Jump Flooding Algorithm for GMS2 made with shaders.
You can test it in HTML5 here: https://terohannula.itch.io/jump-flooding-algorithm
Algorithm fills empty areas of surface texture with given seeds. Filled areas generate approximate Voronoi diagram, and this can also be used for generating distance field.
This asset uses shaders for heavy lifting, but there is wrapper for easy-to-use, check screenshot for how-to-use. Internally jump flooding struct creates a own surface, where every pixel maps coordinates for closest non-empty seed. These coordinates are encoded to color channels, to support larger surfaces, x-coordinate is encoded to RG channels and y-coordinate BA-channels.
This has been made in GMS2.3.3.
More examples and changed how methods are used.