pylab.py

from __future__ import absolute_import
_last_figure = None
import ipywidgets
from IPython.display import display
import IPython
import ipyvolume as ipv
import ipyvolume.embed
import os
import numpy as np
from . import utils
import time
from . import examples
import warnings
import PIL.Image
import traitlets
try:
    from io import BytesIO as StringIO
except:
    from cStringIO import StringIO
import base64


def _docsubst(f):
    """Perform docstring substitutions"""
    f.__doc__ = f.__doc__.format(**_doc_snippets)
    return f

_seq_sn = "If an (S, N) array, the first dimension will be used for frames in an animation."
_seq_snm = "If an (S, N, M) array, the first dimension will be used for frames in an animation."

_doc_snippets = {}
_doc_snippets[
    "color"] = "color for each point/vertex/symbol, can be string format, examples for red:'red', '#f00', '#ff0000' or 'rgb(1,0,0), or rgb array of shape (N, 3) or (S, N, 3)"
_doc_snippets[
    "color2d"] = "color for each point/vertex string format, examples for red:'red', '#f00', '#ff0000' or 'rgb(1,0,0), or rgb array of shape (2, N, 3) or (S, 2, N, 3)"
_doc_snippets[
    "size"] = "float representing the size of the glyph in percentage of the viewport, where 100 is the full size of the viewport"
_doc_snippets["marker"] = "name of the marker, options are: 'arrow', 'box', 'diamond', 'sphere'"
_doc_snippets["x"] = "numpy array of shape (N,) or (S, N) with x positions. {}".format(_seq_sn)
_doc_snippets["y"] = "idem for y"
_doc_snippets["z"] = "idem for z"
_doc_snippets["u_dir"] = "numpy array of shape (N,) or (S, N) indicating the x component of a vector. {}".format(_seq_sn)
_doc_snippets["v_dir"] = "idem for y"
_doc_snippets["w_dir"] = "idem for z"
_doc_snippets["u"] = "numpy array of shape (N,) or (S, N) indicating the u (x) coordinate for the texture. {}".format(_seq_sn)
_doc_snippets["v"] = "numpy array of shape (N,) or (S, N) indicating the v (y) coordinate for the texture. {}".format(_seq_sn)
_doc_snippets["x2d"] = "numpy array of shape (N,M) or (S, N, M) with x positions. {}".format(_seq_snm)
_doc_snippets["y2d"] = "idem for y"
_doc_snippets["z2d"] = "idem for z"
_doc_snippets["texture"] = "PIL.Image object or ipywebrtc.MediaStream (can be a seqence)"

class current:
    figure = None
    container = None
    figures = {}
    containers = {}


def clear():
    """Remove current figure (and container)"""
    current.container = None
    current.figure = None


def figure(key=None, width=400, height=500, lighting=True, controls=True, controls_vr=False, debug=False, **kwargs):
    """Create a new figure (if no key is given) or return the figure associated with key

    :param key: Python object that identifies this figure
    :param int width: pixel width of WebGL canvas
    :param int height:  .. height ..
    :param bool lighting: use lighting or not
    :param bool controls: show controls or not
    :param bool controls_vr: show controls for VR or not
    :param bool debug: show debug buttons or not
    :return: :any:`Figure`
    """
    if key is not None and key in current.figures:
        current.figure = current.figures[key]
        current.container = current.containers[key]
    else:
        current.figure = ipv.Figure(volume_data=None, width=width, height=height, **kwargs)
        current.container = ipywidgets.VBox()
        current.container.children = [current.figure]
        if key is not None:
            current.figures[key] = current.figure
            current.containers[key] = current.container
        if controls:
            #stereo = ipywidgets.ToggleButton(value=current.figure.stereo, description='stereo', icon='eye')
            #l1 = ipywidgets.jslink((current.figure, 'stereo'), (stereo, 'value'))
            #current.container.children += (ipywidgets.HBox([stereo, ]),)
            pass # stereo and fullscreen are now include in the js code (per view)
        if controls_vr:
            eye_separation = ipywidgets.FloatSlider(value=current.figure.eye_separation, min=-10, max=10, icon='eye')
            ipywidgets.jslink((eye_separation, 'value'), (current.figure, 'eye_separation'))
            current.container.children += (eye_separation,)
        if debug:
            show = ipywidgets.ToggleButtons(options=["Volume", "Back", "Front"])
            current.container.children += (show,)
            #ipywidgets.jslink((current.figure, 'show'), (show, 'value'))
            traitlets.link((current.figure, 'show'), (show, 'value'))
    return current.figure


def gcf():
    """Get current figure, or create a new one

    :return: :any:`Figure`
    """
    if current.figure is None:
        return figure()
    else:
        return current.figure


def _grow_limit(limits, values):
    finites = np.isfinite(values)
    newvmin = np.min(values[finites])
    newvmax = np.max(values[finites])
    if limits is None:
        return newvmin, newvmax
    else:
        vmin, vmax = limits
        return min(newvmin, vmin), max(newvmax, vmax)


