1 files changed, 22 insertions, 1 deletions
diff --git a/dev/a5-artrender/shaders/artsy.frag b/dev/a5-artrender/shaders/artsy.frag
index a148eaa..ea5b334 100644
--- a/dev/a5-artrender/shaders/artsy.frag
+++ b/dev/a5-artrender/shaders/artsy.frag
@@ -20,5 +20,26 @@ uniform sampler2D specular_ramp;
 
 
 void main() {
-    color = vec4(0,0,0,1);
+    // normalized normal
+    vec3 n = normalize(normal_in_eye_space);
+
+    // unit vector from the vertex to the light
+    vec3 l = normalize(light_in_eye_space - position_in_eye_space);
+
+    // unit vector from the vertex to the eye point, which is at 0,0,0 in "eye space"
+    vec3 e = normalize(-position_in_eye_space);
+
+    // halfway vector
+    vec3 h = normalize(l + e);
+
+    // calculate color using the light intensity equation
+    vec4 ambient = Ia * ka;
+    float diff_intensity = max(dot(n, l), 0.0);
+    vec2 diffuse_texture = vec2(diff_intensity, 0.0);
+    vec4 diffuse = Id * kd * texture(diffuse_ramp, diffuse_texture);
+    float spec_intensity = pow(max(dot(n, h), 0.0), s);
+    vec2 specular_texture = vec2(spec_intensity, 0.0);
+    vec4 specular = Is * ks * texture(specular_ramp, specular_texture);
+
+    color = diffuse + specular;
 }