bevy_pixel_buffer 0.3.0

A library to draw pixels in bevy
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155

use bevy::{
    diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin},
    prelude::*,
    reflect::TypeUuid,
    render::render_resource::{AsBindGroup, ShaderRef, ShaderType},
};
use bevy_egui::{
    egui::{self, RichText},
    EguiContext, EguiPlugin,
};
use bevy_pixel_buffer::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugin(EguiPlugin)
        .add_plugin(FrameTimeDiagnosticsPlugin::default())
        .add_plugin(PixelBufferPlugin)
        .add_plugin(ComputeShaderPlugin::<MandelbrotSetShader>::default())
        .add_startup_system(setup)
        .add_system(process_input)
        .add_system(ui)
        .run()
}

fn setup(
    mut commands: Commands,
    mut images: ResMut<Assets<Image>>,
    mut cs: ResMut<Assets<MandelbrotSetShader>>,
) {
    PixelBufferBuilder::new()
        .with_size((1280, 720))
        .with_fill(Fill::window().with_stretch(true).with_scaling_multiple(8))
        .spawn(&mut commands, &mut images)
        .entity()
        .insert(cs.add(MandelbrotSetShader::default()));
}

fn process_input(
    pb: Query<&Handle<MandelbrotSetShader>>,
    mut cs: ResMut<Assets<MandelbrotSetShader>>,
    keyboard_input: Res<Input<KeyCode>>,
) {
    let state = &mut cs.get_mut(pb.single()).unwrap().params;

    const MOVE_SPEED: f32 = 0.02;
    if keyboard_input.pressed(KeyCode::A) {
        state.center.x -= state.scale * MOVE_SPEED;
    }
    if keyboard_input.pressed(KeyCode::D) {
        state.center.x += state.scale * MOVE_SPEED;
    }
    if keyboard_input.pressed(KeyCode::W) {
        state.center.y += state.scale * MOVE_SPEED;
    }
    if keyboard_input.pressed(KeyCode::S) {
        state.center.y -= state.scale * MOVE_SPEED;
    }
    const SCALE_SPEED: f32 = 1.1;
    if keyboard_input.pressed(KeyCode::Q) {
        state.scale *= SCALE_SPEED;
    }
    if keyboard_input.pressed(KeyCode::E) {
        state.scale /= SCALE_SPEED;
    }
}

fn ui(
    mut egui_ctx: ResMut<EguiContext>,
    pb: Query<&Handle<MandelbrotSetShader>>,
    mut cs: ResMut<Assets<MandelbrotSetShader>>,
    diagnostics: Res<Diagnostics>,
) {
    let params = &mut cs.get_mut(pb.single()).unwrap().params;
    let fps = diagnostics
        .get(FrameTimeDiagnosticsPlugin::FPS)
        .unwrap()
        .average()
        .unwrap_or_default();

    let ctx = egui_ctx.ctx_mut();
    egui::Window::new("Mandelbrot set visualization").show(ctx, |ui| {
        ui.collapsing(RichText::new("About").heading(), |ui| {
            ui.label(concat!(
                "Mandelbrot set visuzalizer in the GPU. Fast. ",
                "CPU alternative can zoom more because it uses 64 bits of precision, ",
                "which is currently not supported by WGSL."
            ));
        });
        ui.heading("Controls");
        egui::Grid::new("controls")
            .num_columns(2)
            .striped(true)
            .show(ui, |ui| {
                ui.label("Move");
                ui.label("WASD / Arrows");
                ui.end_row();

                ui.label("Zoom in");
                ui.label("Q");
                ui.end_row();
                ui.label("Zoom out");
                ui.label("E");
                ui.end_row();
            });

        ui.separator();
        ui.horizontal(|ui| {
            ui.label("FPS: ");
            ui.label(RichText::new(format!("{fps:.1}")).code());
        });
        ui.horizontal(|ui| {
            ui.label("Max iterations");
            ui.add(egui::Slider::new(&mut params.max_iter, 64..=2048));
        });
    });
}

#[derive(AsBindGroup, TypeUuid, Clone, Debug, Default)]
#[uuid = "f690fdae-d598-45ab-8225-97e2a3f056e0"]
struct MandelbrotSetShader {
    #[uniform(0)]
    params: Params,
}

#[derive(ShaderType, Clone, Debug)]
struct Params {
    max_iter: i32,
    scale: f32,
    center: Vec2,
}

impl Default for Params {
    fn default() -> Self {
        Self {
            max_iter: 128,
            scale: 1.0,
            center: Vec2::ZERO,
        }
    }
}

impl ComputeShader for MandelbrotSetShader {
    fn shader() -> ShaderRef {
        "mandelbrot.wgsl".into()
    }

    fn entry_point() -> std::borrow::Cow<'static, str> {
        "update".into()
    }

    fn workgroups(texture_size: UVec2) -> UVec2 {
        texture_size / 8
    }
}