From 17a2ed676b456abba0092ae0f31c58f8c3144943 Mon Sep 17 00:00:00 2001
From: extrawurst <mail@rusticorn.com>
Date: Wed, 12 Mar 2025 09:07:18 +0100
Subject: [PATCH] test billboard

---
 Cargo.lock        | 10 ++++++++++
 Cargo.toml        |  1 +
 src/billboards.rs | 38 ++++++++++++++++++++++++++++++++++++++
 src/main.rs       |  2 ++
 src/npc.rs        |  0
 src/player.rs     | 16 ++++++++++++++++
 6 files changed, 67 insertions(+)
 create mode 100644 src/billboards.rs
 create mode 100644 src/npc.rs

diff --git a/Cargo.lock b/Cargo.lock
index 58d40d5..e4bcaf1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1268,6 +1268,15 @@ dependencies = [
  "rectangle-pack",
 ]
 
+[[package]]
+name = "bevy_sprite3d"
+version = "4.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "11512eeb84d4106da2bc9bcd2434a2ab9a32da1ee1794c27a7aa55f1df761268"
+dependencies = [
+ "bevy",
+]
+
 [[package]]
 name = "bevy_state"
 version = "0.15.3"
@@ -2808,6 +2817,7 @@ dependencies = [
  "bevy-tnua-avian3d",
  "bevy_asset_loader",
  "bevy_dolly",
+ "bevy_sprite3d",
  "bevy_trenchbroom",
  "nil",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 145ebd4..fc351e3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,3 +16,4 @@ bevy-tnua = "0.21.0"
 bevy-tnua-avian3d = "0.2.0"
 bevy_dolly = { version = "0.0.5", default-features = false }
 bevy_asset_loader = "0.22.0"
+bevy_sprite3d = "4.0.0"
diff --git a/src/billboards.rs b/src/billboards.rs
new file mode 100644
index 0000000..71b9ed2
--- /dev/null
+++ b/src/billboards.rs
@@ -0,0 +1,38 @@
+use bevy::prelude::*;
+use bevy_sprite3d::Sprite3dPlugin;
+
+#[derive(Component, Reflect)]
+#[reflect(Component)]
+pub struct Billboard;
+
+pub fn plugin(app: &mut App) {
+    if !app.is_plugin_added::<Sprite3dPlugin>() {
+        app.add_plugins(Sprite3dPlugin);
+    }
+
+    app.register_type::<Billboard>();
+    app.add_systems(Update, face_camera);
+}
+
+fn face_camera(
+    cam_query: Query<&GlobalTransform, With<Camera>>,
+    mut query: Query<
+        (&mut Transform, &Parent, &InheritedVisibility),
+        (With<Billboard>, Without<Camera>),
+    >,
+    parent_transform: Query<&GlobalTransform>,
+) {
+    let cam_transform = cam_query.single();
+    for (mut transform, parent, visible) in query.iter_mut() {
+        if !matches!(*visible, InheritedVisibility::VISIBLE) {
+            continue;
+        }
+
+        let Ok(parent_global) = parent_transform.get(parent.get()) else {
+            continue;
+        };
+
+        let target = cam_transform.reparented_to(parent_global);
+        transform.look_at(target.translation, Vec3::Y);
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index b007d30..005d04f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,5 @@
 mod alien;
+mod billboards;
 mod camera;
 mod cash;
 mod gates;
@@ -72,6 +73,7 @@ fn main() {
     app.add_plugins(gates::plugin);
     app.add_plugins(platforms::plugin);
     app.add_plugins(movables::plugin);
+    app.add_plugins(billboards::plugin);
 
     app.insert_resource(AmbientLight {
         color: Color::WHITE,
diff --git a/src/npc.rs b/src/npc.rs
new file mode 100644
index 0000000..e69de29
diff --git a/src/player.rs b/src/player.rs
index 50ad00b..56b4e60 100644
--- a/src/player.rs
+++ b/src/player.rs
@@ -3,6 +3,7 @@ use std::{f32::consts::PI, time::Duration};
 use crate::{
     DebugVisuals,
     alien::{ALIEN_ASSET_PATH, Animations},
+    billboards::Billboard,
     camera::GameCameraRig,
     cash::{Cash, CashCollectEvent},
     heads_ui::HeadChanged,
@@ -15,6 +16,7 @@ use bevy::{
     window::{CursorGrabMode, PrimaryWindow},
 };
 use bevy_dolly::prelude::Rig;
+use bevy_sprite3d::{Sprite3dBuilder, Sprite3dParams};
 use bevy_tnua::{TnuaUserControlsSystemSet, prelude::*};
 use bevy_tnua_avian3d::TnuaAvian3dSensorShape;
 
@@ -68,6 +70,7 @@ fn spawn(
     asset_server: Res<AssetServer>,
     query: Query<&Transform, With<SpawnPoint>>,
     mut player_spawned: ResMut<PlayerSpawned>,
+    mut sprite_params: Sprite3dParams,
 ) {
     if player_spawned.spawned {
         return;
@@ -81,6 +84,7 @@ fn spawn(
 
     let mesh = asset_server
         .load(GltfAssetLabel::Scene(0).from_asset("models/heads/angry demonstrator.glb"));
+    let selector = asset_server.load("ui/selector.png");
 
     commands
         .spawn((
@@ -109,6 +113,18 @@ fn spawn(
                 .with_rotation(Quat::from_rotation_y(std::f32::consts::PI))
                 .with_scale(Vec3::splat(1.5)),
             SceneRoot(asset_server.load(GltfAssetLabel::Scene(0).from_asset(ALIEN_ASSET_PATH))),
+        ))
+        .with_child((
+            Billboard,
+            Transform::from_translation(Vec3::new(0., 1.5, 0.)),
+            Sprite3dBuilder {
+                image: selector,
+                pixels_per_metre: 40.,
+                alpha_mode: AlphaMode::Blend,
+                unlit: true,
+                ..default()
+            }
+            .bundle(&mut sprite_params),
         ));
 
     commands.spawn((