I have a problem when trying to build a shape with curveVertex. All curve vertex are drawn round (as they are supposed to be) but the the vertex that closes the shape (first point after beginShape, last point before endShape) is drawn sharp.

Here's an example:

2. void setup() {
3.   size(400, 400);
4. }
5. 
   
6. void draw() {
7. 
   
8.   background(255);
9.   fill(0);
10.   
11.   PVector p_a = PVector.fromAngle(PI/6.0);
12.   p_a.mult(100);
13.   PVector p_b = PVector.fromAngle(2*PI/3.0 + PI/6.0);
14.   p_b.mult(100);
15.   PVector p_c = PVector.fromAngle(2*PI/3.0*2.0 + PI/6.0);
16.   p_c.mult(100);
17. 
    
18.   // Center points between axes
19.   PVector cp_a = PVector.lerp(p_a, p_c, 0.5);
20.   PVector cp_b = PVector.lerp(p_b, p_a, 0.5);
21.   PVector cp_c = PVector.lerp(p_c, p_b, 0.5);
22.   
23.   cp_a.mult(0.7);
24.   cp_b.mult(0.7);
25.   cp_c.mult(0.7);
26.   
27.   //calculateSecondaryPoints(cp_a, cp_b, cp_c);
28. 
    
29.   pushMatrix();
30.   translate(width/2, height/2);
31.   rotate(PI/2.0-PI/5.0);
32.   
33.   fill(0);
34.   noFill();
35.   strokeWeight(2);
36.   
37.   int z = 0;
38.   beginShape();
39.   
40.   curveVertex(p_a.x, p_a.y);
41.   curveVertex(p_a.x, p_a.y);
42.   
43.   curveVertex(cp_b.x, cp_b.y);
44.   curveVertex(p_b.x, p_b.y);
45.   curveVertex(cp_c.x, cp_c.y);
46.   curveVertex(p_c.x, p_c.y);
47.   curveVertex(cp_a.x, cp_a.y);
48.   
49.   curveVertex(p_a.x, p_a.y);
50.   curveVertex(p_a.x, p_a.y);
51.   endShape();
52. 
    
53.   popMatrix();
54. }

In my code I generate the shape with random vertex amplitude. I've seen this thread, but doesn't really work for me.

Thanks for your help!