honeycomb_render/scene/
camera.rs

1use bevy::input::mouse::{MouseMotion, MouseWheel};
2use bevy::math::vec2;
3use bevy::prelude::*;
4
5// use crate::gui::{CustomTab, UiState};
6
7/// Taken from the bevy
8/// [cheatbook](https://bevy-cheatbook.github.io/cookbook/pan-orbit-camera.html).
9#[derive(Component)]
10pub struct PanOrbitCamera {
11    pub(crate) focus: Vec3,
12    pub(crate) radius: f32,
13    pub(crate) upside_down: bool,
14}
15
16impl Default for PanOrbitCamera {
17    fn default() -> Self {
18        Self {
19            focus: Vec3::ZERO,
20            radius: 5.0,
21            upside_down: false,
22        }
23    }
24}
25
26/// Camera update routine.
27pub fn update_camera(
28    window_q: Query<&Window>,
29    mut ev_motion: EventReader<MouseMotion>,
30    mut ev_scroll: EventReader<MouseWheel>,
31    input_mouse: Res<ButtonInput<MouseButton>>,
32    mut query: Query<(&mut PanOrbitCamera, &mut Transform, &Projection)>,
33) {
34    let window = window_q.single();
35    // change input mapping for orbit and panning here
36    let orbit_button = MouseButton::Right;
37    let pan_button = MouseButton::Left;
38
39    let mut pan = Vec2::ZERO;
40    let mut rotation_move = Vec2::ZERO;
41    let mut scroll = 0.0;
42    let mut orbit_button_changed = false;
43
44    if input_mouse.pressed(orbit_button) {
45        for ev in ev_motion.read() {
46            rotation_move += ev.delta;
47        }
48    } else if input_mouse.pressed(pan_button) {
49        // Pan only if we're not rotating at the moment
50        for ev in ev_motion.read() {
51            pan += ev.delta * 2.;
52        }
53    }
54
55    for ev in ev_scroll.read() {
56        scroll += ev.y;
57
58        scroll /= if cfg!(target_arch = "wasm32") {
59            100.0
60        } else {
61            20.0
62        };
63    }
64    if input_mouse.just_released(orbit_button) || input_mouse.just_pressed(orbit_button) {
65        orbit_button_changed = true;
66    }
67
68    for (mut pan_orbit, mut transform, projection) in &mut query {
69        if orbit_button_changed {
70            // only check for upside down when orbiting started or ended this frame
71            // if the camera is "upside" down, panning horizontally would be inverted, so invert the input to make it correct
72            let up = transform.rotation * Vec3::Y;
73            pan_orbit.upside_down = up.y <= 0.0;
74        }
75        let window = vec2(
76            window.physical_width() as f32,
77            window.physical_height() as f32,
78        );
79
80        let mut any = false;
81        if rotation_move.length_squared() > 0.0 {
82            any = true;
83            let delta_x = {
84                let delta = rotation_move.x / window.x * std::f32::consts::PI * 2.0;
85                if pan_orbit.upside_down { -delta } else { delta }
86            };
87            let delta_y = rotation_move.y / window.y * std::f32::consts::PI;
88            let yaw = Quat::from_rotation_y(-delta_x);
89            let pitch = Quat::from_rotation_x(-delta_y);
90            transform.rotation = yaw * transform.rotation; // rotate around global y axis
91            transform.rotation *= pitch; // rotate around local x axis
92        } else if pan.length_squared() > 0.0 {
93            any = true;
94
95            if let Projection::Perspective(projection) = projection {
96                pan *= Vec2::new(projection.fov * projection.aspect_ratio, projection.fov) / window;
97            }
98            // translate by local axes
99            let right = transform.rotation * Vec3::X * -pan.x;
100            let up = transform.rotation * Vec3::Y * pan.y;
101            // make panning proportional to distance away from focus point
102            let translation = (right + up) * pan_orbit.radius;
103            pan_orbit.focus += translation;
104        } else if scroll.abs() > 0.0 {
105            any = true;
106            pan_orbit.radius -= scroll * pan_orbit.radius * 0.2;
107            // dont allow zoom to reach zero or you get stuck
108            pan_orbit.radius = f32::max(pan_orbit.radius, 0.05);
109        }
110
111        if any {
112            let rot_matrix = Mat3::from_quat(transform.rotation);
113            transform.translation =
114                pan_orbit.focus + rot_matrix.mul_vec3(Vec3::new(0.0, 0.0, pan_orbit.radius));
115        }
116    }
117
118    ev_motion.clear();
119}
honeycomb_render/scene/camera.rs

honeycomb_render/scene/
camera.rs
