From 88c46d679d683086fcf3cfd6cdbb4cd93169fb24 Mon Sep 17 00:00:00 2001
From: Kristofers Solo <dev@kristofers.xyz>
Date: Fri, 17 Jan 2025 12:09:55 +0200
Subject: [PATCH] feat(camera): add camera controls #34

---
 src/camera.rs    | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/constants.rs |  6 +++++
 src/lib.rs       | 18 +++-----------
 3 files changed, 73 insertions(+), 15 deletions(-)
 create mode 100644 src/camera.rs

diff --git a/src/camera.rs b/src/camera.rs
new file mode 100644
index 0000000..2701589
--- /dev/null
+++ b/src/camera.rs
@@ -0,0 +1,64 @@
+use bevy::{input::mouse::MouseWheel, prelude::*};
+
+use crate::constants::{BASE_ZOOM_SPEED, DISTANCE_SCALE_FACTOR, MAX_ZOOM, MIN_ZOOM};
+
+pub(super) fn plugin(app: &mut App) {
+    app.add_systems(Update, camera_zoom);
+}
+
+#[derive(Debug, Reflect, Component)]
+#[reflect(Component)]
+pub struct MainCamera;
+
+pub fn spawn_camera(mut commands: Commands) {
+    commands.spawn((
+        Name::new("Camera"),
+        MainCamera,
+        Camera3d::default(),
+        Transform::from_xyz(200., 200., 0.).looking_at(Vec3::ZERO, Vec3::Y),
+        // Render all UI to this camera.
+        // Not strictly necessary since we only use one camera,
+        // but if we don't use this component, our UI will disappear as soon
+        // as we add another camera. This includes indirect ways of adding cameras like using
+        // [ui node outlines](https://bevyengine.org/news/bevy-0-14/#ui-node-outline-gizmos)
+        // for debugging. So it's good to have this here for future-proofing.
+        IsDefaultUiCamera,
+    ));
+}
+
+fn camera_zoom(
+    mut query: Query<&mut Transform, With<MainCamera>>,
+    mut scrool_evr: EventReader<MouseWheel>,
+    keyboard: Res<ButtonInput<KeyCode>>,
+    time: Res<Time>,
+) {
+    let Ok(mut transform) = query.get_single_mut() else {
+        return;
+    };
+
+    let current_distance = transform.translation.length();
+
+    // Calculate zoom speed based on distance
+    let distance_multiplier = (current_distance / MIN_ZOOM).powf(DISTANCE_SCALE_FACTOR);
+    let adjusted_zoom_speed = BASE_ZOOM_SPEED * distance_multiplier;
+
+    let mut zoom_delta = 0.0;
+
+    if keyboard.pressed(KeyCode::Equal) || keyboard.pressed(KeyCode::NumpadAdd) {
+        zoom_delta += adjusted_zoom_speed * time.delta_secs() * 25.;
+    }
+
+    if keyboard.pressed(KeyCode::Minus) || keyboard.pressed(KeyCode::NumpadSubtract) {
+        zoom_delta -= adjusted_zoom_speed * time.delta_secs() * 25.;
+    }
+
+    for ev in scrool_evr.read() {
+        zoom_delta += ev.y * adjusted_zoom_speed;
+    }
+
+    if zoom_delta != 0.0 {
+        let forward = transform.translation.normalize();
+        let new_distance = (current_distance - zoom_delta).clamp(MIN_ZOOM, MAX_ZOOM);
+        transform.translation = forward * new_distance;
+    }
+}
diff --git a/src/constants.rs b/src/constants.rs
index e960a29..2ccdad5 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -12,3 +12,9 @@ pub const BASE_TIME_SCORE: usize = 100;
 pub const FLOOR_DIFFICULTY_MULTIPLIER: f32 = 1.2; // Higher floors are exponentially harder
 pub const MIN_TIME_MULTIPLIER: f32 = 0.1; // Minimum score multiplier for time
 pub const TIME_REFERENCE_SECONDS: f32 = 60.0; // Reference time for score calculation
+
+// Constants for camera control
+pub const BASE_ZOOM_SPEED: f32 = 10.0;
+pub const MIN_ZOOM: f32 = 50.0;
+pub const MAX_ZOOM: f32 = 2500.0;
+pub const DISTANCE_SCALE_FACTOR: f32 = 0.5; // Adjust this to control how much distance affects zoom speed
diff --git a/src/lib.rs b/src/lib.rs
index e634cde..970e8de 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,6 @@
 pub mod asset_tracking;
 pub mod audio;
+pub mod camera;
 pub mod constants;
 #[cfg(feature = "dev")]
 pub mod dev_tools;
@@ -16,6 +17,7 @@ use bevy::{
     audio::{AudioPlugin, Volume},
     prelude::*,
 };
+use camera::spawn_camera;
 use constants::TITLE;
 use theme::{palette::rose_pine, prelude::ColorScheme};
 
@@ -71,6 +73,7 @@ impl Plugin for AppPlugin {
             player::plugin,
             hint::plugin,
             stats::plugin,
+            camera::plugin,
         ));
 
         // Enable dev tools for dev builds.
@@ -92,21 +95,6 @@ enum AppSet {
     Update,
 }
 
-fn spawn_camera(mut commands: Commands) {
-    commands.spawn((
-        Name::new("Camera"),
-        Camera3d::default(),
-        Transform::from_xyz(200., 200., 0.).looking_at(Vec3::ZERO, Vec3::Y),
-        // Render all UI to this camera.
-        // Not strictly necessary since we only use one camera,
-        // but if we don't use this component, our UI will disappear as soon
-        // as we add another camera. This includes indirect ways of adding cameras like using
-        // [ui node outlines](https://bevyengine.org/news/bevy-0-14/#ui-node-outline-gizmos)
-        // for debugging. So it's good to have this here for future-proofing.
-        IsDefaultUiCamera,
-    ));
-}
-
 fn load_background(mut commands: Commands) {
     let colorcheme = rose_pine::RosePineDawn::Base;
     commands.insert_resource(ClearColor(colorcheme.to_color()));