def _grow_limits(x, y, z):
    fig = gcf()
    xlim(*_grow_limit(fig.xlim, x))
    ylim(*_grow_limit(fig.ylim, y))
    zlim(*_grow_limit(fig.zlim, z))


def xlim(xmin, xmax):
    """Set limits of x axis"""
    fig = gcf()
    fig.xlim = [xmin, xmax]


def ylim(ymin, ymax):
    """Set limits of y axis"""
    fig = gcf()
    fig.ylim = [ymin, ymax]


def zlim(zmin, zmax):
    """Set limits of zaxis"""
    fig = gcf()
    fig.zlim = [zmin, zmax]


def xyzlim(vmin, vmax=None):
    """Set limits or all axis the same, if vmax not given, use [-vmin, vmax]"""
    if vmax is None:
        vmin, vmax = -vmin, vmin
    xlim(vmin, vmax)
    ylim(vmin, vmax)
    zlim(vmin, vmax)


def squarelim():
    """Sets all axes with equal aspect ratio, such that the space is 'square'"""
    fig = gcf()
    xmin, xmax = fig.xlim
    ymin, ymax = fig.ylim
    zmin, zmax = fig.zlim
    width = max([abs(xmax - xmin), abs(ymax - ymin), abs(zmax - zmin)])
    xc = (xmin + xmax) / 2
    yc = (ymin + ymax) / 2
    zc = (zmin + zmax) / 2
    xlim(xc - width / 2, xc + width / 2)
    ylim(yc - width / 2, yc + width / 2)
    zlim(zc - width / 2, zc + width / 2)


default_color = "red"
default_color_selected = "white"
default_size = 2
default_size_selected = default_size * 1.3


@_docsubst
def plot_trisurf(x, y, z, triangles=None, lines=None, color=default_color, u=None, v=None, texture=None):
    """Draws a polygon/triangle mesh defined by a coordinate and triangle indices

    The following example plots a rectangle in the z==2 plane, consisting of 2 triangles:

    >>> plot_trisurf([0, 0, 3., 3.], [0, 4., 0, 4.], 2,
           triangles=[[0, 2, 3], [0, 3, 1]])

    Note that the z value is constant, and thus not a list/array. For guidance, the triangles
    refer to the vertices in this manner::

        ^ ydir
        |
        2 3
        0 1  ---> x dir

    Note that if you want per face/triangle colors, you need to duplicate each vertex.


    :param x: {x}
    :param y: {y}
    :param z: {z}
    :param triangles: numpy array with indices referring to the vertices, defining the triangles, with shape (M, 3)
    :param lines: numpy array with indices referring to the vertices, defining the lines, with shape (K, 2)
    :param color: {color}
    :param u: {u}
    :param v: {v}
    :param texture: {texture}
    :return: :any:`Mesh`
    """
    fig = gcf()
    if triangles is not None:
        triangles = np.array(triangles).astype(dtype=np.uint32)
    if lines is not None:
        lines = np.array(lines).astype(dtype=np.uint32)
    mesh = ipv.Mesh(x=x, y=y, z=z, triangles=triangles, lines=lines, color=color, u=u, v=v, texture=texture)
    _grow_limits(np.array(x).reshape(-1), np.array(y).reshape(-1), np.array(z).reshape(-1))
    fig.meshes = fig.meshes + [mesh]
    return mesh


@_docsubst
def plot_surface(x, y, z, color=default_color, wrapx=False, wrapy=False):
    """Draws a 2d surface in 3d, defined by the 2d ordered arrays x,y,z

    :param x: {x2d}
    :param y: {y2d}
    :param z: {z2d}
    :param color: {color2d}
    :param bool wrapx: when True, the x direction is assumed to wrap, and polygons are drawn between the end end begin points
    :param bool wrapy: simular for the y coordinate
    :return: :any:`Mesh`
    """
    return plot_mesh(x, y, z, color=color, wrapx=wrapx, wrapy=wrapy, wireframe=False)


@_docsubst
def plot_wireframe(x, y, z, color=default_color, wrapx=False, wrapy=False):
    """Draws a 2d wireframe in 3d, defines by the 2d ordered arrays x,y,z

    See also :any:`ipyvolume.pylab.plot_mesh`

    :param x: {x2d}
    :param y: {y2d}
    :param z: {z2d}
    :param color: {color2d}
    :param bool wrapx: when True, the x direction is assumed to wrap, and polygons are drawn between the begin and end points
    :param bool wrapy: idem for y
    :return: :any:`Mesh`
    """
    return plot_mesh(x, y, z, color=color, wrapx=wrapx, wrapy=wrapy, wireframe=True, surface=False)


def plot_mesh(x, y, z, color=default_color, wireframe=True, surface=True, wrapx=False, wrapy=False, u=None, v=None,
              texture=None):
    """Draws a 2d wireframe+surface in 3d: generalization of :any:`plot_wireframe` and :any:`plot_surface`

