Prevent drawing of shadow caps when turned off

shader/lighting/cap.geom

@@ -3,6 +3,7 @@ layout (triangles) in;
 layout (triangle_strip, max_vertices = 3) out;
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 layout(location=0)uniform vec3 lightPos;
+in float drawbit[];
 // this code is duplicated in lineShadow.geom, should not be changed on its own
 vec4 projNear (vec4 pos)
 {
@@ -20,7 +21,8 @@ void main()
     vec4 p2 = gl_in[2].gl_Position ;
     if ( //if Light Source is below all vertices, draw cap 
         // TODO think about when LS is beside the object
-            ( p0.z - lightPos.z > 0 )
+            (drawbit[0] == 1)
+            && ( p0.z - lightPos.z > 0 )
             && ( p1.z - lightPos.z > 0 )
             && ( p2.z - lightPos.z > 0 )
             )