From 1442d81549b813cddff511c6e9465c1d90f0f724 Mon Sep 17 00:00:00 2001
From: 4VRDriver <44267643+4VRDriver@users.noreply.github.com>
Date: Sun, 6 Sep 2020 22:32:46 +0200
Subject: [PATCH] Light attenuation

---
 res/shaders/basic.fs | 19 +++++++++++++++----
 src/Controller.cpp   | 10 ++++++++++
 src/Window.cpp       |  2 +-
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/res/shaders/basic.fs b/res/shaders/basic.fs
index 7afec01..9d52cea 100644
--- a/res/shaders/basic.fs
+++ b/res/shaders/basic.fs
@@ -17,10 +17,15 @@ uniform Material u_material;
 
 struct Light {
     vec3 position;
+    //vec3 direction;
 
     vec3 ambient;
     vec3 diffuse;
     vec3 specular;
+
+    float K_c;
+    float K_l;
+    float K_q;
 };
 uniform Light u_light;
 
@@ -29,10 +34,13 @@ uniform vec3 u_viewPosition;
 
 void main() {
 
+    vec3 vecLightToFragment = u_light.position - v_fragmentPosition;
+    vec3 lightDir = normalize(vecLightToFragment);
+    //vec3 lightDir = normalize(-u_light.direction);
+
     // Diffuse lighting
     vec3 diffuseColor0 = vec3(texture(u_material.texture_diffuse0, v_texCoord));
     vec3 normal = normalize(u_normalMatrix * v_normal);
-    vec3 lightDir = normalize(u_light.position - v_fragmentPosition);
     float diff = max(dot(normal, lightDir), 0.0f);
     vec3 diffuse = u_light.diffuse * diff * diffuseColor0;
 
@@ -45,9 +53,12 @@ void main() {
     float spec = pow(max(dot(viewDir, reflectDir), 0.0), u_material.shininess);
     vec3 specular = u_light.specular * spec * vec3(texture(u_material.texture_specular0, v_texCoord));
 
-    //vec4 texColor1 = texture(u_material.u_texture_diffuse0, v_texCoord);
-    //vec4 texColor2 = texture(u_material.u_texture_diffuse1, v_texCoord);
-    //f_color = texColor1;
+    float distanceLightFragment = length(vecLightToFragment);
+    float attenuation = 1.0 / (u_light.K_c + u_light.K_l * distanceLightFragment + u_light.K_q * distanceLightFragment * distanceLightFragment);    
+
+    ambient *= attenuation;
+    diffuse *= attenuation;
+    specular *= attenuation;
 
     f_color = vec4((ambient + diffuse + specular), 1.0f);
 }
diff --git a/src/Controller.cpp b/src/Controller.cpp
index fb5e1a3..14b3128 100644
--- a/src/Controller.cpp
+++ b/src/Controller.cpp
@@ -52,11 +52,15 @@ void Controller::run() {
     //Model model_backpack("res/models/backpack.obj");
     Model model_container("res/models/container.obj");
     Model model_cube("res/models/cube.obj");
+    Model model_sphere("res/models/sphere.obj");
 
     //Entity backpack1(&model_backpack, &shaderProgram);
+    Entity sphere(&model_sphere, &shaderProgram);
     Entity cube(&model_container, &shaderProgram);
     Entity lightSource(&model_cube, &lightProgram);
 
+    sphere.translate(glm::vec3(3.0f, 0.0f, 2.0f));
+
     lightSource.translate(glm::vec3(-5.0f, 1.0f, 0.0f));
     lightSource.scale(0.2f);
 
@@ -66,15 +70,21 @@ void Controller::run() {
 
     shaderProgram.bind();
     shaderProgram.setUniform("u_light.position", lightSource.getPosition());
+    //shaderProgram.setUniform("u_light.direction", glm::vec3(-0.2f, -1.0f, -0.3f));
     shaderProgram.setUniform("u_light.ambient", ambientColor);
     shaderProgram.setUniform("u_light.diffuse", diffuseColor);
     shaderProgram.setUniform("u_light.specular", glm::vec3(1.0f, 1.0f, 1.0f));
 
+    shaderProgram.setUniform("u_light.K_c", 1.0f);
+    shaderProgram.setUniform("u_light.K_l", 0.09f);
+    shaderProgram.setUniform("u_light.K_q", 0.032f);
+
     shaderProgram.setUniform("u_material.shininess", 32.0f);
     shaderProgram.unbind();
 
     scene.push_back(cube);
     scene.push_back(lightSource);
+    scene.push_back(sphere);
     
     camera->translate(glm::vec3(0.0f, 0.0f, 7.5f));
 
diff --git a/src/Window.cpp b/src/Window.cpp
index b98d7ed..4779a45 100644
--- a/src/Window.cpp
+++ b/src/Window.cpp
@@ -8,7 +8,7 @@
 Window::Window() {
     width = INIT_WINDOW_WIDTH; height = INIT_WINDOW_HEIGHT;
 
-    window = glfwCreateWindow(width, height, "Fall-Fever", NULL, NULL);
+    window = glfwCreateWindow(width, height, "OpenGL", NULL, NULL);
     if(!window) {
         std::cout << "Failed to create window" << std::endl;
     }