Implement dasharray and dashoffset params

[Jeremboo]

Hi,

I have implemented two new parameters for the MeshLineMaterial to animate the mesh lines like we can do with the SVG strokes (see: SVG line animation works)

• dasharray: a float which defines the length and space between dashes. (0 by default to have no dash)
• dashOffset: a float to determine the location of the dash. Ideal to animate the stroke when it is incremented.

I also added in the main demo (demo/js/main.js) GUI parameters dashArray and animateDashOffset to manipulate and test them.

Finally, I updated the README.md to define the new parameters and remove the Support for dashArray of the TODO list.

[Jeremboo]

I added another parameter: dashratio.

With this parameter, you can manage the ratio between the dash and the space. This is only useful when the dasharray is set.

Near to 0 -> the dash is longer than the space. Near to 1 -> the space is longer than the dash. By default, it is set to 0.5.

[danyim]

I would love to have this feature be a part of this library. Can we get this reviewed and merged?

Thank you for contributing to the development of this!

[Jeremboo]

I made some examples on codepen during the codevember period:

• Random dashed lines
• Animated lines

dasharray and dashoffset permit to have good animation approach.

[danyim]

@spite @Jared-Sprague Could we merge this in?

[Jared-Sprague]

@Jeremboo @danyim I don't have write access to this repo. I would recommend tweeting at thespite

[Jeremboo]

I sent a private message yesterday :) Thank a lot !

[spite]

Sorry it took such a long time to review and merge. Great work! Thanks!