main_game_loop 0.6.1

A tool collection for building a winit game loop
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

use crate::event::Event;
use winit::{
    dpi::{PhysicalPosition, PhysicalSize},
    event::WindowEvent,
    window::{Window, WindowId},
};

//

#[derive(Debug, Clone, Copy, Default)]
pub struct WindowState {
    /// window size
    pub size: PhysicalSize<u32>,

    /// window aspect ratio
    pub aspect: f32,

    /// is the window focused
    pub focused: bool,

    /// the window is being closed
    pub should_close: bool,

    /// is cursor inside the window?
    pub cursor_in: bool,

    /// cursor position
    pub cursor_pos: PhysicalPosition<f64>,

    /// window scaling factor
    pub scale_factor: f64,

    /// identifier for the window
    /// this struct was initialized for
    ///
    /// when set to `None`: it will take
    /// the id of the first event with a
    /// window id
    pub id: Option<WindowId>,
}

//

impl WindowState {
    pub fn new(window: &Window) -> Self {
        let size = window.inner_size();

        Self {
            size,
            aspect: Self::aspect(size),
            scale_factor: window.scale_factor(),
            id: Some(window.id()),
            ..Default::default()
        }
    }

    pub fn event(&mut self, event: &Event) {
        if !self.filter(event) {
            return;
        }

        match event {
            Event::WindowEvent {
                event: WindowEvent::CursorEntered { .. },
                ..
            } => {
                self.cursor_in = true;
            }
            Event::WindowEvent {
                event: WindowEvent::CursorLeft { .. },
                ..
            } => {
                self.cursor_in = false;
            }
            Event::WindowEvent {
                event: WindowEvent::CursorMoved { position, .. },
                ..
            } => {
                self.cursor_pos = *position;
            }
            Event::WindowEvent {
                event: WindowEvent::Resized(size),
                ..
            } => {
                self.size = *size;
                self.aspect = Self::aspect(*size);
            }
            Event::WindowEvent {
                event: WindowEvent::Focused(focused),
                ..
            } => {
                self.focused = *focused;
            }
            Event::WindowEvent {
                event: WindowEvent::CloseRequested,
                ..
            } => self.should_close = true,
            _ => {}
        }
    }

    fn aspect(size: PhysicalSize<u32>) -> f32 {
        if size.height == 0 {
            0.0
        } else {
            size.width as f32 / size.height as f32
        }
    }

    fn filter(&mut self, event: &Event) -> bool {
        if let Event::WindowEvent { window_id, .. } = event {
            if let Some(id) = self.id {
                *window_id == id
            } else {
                self.id = Some(*window_id);
                true
            }
        } else {
            false
        }
    }
}