Bangle.js screenshots

We finally have a way of doing screenshots! I'm interested to see what you think, but if you paste this code into the IDE:

function screenshot(draw) {
  var _g = g;
  Bluetooth.print("data:image/bmp;base64,"­);
  var l = 26/*header length*/ + 240*3;
  var data = E.toString([66,77,l&255,l>>8, // 0
                0,0,0,0,0,0,      // 4
                26,0,0,0,         // 10
                12,0,0,0,240,0,240,0,1,0,24,0]); // 14

  var b = Graphics.createArrayBuffer(240,1,24);
  g = Graphics.createCallback(240,240,16,{
      setPixel:function(x,y,c) { b.setPixel(x,y-yo,((c&0xF800)<<8) | ((c&0x7E0)<<5) | ((c&0x1F)<<3)); },
      fillRect:function(x1,y1,x2,y2,c) { b.setColor(((c&0xF800)<<8) | ((c&0x7E0)<<5) | ((c&0x1F)<<3)).fillRect(x1,y1-yo,x2,y2-y­o); }
    });
  g.flip = function(){};
  var t = getTime(), t2=t;
  for (var yo=239;yo>=0;yo--) {
    g.setClipRect(0,yo,239,yo);
    b.clear();
    t2 += getTime()-t;setTime(t);
    draw();
    var n = 0;
    while (data.length%3) data += String.fromCharCode(b.buffer[n++]);
    Bluetooth.print(btoa(data));
    data = E.toString(b.buffer).substr(n);
  }
  setTime(t2);
  Bluetooth.println(btoa(data));
  g = _g;
}

And then, assuming your app has a function called draw that redraws the entire screen, you call screenshot(draw) in the IDE, you should get a screenshot.

It's very slow - you're looking at multiple minutes per screen because it's having to re-render the image for every line of pixels.

Still, it is a way of getting screenshots out of Bangle.js!