2d_gizmos/
2d_gizmos.rs

1//! This example demonstrates Bevy's immediate mode drawing API intended for visual debugging.
2
3use std::f32::consts::{FRAC_PI_2, PI, TAU};
4
5use bevy::{color::palettes::css::*, math::Isometry2d, prelude::*};
6
7fn main() {
8    App::new()
9        .add_plugins(DefaultPlugins)
10        .init_gizmo_group::<MyRoundGizmos>()
11        .add_systems(Startup, setup)
12        .add_systems(Update, (draw_example_collection, update_config))
13        .run();
14}
15
16// We can create our own gizmo config group!
17#[derive(Default, Reflect, GizmoConfigGroup)]
18struct MyRoundGizmos {}
19
20fn setup(mut commands: Commands) {
21    commands.spawn(Camera2d);
22    // text
23    commands.spawn((
24        Text::new(
25            "Hold 'Left' or 'Right' to change the line width of straight gizmos\n\
26        Hold 'Up' or 'Down' to change the line width of round gizmos\n\
27        Press '1' / '2' to toggle the visibility of straight / round gizmos\n\
28        Press 'U' / 'I' to cycle through line styles\n\
29        Press 'J' / 'K' to cycle through line joins",
30        ),
31        Node {
32            position_type: PositionType::Absolute,
33            top: px(12),
34            left: px(12),
35            ..default()
36        },
37    ));
38}
39
40fn draw_example_collection(
41    mut gizmos: Gizmos,
42    mut my_gizmos: Gizmos<MyRoundGizmos>,
43    time: Res<Time>,
44) {
45    let sin_t_scaled = ops::sin(time.elapsed_secs()) * 50.;
46    gizmos.line_2d(Vec2::Y * -sin_t_scaled, Vec2::splat(-80.), RED);
47    gizmos.ray_2d(Vec2::Y * sin_t_scaled, Vec2::splat(80.), LIME);
48
49    gizmos
50        .grid_2d(
51            Isometry2d::IDENTITY,
52            UVec2::new(16, 9),
53            Vec2::new(80., 80.),
54            // Dark gray
55            LinearRgba::gray(0.05),
56        )
57        .outer_edges();
58
59    // Triangle
60    gizmos.linestrip_gradient_2d([
61        (Vec2::Y * 300., BLUE),
62        (Vec2::new(-255., -155.), RED),
63        (Vec2::new(255., -155.), LIME),
64        (Vec2::Y * 300., BLUE),
65    ]);
66
67    gizmos.rect_2d(Isometry2d::IDENTITY, Vec2::splat(650.), BLACK);
68
69    gizmos.cross_2d(Vec2::new(-160., 120.), 12., FUCHSIA);
70
71    let domain = Interval::EVERYWHERE;
72    let curve = FunctionCurve::new(domain, |t| Vec2::new(t, ops::sin(t / 25.0) * 100.0));
73    let resolution = ((ops::sin(time.elapsed_secs()) + 1.0) * 50.0) as usize;
74    let times_and_colors = (0..=resolution)
75        .map(|n| n as f32 / resolution as f32)
76        .map(|t| (t - 0.5) * 600.0)
77        .map(|t| (t, TEAL.mix(&HOT_PINK, (t + 300.0) / 600.0)));
78    gizmos.curve_gradient_2d(curve, times_and_colors);
79
80    my_gizmos
81        .rounded_rect_2d(Isometry2d::IDENTITY, Vec2::splat(630.), BLACK)
82        .corner_radius(ops::cos(time.elapsed_secs() / 3.) * 100.);
83
84    // Circles have 32 line-segments by default.
85    // You may want to increase this for larger circles.
86    my_gizmos
87        .circle_2d(Isometry2d::IDENTITY, 300., NAVY)
88        .resolution(64);
89
90    my_gizmos.ellipse_2d(
91        Rot2::radians(time.elapsed_secs() % TAU),
92        Vec2::new(100., 200.),
93        YELLOW_GREEN,
94    );
95
96    // Arcs default resolution is linearly interpolated between
97    // 1 and 32, using the arc length as scalar.
