From 93333821d82bc74919775d0e31a70854f21cd3fd Mon Sep 17 00:00:00 2001
From: Lukian <lulul7018@gmail.com>
Date: Sat, 8 Feb 2025 15:36:41 +0100
Subject: [PATCH] added basic lighting

---
 resources/shaders/shader.fs | 25 +++++++++++++++++++++++--
 resources/shaders/shader.vs |  8 ++++++--
 src/main.cpp                |  7 +++++++
 3 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/resources/shaders/shader.fs b/resources/shaders/shader.fs
index 9da78b1..8a6e635 100644
--- a/resources/shaders/shader.fs
+++ b/resources/shaders/shader.fs
@@ -1,11 +1,32 @@
 #version 330 core
 out vec4 FragColor;
 
+in vec3 Normal;
 in vec2 TexCoords;
+in vec3 FragPos;
 
 uniform sampler2D texture_diffuse1;
+uniform vec3 lightColor;
+uniform vec3 lightPos;
+uniform vec3 viewPos;
 
 void main()
-{    
-    FragColor = texture(texture_diffuse1, TexCoords);
+{
+    float ambientStrength = 0.1;
+    vec3 ambient = ambientStrength * lightColor;
+
+    vec3 norm = normalize(Normal);
+    vec3 lightDir = normalize(lightPos - FragPos);
+    float diff = max(dot(norm, lightDir), 0.0);
+    vec3 diffuse = diff * lightColor;
+
+    float specularStrength = 0.5;
+    vec3 viewDir = normalize(viewPos - FragPos);
+    vec3 reflectDir = reflect(-lightDir, norm);  
+    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32);
+    vec3 specular = specularStrength * spec * lightColor;  
+
+    vec3 result = (ambient + diffuse + specular) * vec3(1.0, 0.5, 0.2);
+    vec4 light = vec4(result, 1.0);
+    FragColor = texture(texture_diffuse1, TexCoords) * light;
 }
\ No newline at end of file
diff --git a/resources/shaders/shader.vs b/resources/shaders/shader.vs
index 253b79e..9f56c26 100644
--- a/resources/shaders/shader.vs
+++ b/resources/shaders/shader.vs
@@ -3,7 +3,9 @@ layout (location = 0) in vec3 aPos;
 layout (location = 1) in vec3 aNormal;
 layout (location = 2) in vec2 aTexCoords;
 
+out vec3 Normal;
 out vec2 TexCoords;
+out vec3 FragPos;
 
 uniform mat4 model;
 uniform mat4 view;
@@ -11,6 +13,8 @@ uniform mat4 projection;
 
 void main()
 {
-    TexCoords = aTexCoords;    
-    gl_Position = projection * view * model * vec4(aPos, 1.0);
+	TexCoords = aTexCoords;
+	Normal = mat3(transpose(inverse(model))) * aNormal;
+	FragPos = vec3(model * vec4(aPos, 1.0));
+	gl_Position = projection * view * model * vec4(aPos, 1.0);
 }
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 2035d77..7ecaf33 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -67,6 +67,9 @@ int main()
 	glm::mat4 model = glm::mat4(1.0f);
 	model = glm::rotate(model, glm::radians(-55.0f), glm::vec3(1.0f, 0.0f, 0.0f));
 
+	glm::vec3 lightPos = glm::vec3(1.2f, 1.0f, 2.0f);
+	glm::vec3 lightColor = glm::vec3(1.0f, 1.0f, 1.0f);
+
 	while(!glfwWindowShouldClose(window))
 	{
 		float currentFrame = glfwGetTime();
@@ -80,6 +83,10 @@ int main()
 
 		ourShader.use();
 
+		ourShader.setVec3("lightPos", lightPos);
+		ourShader.setVec3("lightColor", lightColor);
+		ourShader.setVec3("viewPos", camera.Position);
+
 		glm::mat4 view = camera.GetViewMatrix();
 		glm::mat4 projection = glm::perspective(glm::radians(45.0f), float(width) / float(height), 0.1f, 100.0f);
 		ourShader.setMat4("view", view);