A javascript program that generates plausible maps using a simple implementation of the marching sqaures algorithm.
The input field for the marching squares is a fractal noise grid constructed from a 2D simplex noise (using this js library). The fractal noise function takes scale, octaves, and persistence as its parameters. Scale affects the size of the noise features, and lowering it usually results in more intricate contour lines. However, instead of directly drawing the land masses, my implementation draws the negative spaces because I wanted random textures for the background (there might be more efficient ways to do this... ), so the effect of scale is inverted. For both persistence and octaves, a higher value produces more detailed contours, and a lower value results in smoother lines. There is another parameter threshold, which is used for the marching squares algorithm. Threshold determines which cells in the input noise grid are included in the binary map, and a higher value normally results in more details. But in my implementation, the effect of threshold is inverted just like with scale since the contours are "drawn" as negative spaces.
Play around with the parameters and make your own maps here 🗺️