bsplines

components/sections/bsplines/rational-uniform-bspline.js

@@ -0,0 +1,50 @@
+module.exports = {
+  degree: 3,
+  activeDistance: 9,
+  weights: [],
+
+  setup() {
+    this.size(400, 400);
+
+    var TAU = Math.PI*2;
+    var r = this.width/3;
+    for (let i=0; i<6; i++) {
+      this.points.push({
+        x: this.width/2 + r * Math.cos(i/6 * TAU),
+        y: this.height/2 + r * Math.sin(i/6 * TAU)
+      });
+    }
+    this.points = this.points.concat(this.points.slice(0,3));
+    this.closed = this.degree;
+
+    this.knots = this.formKnots(this.points);
+    this.weights = this.formWeights(this.points);
+
+    if(this.props.controller) {
+      this.props.controller(this, this.knots, this.weights, this.closed);
+    }
+
+    this.draw();
+  },
+
+  draw() {
+    this.clear();
+    this.grid(25);
+    var p = this.points[0];
+    this.points.forEach(n => {
+      this.stroke(200);
+      this.line(n.x, n.y, p.x, p.y);
+      p = n;
+      this.stroke(0);
+      this.circle(p.x, p.y, 4);
+    });
+    this.drawSplineData();
+  },
+
+  drawSplineData() {
+    if (this.points.length <= this.degree) return;
+    var mapped = this.points.map(p => [p.x, p.y]);
+    this.drawCurve(mapped);
+    this.drawKnots(mapped);
+  }
+};