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

#

# Licensed under the terms of the BSD 3-Clause

# (see plotpy/LICENSE for details)

# pylint: disable=C0103

"""

Scaling functions

-----------------

Overview

^^^^^^^^

The :py:mod:`.scaler` module provides scaling functions for images, thanks to

the C++ scaler engine (`_scaler` extension).

The following functions are available:

* :py:func:`.resize`: resize an image using the scaler engine

Reference

^^^^^^^^^

.. autofunction:: resize

"""

# TODO: Move all _scaler imports in this module and do something to avoid

# the need to import INTERP_LINEAR, INTERP_AA, ... in all modules using the

# scaler (code refactoring between pyplot.imshow,

# styles.BaseImageParam.update_item)

# TODO: Other functions like resize could be written in the future

import numpy as np

from plotpy._scaler import INTERP_AA, INTERP_LINEAR, INTERP_NEAREST, _scale_rect

def resize(data, shape, interpolation=None):

"""Resize array *data* to *shape* (tuple)

interpolation: 'nearest', 'linear' (default), 'antialiasing'"""

interpolate = (INTERP_NEAREST,)

if interpolation is not None:

interp_dict = {

"nearest": INTERP_NEAREST,

"linear": INTERP_LINEAR,

"antialiasing": INTERP_AA,

}

assert interpolation in interp_dict, "invalid interpolation option"

interp_mode = interp_dict[interpolation]

if interp_mode in (INTERP_NEAREST, INTERP_LINEAR):

interpolate = (interp_mode,)

if interp_mode == INTERP_AA:

aa = np.ones((5, 5), data.dtype)

interpolate = (interp_mode, aa)

out = np.empty(shape)

src_rect = (0, 0, data.shape[1], data.shape[0])

dst_rect = (0, 0, out.shape[1], out.shape[0])

_scale_rect(data, src_rect, out, dst_rect, (1.0, 0.0, None), interpolate)

return out