    :param x: {x2d}
    :param y: {y2d}
    :param z: {z2d}
    :param color: {color2d}
    :param bool wireframe: draw lines between the vertices
    :param bool surface: draw faces/triangles between the vertices
    :param bool wrapx: when True, the x direction is assumed to wrap, and polygons are drawn between the begin and end points
    :param boool wrapy: idem for y
    :param u: {u}
    :param v: {v}
    :param texture: {texture}
    :return: :any:`Mesh`
    """
    fig = gcf()

    # assert len(x.shape) == 2
    # assert len(y.shape) == 2
    # assert len(z.shape) == 2
    # if isinstance(color, np.ndarray):
    # 	assert len(color.shape) == 3
    # 	assert color.shape[:2] == x.shape
    # 	color = color.reshape(-1)

    def dim(x):
        d = 0
        el = x
        while True:
            try:
                el = el[0]
                d += 1
            except:
                break
        return d

    if dim(x) == 2:
        nx, ny = shape = x.shape
    else:
        nx, ny = shape = x[0].shape

    def reshape(ar):
        if dim(ar) == 3:
            return [k.reshape(-1) for k in ar]
        else:
            return ar.reshape(-1)

    def reshape_color(ar):
        if dim(ar) == 4:
            return [k.reshape(-1, 3) for k in ar]
        else:
            return ar.reshape(-1, 3)

    if isinstance(color, np.ndarray):
        # if dim(color) == 4:
        #	color = color.reshape((color.shape[0], -1, color.shape[-1]))
        color = reshape_color(color)
        # print(color.shape)

    x = reshape(x)
    y = reshape(y)
    z = reshape(z)
    if u is not None:
        u = reshape(u)
    if v is not None:
        v = reshape(v)
    _grow_limits(np.array(x).reshape(-1), np.array(y).reshape(-1), np.array(z).reshape(-1))
    mx = nx if wrapx else nx - 1
    my = ny if wrapy else ny - 1
    triangles = np.zeros(((mx) * (my) * 2, 3), dtype=np.uint32)
    lines = np.zeros(((mx) * (my) * 4, 2), dtype=np.uint32)

    def index_from2d(i, j):
        xi = (i % nx)
        yi = (j % ny)
        return ny * xi + yi
        """
        ^ ydir
        |
        2 3
        0 1  ---> x dir
        """

    for i in range(mx):
        for j in range(my):
            p0 = index_from2d(i, j)
            p1 = index_from2d(i + 1, j)
            p2 = index_from2d(i, j + 1)
            p3 = index_from2d(i + 1, j + 1)
            triangle_index = (i * my) + j
            triangles[triangle_index * 2 + 0, :] = [p0, p1, p3]
            triangles[triangle_index * 2 + 1, :] = [p0, p3, p2]
            lines[triangle_index * 4 + 0, :] = [p0, p1]
            lines[triangle_index * 4 + 1, :] = [p0, p2]
            lines[triangle_index * 4 + 2, :] = [p2, p3]
            lines[triangle_index * 4 + 3, :] = [p1, p3]
    # print(i, j, p0, p1, p2, p3)
    mesh = ipv.Mesh(x=x, y=y, z=z, triangles=triangles if surface else None, color=color,
                       lines=lines if wireframe else None,
                       u=u, v=v, texture=texture)
    fig.meshes = fig.meshes + [mesh]
    return mesh

@_docsubst
def plot(x, y, z, color=default_color, **kwargs):
    """Plot a line in 3d

    :param x: {x}
    :param y: {y}
    :param z: {z}
    :param color: {color}
    :param kwargs: extra arguments passed to the Scatter constructor
    :return: :any:`Scatter`
    """
    fig = gcf()
    _grow_limits(x, y, z)
    defaults = dict(visible_lines=True, color_selected=None, size_selected=1,
                    size=1, connected=True, visible_markers=False)
    kwargs = dict(defaults, **kwargs)
    s = ipv.Scatter(x=x, y=y, z=z, color=color, **kwargs)
    fig.scatters = fig.scatters + [s]
    return s


@_docsubst
def scatter(x, y, z, color=default_color, size=default_size,
            size_selected=default_size_selected,
            color_selected=default_color_selected, marker="diamond",
            selection=None, **kwargs):
    """Plots many markers/symbols in 3d

    :param x: {x}
    :param y: {y}
    :param z: {z}
    :param color: {color}
    :param size: {size}
    :param size_selected: like size, but for selected glyphs
    :param color_selected:  like color, but for selected glyphs
    :param marker: {marker}
    :param selection: numpy array of shape (N,) or (S, N) with indices of x,y,z arrays of the selected markers, which can have a different size and color
    :param kwargs:
    :return: :any:`Scatter`
    """
    fig = gcf()
    _grow_limits(x, y, z)
    s = ipv.Scatter(x=x, y=y, z=z, color=color, size=size,
                    color_selected=color_selected, size_selected=size_selected,
                    geo=marker, selection=selection, **kwargs)
    fig.scatters = fig.scatters + [s]
    return s

