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

.. only:: html

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

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

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

.. _sphx_glr_gallery_gloo_rotating_quad.py:


Rotating Quad
=============

Use a Timer to animate a quad

.. GENERATED FROM PYTHON SOURCE LINES 17-81



.. image-sg:: /gallery/gloo/images/sphx_glr_rotating_quad_001.gif
   :alt: rotating quad
   :srcset: /gallery/gloo/images/sphx_glr_rotating_quad_001.gif
   :class: sphx-glr-single-img





.. code-block:: Python


    from vispy import gloo, app
    from vispy.gloo import Program

    vertex = """
        uniform float theta;
        attribute vec4 color;
        attribute vec2 position;
        varying vec4 v_color;
        void main()
        {
            float ct = cos(theta);
            float st = sin(theta);
            float x = 0.75* (position.x*ct - position.y*st);
            float y = 0.75* (position.x*st + position.y*ct);
            gl_Position = vec4(x, y, 0.0, 1.0);
            v_color = color;
        } """

    fragment = """
        varying vec4 v_color;
        void main()
        {
            gl_FragColor = v_color;
        } """


    class Canvas(app.Canvas):
        def __init__(self):
            super().__init__(size=(512, 512), title='Rotating quad',
                             keys='interactive')
            # Build program & data
            self.program = Program(vertex, fragment, count=4)
            self.program['color'] = [(1, 0, 0, 1), (0, 1, 0, 1),
                                     (0, 0, 1, 1), (1, 1, 0, 1)]
            self.program['position'] = [(-1, -1), (-1, +1),
                                        (+1, -1), (+1, +1)]
            self.program['theta'] = 0.0

            gloo.set_viewport(0, 0, *self.physical_size)
            gloo.set_clear_color('white')

            self.timer = app.Timer('auto', self.on_timer)
            self.clock = 0
            self.timer.start()

            self.show()

        def on_draw(self, event):
            gloo.clear()
            self.program.draw('triangle_strip')

        def on_resize(self, event):
            gloo.set_viewport(0, 0, *event.physical_size)

        def on_timer(self, event):
            self.clock += 0.001 * 1000.0 / 60.
            self.program['theta'] = self.clock
            self.update()


    if __name__ == '__main__':
        c = Canvas()
        app.run()


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

   **Total running time of the script:** (0 minutes 0.624 seconds)


.. _sphx_glr_download_gallery_gloo_rotating_quad.py:

.. only:: html

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

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

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

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

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


.. only:: html

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

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