I have a 3-dimensional view, where I have drawn a line $L$. I know the line direction vector $(x,y,z)$, where $L$ is also the center of a cylinder with given radius $r$.
I wish, based on the radius $r$ and direction vector $(x,y,z)$ to draw the cylinder. For that, given my working environment capabilities, I only need to calculate the points of the two disks which are the limits of the cylinder.
For that, I have the $(x_1,y_1,z_1)$, $(x_2,y_2,z_2)$ which are the coordinates of the start and the end of the cylinder center on the line $L$.
I need to take calculate all points of the disks that are orthogonal to the line L and which have their center at either $(x_1,y_1,z_1)$, or $(x_2,y_2,z_2)$, having radius $r$. Of course, everything is descrete, so 360 points (going with difference of $1^\circ$) is good enough.