Use immutable storage for fullscreen vbo

shader/cloud/basic.frag

@@ -8,14 +8,27 @@ layout (location=1) out vec4 fPos;
 layout (location=2) out vec4 fNorm;
 void main()
 {
+    // there are quite a few intricate controls concerning the normals
+    // we want normals to be bigger towards the center, so that when two clouds
+    // are blended central normals predominate
+    // similarly, we want normals to be bigger the further up the cloud is
+    // finally, we want normals to allow for shadows at the edge of a cloud
+    // when a light is direcly above the cloud
     float d = dot(vControls,vControls);
     if (d > 1) {discard;}
     //fCol = vCol;
     fCol = vec4(vCol.xyz,vCol.w*(1-d));
-    fPos = vec4(vPosID.xy, vPosID.z + (1-d) * vCenterSize.w, 0.5);
-    vec3 fn1 = (1-d)*vec3(vCenterSize.xyz - fPos.xyz);
+    //float rad = vCenterSize.w;
+    float rad = vCenterSize.w*0.5;
+    float h = (1-d) * rad;
+    fPos = vec4(vPosID.xy, vPosID.z + h, 1);
+    float h1 = float (1 - 0.01*fPos.z);
+    //vec3 fn1 = fPos.z*(1-d)*normalize(vec3(vCenterSize.xyz - fPos.xyz));
+    //vec3 fn1 = fPos.z*normalize(vec3(vCenterSize.xyz - fPos.xyz));
     //vec3 fn1 = vec3(vCenterSize.xyz - fPos.xyz);
+    vec3 fn1 = fPos.z*(1-d)*normalize(vec3(vCenterSize.xyz - (fPos.xyz + vec3(0,0,0.5*h))));
     //fNorm = vec4(0.5*fn1.xy,fn1.z, 0.5);
-    fNorm = vec4(fn1.xyz, 0.5);
+    //fNorm = vec4(fn1.xyz, fCol.w);
+    fNorm = vec4(fn1,1);
     //fNorm = vec4(0,0,1, 1);
 }