index.rst

CRT Filter

If you'd like an 80s feel to your games, you can use the built-in CRT filter.

You can create a CRT filter with code like this:

# Create the crt filter
self.crt_filter = CRTFilter(width, height,
                            resolution_down_scale=6.0,
                            hard_scan=-8.0,
                            hard_pix=-3.0,
                            display_warp = Vec2(1.0 / 32.0, 1.0 / 24.0),
                            mask_dark=0.5,
                            mask_light=1.5)

You can play around with the parameters to get an idea of what they do. For example:

Resolution Down Sampling

resolution_down_scale = 1

resolution_down_scale = 6

To use the CRT Filter, your on_draw method should first draw everything to the CRT filter. At this point, nothing draws to the screen, we are just drawing to an internal frame buffer.

Then, once everything is drawn to the CRT filter, render that filter to the screen.

# Draw our stuff into the CRT filter instead of on screen
self.crt_filter.use()
self.crt_filter.clear()
self.sprite_list.draw()

# Next, switch back to the screen and dump the contents of the CRT filter
# to it.
self.use()
self.clear()
self.crt_filter.draw()

Full Example Code

The example code just animates a Pac-Man image. You can toggle the CRT filter on or off by hitting the space bar.

Images to run this example can be found here: https://github.com/pythonarcade/arcade/tree/development/doc/tutorials/crt_filter

crt_filter_example.py