Allow to change menu options with rclick, move towards shader experiment

shader/lighting/lineShadow.geom

@@ -3,8 +3,10 @@ layout (lines_adjacency) in;
 layout (triangle_strip, max_vertices = 4) out;
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 uniform vec3 lightPos;
-//vec4 shift (vec4 p) { return (vec4 (p.xyz + (100000*(p.xyz-lightPos)), 1));}
-vec4 shift (vec4 p) { return (vec4 (p.xyz + (1000*(p.xyz-lightPos)), 1));}
+uniform vec4 lumRad;
+//vec4 shift (vec4 p) { return (vec4 (p.xyz + (lumRad.a*normalize(p.xyz-lightPos)), 1));}
+vec4 shift (vec4 p) { return (vec4 (p.xyz + (100000*(p.xyz-lightPos)), 1));}
+//vec4 shift (vec4 p) { return (vec4 (lightPos + (lumRad.a*normalize(p.xyz-lightPos)), 1));}
 // copied from lighting/cap.geom, should not be changed on its own
 vec4 projNear (vec4 pos)
 {
@@ -27,6 +29,7 @@ void main()
 {
     vec4 p0 = gl_in[0].gl_Position;
     vec4 p1 = gl_in[1].gl_Position;
+    vec4 mid = 0.5*(p0 + p1);
     vec3 n0a = gl_in[2].gl_Position.xyz;
     vec3 n1a = gl_in[3].gl_Position.xyz;
     vec3 n0 = cross(p1.xyz - p0.xyz, n0a - p0.xyz) ;
@@ -34,10 +37,11 @@ void main()
     
     //vec3 n2 = n0 + n1; // assumes the summands are normalized
     vec3 lightDir = p0.xyz - lightPos.xyz;
+    vec3 lightDir2 = p1.xyz - lightPos.xyz;
     // first test if the edge is part of the silhouette
     // that is, if the normals of the faces connected by the edge point are in
     // "different directions" wrt the light direction
-    if ( dot(n0 , lightDir) * dot(n1 , lightDir) <= 0 ) 
+    if ( dot(n0 , lightDir) * dot(n1 , lightDir) <= 0 )
                 // using <= rather than < seems to get rid of overlapping shadow
                 // artefacts
     {