rewrite to handler.js format

components/sections/tightbounds/handler.js

@@ -0,0 +1,71 @@
+module.exports = {
+  setupQuadratic: function(api) {
+    var curve = api.getDefaultQuadratic();
+    api.setCurve(curve);
+  },
+
+  setupCubic: function(api) {
+    var curve = api.getDefaultCubic();
+    api.setCurve(curve);
+  },
+
+  align: function(points, line) {
+    var tx = line.p1.x,
+        ty = line.p1.y,
+        a = -Math.atan2(line.p2.y-ty, line.p2.x-tx),
+        cos = Math.cos,
+        sin = Math.sin,
+        d = function(v) {
+          return {
+            x: (v.x-tx)*cos(a) - (v.y-ty)*sin(a),
+            y: (v.x-tx)*sin(a) + (v.y-ty)*cos(a),
+            a: a
+          };
+        };
+    return points.map(d);
+  },
+
+  // FIXME: I'm not satisfied with needing to turn a bbox[] into a point[],
+  //        this needs a bezier.js solution, really, with a  call curve.tightbbox()
+  transpose: function(points, angle, offset) {
+    var tx = offset.x,
+        ty = offset.y,
+        cos = Math.cos,
+        sin = Math.sin,
+        v = [points.x.min, points.y.min, points.x.max, points.y.max];
+    return [
+      {x: v[0], y: v[1] },
+      {x: v[2], y: v[1] },
+      {x: v[2], y: v[3] },
+      {x: v[0], y: v[3] }
+    ].map(p => {
+      var x=p.x, y=p.y;
+      return {
+        x: x*cos(angle) - y*sin(angle) + tx,
+        y: x*sin(angle) + y*cos(angle) + ty
+      };
+    });
+  },
+
+  draw: function(api, curve) {
+    api.reset();
+
+    var pts = curve.points;
+    var line = {p1: pts[0], p2: pts[pts.length-1]};
+    var apts = this.align(pts, line);
+    var angle = -apts[0].a;
+    var aligned = new api.Bezier(apts);
+    var bbox = aligned.bbox();
+    var tpts = this.transpose(bbox, angle, pts[0]);
+
+    api.setColor("#00FF00");
+    api.drawLine(tpts[0], tpts[1]);
+    api.drawLine(tpts[1], tpts[2]);
+    api.drawLine(tpts[2], tpts[3]);
+    api.drawLine(tpts[3], tpts[0]);
+
+    api.setColor("black");
+    api.drawSkeleton(curve);
+    api.drawCurve(curve);
+  }
+};