From f85b5cf7af6040e554a090d1e117208074c221b8 Mon Sep 17 00:00:00 2001
From: Felix Ableitner <me@nutomic.com>
Date: Fri, 1 Jan 2021 18:31:38 +0100
Subject: [PATCH] Improved camera control

---
 src/player.rs | 66 +++++++++++++++++++++++----------------------------
 1 file changed, 30 insertions(+), 36 deletions(-)

diff --git a/src/player.rs b/src/player.rs
index 42534e8..d112119 100644
--- a/src/player.rs
+++ b/src/player.rs
@@ -1,4 +1,4 @@
-use bevy::{input::mouse::MouseMotion, math::clamp, prelude::*};
+use bevy::{input::mouse::MouseMotion, prelude::*};
 use bevy_rapier3d::{
   na::Matrix3x1,
   physics::RigidBodyHandleComponent,
@@ -25,32 +25,33 @@ struct State {
   mouse_motion_event_reader: EventReader<MouseMotion>,
 }
 
-struct Player {
-  /// The current pitch of the FlyCamera in degrees. This value is always up-to-date, enforced by [FlyCameraPlugin](struct.FlyCameraPlugin.html)
-  pitch: f32,
-  /// The current pitch of the FlyCamera in degrees. This value is always up-to-date, enforced by [FlyCameraPlugin](struct.FlyCameraPlugin.html)
-  yaw: f32,
-}
+#[derive(Default)]
+struct Player;
 
 const PLAYER_SPEED: f32 = 320.0;
-const MOUSE_SENSITIVITY: f32 = 6.0;
+const MOUSE_SENSITIVITY: f32 = 1.0;
 
-impl Player {
-  fn create() -> Self {
-    Self {
-      pitch: 0.0,
-      yaw: 0.0,
-    }
-  }
-}
-
-fn init_player(commands: &mut Commands) {
+fn init_player(
+  commands: &mut Commands,
+  mut meshes: ResMut<Assets<Mesh>>,
+  mut materials: ResMut<Assets<StandardMaterial>>,
+) {
   commands
     .spawn(Camera3dBundle {
-      transform: Transform::from_translation(Vec3::new(0.0, 3.0, 3.0)),
+      transform: Transform::from_translation(Vec3::new(0.0, 1.0, 3.0)),
       ..Default::default()
     })
-    .with(Player::create())
+    .with(Player::default());
+
+  // TODO: temporarily create a separate bundle for movement, to test mouse look
+  commands
+    .spawn(PbrBundle {
+      mesh: meshes.add(Mesh::from(shape::Cube { size: 0.25 })),
+      material: materials.add(Color::rgb(0.0, 1.0, 0.3).into()),
+      transform: Transform::from_translation(Vec3::new(0.0, 0.0, 0.0)),
+      ..Default::default()
+    })
+    .with(Player::default())
     .with(
       RigidBodyBuilder::new_dynamic()
         .translation(0.0, 3.0, 0.0)
@@ -111,9 +112,8 @@ fn movement_axis(input: &Res<Input<KeyCode>>, plus: KeyCode, minus: KeyCode) ->
 fn player_look_system(
   time: Res<Time>,
   mut state: ResMut<State>,
-  mut bodies: ResMut<RigidBodySet>,
   mouse_motion_events: Res<Events<MouseMotion>>,
-  mut query: Query<(&mut Player, &mut Transform, &RigidBodyHandleComponent)>,
+  mut query: Query<&mut Transform, With<Player>>,
 ) {
   let mut delta: Vec2 = Vec2::zero();
   for event in state.mouse_motion_event_reader.iter(&mouse_motion_events) {
@@ -123,21 +123,15 @@ fn player_look_system(
     return;
   }
 
-  for (mut player, mut transform, handle) in query.iter_mut() {
-    let body: &mut RigidBody = bodies.get_mut(handle.handle()).unwrap();
-    player.yaw -= delta.x * MOUSE_SENSITIVITY * time.delta_seconds();
-    player.pitch += delta.y * MOUSE_SENSITIVITY * time.delta_seconds();
+  // TODO: need to keep the camera level
+  for mut transform in query.iter_mut() {
+    let yaw = -delta.y * MOUSE_SENSITIVITY * time.delta_seconds();
+    let pitch = -delta.x * MOUSE_SENSITIVITY * time.delta_seconds();
 
-    player.pitch = clamp(player.pitch, -89.9, 89.9);
-    // println!("pitch: {}, yaw: {}", options.pitch, options.yaw);
+    let quat_yaw = Quat::from_axis_angle(Vec3::unit_x(), yaw);
+    let quat_pitch = Quat::from_axis_angle(Vec3::unit_y(), pitch);
 
-    let yaw_radians = player.yaw.to_radians();
-    let pitch_radians = player.pitch.to_radians();
-
-    transform.rotation = Quat::from_axis_angle(Vec3::unit_y(), yaw_radians)
-      * Quat::from_axis_angle(-Vec3::unit_x(), pitch_radians)
-      * 10.;
-
-    body.set_angvel(Matrix3x1::new(pitch_radians, yaw_radians, 0.), true);
+    let orientation_change: Quat = (quat_pitch * quat_yaw).normalize();
+    transform.rotate(orientation_change);
   }
 }