From 5de28c7d7c2306e058320093be49d22a7981e61a Mon Sep 17 00:00:00 2001
From: Daniel <danwip@hotmail.com>
Date: Tue, 23 Jan 2024 12:22:37 +0100
Subject: [PATCH] Made normal calculations to work and added diffuse lighting
 (TODO: get rid of seams)

---
 Nebulix/Rendering/Mesh.cs      | 14 +++++++-------
 src/Program.cs                 | 20 ++++++++++++++++----
 src/Shaders/Sphere/sphere.frag | 34 +++++++++++++++++++++++++++++++++-
 3 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/Nebulix/Rendering/Mesh.cs b/Nebulix/Rendering/Mesh.cs
index f9a29ad..66f22e1 100644
--- a/Nebulix/Rendering/Mesh.cs
+++ b/Nebulix/Rendering/Mesh.cs
@@ -30,18 +30,18 @@ namespace Nebulix.Rendering
 			// 	normals[j] = Vector3D<float>.Zero;
 			// }
 
-			return;
+			// return;
 			for (int i = 0; i < indices.Length; i += 3)
 			{
-				Vector3D<float> a = vertices[indices[i] - 1];
-				Vector3D<float> b = vertices[indices[i + 1] - 1];
-				Vector3D<float> c = vertices[indices[i + 2] - 1];
+				Vector3D<float> a = vertices[indices[i]];
+				Vector3D<float> b = vertices[indices[i + 1]];
+				Vector3D<float> c = vertices[indices[i + 2]];
 
 				Vector3D<float> normal = Vector3D.Cross(b-a, c-a);
 				normal = Vector3D.Normalize(normal);
-				normals[indices[i] - 1] = normal;
-				normals[indices[i + 1] - 1] = normal;
-				normals[indices[i + 2] - 1] = normal;
+				normals[indices[i]] = normal;
+				normals[indices[i + 1]] = normal;
+				normals[indices[i + 2]] = normal;
 			}
 		}
 		
diff --git a/src/Program.cs b/src/Program.cs
index d600cce..767e749 100644
--- a/src/Program.cs
+++ b/src/Program.cs
@@ -19,6 +19,8 @@ using System.Numerics;
 // Next to do will be cleaning this up by creating a shader class and maybe even an engine class
 // IEngine -> IEngine.Create(WindowOptions) -> return OpenGLEngine/VulkanEngine maybe?
 
+using Vector3 = Silk.NET.Maths.Vector3D<float>;
+
 public static class Program
 {
 	private const int Width = 800;
@@ -201,11 +203,21 @@ public static class Program
 		
 		_sphereShader.SetVector("viewPosition", _cam.Position);
 		
-		_sphereShader.SetVector("dirLight.direction", new Vector3D<float>(-0.2f, -1.0f, -0.3f));
-		_sphereShader.SetVector("dirLight.ambient", new Vector3D<float>(0.1f));
-		_sphereShader.SetVector("dirLight.diffuse", new Vector3D<float>(1f));
-		_sphereShader.SetVector("dirLight.specular", new Vector3D<float>(0.5f));
+		_sphereShader.SetVector("dirLight.direction", new Vector3(-0.2f, -1.0f, -0.3f));
+		_sphereShader.SetVector("dirLight.ambient", new Vector3(0.1f));
+		_sphereShader.SetVector("dirLight.diffuse", new Vector3(1f));
+		_sphereShader.SetVector("dirLight.specular", new Vector3(0.5f));
 
+		_sphereShader.SetVector("pointLight.position", new Vector3(0.0f, 2.0f, 0.0f));
+
+		_sphereShader.SetFloat("pointLight.constant", 1.0f);
+		_sphereShader.SetFloat("pointLight.linear", 0.09f);
+		_sphereShader.SetFloat("pointLight.quadratic", 0.032f);
+
+		_sphereShader.SetVector("pointLight.ambient", new Vector3(1.0f) * 0.1f);
+		_sphereShader.SetVector("pointLight.diffuse", new Vector3(1.0f));
+		_sphereShader.SetVector("pointLight.specular", new Vector3(1.0f));
+		
 		sphere.RenderSphere(_gl);
 	}
 
diff --git a/src/Shaders/Sphere/sphere.frag b/src/Shaders/Sphere/sphere.frag
index b96d17c..7e7f075 100644
--- a/src/Shaders/Sphere/sphere.frag
+++ b/src/Shaders/Sphere/sphere.frag
@@ -12,9 +12,21 @@ struct DirectionalLight {
     vec3 diffuse;
     vec3 specular;
 };
+struct PointLight {
+    vec3 position;
+
+    float constant;
+    float linear;
+    float quadratic;
+
+    vec3 ambient;
+    vec3 diffuse;
+    vec3 specular;
+};
 
 uniform vec3 viewPosition;
 uniform DirectionalLight dirLight;
+uniform PointLight pointLight;
 
 vec3 CalculateDirectionalLight(DirectionalLight light, vec3 normal, vec3 viewDir)
 {
@@ -31,6 +43,25 @@ vec3 CalculateDirectionalLight(DirectionalLight light, vec3 normal, vec3 viewDir
 
     return ambient + diffuse + specular;
 }
+vec3 CalculatePointLight(PointLight light, vec3 normal, vec3 fragPos, vec3 viewDir)
+{
+    vec3 lightDir = normalize(light.position - fragPos);
+
+    float diff = max(dot(normal, lightDir), 0.0);
+
+    vec3 reflectionDir = reflect(-lightDir, normal);
+    float spec = pow(max(dot(viewDir, reflectionDir), 0.0), 32);
+
+    float distance = length(light.position - fragPos);
+    float attenuation = 1.0 / (light.constant + light.linear * distance + light.quadratic * (distance * distance));
+
+    vec3 ambientLight = light.ambient * attenuation;// * texture(material.diffuseMap, TexCoords).rgb;
+    vec3 diffuseLight = light.diffuse * diff * attenuation;// * texture(material.diffuseMap, TexCoords).rgb;
+    vec3 specularLight = light.specular * spec * attenuation;// * texture(material.specularMap, TexCoords).rgb;
+
+    return ambientLight + diffuseLight + specularLight;
+}
+
 
 void main()
 {
@@ -38,6 +69,7 @@ void main()
     vec3 viewDir = normalize(viewPosition - FragPos);
 
 //    vec3 col = vec3(1.0, 0.5, 0.2) * FragPos;
-    vec3 col = CalculateDirectionalLight(dirLight, normal, viewDir);
+    vec3 col = vec3(0);//CalculateDirectionalLight(dirLight, normal, viewDir);
+    col += CalculatePointLight(pointLight, normal, FragPos, viewDir);
     FragColour = vec4(col, 1);
 }
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