shaderf.fs

    uniform vec4 ambience;

    uniform vec4 liteColor;
    uniform vec3 lightPos;

    in vec3 Normal;
    in vec3 FragmentPos;

    uniform vec3 viewPos;
    uniform float specularStrength;
    uniform int metallic;
        
    vec4 color(vec4 graphicsColor, sampler2D image, vec2 uv) 
    {    
        //diffuse
        vec3 norm = normalize(Normal);
        vec3 lightDir = normalize(lightPos - FragmentPos);
        float diff = max(dot(norm, lightDir), 0.0);
        vec4 diffuse = diff * liteColor;
            
        //specular
        vec3 viewDir = normalize(viewPos - FragmentPos);
        vec3 reflectDir = reflect(-lightDir, norm);
        float spec = pow(max(dot(viewDir, reflectDir), 0.0), metallic);
        vec4 specular = specularStrength * spec * liteColor;
            
        vec4 baseColor = graphicsColor * texture(image, uv);            
        return baseColor * (ambience + diffuse + specular);
    }