#version 450

const int MAX_TEXTURES = 256;

out vec4 outPos;
out vec3 outNormal;
out vec3 outTangent;
out vec3 outBitangent;
out vec2 outTextCoords;

out vec4 outAlbedo ;
out vec4 outPosition;
out vec4 outNormals;
out vec4 outPBR;

struct Material {
    vec4 diffuse;
    int hasTexture;
    int hasNormalMap;
    int hasRoughMap;
    float roughnessFactor;
    float metallicFactor;
};

uniform sampler2D textureSampler;
uniform sampler2D normalSampler;
uniform sampler2D roughnessSampler;
uniform Material material;

vec3 calcNormal(Material material, vec3 normal, vec2 textCoords, mat3 TBN)
{
    vec3 newNormal = normal;
    if (material.hasNormalMap > 0)
    {
        newNormal = texture(normalSampler, textCoords).rgb;
        newNormal = normalize(newNormal * 2.0 - 1.0);
        newNormal = normalize(TBN * newNormal);
    }
    return newNormal;
}

layout(push_constant) uniform pc {
    layout(offset = 64) uint materialIdx;
} push_constants;

void main()
{
    outPosition = outPos;

    if (material.hasTexture == 1) {
        outAlbedo = texture(textureSampler, outTextCoords);
    } else {
        outAlbedo = material.diffuse;
    }


    if(outAlbedo.a < 0.5) discard;

    mat3 TBN = mat3( outTangent,  outBitangent,  outNormal);
    vec3 newNormal = calcNormal(material,  outNormal,  outTextCoords, TBN);
    outNormals = vec4(newNormal, 1.0f);

    float ao = 0.5f;
    float roughnessFactor = 0.0f;
    float metallicFactor = 0.0f;
    if (material.hasRoughMap > 0) {
        vec4 metRoughValue = texture(roughnessSampler,  outTextCoords);
        roughnessFactor = metRoughValue.g;
        metallicFactor = metRoughValue.b;
    } else {
        roughnessFactor = material.roughnessFactor;
        metallicFactor = material.metallicFactor;
    }

    outPBR = vec4(ao, roughnessFactor, metallicFactor, 1.0f);

}