Commit before attempting to use volume shadows for walls

shader/wallLight.vert

@@ -0,0 +1,24 @@
+#version 430 core
+layout (location = 0) in vec3 pos;
+
+out vec2 vDistField;
+out float vLum;
+
+uniform mat4 worldMat;
+uniform vec4 lightPosRadLum;
+
+mat4 perspective =  
+    mat4 (1,0,0,0
+         ,0,1,0,0
+         ,0,0,1,1
+         ,0,0,0,1
+         ) ;
+void main()
+{
+  float r = lightPosRadLum.z ;
+  float x = lightPosRadLum.x ;
+  float y = lightPosRadLum.y ;
+  gl_Position = perspective * worldMat * vec4(pos, 1);
+  vDistField = vec2 ( (pos.x - x)/r , (pos.y - y)/(r*100) ) ;
+  vLum = lightPosRadLum.w;
+}