heroes-renaissance/pyglet/image/codecs/png.py

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2008-11-23 20:07:47 +00:00
# ----------------------------------------------------------------------------
# pyglet
# Copyright (c) 2006-2008 Alex Holkner
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
# * Neither the name of pyglet nor the names of its
# contributors may be used to endorse or promote products
# derived from this software without specific prior written
# permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# ----------------------------------------------------------------------------
'''Encoder and decoder for PNG files, using PyPNG (pypng.py).
'''
__docformat__ = 'restructuredtext'
__version__ = '$Id: $'
import array
from pyglet.gl import *
from pyglet.image import *
from pyglet.image.codecs import *
import pyglet.image.codecs.pypng
class PNGImageDecoder(ImageDecoder):
def get_file_extensions(self):
return ['.png']
def decode(self, file, filename):
try:
reader = pyglet.image.codecs.pypng.Reader(file=file)
width, height, pixels, metadata = reader.read()
except Exception, e:
raise ImageDecodeException(
'PyPNG cannot read %r: %s' % (filename or file, e))
if metadata['greyscale']:
if metadata['has_alpha']:
format = 'LA'
else:
format = 'L'
else:
if metadata['has_alpha']:
format = 'RGBA'
else:
format = 'RGB'
pitch = len(format) * width
return ImageData(width, height, format, pixels.tostring(), -pitch)
class PNGImageEncoder(ImageEncoder):
def get_file_extensions(self):
return ['.png']
def encode(self, image, file, filename):
image = image.get_image_data()
has_alpha = 'A' in image.format
greyscale = len(image.format) < 3
if has_alpha:
if greyscale:
image.format = 'LA'
else:
image.format = 'RGBA'
else:
if greyscale:
image.format = 'L'
else:
image.format = 'RGB'
image.pitch = -(image.width * len(image.format))
writer = pyglet.image.codecs.pypng.Writer(
image.width, image.height,
bytes_per_sample=1,
greyscale=greyscale,
has_alpha=has_alpha)
data = array.array('B')
data.fromstring(image.data)
writer.write_array(file, data)
def get_decoders():
return [PNGImageDecoder()]
def get_encoders():
return [PNGImageEncoder()]