#version 330 core

layout(location = 0) in vec3 position;
layout(location = 1) in vec3 normal;

uniform mat4 model, view, projection;

// position and normal for the fragment shader, in WORLD coordinates
out vec3 w_position, w_normal;   // in world coordinates

void main() {
    vec4 w_position4 = model * vec4(position, 1.0);
    gl_Position = projection * view * w_position4;

    // fragment position in world coordinates
    w_position = w_position4.xyz / w_position4.w;  // dehomogenize

    // fragment normal in world coordinates
    mat3 nit_matrix = transpose(inverse(mat3(model)));
    w_normal = normalize(nit_matrix * normal);
}