@_docsubst
def quiver(x, y, z, u, v, w, size=default_size * 10,
           size_selected=default_size_selected * 10, color=default_color,
           color_selected=default_color_selected, marker="arrow", **kwargs):
    """Create a quiver plot, which is like a scatter plot but with arrows pointing in the direction given by u, v and w

    :param x: {x}
    :param y: {y}
    :param z: {z}
    :param u: {u_dir}
    :param v: {v_dir}
    :param w: {w_dir}
    :param size: {size}
    :param size_selected: like size, but for selected glyphs
    :param color: {color}
    :param color_selected: like color, but for selected glyphs
    :param marker: (currently only 'arrow' would make sense)
    :param kwargs: extra arguments passed on to the Scatter constructor
    :return: :any:`Scatter`
    """
    fig = gcf()
    _grow_limits(x, y, z)
    if 'vx' in kwargs or 'vy' in kwargs or 'vz' in kwargs:
        raise KeyError('Please use u, v, w instead of vx, vy, vz')
    s = ipv.Scatter(x=x, y=y, z=z, vx=u, vy=v, vz=w, color=color, size=size,
                    color_selected=color_selected, size_selected=size_selected,
                    geo=marker, **kwargs)
    fig.scatters = fig.scatters + [s]
    return s


def show(extra_widgets=[]):
    """Display (like in IPython.display.dispay(...)) the current figure"""
    gcf()  # make sure we have something..
    display(gcc())
    for widget in extra_widgets:
        display(widget)


def animate_glyphs(*args, **kwargs):
    """Deprecated: please use animation_control"""
    warnings.warn("Please use animation_control(...)", DeprecationWarning, stacklevel=2)
    animation_control(*args, **kwargs)


def animation_control(object, sequence_length=None, add=True, interval=200):
    """Animate scatter, quiver or mesh by adding a slider and play button.

    :param object: :any:`Scatter` or :any:`Mesh` object (having an sequence_index property), or a list of these to control multiple.
    :param sequence_length: If sequence_length is None we try try our best to figure out, in case we do it badly,
            you can tell us what it should be. Should be equal to the S in the shape of the numpy arrays as for instance documented
            in :any:`scatter` or :any:`plot_mesh`.
    :param add: if True, add the widgets to the container, else return a HBox with the slider and play button. Useful when you
            want to customise the layout of the widgets yourself.
    :param interval: interval in msec between each frame
    :return: If add is False, if returns the ipywidgets.HBox object containing the controls
    """
    if isinstance(object, (list, tuple)):
        objects = object
    else:
        objects = [object]
    del object
    if sequence_length is None:
        # get all non-None arrays
        sequence_lengths = []
        for object in objects:
            values = [getattr(object, name) for name in "x y z vx vy vz".split() if hasattr(object, name)]
            values = [k for k in values if k is not None]
            # sort them such that the higest dim is first
            values.sort(key=lambda key: -len(key.shape))
            sequence_length = values[0].shape[0]  # assume this defines the sequence length
            sequence_lengths.append(sequence_length)
        sequence_length = max(sequence_lengths)
    fig = gcf()
    fig.animation = interval
    fig.animation_exponent = 1.
    play = ipywidgets.Play(min=0, max=sequence_length - 1, interval=interval, value=0, step=1)
    slider = ipywidgets.FloatSlider(min=0, max=play.max, step=1)
    ipywidgets.jslink((play, 'value'), (slider, 'value'))
    for object in objects:
        ipywidgets.jslink((slider, 'value'), (object, 'sequence_index'))
    control = ipywidgets.HBox([play, slider])
    if add:
        current.container.children += (control,)
    else:
        return control


def gcc():
    """Return the current container, that is the widget holding the figure and all the control widgets, buttons etc."""
    gcf()  # make sure we have something..
    return current.container


def transfer_function(level=[0.1, 0.5, 0.9], opacity=[0.01, 0.05, 0.1], level_width=0.1, controls=True, max_opacity=0.2):
    """Create a transfer function, see volshow"""
    tf_kwargs = {}
    # level, opacity and widths can be scalars
    try:
        level[0]
    except:
        level = [level]
    try:
        opacity[0]
    except:
        opacity = [opacity] * 3
    try:
        level_width[0]
    except:
        level_width = [level_width] * 3
        # clip off lists
    min_length = min(len(level), len(level_width), len(opacity))
    level = list(level[:min_length])
    opacity = list(opacity[:min_length])
    level_width = list(level_width[:min_length])
    # append with zeros
    while len(level) < 3:
        level.append(0)
    while len(opacity) < 3:
        opacity.append(0)
    while len(level_width) < 3:
        level_width.append(0)
    for i in range(1, 4):
        tf_kwargs["level" + str(i)] = level[i - 1]
        tf_kwargs["opacity" + str(i)] = opacity[i - 1]
        tf_kwargs["width" + str(i)] = level_width[i - 1]
    tf = ipv.TransferFunctionWidgetJs3(**tf_kwargs)
    fig = gcf()
    if controls:
        current.container.children = (tf.control(max_opacity=max_opacity),) + current.container.children
    return tf

def plot_isosurface(data, level=None, color=default_color, wireframe=True, surface=True, controls=True):
    """Plot a surface at constant value (like a 2d contour)

