From 1b05c0ac8201d7021c1e1b97662c240ca6926415 Mon Sep 17 00:00:00 2001
From: Peder Bergebakken Sundt <pbsds@hotmail.com>
Date: Fri, 15 Mar 2019 17:29:59 +0100
Subject: [PATCH] Move MV transform of lights from fragmentshader to cpu

---
 res/shaders/simple.frag | 16 +++++-----------
 src/gamelogic.cpp       | 10 ++++------
 2 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/res/shaders/simple.frag b/res/shaders/simple.frag
index 1500020..f571640 100644
--- a/res/shaders/simple.frag
+++ b/res/shaders/simple.frag
@@ -18,11 +18,10 @@ uniform bool isNormalMapped;
 uniform bool isInverted;
 
 // lights
-struct Light {
+struct Light { // coordinates in MV space
     vec3 position;
-    mat4 MV;
+    vec3 spot_target; 
     bool is_spot; // false means point light
-    vec3 spot_target; // MV space coordinates for spots
 };
 
 //named 
@@ -53,13 +52,13 @@ void main_(vec4 basecolor) {
     float specular_intensity = 0.0;
 
     for (int i = 0; i<3; i++) {
-        vec3 L = vec3(light[i].MV * vec4(light[i].position, 1.0f)) - vertex;
+        vec3 L = light[i].position - vertex;
         float l = length(L);
         float attenuation = clamp(2000/(1 + 1*l + 0.1*l*l), 0.0, 1.25);
         L = normalize(L);
 
         if (light[i].is_spot) {
-            vec3 L2 = normalize(vec3(light[i].MV * vec4(light[i].position, 1.0f)) - light[i].spot_target);
+            vec3 L2 = normalize(light[i].position - light[i].spot_target);
             if (dot(L2, L) < spot_cuttof_angle) {
                 continue;
             }
@@ -101,11 +100,6 @@ void main() {
         }
     } else {
         color = texture(diffuseTexture, UV);
-        
-    }
-    if (isInverted) {
-        color.r = 1 - color.r;
-        color.g = 1 - color.g;
-        color.b = 1 - color.b;
     }
+    if (isInverted) color.rgb = 1 - color.rgb;
 }
diff --git a/src/gamelogic.cpp b/src/gamelogic.cpp
index 9d3794c..dca9d63 100644
--- a/src/gamelogic.cpp
+++ b/src/gamelogic.cpp
@@ -395,14 +395,13 @@ void updateFrame(GLFWwindow* window) {
 
 void renderNode(SceneNode* node) {
     struct Light { // lights as stored in the shader
-    	glm::vec3 position;
-        glm::mat4 MV;
+        // coordinates in MV space
+        vec3 position;
+        vec3 spot_target;
         bool is_spot;
-        glm::vec3 spot_target; // MV space coordinates
         
         void push_to_shader(Gloom::Shader* shader, uint id) {
             #define l(x) shader->location("light[" + std::to_string(id) + "]." + #x)
-                glUniformMatrix4fv(l(MV)         , 1, GL_FALSE, glm::value_ptr(MV));
                 glUniform3fv      (l(position)   , 1, glm::value_ptr(position));
                 glUniform3fv      (l(spot_target), 1, glm::value_ptr(spot_target));
                 glUniform1i       (l(is_spot)    ,    is_spot);
@@ -449,8 +448,7 @@ void renderNode(SceneNode* node) {
         case SPOT_LIGHT:
         case POINT_LIGHT: {
             uint id = node->lightID;
-            lights[id].position    = node->position;
-            lights[id].MV          = node->MV;
+            lights[id].position    = vec3(node->MV * glm::vec4(node->position, 1.0));
             lights[id].is_spot     = node->nodeType == SPOT_LIGHT;
             lights[id].spot_target = node->rotation;
             lights[id].push_to_shader(s, id);