Cleanup, correcly filter unimportant shadow silhouettes

shader/lighting/cap.vert

@@ -1,15 +1,16 @@
 #version 450 core
 struct PosColNorm { vec4 pos; vec4 dummy; };
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
+layout (std140, binding = 1) uniform TheLight { vec4 lightPos; vec4 lumRad; };
 layout (std430, binding = 3) readonly buffer Data { PosColNorm data[]; };
 layout (std430, binding = 4) readonly buffer Indices { uint indices[]; };
-layout(location=0)uniform vec3 lightPos;
-layout(location=1)uniform vec4 lumRad;
+//layout(location=0)uniform vec3 lightPos;
+//layout(location=1)uniform vec4 lumRad;
 vec4 projNear (vec4 pos)
 {
     // note we project to a specific height
     // this is quite brittle, not ideal
-    vec3 dir = pos.xyz - lightPos ;
+    vec3 dir = pos.xyz - lightPos.xyz ;
     float a = (100 - pos.z) / dir.z ;
     vec2 xy = (pos.xyz + a * dir).xy ;
     return vec4 ( xy, 100 , 1) ;
@@ -27,13 +28,3 @@ void main() {
             : vec4(1,1,1,0)
             );
 }
-//layout (location = 0) in vec4 position;
-//layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
-//uniform vec3 lightPos;
-//uniform vec4 lumRad;
-//out float drawbit;
-//void main()
-//{
-//    gl_Position = vec4(position.xyz,1);
-//    drawbit = position.w;
-//}

shader/lighting/lineShadow.vert

@@ -54,16 +54,16 @@ void main()
     vec3 n1 = cross(p0.xyz - p1.xyz, n1a - p1.xyz);
     vec3 lightDir = p0.xyz - lightPos.xyz;
     vec3 lightDir2 = p1.xyz - lightPos.xyz;
-    vec4 p2 = shiftNear(p0);
-    vec4 p3 = shiftNear(p1);
   // test if the edge is part of the silhouette
-  // that is, if the slopes of the faces connected to the edge are in
+  // that is, if the normals of the faces connected to the edge are in
   // "different directions" wrt the light direction
-  if (dot(n0, lightDir) * dot(n1, lightDir) <= 0 &&
+  if (p0.w==1 && dot(n0, lightDir) * dot(n1, lightDir) <= 0 &&
       (dot(lightDir, lightDir) < ru2 || dot(lightDir2, lightDir2) < ru2))
   // using <= rather than < seems to get rid of overlapping shadow
   // artefacts
   { 
+    vec4 p2 = shiftNear(p0);
+    vec4 p3 = shiftNear(p1);
     if (dot(n0, lightDir) < 0) 
         {
             vec4 sp[4] = {p1,p0,p3,p2};