#version 330 core

uniform vec3 lightColor;

uniform float materialNs;
uniform int objectId;

#ifdef ALPHA_MASK
uniform sampler2D alphaMask;
#endif

#ifdef AMBIENT_TEXTURE
uniform sampler2D ambientTexture;
#else
uniform vec3 materialKa;
#endif

#ifdef DIFFUSE_TEXTURE
uniform sampler2D diffuseTexture;
#else
uniform vec3 materialKd;
#endif

#ifdef SPECULAR_TEXTURE
uniform sampler2D specularTexture;
#else
uniform vec3 materialKs;
#endif

#ifdef NORMAL_MAP
uniform sampler2D normalMap;

in mat3 tangentSpace;
#else
in vec3 varNormal;
#endif

in vec2 varTexCoord;

in vec3 lightDirInView;
in vec3 halfVecInView;

layout(location = 0)out vec4 outColor;

vec3 phongLighting(in vec3 kd, in vec3 ks, in float ns, in vec3 color, in vec3 normal, in vec3 lightDir, in vec3 halfVec){
        float diffuseComponent = max(dot(normal, lightDir), 0);
        float specularComponent = max(dot(halfVec, normal), 0);
        return color*diffuseComponent*(kd+ks*pow(specularComponent, ns));
}

void main(void) {
#ifdef
#ifdef ALPHA_MASK
    if(texture(alphaMask, varTexCoord).r < 0.5)
        discard;
#endif

#ifdef NORMAL_MAP
    vec3 normal = normalize(texture(normalMap, varTexCoord).xyz * tangentSpace);
#else
    vec3 normal = normalize(varNormal);
#endif

#ifdef AMBIENT_TEXTURE
    vec3 ambient = texture(ambientTexture, varTexCoord).rgb;
#else
    vec3 ambient = materialKa;
#endif

#ifdef DIFFUSE_TEXTURE
    vec3 diffuse = texture(diffuseTexture, varTexCoord).rgb;
#else
    vec3 diffuse = materialKd;
#endif

#ifdef SPECULAR_TEXTURE
    vec3 specular = texture(specularTexture, varTexCoord).rgb;
#else
    vec3 specular = materialKs;
#endif

    vec3 light = phongLighting(diffuse, specular, materialNs, lightColor, normal, lightDirInView, halfVecInView);
    outColor = vec4(ambient + light, 1);
}