image_utils.py

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# <pep8-80 compliant>

__all__ = (
    "load_image",
)


# limited replacement for BPyImage.comprehensiveImageLoad
def load_image(
        imagepath,
        dirname="",
        place_holder=False,
        recursive=False,
        ncase_cmp=True,
        convert_callback=None,
        verbose=False,
        relpath=None,
        check_existing=False,
        force_reload=False,
):
    """
    Return an image from the file path with options to search multiple paths
    and return a placeholder if its not found.

    :arg filepath: The image filename
       If a path precedes it, this will be searched as well.
    :type filepath: string
    :arg dirname: is the directory where the image may be located - any file at
       the end will be ignored.
    :type dirname: string
    :arg place_holder: if True a new place holder image will be created.
       this is useful so later you can relink the image to its original data.
    :type place_holder: bool
    :arg recursive: If True, directories will be recursively searched.
       Be careful with this if you have files in your root directory because
       it may take a long time.
    :type recursive: bool
    :arg ncase_cmp: on non windows systems, find the correct case for the file.
    :type ncase_cmp: bool
    :arg convert_callback: a function that takes an existing path and returns
       a new one. Use this when loading image formats blender may not support,
       the CONVERT_CALLBACK can take the path for a GIF (for example),
       convert it to a PNG and return the PNG's path.
       For formats blender can read, simply return the path that is given.
    :type convert_callback: function
    :arg relpath: If not None, make the file relative to this path.
    :type relpath: None or string
    :arg check_existing: If true,
       returns already loaded image datablock if possible
       (based on file path).
    :type check_existing: bool
    :arg force_reload: If true,
       force reloading of image (only useful when `check_existing`
       is also enabled).
    :type force_reload: bool
    :return: an image or None
    :rtype: :class:`bpy.types.Image`
    """
    import os
    import bpy

    # -------------------------------------------------------------------------
    # Utility Functions

    def _image_load_placeholder(path):
        name = path
        if type(path) is str:
            name = name.encode("utf-8", "replace")
        name = name.decode("utf-8", "replace")
        name = os.path.basename(name)

        image = bpy.data.images.new(name, 128, 128)
        # allow the path to be resolved later
        image.filepath = path
        image.source = 'FILE'
        return image

    def _image_load(path):
        import bpy

        if convert_callback:
            path = convert_callback(path)

        # Ensure we're not relying on the 'CWD' to resolve the path.
        if not os.path.isabs(path):
            path = os.path.abspath(path)

        try:
            image = bpy.data.images.load(path, check_existing=check_existing)
        except RuntimeError:
            image = None

        if verbose:
            if image:
                print("    image loaded '%s'" % path)
            else:
                print("    image load failed '%s'" % path)

        # image path has been checked so the path could not be read for some
        # reason, so be sure to return a placeholder
        if place_holder and image is None:
            image = _image_load_placeholder(path)

        if image:
            if force_reload:
                image.reload()
            if relpath is not None:
                # make relative
                from bpy.path import relpath as relpath_fn
                # can't always find the relative path
                # (between drive letters on windows)
                try:
                    filepath_rel = relpath_fn(path, start=relpath)
                except ValueError:
                    filepath_rel = None

                if filepath_rel is not None:
                    image.filepath_raw = filepath_rel

        return image

    def _recursive_search(paths, filename_check):
        for path in paths:
            for dirpath, _dirnames, filenames in os.walk(path):

                # skip '.svn'
                if dirpath[0] in {".", b'.'}:
                    continue

                for filename in filenames:
                    if filename_check(filename):
                        yield os.path.join(dirpath, filename)

    # -------------------------------------------------------------------------

    imagepath = bpy.path.native_pathsep(imagepath)

    if verbose:
        print("load_image('%s', '%s', ...)" % (imagepath, dirname))

    if os.path.exists(imagepath):
        return _image_load(imagepath)

    variants = [imagepath]

    if dirname:
        variants += [
            os.path.join(dirname, imagepath),
            os.path.join(dirname, bpy.path.basename(imagepath)),
        ]

    for filepath_test in variants:
        if ncase_cmp:
            ncase_variants = (
                filepath_test,
                bpy.path.resolve_ncase(filepath_test),
            )
        else:
            ncase_variants = (filepath_test, )

        for nfilepath in ncase_variants:
            if os.path.exists(nfilepath):
                return _image_load(nfilepath)

    if recursive:
        search_paths = []

        for dirpath_test in (os.path.dirname(imagepath), dirname):
            if os.path.exists(dirpath_test):
                search_paths.append(dirpath_test)
        search_paths[:] = bpy.path.reduce_dirs(search_paths)

        imagepath_base = bpy.path.basename(imagepath)
        if ncase_cmp:
            imagepath_base = imagepath_base.lower()

            def image_filter(fn):
                return (imagepath_base == fn.lower())
        else:
            def image_filter(fn):
                return (imagepath_base == fn)

        nfilepath = next(_recursive_search(search_paths, image_filter), None)
        if nfilepath is not None:
            return _image_load(nfilepath)

    # None of the paths exist so return placeholder
    if place_holder:
        return _image_load_placeholder(imagepath)

    # TODO comprehensiveImageLoad also searched in bpy.config.textureDir
    return None