1struct VertexOutput {
2    /// this is `clip position` when the struct is used as a vertex stage output
3    /// and `frag coord` when used as a fragment stage input
4    @builtin(position) position: vec4<f32>,
5    @location(0) world_position: vec4<f32>,
6    @location(1) world_normal: vec3<f32>,
7    @location(2) uv: vec2<f32>,
8    @if(VERTEX_TANGENTS)
9    @location(3) world_tangent: vec4<f32>,
10    @if(VERTEX_COLORS)
11    @location(4) color: vec4<f32>,
12    @location(5) @interpolate(flat) instance_index: u32,
13}