From c26b36bee465f16e3e3ed1b01ad613e7d2017102 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 3 Oct 2022 23:44:46 +0300
Subject: [PATCH] Refactor handling some material parameters in
 cooktorrance.glsl

Occlusion is now passed as a parameter to the lighting function.
Emission is handled outside of it since it's not properly a part of the
Cook-Torrance BRDF.
---
 shaderlib/cooktorrance.glsl | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/shaderlib/cooktorrance.glsl b/shaderlib/cooktorrance.glsl
index 25289ed5..5e933d5a 100644
--- a/shaderlib/cooktorrance.glsl
+++ b/shaderlib/cooktorrance.glsl
@@ -153,7 +153,7 @@ vec3 cooktorrance_environment(vec3 normal, vec3 look, vec3 base_color, float met
 		return (k_diff*base_color+k_spec)*ambient_color.rgb;
 }
 
-vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metalness, float roughness)
+vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metalness, float roughness, float occlusion)
 {
 	vec3 color = vec3(0.0);
 	for(int i=0; i<max_lights; ++i)
@@ -164,12 +164,8 @@ vec3 cooktorrance_lighting(vec3 normal, vec3 look, vec3 base_color, float metaln
 			color += cooktorrance_one_light_direct(normal, look, incoming.direction, base_color, metalness, roughness)*incoming.color*shadow;
 		}
 
-	float occlusion = get_occlusion_value();
 	color += cooktorrance_environment(normal, look, base_color, metalness, roughness)*occlusion;
 
-	if(use_emission)
-		color += get_emission_color();
-
 	return color;
 }
 
@@ -183,8 +179,11 @@ void main()
 
 	float metalness = get_metalness_value();
 	float roughness = get_roughness_value();
+	float occlusion = get_occlusion_value();
 
-	vec3 lit_color = cooktorrance_lighting(normal, look, base_color.rgb, metalness, roughness);
+	vec3 lit_color = cooktorrance_lighting(normal, look, base_color.rgb, metalness, roughness, occlusion);
+	if(use_emission)
+		lit_color += get_emission_color();
 
 	frag_color = vec4(lit_color, alpha);
 }
-- 
2.43.0