do a basic scene and way too much organization and fail to implement panning

src/game/camera.rs

@@ -0,0 +1,65 @@
+//! Sets up the game's camera controls etc.
+
+use bevy::{
+    input::mouse::{AccumulatedMouseMotion, MouseButtonInput},
+    prelude::*,
+};
+
+use super::GameplaySet;
+
+pub fn plugin(app: &mut App) {
+    app.init_resource::<MouseButtonsPressed>().add_systems(
+        Update,
+        (
+            detect_mouse_button_press,
+            panning_basic.after(detect_mouse_button_press),
+        )
+            .in_set(GameplaySet),
+    );
+}
+
+/// Resource to store current mouse button state.
+#[derive(Resource, Default)]
+struct MouseButtonsPressed {
+    left: bool,
+}
+
+/// Detect whether mouse buttons (currently only left) are pressed.
+fn detect_mouse_button_press(
+    mut button_events: EventReader<MouseButtonInput>,
+    mut pressed: ResMut<MouseButtonsPressed>,
+) {
+    for event in button_events.read() {
+        if event.button == MouseButton::Left {
+            pressed.left = dbg!(event.state.is_pressed());
+        }
+    }
+}
+
+/// is SUPPOSED to do proper panning
+/// i hate 3d math
+fn panning_basic(
+    accumulated_mouse_motion: Res<AccumulatedMouseMotion>,
+    mut cam_transform: Single<&mut Transform, With<Camera>>,
+    pressed: Res<MouseButtonsPressed>,
+) {
+    if pressed.left && accumulated_mouse_motion.delta != Vec2::ZERO {
+        let yaw = Quat::from_rotation_y(accumulated_mouse_motion.delta.x / 150.);
+        // cam_transform.rotate_around(Vec3::ZERO, yaw);
+        cam_transform.rotation *= yaw;
+
+        let pitch = Quat::from_rotation_x(accumulated_mouse_motion.delta.y / 150.);
+        let new_rot = cam_transform.rotation * pitch;
+        // cam_transform.rotate_around(Vec3::ZERO, pitch);
+        // cam_transform.rotation *= pitch;
+        let up_vector = new_rot * Vec3::Y;
+        if up_vector.y > 0.0 {
+            cam_transform.rotation = new_rot;
+        }
+    }
+    // ???????
+    // TODO: figure out/understand how they do it https://github.com/The-DevBlog/bevy_third_person_camera/blob/a7c6b458573fcb0730b65eda6507ca27fb58f571/src/mouse.rs#L29-L74
+    //
+    let rot_matrix = Mat3::from_quat(cam_transform.rotation);
+    cam_transform.translation = rot_matrix.mul_vec3(Vec3::new(0.0, 0.0, 20.));
+}