Clean up n_dot_l and n_dot_v < 0 clamping.

This is actually a significant performance improvement, by reducing extra
comparisons and multiplies.

1 files changed, 1 insertions, 4 deletions

diff --git a/glass.frag b/glass.frag
index 17fc9ad..0d5c129 100644
--- a/glass.frag
+++ b/glass.frag
@@ -61,9 +61,6 @@ void main()
 	Rs = 2 * schlick_fresnel(n_dot_l) * D /
 	  sqrt(n_dot_l * n_dot_v) / (ward_m * ward_n);
 
-	Rs *= step(0, n_dot_l);
-	Rs *= step(0, n_dot_v);
-
 	float Rd = (1 - F0) * 2;
 	/* Ambient occlusion factor -- sample the height map we
 	 * used to generate the normal map, and reduce intensity in
@@ -72,7 +69,7 @@ void main()
 	float heightmap = texture2D(heightmap_sampler, texcoord).x;
 	float Ra = Rd * (.8 + .2 * heightmap);
 
-	gl_FragColor = n_dot_l * step(0, n_dot_l) *
+	gl_FragColor = max(0, n_dot_l) * step(0, n_dot_v) *
 	  vec4(material_color.xyz *
 	       ((Rd * d + Rs * s) * Ii * shadow),
 	       material_color.w) +