picture-tuber/index.js

render 256 color images on the terminal

var PNG = require("png-js");
var charm = require("charm");
var x256 = require("x256");
var buffers = require("buffers");
var es = require("event-stream");

var Stream = require("stream").Stream;

module.exports = function(opts) {
  if (!opts) opts = {};
  if (!opts.cols) opts.cols = 80;

  var c = charm();
  var bufs = buffers();

  var ws = es.writeArray(function(err, bufs) {
    var data = buffers(bufs).slice();
    var png = new PNG(data);

    png.decode(function(pixels) {
      var dx = png.width / opts.cols;
      var dy = 2 * dx;

      for (var y = 0; y < png.height; y += dy) {
        for (var x = 0; x < png.width; x += dx) {
          var i = (Math.floor(y) * png.width + Math.floor(x)) * 4;

          var ix = x256([pixels[i], pixels[i + 1], pixels[i + 2]]);
          if (pixels[i + 3] > 0) {
            c.background(ix).write(" ");
          } else {
            c.display("reset").write(" ");
          }
        }
        c.display("reset").write("\r\n");
      }

      c.display("reset").end();
    });
  });

  return es.duplex(ws, c);
};