#!/usr/bin/env python
from vispy import __version__, app, scene, use
from skimage import data


print('vispy version:', __version__)
use(app='PyQt5')

canvas = scene.SceneCanvas(show=True)
view = canvas.central_widget.add_view()
view.camera = scene.PanZoomCamera(aspect=1)
view.camera.flip = (0, 1, 0)

astro = scene.Image(data.astronaut(), parent=view.scene)
cam = scene.Image(data.camera(), parent=view.scene)

astro.order = 0
cam.order = -1  # will be displayed in front

# redraw the scenegraph
canvas._draw_order.clear()
canvas.update()

# offset to show that astro is really underneath cam
astro.transform = scene.STTransform(translate=(astro.size[0] / 2,
                                               astro.size[1] / 2))

# workaround since 'opacity' property does not function as intended
# fixed in development version of vispy
cam._opacity_filter.filter = (1, 1, 1, 0)  # 0 opacity

# set the view to show the images
view.camera.set_range((0, cam.size[0] + astro.size[0] / 2),
                      (0, cam.size[1] + astro.size[1] / 2))

# we expect to see the entirety of the astronaut here
app.run()
# we instead see the astronaut image with a corner cut out of it
# ie the camera image is still blocking light at 0 opacity