98    my_gizmos.arc_2d(
99        Rot2::radians(sin_t_scaled / 10.),
100        FRAC_PI_2,
101        310.,
102        ORANGE_RED,
103    );
104    my_gizmos.arc_2d(Isometry2d::IDENTITY, FRAC_PI_2, 80.0, ORANGE_RED);
105    my_gizmos.long_arc_2d_between(Vec2::ZERO, Vec2::X * 20.0, Vec2::Y * 20.0, ORANGE_RED);
106    my_gizmos.short_arc_2d_between(Vec2::ZERO, Vec2::X * 40.0, Vec2::Y * 40.0, ORANGE_RED);
107
108    gizmos.arrow_2d(
109        Vec2::ZERO,
110        Vec2::from_angle(sin_t_scaled / -10. + PI / 2.) * 50.,
111        YELLOW,
112    );
113
114    // You can create more complex arrows using the arrow builder.
115    gizmos
116        .arrow_2d(
117            Vec2::ZERO,
118            Vec2::from_angle(sin_t_scaled / -10.) * 50.,
119            GREEN,
120        )
121        .with_double_end()
122        .with_tip_length(10.);
123}
124
125fn update_config(
126    mut config_store: ResMut<GizmoConfigStore>,
127    keyboard: Res<ButtonInput<KeyCode>>,
128    time: Res<Time>,
129) {
130    let (config, _) = config_store.config_mut::<DefaultGizmoConfigGroup>();
131    if keyboard.pressed(KeyCode::ArrowRight) {
132        config.line.width += 5. * time.delta_secs();
133        config.line.width = config.line.width.clamp(0., 50.);
134    }
135    if keyboard.pressed(KeyCode::ArrowLeft) {
136        config.line.width -= 5. * time.delta_secs();
137        config.line.width = config.line.width.clamp(0., 50.);
138    }
139    if keyboard.just_pressed(KeyCode::Digit1) {
140        config.enabled ^= true;
141    }
142    if keyboard.just_pressed(KeyCode::KeyU) {
143        config.line.style = match config.line.style {
144            GizmoLineStyle::Solid => GizmoLineStyle::Dotted,
145            GizmoLineStyle::Dotted => GizmoLineStyle::Dashed {
146                gap_scale: 3.0,
147                line_scale: 5.0,
148            },
149            _ => GizmoLineStyle::Solid,
150        };
151    }
152    if keyboard.just_pressed(KeyCode::KeyJ) {
153        config.line.joints = match config.line.joints {
154            GizmoLineJoint::Bevel => GizmoLineJoint::Miter,
155            GizmoLineJoint::Miter => GizmoLineJoint::Round(4),
156            GizmoLineJoint::Round(_) => GizmoLineJoint::None,
157            GizmoLineJoint::None => GizmoLineJoint::Bevel,
158        };
159    }
160
161    let (my_config, _) = config_store.config_mut::<MyRoundGizmos>();
162    if keyboard.pressed(KeyCode::ArrowUp) {
163        my_config.line.width += 5. * time.delta_secs();
164        my_config.line.width = my_config.line.width.clamp(0., 50.);
165    }
166    if keyboard.pressed(KeyCode::ArrowDown) {
167        my_config.line.width -= 5. * time.delta_secs();
168        my_config.line.width = my_config.line.width.clamp(0., 50.);
169    }
170    if keyboard.just_pressed(KeyCode::Digit2) {
171        my_config.enabled ^= true;
172    }
173    if keyboard.just_pressed(KeyCode::KeyI) {
174        my_config.line.style = match my_config.line.style {
175            GizmoLineStyle::Solid => GizmoLineStyle::Dotted,
176            GizmoLineStyle::Dotted => GizmoLineStyle::Dashed {
177                gap_scale: 3.0,
178                line_scale: 5.0,
179            },
180            _ => GizmoLineStyle::Solid,
181        };
182    }
183    if keyboard.just_pressed(KeyCode::KeyK) {
184        my_config.line.joints = match my_config.line.joints {
185            GizmoLineJoint::Bevel => GizmoLineJoint::Miter,
186            GizmoLineJoint::Miter => GizmoLineJoint::Round(4),
187            GizmoLineJoint::Round(_) => GizmoLineJoint::None,
188            GizmoLineJoint::None => GizmoLineJoint::Bevel,
189        };
190    }
191}
2d_gizmos/2d_gizmos.rs

2d_gizmos/
2d_gizmos.rs
