#version 430 core

float AMBIENT = 0.2; 

uniform vec3 lightPos;
uniform vec3 viewPos;

in vec3 FragPos; // Pozycja fragmentu
in vec3 Normal; // Normalna fragmentu
out vec4 FragColor;

// Obliczenie faktora odbicia ?wietlnego dla modelu PBR
float DistributionGGX(vec3 N, vec3 H, float roughness);
float GeometrySchlickGGX(float NdotV, float roughness);
float GeometrySmith(vec3 N, vec3 V, vec3 L, float roughness);

const float PI = 3.14159265359;

in vec3 vecNormal;
in vec3 worldPos;
in vec2 texCoord;
out vec4 outColor;

void main()
{
 
    vec3 lightDir = normalize(lightPos - worldPos);
    vec3 normal = normalize(vecNormal);
    
   
    float diffuse = max(0.0, dot(normal, lightDir));
    diffuse = clamp(diffuse + 0.2, 0.0, 1.0); 
    
  
    vec3 viewDir = normalize(-worldPos); 
    vec3 halfwayDir = normalize(lightDir + viewDir);
    float specularStrength = 0.7; // Increase specular strength
    float specular = pow(max(0.0, dot(normal, halfwayDir)), 32);
 
    vec4 textureColor = texture(colorTexture, texCoord);
    vec3 finalColor = textureColor.rgb * (AMBIENT + diffuse) + specularStrength * specular;
    
    outColor = vec4(finalColor, textureColor.a);
}