polygon snippets

round-corners.js

    var roundCorner = function(p, c, n) {
      var v = Vec2(1, 0);
      var oangle = v.angleTo(p.subtract(c, true))
      var ae1 = v.angleTo(c.subtract(p, true));
      var ae2 = v.angleTo(n.subtract(c, true))

      var range = (ae2 > ae1) ? ae2-ae1 : TAU-(ae1 - ae2);

      oangle += TAU/4

      if (delta < 0) {
        range = TAU - range;
        if (range > TAU/2) {
          return;
        }
      }

      var steps = 10 + Math.floor(delta*.025);
      var stepSize = range / steps;

      if (delta < 0) {
        range /= 2;
        stepSize = -stepSize;
      }

      var b = Vec2(delta, 0).rotate(oangle);
      for (var i = 0; i<steps; i++) {
        collect(c.add(b.rotate(stepSize), true), c, 'green')
      }
    };