In the processing app (JAVA), create a variable called theta that keeps the value of it from 0 to 6.28 (TWO_PI) using modulo. can't figure it out, as the code keeps refreshing (void draw) and it does...

In the processing app (JAVA), create a variable called theta that keeps the value of it from 0 to 6.28 (TWO_PI) using modulo. can't figure it out, as the code keeps refreshing (void draw) and it does start from 0 but doesn't stop at 6.28 (I have that global variable as local var in void draw as theta+=0.02)