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

.. only:: html

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

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

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

.. _sphx_glr__gallery_feature_demo_image_click_events.py:


Image Click Events
==================

Show an image and print the x, y image data coordinates for click events.

.. GENERATED FROM PYTHON SOURCE LINES 7-88



.. image-sg:: /_gallery/feature_demo/images/sphx_glr_image_click_events_001.webp
   :alt: image click events
   :srcset: /_gallery/feature_demo/images/sphx_glr_image_click_events_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python



    import imageio.v3 as iio
    from rendercanvas.auto import RenderCanvas, loop
    import pygfx as gfx
    import numpy as np

    canvas = RenderCanvas()
    renderer = gfx.renderers.WgpuRenderer(canvas)
    scene = gfx.Scene()

    # add image


    im = iio.imread("imageio:astronaut.png")

    image = gfx.Image(
        gfx.Geometry(grid=gfx.Texture(im, dim=2)),
        gfx.ImageBasicMaterial(clim=(0, 255), pick_write=True),
    )
    scene.add(image)

    camera = gfx.OrthographicCamera(512, 512)
    camera.local.position = (256, 256, 0)
    camera.local.scale_y = -1

    xx = [182, 180, 161, 153, 191, 237, 293, 300, 272, 267, 254]
    yy = [145, 131, 112, 59, 29, 14, 48, 91, 136, 137, 172]

    colors = np.vstack([[0.0, 0.0, 1.0, 1.0]] * len(xx)).astype(np.float32)

    points = gfx.Points(
        gfx.Geometry(
            positions=[(x, y, 0) for x, y in zip(xx, yy, strict=True)], colors=colors
        ),
        gfx.PointsMaterial(color_mode="vertex", size=10),
    )
    points.local.z = 1  # move points in front of the image
    scene.add(points)


    previous_selection = None


    def event_handler(event):
        print(
            f"Canvas click coordinates: {event.x, event.y}\n"
            f"Click position in coordinate system of image, i.e. data coordinates of click event: {event.pick_info['index']}\n"
            f"Other `pick_info`: {event.pick_info}"
        )

        global previous_selection

        if previous_selection is not None:
            # reset colors to blue
            blues = np.vstack([[0.0, 0.0, 1.0, 1.0]] * 3).astype(np.float32)
            points.geometry.colors.data[previous_selection] = blues

            for idx in previous_selection.tolist():
                points.geometry.colors.update_range(idx, size=1)

        # set the color of the 3 closest points to red
        positions = points.geometry.positions.data
        event_position = np.array([*event.pick_info["index"], 0])
        closest = np.linalg.norm(positions - event_position, axis=1).argsort()
        points.geometry.colors.data[closest[:3]] = np.array([1.0, 0.0, 0.0, 1.0])
        for idx in closest[:3].tolist():
            # only mark the changed points for synchronization to the GPU
            points.geometry.colors.update_range(idx, size=1)

        previous_selection = closest[:3]

        renderer.request_draw()


    image.add_event_handler(event_handler, "click")


    if __name__ == "__main__":
        canvas.request_draw(lambda: renderer.render(scene, camera))
        loop.run()


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

   **Total running time of the script:** (0 minutes 0.386 seconds)


.. _sphx_glr_download__gallery_feature_demo_image_click_events.py:

.. only:: html

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

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

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

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

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

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

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


.. only:: html

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

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

.. only:: html

    Interactive example
    -------------------

    Try this example in your browser using Pyodide. Might not work with all examples and all devices. Check the output and your browser's console for details.

    .. raw:: html

        <iframe src="./../pyodide.html#image_click_events.py"></iframe>