From deec629ef4b6d13f2f1cb72fc702682b8db33ad5 Mon Sep 17 00:00:00 2001
From: Dane Johnson <dane_johnson@ymail.com>
Date: Fri, 22 Jan 2021 14:40:45 -0600
Subject: [PATCH] Vertex exports all lights independently

---
 shaders/flat.frag |  7 +++++--
 shaders/flat.vert | 13 +++++++------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/shaders/flat.frag b/shaders/flat.frag
index 8aed153..ef55898 100644
--- a/shaders/flat.frag
+++ b/shaders/flat.frag
@@ -2,7 +2,10 @@
 
 noperspective in vec2 UV;
 in vec3 NORMAL;
-flat in vec3 LIGHT;
+
+flat in vec3 AMBIENT;
+flat in vec3 DIFFUSE;
+flat in vec3 SPECULAR;
 
 out vec4 FragColor;
 
@@ -30,6 +33,6 @@ void main() {
   }
 
   if (!material.unshaded) {
-    FragColor *= vec4(LIGHT, 1.0);
+    FragColor *= vec4(AMBIENT + DIFFUSE + SPECULAR, 1.0);
   }
 }
diff --git a/shaders/flat.vert b/shaders/flat.vert
index 8e1176f..45112e7 100644
--- a/shaders/flat.vert
+++ b/shaders/flat.vert
@@ -10,7 +10,10 @@ uniform mat4 PROJECTION;
 
 noperspective out vec2 UV; // PSX use affine texture mapping
 out vec3 NORMAL;
-flat out vec3 LIGHT;
+
+flat out vec3 AMBIENT;
+flat out vec3 DIFFUSE;
+flat out vec3 SPECULAR;
 
 struct DirectionalLight {
   vec3 direction;
@@ -31,19 +34,17 @@ void main() {
   NORMAL = (VIEW * MODEL * vec4(normal, 0.0)).xyz;
 
   // Flat shading, we compute light per vertex
-  vec3 ambient = directionalLight.ambient * directionalLight.color;
+  AMBIENT = directionalLight.ambient * directionalLight.color;
 
   vec3 direction = -(VIEW * vec4(directionalLight.direction, 0.0)).xyz;
   float diff = dot(normalize(direction), normalize(NORMAL));
   diff = max(diff, 0.0);
-  vec3 diffuse = directionalLight.diffuse * diff * directionalLight.color;
+  DIFFUSE = directionalLight.diffuse * diff * directionalLight.color;
 
   vec3 viewDir = (VIEW * MODEL * vec4(pos, 1.0)).xyz;
   vec3 reflectionDir = reflect(normalize(direction), normalize(NORMAL));
   float spec = dot(viewDir, reflectionDir);
   spec = max(spec, 0.0);
   spec = pow(spec, 2);
-  vec3 specular = directionalLight.specular * spec * directionalLight.color;
-
-  LIGHT = ambient + diffuse + specular;
+  SPECULAR = directionalLight.specular * spec * directionalLight.color;
 }