# TinySDF TinySDF is a tiny and fast JavaScript library for generating SDF (signed distance field) from system fonts on the browser using Canvas 2D and [Felzenszwalb/Huttenlocher distance transform](https://cs.brown.edu/~pff/papers/dt-final.pdf). This is very useful for [rendering text with WebGL](https://www.mapbox.com/blog/text-signed-distance-fields/). This implementation is based directly on the algorithm published in the Felzenszwalb/Huttenlocher paper, and is not a port of the existing C++ implementation provided by the paper's authors. Demo: http://mapbox.github.io/tiny-sdf/ ## Usage Create a TinySDF for drawing SDFs based on font parameters: ```js var fontsize = 24; // Font size in pixels var buffer = 3; // Whitespace buffer around a glyph in pixels var radius = 8; // How many pixels around the glyph shape to use for encoding distance var cutoff = 0.25 // How much of the radius (relative) is used for the inside part the glyph var fontFamily = 'sans-serif'; // css font-family var fontWeight = 'normal'; // css font-weight var tinySDFGenerator = new TinySDF(fontsize, buffer, radius, cutoff, fontFamily, fontWeight); var oneSDF = tinySDFGenerator.draw('泽'); // returns a Uint8ClampedArray array of alpha values (0–255) for a size x size square grid ```