From 9a7b3b511a93e0f8d9488b338033b34ac64b9ba1 Mon Sep 17 00:00:00 2001
From: Joe Ardent <code@ardent.nebcorp.com>
Date: Wed, 5 Jan 2022 00:16:22 -0800
Subject: [PATCH] Corrects orientation for local up. Adds dbg ui for
 orientation.

Still using the model as the camera stand-in. Next up is enabling collision detection and gravity.
---
 src/flycam.rs | 89 ++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 77 insertions(+), 12 deletions(-)

diff --git a/src/flycam.rs b/src/flycam.rs
index 8dcdb40..3256a19 100644
--- a/src/flycam.rs
+++ b/src/flycam.rs
@@ -8,10 +8,6 @@ use bevy::{
     utils::tracing::info,
 };
 
-// stolen with neither shame nor pity from
-// git@github.com:sburris0/bevy_flycam.git, b90f6fc, which is copyright 2020
-// Spencer Burris
-
 pub const PLANET_RADIUS: f32 = 75.0;
 
 const PLAYER_DIST: f32 = PLANET_RADIUS + 300.0;
@@ -21,6 +17,12 @@ struct PlayerState {
     velocity: Vec3,
 }
 
+#[derive(Default)]
+struct UpState {
+    player_up: Vec3,
+    cam_up: Vec3,
+}
+
 impl Default for PlayerState {
     fn default() -> Self {
         PlayerState {
@@ -63,6 +65,9 @@ pub struct FlyCam;
 #[derive(Component, Debug)]
 pub struct CyberBike;
 
+#[derive(Component)]
+struct UpText;
+
 /// Spawns the `Camera3dBundle` to be controlled
 fn setup_player(mut commands: Commands, asset_server: Res<AssetServer>) {
     commands
@@ -88,9 +93,49 @@ fn setup_player(mut commands: Commands, asset_server: Res<AssetServer>) {
         .insert(CyberBike);
 }
 
+fn setup_dbg_ui(mut commands: Commands, asset_server: Res<AssetServer>) {
+    commands.spawn_bundle(UiCameraBundle::default());
+
+    commands
+        .spawn_bundle(TextBundle {
+            style: Style {
+                align_self: AlignSelf::FlexEnd,
+                ..Default::default()
+            },
+            // Use `Text` directly
+            text: Text {
+                // Construct a `Vec` of `TextSection`s
+                sections: vec![TextSection {
+                    value: "".to_string(),
+                    style: TextStyle {
+                        font: asset_server.load("fonts/FiraMono-Medium.ttf"),
+                        font_size: 40.0,
+                        color: Color::GOLD,
+                    },
+                }],
+                ..Default::default()
+            },
+            ..Default::default()
+        })
+        .insert(UpText);
+}
+
+fn dbg_ui_system(state: Res<UpState>, mut query: Query<&mut Text, With<UpText>>) {
+    let cos = state.player_up.dot(state.cam_up);
+
+    let mut text = query.single_mut();
+    text.sections[0].value = format!(
+        "up: {:?}\ncam_up: {:?}\ntheta: {:.2}",
+        state.player_up,
+        state.cam_up,
+        cos.acos().to_degrees()
+    );
+}
+
 fn player_move(
     time: Res<Time>,
     _settings: Res<MovementSettings>,
+    mut up_state: ResMut<UpState>,
     mut state: ResMut<PlayerState>,
     mut bike_query: Query<&mut Transform, (With<CyberBike>, Without<FlyCam>)>,
     mut cam_query: Query<&mut Transform, (With<FlyCam>, Without<CyberBike>)>,
@@ -100,16 +145,25 @@ fn player_move(
     let mut bike_xform = bike_query.single_mut();
     let up = bike_xform.translation.normalize();
     let cam_up = bike_xform.up();
-    let hlevel = up.cross(cam_up).normalize();
-    let roll = bike_xform.left().dot(hlevel).acos() * 0.5 * dt;
-    let roll = Quat::from_axis_angle(bike_xform.forward(), roll);
+    let cos = up.dot(cam_up);
 
-    let vlevel = up.cross(hlevel).normalize();
-    let pitch = bike_xform.forward().dot(vlevel).acos() * 0.5 * dt;
-    let pitch = Quat::from_axis_angle(bike_xform.right(), pitch);
+    let theta = cos.acos();
+    let rate = if !theta.is_normal() {
+        0.0
+    } else if theta.is_sign_negative() {
+        -0.4
+    } else {
+        0.4
+    } * dt;
+    let angle = if rate.is_sign_negative() {
+        rate.max(theta)
+    } else {
+        rate.min(theta)
+    };
 
-    let rot = pitch; // * roll;
-    if rot.is_finite() {
+    let rot = Quat::from_axis_angle(cam_up.cross(up).normalize(), angle);
+
+    if rot.is_finite() && theta.abs() > 0.0085 {
         bike_xform.rotate(rot);
     }
 
@@ -120,6 +174,9 @@ fn player_move(
         //state.velocity = -up * settings.gravity * dt;
     }
 
+    up_state.cam_up = cam_up;
+    up_state.player_up = up;
+
     let mut cam_xform = cam_query.single_mut();
     cam_xform.translation = bike_xform.translation + (up * CAM_DIST);
     cam_xform.look_at(bike_xform.translation, Vec3::Y);
@@ -149,6 +206,11 @@ fn player_look(
                 GamepadEventType::ButtonChanged(GamepadButtonType::LeftTrigger2, val) => {
                     istate.throttle = -val;
                 }
+                GamepadEventType::ButtonChanged(GamepadButtonType::East, val) => {
+                    if val > 0.5 {
+                        vel = Vec3::ZERO;
+                    }
+                }
                 GamepadEventType::AxisChanged(GamepadAxisType::LeftStickX, val) => {
                     istate.yaw = -val;
                 }
@@ -214,7 +276,10 @@ impl Plugin for PlayerPlugin {
         app.init_resource::<PlayerState>()
             .init_resource::<MovementSettings>()
             .init_resource::<InputState>()
+            .init_resource::<UpState>()
             .add_startup_system(setup_player)
+            .add_startup_system(setup_dbg_ui)
+            .add_system(dbg_ui_system)
             .add_system(player_move.label("move"))
             .add_system(player_look.after("move"))
             .add_system(cursor_grab);