#! /usr/bin/env python

"""Simple test script for imgfile.c

   Roger E. Masse

"""

from test.test_support import verbose, unlink, findfile, import_module

imgfile = import_module('imgfile', deprecated=True)

import uu

def testimage(name):

    """Run through the imgfile's battery of possible methods

       on the image passed in name.

    """

    import sys

    import os

    outputfile = '/tmp/deleteme'

    # try opening the name directly

    try:

        # This function returns a tuple (x, y, z) where x and y are the size

        # of the image in pixels and z is the number of bytes per pixel. Only

        # 3 byte RGB pixels and 1 byte greyscale pixels are supported.

        sizes = imgfile.getsizes(name)

    except imgfile.error:

        # get a more qualified path component of the script...

        if __name__ == '__main__':

            ourname = sys.argv[0]

        else: # ...or the full path of the module

            ourname = sys.modules[__name__].__file__

        parts = ourname.split(os.sep)

        parts[-1] = name

        name = os.sep.join(parts)

        sizes = imgfile.getsizes(name)

    if verbose:

        print 'Opening test image: %s, sizes: %s' % (name, str(sizes))

    # This function reads and decodes the image on the specified file,

    # and returns it as a python string. The string has either 1 byte

    # greyscale pixels or 4 byte RGBA pixels. The bottom left pixel

    # is the first in the string. This format is suitable to pass

    # to gl.lrectwrite, for instance.

    image = imgfile.read(name)

    # This function writes the RGB or greyscale data in data to

    # image file file. x and y give the size of the image, z is

    # 1 for 1 byte greyscale images or 3 for RGB images (which

    # are stored as 4 byte values of which only the lower three

    # bytes are used). These are the formats returned by gl.lrectread.

    if verbose:

        print 'Writing output file'

    imgfile.write (outputfile, image, sizes[0], sizes[1], sizes[2])

    if verbose:

        print 'Opening scaled test image: %s, sizes: %s' % (name, str(sizes))

    # This function is identical to read but it returns an image that

    # is scaled to the given x and y sizes. If the filter and blur

    # parameters are omitted scaling is done by simply dropping

    # or duplicating pixels, so the result will be less than perfect,

    # especially for computer-generated images.  Alternatively,

    # you can specify a filter to use to smoothen the image after

    # scaling. The filter forms supported are 'impulse', 'box',

    # 'triangle', 'quadratic' and 'gaussian'. If a filter is

    # specified blur is an optional parameter specifying the

    # blurriness of the filter. It defaults to 1.0.  readscaled

    # makes no attempt to keep the aspect ratio correct, so that

    # is the users' responsibility.

    if verbose:

        print 'Filtering with "impulse"'

    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'impulse', 2.0)

    # This function sets a global flag which defines whether the

    # scan lines of the image are read or written from bottom to

    # top (flag is zero, compatible with SGI GL) or from top to

    # bottom(flag is one, compatible with X). The default is zero.

    if verbose:

        print 'Switching to X compatibility'

    imgfile.ttob (1)

    if verbose:

        print 'Filtering with "triangle"'

    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'triangle', 3.0)

    if verbose:

        print 'Switching back to SGI compatibility'

    imgfile.ttob (0)

    if verbose: print 'Filtering with "quadratic"'

    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'quadratic')

    if verbose: print 'Filtering with "gaussian"'

    simage = imgfile.readscaled (name, sizes[0]/2, sizes[1]/2, 'gaussian', 1.0)

    if verbose:

        print 'Writing output file'

    imgfile.write (outputfile, simage, sizes[0]/2, sizes[1]/2, sizes[2])

    os.unlink(outputfile)

def test_main():

    uu.decode(findfile('testrgb.uue'), 'test.rgb')

    uu.decode(findfile('greyrgb.uue'), 'greytest.rgb')

    # Test a 3 byte color image

    testimage('test.rgb')

    # Test a 1 byte greyscale image

    testimage('greytest.rgb')

    unlink('test.rgb')

    unlink('greytest.rgb')

if __name__ == '__main__':

    test_main()