# Implement 'jpeg' interface using SGI's compression library

# XXX Options 'smooth' and 'optimize' are ignored.

# XXX It appears that compressing grayscale images doesn't work right;

# XXX the resulting file causes weirdness.

from warnings import warnpy3k

warnpy3k("the jpeg module has been removed in Python 3.0", stacklevel=2)

del warnpy3k

class error(Exception):

    pass

options = {'quality': 75, 'optimize': 0, 'smooth': 0, 'forcegray': 0}

comp = None

decomp = None

def compress(imgdata, width, height, bytesperpixel):

    global comp

    import cl

    if comp is None: comp = cl.OpenCompressor(cl.JPEG)

    if bytesperpixel == 1:

        format = cl.GRAYSCALE

    elif bytesperpixel == 4:

        format = cl.RGBX

    if options['forcegray']:

        iformat = cl.GRAYSCALE

    else:

        iformat = cl.YUV

    # XXX How to support 'optimize'?

    params = [cl.IMAGE_WIDTH, width, cl.IMAGE_HEIGHT, height, \

              cl.ORIGINAL_FORMAT, format, \

              cl.ORIENTATION, cl.BOTTOM_UP, \

              cl.QUALITY_FACTOR, options['quality'], \

              cl.INTERNAL_FORMAT, iformat, \

             ]

    comp.SetParams(params)

    jpegdata = comp.Compress(1, imgdata)

    return jpegdata

def decompress(jpegdata):

    global decomp

    import cl

    if decomp is None: decomp = cl.OpenDecompressor(cl.JPEG)

    headersize = decomp.ReadHeader(jpegdata)

    params = [cl.IMAGE_WIDTH, 0, cl.IMAGE_HEIGHT, 0, cl.INTERNAL_FORMAT, 0]

    decomp.GetParams(params)

    width, height, format = params[1], params[3], params[5]

    if format == cl.GRAYSCALE or options['forcegray']:

        format = cl.GRAYSCALE

        bytesperpixel = 1

    else:

        format = cl.RGBX

        bytesperpixel = 4

    # XXX How to support 'smooth'?

    params = [cl.ORIGINAL_FORMAT, format, \

              cl.ORIENTATION, cl.BOTTOM_UP, \

              cl.FRAME_BUFFER_SIZE, width*height*bytesperpixel]

    decomp.SetParams(params)

    imgdata = decomp.Decompress(1, jpegdata)

    return imgdata, width, height, bytesperpixel

def setoption(name, value):

    if type(value) is not type(0):

        raise TypeError, 'jpeg.setoption: numeric options only'

    if name == 'forcegrey':

        name = 'forcegray'

    if not options.has_key(name):

        raise KeyError, 'jpeg.setoption: unknown option name'

    options[name] = int(value)

def test():

    import sys

    if sys.argv[1:2] == ['-g']:

        del sys.argv[1]

        setoption('forcegray', 1)

    if not sys.argv[1:]:

        sys.argv.append('/usr/local/images/data/jpg/asterix.jpg')

    for file in sys.argv[1:]:

        show(file)

def show(file):

    import gl, GL, DEVICE

    jpegdata = open(file, 'r').read()

    imgdata, width, height, bytesperpixel = decompress(jpegdata)

    gl.foreground()

    gl.prefsize(width, height)

    win = gl.winopen(file)

    if bytesperpixel == 1:

        gl.cmode()

        gl.pixmode(GL.PM_SIZE, 8)

        gl.gconfig()

        for i in range(256):

            gl.mapcolor(i, i, i, i)

    else:

        gl.RGBmode()

        gl.pixmode(GL.PM_SIZE, 32)

        gl.gconfig()

    gl.qdevice(DEVICE.REDRAW)

    gl.qdevice(DEVICE.ESCKEY)

    gl.qdevice(DEVICE.WINQUIT)

    gl.qdevice(DEVICE.WINSHUT)

    gl.lrectwrite(0, 0, width-1, height-1, imgdata)

    while 1:

        dev, val = gl.qread()

        if dev in (DEVICE.ESCKEY, DEVICE.WINSHUT, DEVICE.WINQUIT):

            break

        if dev == DEVICE.REDRAW:

            gl.lrectwrite(0, 0, width-1, height-1, imgdata)

    gl.winclose(win)

    # Now test the compression and write the result to a fixed filename

    newjpegdata = compress(imgdata, width, height, bytesperpixel)

    open('/tmp/j.jpg', 'w').write(newjpegdata)