public void DrawCylinder(float radius, float halfHeight, int upAxis, ref Matrix4 transform, OpenTK.Graphics.Color4 color)
{
Vector3 up = new[] { Vector3.UnitX, Vector3.UnitY, Vector3.UnitZ }[upAxis]; //get on my level
Matrix4 transCopy = Matrix4.CreateFromQuaternion(AuxFunctions.RotateTo(Vector3.UnitY, up)) * transform;
Vector3 previousPos = Vector3.Transform(new Vector3(0, halfHeight, radius), transCopy);
Vector3 previousNPos = Vector3.Transform(new Vector3(0, -halfHeight, radius), transCopy);
GL.Begin(PrimitiveType.LineLoop);
GL.Color3(0f, 1f, 0f);
for (float a = 0; a <= Math.PI * 2; a += (float)Math.PI / 8)
{
float z = (float)Math.Cos(a) * radius;
float x = (float)Math.Sin(a) * radius;
// positive
Vector3 pos = Vector3.Transform(new Vector3(x, halfHeight, z), transCopy);
GL.Vertex3(previousPos);
GL.Vertex3(pos);
previousPos = pos;
// negative
Vector3 npos = Vector3.Transform(new Vector3(x, -halfHeight, z), transCopy);
GL.Vertex3(previousNPos);
GL.Vertex3(npos);
previousNPos = npos;
// the sides
GL.Vertex3(pos);
GL.Vertex3(npos);
}
GL.End();
}