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

.. only:: html

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

        Click :ref:`here <sphx_glr_download_gallery_gloo_animate_shape.py>`
        to download the full example code

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

.. _sphx_glr_gallery_gloo_animate_shape.py:


Animate a Shape
===============

Example demonstrating showing a quad using
a Texture2D and VertexBuffer and a timer to control the drawing.

.. GENERATED FROM PYTHON SOURCE LINES 12-113



.. image-sg:: /gallery/gloo/images/sphx_glr_animate_shape_001.gif
   :alt: animate shape
   :srcset: /gallery/gloo/images/sphx_glr_animate_shape_001.gif
   :class: sphx-glr-single-img





.. code-block:: default


    import time
    import numpy as np

    from vispy import gloo
    from vispy import app


    # Create a texture
    im1 = np.zeros((100, 100, 3), 'float32')
    im1[:50, :, 0] = 1.0
    im1[:, :50, 1] = 1.0
    im1[50:, 50:, 2] = 1.0

    # Create vertices and texture coords, combined in one array for high performance
    vertex_data = np.zeros(4, dtype=[('a_position', np.float32, 3),
                                     ('a_texcoord', np.float32, 2)])
    vertex_data['a_position'] = np.array([[-0.8, -0.8, 0.0], [+0.7, -0.7, 0.0],
                                          [-0.7, +0.7, 0.0], [+0.8, +0.8, 0.0, ]])
    vertex_data['a_texcoord'] = np.array([[0.0, 0.0], [0.0, 1.0],
                                          [1.0, 0.0], [1.0, 1.0]])

    # Create indices and an ElementBuffer for it
    indices = np.array([0, 1, 2, 1, 2, 3], np.uint16)
    indices_buffer = gloo.IndexBuffer(indices)
    client_indices_buffer = gloo.IndexBuffer(indices)


    VERT_SHADER = """ // simple vertex shader

    attribute vec3 a_position;
    attribute vec2 a_texcoord;
    uniform float sizeFactor;

    void main (void) {
        // Pass tex coords
        gl_TexCoord[0] = vec4(a_texcoord.x, a_texcoord.y, 0.0, 0.0);
        // Calculate position
        gl_Position = sizeFactor*vec4(a_position.x, a_position.y, a_position.z,
                                                            1.0/sizeFactor);
    }
    """

    FRAG_SHADER = """ // simple fragment shader
    uniform sampler2D texture1;

    void main()
    {
        gl_FragColor = texture2D(texture1, gl_TexCoord[0].st);
    }

    """


    class Canvas(app.Canvas):

        def __init__(self):
            app.Canvas.__init__(self, keys='interactive')

            # Create program
            self._program = gloo.Program(VERT_SHADER, FRAG_SHADER)

            # Create vertex buffer
            self._vbo = gloo.VertexBuffer(vertex_data)

            # Set uniforms, samplers, attributes
            # We create one VBO with all vertex data (array of structures)
            # and create two views from it for the attributes.
            self._program['texture1'] = gloo.Texture2D(im1)
            self._program.bind(self._vbo)  # This does:
            # self._program['a_position'] = self._vbo['a_position']
            # self._program['a_texcoords'] = self._vbo['a_texcoords']

            gloo.set_clear_color('white')

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

            self.show()

        def on_resize(self, event):
            width, height = event.physical_size
            gloo.set_viewport(0, 0, width, height)

        def on_draw(self, event):

            # Clear
            gloo.clear()

            # Draw
            self._program['sizeFactor'] = 0.5 + np.sin(time.time() * 3) * 0.2

            # Draw (pick one!)
            # self._program.draw('triangle_strip')
            self._program.draw('triangles', indices_buffer)
            # self._program.draw('triangles', client_indices_buffer)  # Not
            # recommended


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


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

   **Total running time of the script:** ( 0 minutes  0.723 seconds)


.. _sphx_glr_download_gallery_gloo_animate_shape.py:


.. only :: html

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



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

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



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

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


.. only:: html

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

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