layout(points) in;
layout(line_strip, max_vertices = 2) out;

flat in vec4 v1[1];
flat in vec4 v2[1];

void main()
{
  for (int v = 0; v < 2; v++) {
    gl_Position = (v == 0) ? v1[0] : v2[0];
#ifdef USE_WORLD_CLIP_PLANES
    world_clip_planes_set_clip_distance(gl_in[0].gl_ClipDistance);
#endif
    EmitVertex();
  }
  EndPrimitive();
}