cpp ROS circle

circle.cpp

#include <visualization_msgs/Marker.h>
#include <math.h>

///....


    ros::Publisher circ_marker_pub = n.advertise<visualization_msgs::Marker>("pure_circle", 1);

///....

   visualization_msgs::Marker circle_marker;
    circle_marker.header.frame_id = "map";
    circle_marker.header.stamp = ros::Time::now();
    circle_marker.ns = "basic_shapes";
    circle_marker.id = 0;
    circle_marker.type = circle_marker.LINE_STRIP;
    circle_marker.action = visualization_msgs::Marker::ADD;
    circle_marker.pose.position.x = 0;
    circle_marker.pose.position.y = 0;
    circle_marker.pose.position.z = 0;
    circle_marker.pose.orientation.x = 0.0;
    circle_marker.pose.orientation.y = 0.0;
    circle_marker.pose.orientation.z = 0.0;
    circle_marker.pose.orientation.w = 1.0;
    circle_marker.scale.x = 1.0;
    circle_marker.color.r = 0.1f;
    circle_marker.color.g = 0.4f;
    circle_marker.color.b = 0.9f;
    circle_marker.color.a = 1.0;

    circle_marker.lifetime = ros::Duration();
    float f = 0.0;
    float cent_x = 2.1; // Matyi
    float cent_y = 8.1; // Matyi
    float radius = 4.1; // Matyi

    for (double i = 0.0; i < M_PI*2; i = i + 0.1)
    {
      double x = cent_x + radius * cos(i);
      double y = cent_x + radius * sin(i);

      geometry_msgs::Point p;
      p.x = x;
      p.y = y;
      p.z = 0.0;

      circle_marker.points.push_back(p);
    }

    circ_marker_pub.publish(circle_marker);

circle_marker.points.clear(); is needed in the for loop 😉