#version 450 core
out gl_PerVertex {
  vec4 gl_Position;
};

layout(std140, binding = 0) uniform PerFrame {
  mat4 uView;
  mat4 uProj;
  vec4 uLightDir; // xyz used, w padding
};
layout(std140, binding = 1) uniform PerObject {
  mat4 uModel;
};

layout(location = 0) in vec3 aPos;
layout(location = 1) in vec3 aNormal;
layout(location = 2) in vec2 aUV;

out VS_OUT {
  vec3 wPos;
  vec3 wNrm;
  vec2 uv;
  flat int hasNrm;
  flat int hasUV;
} v;

void main() {
  vec4 wpos4 = uModel * vec4(aPos, 1.0);
  v.wPos = wpos4.xyz;

  float nLen2 = dot(aNormal, aNormal);
  if(nLen2 > 1e-10) {
    mat3 nrmMat = mat3(transpose(inverse(uModel)));
    v.wNrm = normalize(nrmMat * aNormal);
    v.hasNrm = 1;
  } else {
    v.wNrm = vec3(0.0);
    v.hasNrm = 0;
  }

  v.uv = aUV;
  v.hasUV = (abs(aUV.x) + abs(aUV.y)) > 1e-10 ? 1 : 0;

  gl_Position = uProj * uView * wpos4;
}