Add lighting on walls, imperfect

shader/wallShadow.geom

@@ -23,12 +23,12 @@ vec4 p1 = vec4 (gl_in[0].gl_Position.xy,0,1);
 vec4 p2 = vec4 (gl_in[0].gl_Position.zw,0,1);
 if (isLHS (p1.xy - lightPos, p2.xy - lightPos) < 0)
 {
-vec4 p3 = vec4 (p1.xy,-0.2,1);
-vec4 p4 = vec4 (p2.xy,-0.2,1);
+vec4 p3 = vec4 (p1.xy,-0.5,1);
+vec4 p4 = vec4 (p2.xy,-0.5,1);
 vec4 p5 = shift(p1);
 vec4 p6 = shift(p2);
-vec4 p7 = vec4 (p6.xy,-0.2,1);
-vec4 p8 = vec4 (p5.xy,-0.2,1);
+vec4 p7 = vec4 (p6.xy,-0.5,1);
+vec4 p8 = vec4 (p5.xy,-0.5,1);
 
 vec4 a1 = perpMat * p1;
 vec4 a2 = perpMat * p2;