Fix per-fragment lighting.

The code in the slides uses vec3s, but the supplied shaders use vec4s.
My implementation incorrectly included the 'w' component in the
normalize call, which threw off the results.

This patch is quite ugly; fixing the code to use vec3s would almost
certainly be superior.  Or at least factoring the .xyz into one place.

1 files changed, 5 insertions, 5 deletions

diff --git a/src/phong.frag b/src/phong.frag
index f946cc7..026427d 100755
--- a/src/phong.frag
+++ b/src/phong.frag
@@ -12,12 +12,12 @@ const vec4 light_es = vec4(0.0, 3.0, 0.0, 1.0);
 
 void main(void)
 {
-	vec4 l = normalize(light_es - position_es);
-	vec4 v = normalize(-position_es);
-	vec4 h = normalize(l + v);
-	float n_dot_l = dot(normal_es, l);
+	vec3 l = normalize((light_es - position_es).xyz);
+	vec3 v = normalize(-position_es.xyz);
+	vec3 h = normalize(l + v);
+	float n_dot_l = dot(normal_es.xyz, l);
 	vec4 diff = diffuse_color * n_dot_l;
-	float spec = pow(dot(normal_es, h), s);
+	float spec = pow(dot(normal_es.xyz, h), s);
 
 	vec4 color = vec4(1.0, 0.0, 0.0, 1.0);