    :param float level: value where the surface should lie
    :param color: color of the surface, although it can be an array, the length is difficult to predict beforehand,
                  if per vertex color are needed, it is better to set them on the returned mesh afterwards.
    :param bool wireframe: draw lines between the vertices
    :param bool surface: draw faces/triangles between the vertices
    :param bool controls: add controls to change the isosurface
    :return: :any:`Mesh`
    """
    from skimage import measure
    if level is None:
        level = np.median(data)
    if hasattr(measure, 'marching_cubes_lewiner'):
        values = measure.marching_cubes_lewiner(data, level)
    else:
        values = measure.marching_cubes(data, level)
    verts, triangles = values[:2] # version 0.13 returns 4 values, normals, values
    # in the future we may want to support normals and the values (with colormap)
    # and require skimage >= 0.13
    x, y, z = verts.T
    mesh = plot_trisurf(x, y, z, triangles=triangles, color=color)
    if controls:
        vmin, vmax = np.percentile(data, 1),  np.percentile(data, 99)
        step = (vmax - vmin)/250
        level_slider = ipywidgets.FloatSlider(value=level, min=vmin, max=vmax, step=step, icon='eye')
        recompute_button = ipywidgets.Button(description='update')
        controls = ipywidgets.HBox(children=[level_slider, recompute_button])
        current.container.children += (controls,)
        def recompute(*_ignore):
            level = level_slider.value
            recompute_button.description = "updating..."
            if hasattr(measure, 'marching_cubes_lewiner'):
                values = measure.marching_cubes_lewiner(data, level)
            else:
                values = measure.marching_cubes(data, level)
            verts, triangles = values[:2] # version 0.13 returns 4 values, normals, values
            # in the future we may want to support normals and the values (with colormap)
            # and require skimage >= 0.13
            x, y, z = verts.T
            with mesh.hold_sync():
                mesh.x = x
                mesh.y = y
                mesh.z = z
                mesh.triangles = triangles.astype(dtype=np.uint32)
                recompute_button.description = "update"

        recompute_button.on_click(recompute)
    return mesh


def volshow(data, lighting=False, data_min=None, data_max=None, tf=None, stereo=False,
            ambient_coefficient=0.5, diffuse_coefficient=0.8,
            specular_coefficient=0.5, specular_exponent=5,
            downscale=1,
            level=[0.1, 0.5, 0.9], opacity=[0.01, 0.05, 0.1], level_width=0.1,
            controls=True, max_opacity=0.2):
    """Visualize a 3d array using volume rendering.

    Currently only 1 volume can be rendered.


    :param data: 3d numpy array
    :param bool lighting: use lighting or not, if set to false, lighting parameters will be overriden
    :param float data_min: minimum value to consider for data, if None, computed using np.nanmin
    :param float data_max: maximum value to consider for data, if None, computed using np.nanmax
    :param tf: transfer function (or a default one)
    :param bool stereo: stereo view for virtual reality (cardboard and similar VR head mount)
    :param ambient_coefficient: lighting parameter
    :param diffuse_coefficient: lighting parameter
    :param specular_coefficient: lighting parameter
    :param specular_exponent: lighting parameter
    :param float downscale: downscale the rendering for better performance, for instance when set to 2, a 512x512 canvas will show a 256x256 rendering upscaled, but it will render twice as fast.
    :param level: level(s) for the where the opacity in the volume peaks, maximum sequence of length 3
    :param opacity: opacity(ies) for each level, scalar or sequence of max length 3
    :param level_width: width of the (gaussian) bumps where the opacity peaks, scalar or sequence of max length 3
    :param bool controls: add controls for lighting and transfer function or not
    :param float max_opacity: maximum opacity for transfer function controls
    :return:
    """
    vol = gcf()
    if tf is None:
        tf = vol.tf or transfer_function(level, opacity, level_width, controls=controls, max_opacity=max_opacity)
    if data_min is None:
        data_min = np.nanmin(data)
    if data_max is None:
        data_max = np.nanmax(data)
    vol.tf = tf
    vol.data_min = data_min
    vol.data_max = data_max
    vol.volume_data = data
    vol.stereo = stereo
    vol.ambient_coefficient = ambient_coefficient
    vol.diffuse_coefficient = diffuse_coefficient
    vol.specular_coefficient = specular_coefficient
    vol.specular_exponent = specular_exponent

