import, division, print_function, unicode_literals
)

import io
import logging

from pngcanvas import *

BUFSIZE=8*1024 # Taken from filecmp module
HEIGHT=WIDTH=512

logging.debug("Creating canvas: %d, %d",WIDTH, HEIGHT)
c=PNGCanvas(WIDTH, HEIGHT, color=(0xff,0,0,0xff))
c.rectangle(0,0,WIDTH-1,HEIGHT-1)

logging.debug("Generating gradient...")
c.vertical_gradient(1,1,WIDTH-2,HEIGHT-2,(0xff,0,0,0xff),(0x20,0,0xff,0x80))

logging.debug("Drawing some lines...")
c.color=bytearray((0,0,0,0xff))
c.line(0,0,WIDTH-1,HEIGHT-1)
c.line(0,0,WIDTH/2,HEIGHT-1)
c.line(0,0,WIDTH-1,HEIGHT/2)

with open("/python/try_pngcanvas.png","wb") as png_fil:
  logging.debug("Writing to file...")
  png_fil.write(c.dump())