#import bevy_pbr::mesh_view_bindings
#import bevy_pbr::mesh_bindings

// NOTE: Bindings must come before functions that use them!
#import bevy_pbr::mesh_functions

struct Vertex {
    [[location(0)]] position: vec3<f32>;
    [[location(1)]] normal: vec3<f32>;
    [[location(2)]] uv: vec2<f32>;
#ifdef VERTEX_TANGENTS
    [[location(3)]] tangent: vec4<f32>;
#endif
#ifdef VERTEX_COLORS
    [[location(4)]] color: vec4<f32>;
#endif
#ifdef SKINNED
    [[location(5)]] joint_indices: vec4<u32>;
    [[location(6)]] joint_weights: vec4<f32>;
#endif
};

struct VertexOutput {
    [[builtin(position)]] clip_position: vec4<f32>;
    [[location(0)]] world_position: vec4<f32>;
    [[location(1)]] world_normal: vec3<f32>;
    [[location(2)]] uv: vec2<f32>;
#ifdef VERTEX_TANGENTS
    [[location(3)]] world_tangent: vec4<f32>;
#endif
#ifdef VERTEX_COLORS
    [[location(4)]] color: vec4<f32>;
#endif
};

[[stage(vertex)]]
fn vertex(vertex: Vertex) -> VertexOutput {
    var out: VertexOutput;
#ifdef SKINNED
    var model = skin_model(vertex.joint_indices, vertex.joint_weights);
    out.world_normal = skin_normals(model, vertex.normal);
#else
    var model = mesh.model;
#endif
    out.world_position = mesh_position_local_to_world(model, vec4<f32>(vertex.position, 1.0));
    out.world_normal = mesh_normal_local_to_world(vertex.normal);
    out.uv = vertex.uv;
#ifdef VERTEX_TANGENTS
    out.world_tangent = mesh_tangent_local_to_world(model, vertex.tangent);
#endif
#ifdef VERTEX_COLORS
    out.color = vertex.color;
#endif

    out.clip_position = mesh_position_world_to_clip(out.world_position);
    return out;
}

struct FragmentInput {
    [[builtin(front_facing)]] is_front: bool;
    [[location(0)]] world_position: vec4<f32>;
    [[location(1)]] world_normal: vec3<f32>;
    [[location(2)]] uv: vec2<f32>;
#ifdef VERTEX_TANGENTS
    [[location(3)]] world_tangent: vec4<f32>;
#endif
#ifdef VERTEX_COLORS
    [[location(4)]] color: vec4<f32>;
#endif
};

[[stage(fragment)]]
fn fragment(in: FragmentInput) -> [[location(0)]] vec4<f32> {
#ifdef VERTEX_COLORS
    return in.color;
#else
    return vec4<f32>(1.0, 0.0, 1.0, 1.0);
#endif
}