
.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "gallery/scene/line.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_gallery_scene_line.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_gallery_scene_line.py:


Draw a Line
===========

Simple demonstration of SceneCanvas containing a single line entity
as its entire scenegraph.

.. GENERATED FROM PYTHON SOURCE LINES 14-53



.. image-sg:: /gallery/scene/images/sphx_glr_line_001.gif
   :alt: line
   :srcset: /gallery/scene/images/sphx_glr_line_001.gif
   :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    Generating points...
    Done






|

.. code-block:: Python

    import sys
    import numpy as np

    from vispy import app, scene

    canvas = scene.SceneCanvas(size=(800, 600), keys='interactive')

    N = 1000
    pos = np.empty((N, 2), np.float32)
    pos[:, 0] = np.linspace(50., 750., N)
    #
    color = np.ones((N, 4), dtype=np.float32)
    color[:, 0] = np.linspace(0, 1, N)
    color[:, 1] = color[::-1, 0]

    lines = []

    print('Generating points...')
    for i in range(20):
        pos = pos.copy()
        pos[:, 1] = np.random.normal(scale=5, loc=(i+1)*30, size=N)
        line = scene.visuals.Line(pos=pos, color=color, parent=canvas.scene)
        lines.append(line)
        line.transform = scene.transforms.STTransform()
    print('Done')


    def update(event):
        for line in lines:
            scale = [np.sin(np.pi * event.elapsed)+2,
                     np.cos(np.pi * event.elapsed)+2]
            line.transform.scale = scale

    timer = app.Timer('auto', connect=update, start=True)

    if __name__ == '__main__':
        canvas.show()
        if sys.flags.interactive == 0:
            app.run()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.975 seconds)


.. _sphx_glr_download_gallery_scene_line.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: line.ipynb <line.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: line.py <line.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: line.zip <line.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_
