From 0e4e0572ca74b33c145a0baea6d46e82f60237b2 Mon Sep 17 00:00:00 2001
From: taw27 <taw27@84d2e878-0bd5-11dd-ad15-13eda11d74c5>
Date: Wed, 6 Aug 2008 11:57:50 +0000
Subject: Shuffle stuff around.  Back to Phong...

git-svn-id: svn://cook.msm.cam.ac.uk:745/thrust3d/thrust3d@216 84d2e878-0bd5-11dd-ad15-13eda11d74c5
---
 data/shaders/lighting.frag | 19 ++++++++++++-------
 data/shaders/lighting.vert | 15 ++++++++++-----
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/data/shaders/lighting.frag b/data/shaders/lighting.frag
index 1bc0afd..39caf72 100644
--- a/data/shaders/lighting.frag
+++ b/data/shaders/lighting.frag
@@ -9,10 +9,11 @@
  *
  */
 
+varying vec3 pos;
 varying vec3 normal;
 
 varying vec3 light0vc;
-varying vec3 light0hvc;
+varying vec3 light0half;
 varying vec3 light1vc;
 varying vec3 light2vc;
 varying vec3 light2hvc;
@@ -61,22 +62,26 @@ void main() {
 	} else {
 	
 		/* Spotlight (light 0) - positional, spotlight */
-		float falloff;
-		float spot;
-		float ndothv;
+		float falloff, spot;
+		float spec_fac;
+		vec3 L, E, R;
 		
-		falloff = 1/ (  gl_LightSource[0].constantAttenuation
+		falloff = 1.0 / (  gl_LightSource[0].constantAttenuation
 			            + gl_LightSource[0].linearAttenuation * length(light0vc)
 			            + gl_LightSource[0].quadraticAttenuation * pow(length(light0vc), 2.0) );
 		spot = max(dot(normalize(-light0vc), gl_LightSource[0].spotDirection), 0.0);
 		spot = pow(spot, gl_LightSource[0].spotExponent);
 		
-		ndothv = max(dot(norm, normalize(light0hvc)), 0.0);
+		L = normalize(gl_LightSource[0].position.xyz - pos); 
+		E = normalize(-pos);
+		R = normalize(-reflect(L, norm)); 
+		
+		spec_fac = max(0.0, dot(R, E));
 		
 		diff += col_ambi_diff * gl_LightSource[0].diffuse.rgb * spot * falloff *
 									max(dot(normalize(light0vc).xyz, norm), 0.0);
 		
-		spec += vec3(1.0, 1.0, 1.0) * gl_LightSource[0].specular.rgb * spot * falloff * pow(ndothv, 80.0);
+		spec += vec3(1.0, 1.0, 1.0) * gl_LightSource[0].specular.rgb * spot * falloff * pow(spec_fac, 80.0);
 		
 		/* Background glow (light 1) - diffuse only, directional */
 		diff += col_ambi_diff * gl_LightSource[1].diffuse.rgb * max(dot(vec3(light1vc), norm), 0.0);
diff --git a/data/shaders/lighting.vert b/data/shaders/lighting.vert
index 914d6ac..d9306e6 100644
--- a/data/shaders/lighting.vert
+++ b/data/shaders/lighting.vert
@@ -9,10 +9,11 @@
  *
  */
 
+varying vec3 pos;
 varying vec3 normal;
 
 varying vec3 light0vc;
-varying vec3 light0hvc;
+varying vec3 light0half;
 varying vec3 light1vc;
 varying vec3 light2vc;
 varying vec3 light2hvc;
@@ -22,10 +23,15 @@ varying vec3 col_emit;
 
 void main() {
 	
+	vec4 vert;
+	
+	vert = gl_ModelViewMatrix * gl_Vertex;
+	pos = vert.xyz;
+	normal = gl_NormalMatrix * gl_Normal;
+	
 	/* Spotlight - positional light */
-	vec4 vert = gl_ModelViewMatrix * gl_Vertex;
-	light0vc = gl_LightSource[0].position.xyz - vert.xyz;
-	light0hvc = vec3(gl_LightSource[0].halfVector - vert);
+	light0vc = gl_LightSource[0].position.xyz - vert.xyz;	/* Don't normalise here */
+	light0half = normalize(normalize(light0vc) + normalize(-vert.xyz));
 	
 	/* Diffuse "background glow" - this can be normalised only once, here, since 'position'
 	 * is really 'direction' and is the same for all vertices. */
@@ -36,7 +42,6 @@ void main() {
 	light2hvc = normalize(vec3(gl_LightSource[2].halfVector - vert));
 	
 	/* Material properties */
-	normal = gl_NormalMatrix * gl_Normal;
 	col_ambi_diff = gl_Color.rgb;
 	col_emit = gl_FrontMaterial.emission.rgb;
 	
-- 
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