    if controls:
        ambient_coefficient = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=vol.ambient_coefficient,
                                                     description="ambient")
        diffuse_coefficient = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=vol.diffuse_coefficient,
                                                     description="diffuse")
        specular_coefficient = ipywidgets.FloatSlider(min=0, max=1, step=0.001, value=vol.specular_coefficient,
                                                      description="specular")
        specular_exponent = ipywidgets.FloatSlider(min=0, max=10, step=0.001, value=vol.specular_exponent,
                                                   description="specular exp")
        # angle2 = ipywidgets.FloatSlider(min=0, max=np.pi*2, value=v.angle2, description="angle2")
        ipywidgets.jslink((vol, 'ambient_coefficient'), (ambient_coefficient, 'value'))
        ipywidgets.jslink((vol, 'diffuse_coefficient'), (diffuse_coefficient, 'value'))
        ipywidgets.jslink((vol, 'specular_coefficient'), (specular_coefficient, 'value'))
        ipywidgets.jslink((vol, 'specular_exponent'), (specular_exponent, 'value'))
        widgets_bottom = [ipywidgets.HBox([ambient_coefficient, diffuse_coefficient]),
                          ipywidgets.HBox([specular_coefficient, specular_exponent])]
        current.container.children += tuple(widgets_bottom, )

    return vol


def save(filepath, makedirs=True, title=u'IPyVolume Widget', all_states=False,
         offline=False, scripts_path='js',
         drop_defaults=False, template_options=(("extra_script_head", ""), ("body_pre", ""), ("body_post", "")),
         devmode=False, offline_cors=False):
    """Save the current container to a HTML file

    By default the HTML file is not standalone and requires an internet connection to fetch a few javascript
    libraries. Use offline=True to download these and make the HTML file work without an internet connection.

    :param str filepath: The file to write the HTML output to.
    :param bool makedirs: whether to make directories in the filename path, if they do not already exist
    :param str title: title for the html page
    :param bool all_states: if True, the state of all widgets know to the widget manager is included, else only those in widgets
    :param bool offline: if True, use local urls for required js/css packages and download all js/css required packages
            (if not already available), such that the html can be viewed with no internet connection
    :param str scripts_path: the folder to save required js/css packages to (relative to the filepath)
    :param bool drop_defaults: Whether to drop default values from the widget states
    :param template_options: list or dict of additional template options
    :param bool devmode: if True, attempt to get index.js from local js/dist folder
    :param bool offline_cors: if True, sets crossorigin attribute of script tags to anonymous

    """
    ipyvolume.embed.embed_html(filepath, current.container, makedirs=makedirs, title=title, all_states=all_states,
                               offline=offline, scripts_path=scripts_path,
                               drop_defaults=drop_defaults, template_options=template_options, devmode=devmode,
                               offline_cors=offline_cors)


def _change_y_angle(fig, frame, fraction):
    fig.angley = fraction * np.pi * 2


def movie(f="movie.mp4", function=_change_y_angle, fps=30, frames=30, endpoint=False, \
          cmd_template_ffmpeg="ffmpeg -y -r {fps} -i {tempdir}/frame-%5d.png -vcodec h264 -pix_fmt yuv420p {filename}",
          cmd_template_gif="convert -delay {delay} {loop} {tempdir}/frame-*.png {filename}",
          gif_loop=0):
    """Create a movie (mp4/gif) out of many frames

    If the filename ends in `.gif`, `convert` is used to convert all frames to an animated gif using the `cmd_template_gif`
    template. Otherwise `ffmpeg is assumed to know the file format`.

    Example:

    >>> def set_angles(fig, i, fraction):
    >>>     fig.angley = fraction*np.pi*2
    >>> # 4 second movie, that rotates around the y axis
    >>> p3.movie('test2.gif', set_angles, fps=20, frames=20*4,
            endpoint=False)

    Note that in the example above we use `endpoint=False` to avoid to first and last frame to be the same

    :param str f: filename out output movie (e.g. 'movie.mp4' or 'movie.gif')
    :param function: function called before each frame with arguments (figure, framenr, fraction)
    :param fps: frames per seconds
    :param int frames: total number of frames
    :param bool endpoint: if fraction goes from [0, 1] (inclusive) or [0, 1) (endpoint=False is useful for loops/rotatations)
    :param str cmd_template_ffmpeg: template command when running ffmpeg (non-gif ending filenames)
    :param str cmd_template_gif: template command when running imagemagick's convert (if filename ends in .gif)
    :param gif_loop: None for no loop, otherwise the framenumber to go to after the last frame
    :return: the temp dir where the frames are stored
    """
    movie_filename = f
    import tempfile
    tempdir = tempfile.mkdtemp()
    output = ipywidgets.Output()
    display(output)
    fig = gcf()
    for i in range(frames):
        with output:
            fraction = i / (frames - 1. if endpoint else frames)
            function(fig, i, fraction)
            frame_filename = os.path.join(tempdir, "frame-%05d.png" % i)
            savefig(frame_filename, output_widget=output)
    with output:
        if movie_filename.endswith(".gif"):
            if gif_loop is None:
                loop = ""
            else:
                loop = "-loop %d" % gif_loop
            delay = 100 / fps
            cmd = cmd_template_gif.format(delay=delay, loop=loop, tempdir=tempdir, filename=movie_filename)
        else:
            cmd = cmd_template_ffmpeg.format(fps=fps, tempdir=tempdir, filename=movie_filename)
        print(cmd)
        os.system(cmd)
    return tempdir


