Draw circle in Android RenderScript

Modify MyRSSurfaceView.java from last exercise "Perform transform of Translate and Rotate on RenderScript", to draw circle by combine a series of Triangle. Refer to the code, the larger the constant number_of_section, the more the shape close to circle.

package com.exercise.AndroidRenderScript;

import android.content.Context;
import android.renderscript.Mesh;
import android.renderscript.RSSurfaceView;
import android.renderscript.RenderScriptGL;
import android.renderscript.RenderScriptGL.SurfaceConfig;

public class MyRSSurfaceView extends RSSurfaceView {
 
 private RenderScriptGL renderScriptGL;
 private ScriptC_RenderScript myScriptC;

 public MyRSSurfaceView(Context context) {
  super(context);
  // TODO Auto-generated constructor stub
  final RenderScriptGL.SurfaceConfig surfaceConfig
   = new SurfaceConfig();
  renderScriptGL = createRenderScriptGL(surfaceConfig);
  
  myScriptC = new ScriptC_RenderScript(
    renderScriptGL, getResources(), R.raw.renderscript);

  myScriptC.set_my_rs_mesh(createMesh());
  
  renderScriptGL.bindRootScript(myScriptC);
 }
 
 private Mesh createMesh(){
  
  double radius = 100.0;
  double angleInDegree, angleInRadian;
  
  final int number_of_section = 18;
  double ptX, ptY;
  
  Mesh.TriangleMeshBuilder myMesh 
  = new Mesh.TriangleMeshBuilder(
    renderScriptGL, 
    2, 
    Mesh.TriangleMeshBuilder.COLOR);

  //index 0
  myMesh.addVertex(0, 0);
  
  //index 1
  angleInDegree = 0;
  angleInRadian = Math.toRadians(angleInDegree);
  ptX = radius * Math.cos(angleInRadian);
  ptY = radius * Math.sin(angleInRadian);
  myMesh.addVertex((float)ptX, (float)ptY);
  
  for(int i=0; i<number_of_section; i++){
   angleInDegree += 360/number_of_section;
   angleInRadian = Math.toRadians(angleInDegree);
   ptX = radius * Math.cos(angleInRadian);
   ptY = radius * Math.sin(angleInRadian);
   myMesh.addVertex((float)ptX, (float)ptY);
   
   myMesh.addTriangle(0, i+2, i+1);
   
  }

  return(myMesh.create(true));
 };

}

Download the files.