# Scrawl-canvas v8 - Particles test 002

## Emitter using artefacts

World speed
Opacity
Outline color
Background color
Minimum fill color
Maximum fill color
Generation rate (per sec)
History length
Kill radius (px)
Kill radius variation (px)
Artefact

#### Test purpose

- Create a particle world object
- Create some Scrawl-canvas entitys which we can use with our Emitter entity
- Create a particle Emitter entity
- Check to see that the Emitter entity can lock to the mouse cursor
- Check the effect of changing the world object's tickMultiplier (world speed) attribute
- Check that particle color, and opacity appearance, can be controlled via the user-defined attributes in the world object (particle stroke color, minimum fill color, maximum fill color, opacity)
- Check the effects of changing the following emitter/particle attributes: historyLength; generationRate
- Confirm that particles comply with changes in the emitter's kill radius attributes
- Check that the canvas backgroundColor attribute can be updated (background color)
- Change the emitter's artefact; check that the update is immediate and impacts on all existing particles as well as new ones
- Navigate away from the web page (open another tab in the browser) and, a few seconds later, navigate back to the page - check that the animation resets and starts, and does not freeze the page

Touch test: should work as expected

Annotated code