def _screenshot_data(timeout_seconds=10, output_widget=None, format="png", width=None, height=None, fig=None, headless=False):
    if fig is None:
        fig = gcf()
    else:
        assert isinstance(fig, ipv.Figure)
    if headless:
        from . import headless
        import tempfile
        tempdir = tempfile.mkdtemp()
        tempdir = '/var/folders/vn/_rmzj8jd0215_g9yfrn8pmgm0000gn/T/tmpxv07_m6l/'
        tempfile = os.path.join(tempdir, 'headless.html')
        #tempfile = os.path.abspath(tempfile)
        save(tempfile, offline=True, scripts_path=tempdir, devmode=True)
        print(tempfile)
        data = headless._screenshot_data("file://" + tempfile)
    else:
        if output_widget is None:
            output_widget = ipywidgets.Output()
            display(output_widget)
        # use lists to avoid globals
        done = [False]
        data = [None]

        def screenshot_handler(image_data):
            with output_widget:
                # print("data")
                # print(data)
                done[0] = True
                data[0] = image_data

        fig.on_screenshot(screenshot_handler)
        try:
            fig.screenshot(width=width, height=height,mime_type="image/"+format)
            t0 = time.time()
            timeout = False
            ipython = IPython.get_ipython()
            while (not done[0]) and not timeout:
                ipython.kernel.do_one_iteration()
                with output_widget:
                    time.sleep(0.05)
                    timeout = (time.time() - t0) > timeout_seconds
            with output_widget:
                if timeout and not done[0]:
                    raise ValueError("timed out, no image data returned")
        finally:
            with output_widget:
                fig.on_screenshot(screenshot_handler, remove=True)
        data = data[0]
    data = data[data.find(",") + 1:]
    return base64.b64decode(data)

def screenshot(width=None, height=None, format="png", fig=None, timeout_seconds=10, output_widget=None, headless=False):
    """Save the figure to a PIL.Image object.

    :param int width: the width of the image in pixels
    :param int height: the height of the image in pixels
    :param format: format of output data (png, jpeg or svg)
    :type fig: ipyvolume.widgets.Figure or None
    :param fig: if None use the current figure
    :type timeout_seconds: int
    :param timeout_seconds: maximum time to wait for image data to return
    :type output_widget: ipywidgets.Output
    :param output_widget: a widget to use as a context manager for capturing the data
    :return: PIL.Image

    """
    assert format in ['png','jpeg','svg'], "image format must be png, jpeg or svg"
    data = _screenshot_data(timeout_seconds=timeout_seconds, output_widget=output_widget,
    format=format, width=width, height=height, fig=fig, headless=headless)
    f = StringIO(data)
    return PIL.Image.open(f)

def savefig(filename, width=None, height=None, fig=None, timeout_seconds=10, output_widget=None, headless=False):
    """Save the figure to an image file.

    :param str filename: must have extension .png, .jpeg or .svg
    :param int width: the width of the image in pixels
    :param int height: the height of the image in pixels
    :type fig: ipyvolume.widgets.Figure or None
    :param fig: if None use the current figure
    :param float timeout_seconds: maximum time to wait for image data to return
    :param ipywidgets.Output output_widget: a widget to use as a context manager for capturing the data
    """
    __, ext = os.path.splitext(filename)
    format = ext[1:]
    assert format in ['png','jpeg','svg'], "image format must be png, jpeg or svg"
    with open(filename, "wb") as f:
        f.write(_screenshot_data(timeout_seconds=timeout_seconds, output_widget=output_widget,
        format=format, width=width, height=height, fig=fig, headless=headless))


def xlabel(label):
    """Set the labels for the x-axis"""
    fig = gcf()
    fig.xlabel = label


def ylabel(label):
    """Set the labels for the y-axis"""
    fig = gcf()
    fig.ylabel = label


def zlabel(label):
    """Set the labels for the z-axis"""
    fig = gcf()
    fig.zlabel = label


def xyzlabel(labelx, labely, labelz):
    """Set all labels at once"""
    xlabel(labelx)
    ylabel(labely)
    zlabel(labelz)

def view(azimuth, elevation):
    """Sets camera angles

    :param float azimuth: rotation around the axis pointing up in degrees
    :param float elevation: rotation where +90 means 'up', -90 means 'down', in degrees
    """
    fig = gcf()
    fig.anglex = np.radians(elevation)
    fig.angley = np.radians(azimuth)



