ogltest/data/shaders/test.vert

#version 330 core

layout (location = 0) in vec3 aVertexPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;
layout (location = 4) in vec3 aTangent;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
uniform bool skyboxON;

out vec3 Normal;
out vec3 FragPos;
out vec3 theTexCoord;
out mat3 TBN;

void main() 
{ 
    gl_Position = projection * view * model * vec4( aVertexPos, 1.0);


    if (skyboxON) {
        theTexCoord = aVertexPos;
        FragPos = aVertexPos; // vec3(model * vec4(aVertexPos, 1.0));
        return;
    }

    // calculating TBN
    vec3 T = normalize(vec3(model * vec4(aTangent,   0.0)));
    vec3 N = normalize(vec3(model * vec4(aNormal,    0.0)));

    T = normalize(T - dot(T, N) * N);
    vec3 B = cross(N,T);

    TBN = mat3(T, B, N);

    // calculating normal
    theTexCoord = vec3(aTexCoords, 1.0);
    Normal = mat3(transpose(inverse(model))) * aNormal;
    FragPos = vec3(model * vec4(aVertexPos, 1.0));
}