From 93dd8bde9272f762c33726279d052b6e1e0c7a31 Mon Sep 17 00:00:00 2001
From: Joe Ardent <code@ardent.nebcorp.com>
Date: Tue, 1 Mar 2022 21:42:16 -0800
Subject: [PATCH] Add debug camera and switching.

Debug camera is in front and off to the side.
---
 src/camera.rs | 118 ++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 91 insertions(+), 27 deletions(-)

diff --git a/src/camera.rs b/src/camera.rs
index 9305bfa..0667d90 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -1,58 +1,122 @@
-use bevy::prelude::*;
-
-use crate::{
-    geometry::{CyberBikeModel, SPAWN_ALTITUDE},
-    input::InputState,
+use bevy::{
+    prelude::*,
+    render::camera::{ActiveCameras, Camera, CameraPlugin},
 };
 
-pub(crate) const CAM_DIST: f32 = 15.0;
+use crate::{geometry::CyberBikeModel, input::InputState};
 
 // 85 degrees in radians
 const MAX_PITCH: f32 = 1.48353;
 
-#[derive(Component, Debug)]
-pub struct CyberCam;
+#[derive(Clone, Copy, Eq, PartialEq, Debug, Hash, Component)]
+enum CyberCameras {
+    Hero,
+    Debug,
+}
 
-fn setup_cybercam(mut commands: Commands) {
-    let projection = PerspectiveProjection {
+impl CyberCameras {
+    fn next(self) -> Self {
+        match self {
+            CyberCameras::Debug => CyberCameras::Hero,
+            CyberCameras::Hero => CyberCameras::Debug,
+        }
+    }
+}
+
+fn setup_cybercams(mut commands: Commands) {
+    let hero_projection = PerspectiveProjection {
         fov: std::f32::consts::FRAC_PI_3,
         ..Default::default()
     };
     commands
         .spawn_bundle(PerspectiveCameraBundle {
-            transform: Transform::from_xyz(SPAWN_ALTITUDE + CAM_DIST, 0.0, 0.0)
-                .looking_at(Vec3::ZERO, Vec3::Y),
-            perspective_projection: projection,
+            perspective_projection: hero_projection,
             ..Default::default()
         })
-        .insert(CyberCam);
+        .insert(CyberCameras::Hero);
+
+    commands
+        .spawn_bundle(PerspectiveCameraBundle::with_name("Inactive"))
+        .insert(CyberCameras::Debug);
 }
 
 fn follow_cyberbike(
-    bike_query: Query<&Transform, (Without<CyberCam>, With<CyberBikeModel>)>,
-    mut cam_query: Query<&mut Transform, (With<CyberCam>, Without<CyberBikeModel>)>,
+    mut query: QuerySet<(
+        // 0: the bike
+        QueryState<&Transform, With<CyberBikeModel>>,
+        // 1: the cameras
+        QueryState<(&mut Transform, &CyberCameras)>,
+    )>,
     input: Res<InputState>,
 ) {
-    let bike_xform = bike_query.single();
+    let bike_xform = *query.q0().single();
     let up = bike_xform.translation.normalize();
 
-    let look_at = bike_xform.translation + (bike_xform.forward() * 200.0);
-    let cam_pos = bike_xform.translation + (bike_xform.back() * 2.7) + (up * 2.4);
+    for (mut cam_xform, cam_type) in query.q1().iter_mut() {
+        match *cam_type {
+            CyberCameras::Hero => {
+                let look_at = bike_xform.translation + (bike_xform.forward() * 200.0);
+                let cam_pos = bike_xform.translation + (bike_xform.back() * 2.7) + (up * 2.4);
 
-    let mut cam_xform = cam_query.single_mut();
-    cam_xform.translation = cam_pos;
-    cam_xform.look_at(look_at, up);
+                cam_xform.translation = cam_pos;
+                cam_xform.look_at(look_at, up);
 
-    // handle input pitch
-    let angle = input.pitch.powi(3) * MAX_PITCH;
-    let axis = cam_xform.right();
-    cam_xform.rotate(Quat::from_axis_angle(axis, angle));
+                // handle input pitch
+                let angle = input.pitch.powi(3) * MAX_PITCH;
+                let axis = cam_xform.right();
+                cam_xform.rotate(Quat::from_axis_angle(axis, angle));
+            }
+            CyberCameras::Debug => {
+                let pos = bike_xform.translation
+                    + (bike_xform.forward() * 10.0)
+                    + (bike_xform.left() * 30.0)
+                    + (bike_xform.up() * 7.0);
+                cam_xform.translation = pos;
+                cam_xform.look_at(bike_xform.translation, up);
+            }
+        }
+    }
+}
+
+fn update_active_camera(
+    mut active_cams: ResMut<ActiveCameras>,
+    state: Res<State<CyberCameras>>,
+    mut query: Query<(&mut Camera, &CyberCameras)>,
+) {
+    active_cams.remove(CameraPlugin::CAMERA_3D);
+
+    // set all cameras to inactive
+    for (mut cam, _) in query.iter_mut() {
+        cam.name = Some("Inactive".to_string());
+    }
+
+    // find the camera with the current state, set its name to be active
+    for (mut cam, _) in query
+        .iter_mut()
+        .filter(|(_, cybercam)| state.current().eq(cybercam))
+    {
+        cam.name = Some(CameraPlugin::CAMERA_3D.to_string());
+    }
+
+    active_cams.add(CameraPlugin::CAMERA_3D);
+}
+
+fn cycle_cam_state(mut state: ResMut<State<CyberCameras>>, mut keys: ResMut<Input<KeyCode>>) {
+    if keys.just_pressed(KeyCode::D) {
+        let new_state = state.current().next();
+        info!("{:?}", new_state);
+        state.set(new_state).unwrap();
+        keys.reset(KeyCode::D);
+    }
 }
 
 pub struct CyberCamPlugin;
 impl Plugin for CyberCamPlugin {
     fn build(&self, app: &mut bevy::prelude::App) {
-        app.add_startup_system(setup_cybercam)
+        app.add_startup_system(setup_cybercams)
+            .add_state(CyberCameras::Hero)
+            .add_system(cycle_cam_state)
+            .add_system(update_active_camera)
             .add_system(follow_cyberbike);
     }
 }