# mimic matplotlib namesace
class style:
    """'Static class that mimics a matplotlib module.

    Example:
    >>> import ipyvolume.pylab as p3
    >>> p3.style.use('light'])
    >>> p3.style.use('seaborn-darkgrid'])
    >>> p3.style.use(['seaborn-darkgrid', {'axes.x.color':'orange'}])

    Possible style values:
     * figure.facecolor: background color
     * axes.color: color of the box around the volume/viewport
     * xaxis.color: color of xaxis
     * yaxis.color: color of xaxis
     * zaxis.color: color of xaxis

    """

    @staticmethod
    def use(style):
        """Set the style of the current figure/visualization

        :param style: matplotlib style name, or dict with values, or a sequence of these, where the last value overrides previous
        :return:
        """
        import six
        def valid(value):  # checks if json'able
            return isinstance(value, six.string_types)

        def translate(mplstyle):
            style = {}
            mapping = [
                ['figure.facecolor', 'background-color'],
                ['xtick.color', 'axes.x.color'],  # TODO: is this the right thing?
                ['xtick.color', 'axes.z.color'],  # map x to z as well
                ['ytick.color', 'axes.y.color'],
                ['axes.labelcolor', 'axes.label.color'],
                ['text.color', 'color'],
                ['axes.edgecolor', 'axes.color']
            ]
            for from_name, to_name in mapping:
                if from_name in mplstyle:
                    value = mplstyle[from_name]
                    if "color" in from_name:
                        try:  # threejs doesn't like a color like '.13', so try to convert to proper format
                            value = float(value) * 255
                            value = "rgb(%d, %d, %d)" % (value, value, value)
                        except:
                            pass

                    utils.nested_setitem(style, to_name, value)
            return style

        if isinstance(style, six.string_types):
            styles = [style]
        else:
            styles = style
        totalstyle = utils.dict_deep_update({}, ipyvolume.styles._defaults)
        for style in styles:
            if isinstance(style, six.string_types):
                if hasattr(ipyvolume.styles, style):
                    style = getattr(ipyvolume.styles, style)
                else:
                    # lets see if we can copy matplotlib's style
                    # we assume now it's a matplotlib style, get all properties that we understand
                    import matplotlib.style
                    cleaned_style = {key: value for key, value in dict(matplotlib.style.library[style]).items() if
                                     valid(value)}
                    style = translate(cleaned_style)
                    # totalstyle.update(cleaned_style)
            else:
                # otherwise assume it's a dict
                pass
            totalstyle = utils.dict_deep_update(totalstyle, style)

        fig = gcf()
        fig.style = totalstyle

@_docsubst
def plot_plane(where="back", texture=None):
    """Plots a plane at a particular location in the viewbox

    :param str where: 'back', 'front', 'left', 'right'
    :param texture: {texture}
    :return: :any:`Mesh`
    """
    fig = gcf()
    xmin, xmax = fig.xlim
    ymin, ymax = fig.ylim
    zmin, zmax = fig.ylim
    if where == "back":
        x = [xmin, xmax, xmax, xmin]
        y = [ymin, ymin, ymax, ymax]
        z = [zmin, zmin, zmin, zmin]
    if where == "front":
        x = [xmin, xmax, xmax, xmin][::-1]
        y = [ymin, ymin, ymax, ymax]
        z = [zmax, zmax, zmax, zmax]
    if where == "left":
        x = [xmin, xmin, xmin, zmin]
        y = [ymin, ymin, ymax, ymax]
        z = [zmin, zmax, zmax, zmin]
    if where == "right":
        x = [xmax, xmax, xmax, zmax]
        y = [ymin, ymin, ymax, ymax]
        z = [zmin, zmax, zmax, zmin][::-1]
    triangles = [(0, 1, 2), (0, 2, 3)]
    u = v = None
    if texture is not None:
        u = [0., 1., 1., 0.]
        v = [0., 0., 1., 1.]
    mesh = plot_trisurf(x, y, z, triangles, texture=texture, u=u, v=v)
    return mesh

def selector_lasso(output_widget=None):
    fig = gcf()
    if output_widget is None:
        output_widget = ipywidgets.Output()
        display(output_widget)
    def lasso(data, other=None, fig=fig):
        with output_widget:
            if data['device']:
                import shapely.geometry
                region = shapely.geometry.Polygon(data['device'])
                for scatter in fig.scatters:
                    xyz_projected = fig.project(scatter.x, scatter.y, scatter.z)
                    points = xyz_projected.T[:,:2]
                    selected = []
                    for i, p in enumerate(points):
                        #print(i, p)
                        if region.contains(shapely.geometry.Point(p)):
                            selected.append(i)
                    if selected:
                        scatter.selected = selected
    fig.on_lasso(lasso)