#version 430 core

out vec4 FragColor;
in vec2 fragUV;
in vec3 fragPos;
in float lighting;

uniform sampler2D uTexture;
uniform vec3 cameraPosition;

void main()
{
    // Use squared distance
    vec3 delta = cameraPosition - fragPos;
    float distSq = dot(delta, delta);
    
    // Precomputed fog parameters
    const float fogEndSq = 65536.0; // 128^2
    const float fogStartSq = 1024.0; // 32^2
    const float fogRangeInv = 1.0 / (fogEndSq - fogStartSq);
    
    float fogFactor = (fogEndSq - distSq) * fogRangeInv;
    fogFactor = clamp(fogFactor, 0.0, 1.0);
    
    // Texture and lighting
    vec4 texColor = texture(uTexture, fragUV);
    texColor.rgb *= lighting;
    
    // Fog blend
    const vec3 fogColor = vec3(0.8, 0.8, 0.8);
    FragColor = vec4(mix(fogColor, texColor.rgb, fogFactor), texColor.a);
}