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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192

use std::error::Error;
use std::time::Instant;

use enum_map::EnumMap;
use three_d::{Camera, CameraAction, CameraControl, MetricSpace, Radians};
use xias::Xias;

#[derive(Debug, enum_map::Enum)]
pub enum Button {
    MoveLeft,
    MoveRight,
    MoveUp,
    MoveDown,
    MoveForward,
    MoveBackward,
    RotateClockwise,
    RotateCounterClockwise,
}

impl Button {
    pub fn from_key(key: three_d::Key) -> Option<Self> {
        Some(match key {
            three_d::Key::W => Self::MoveUp,
            three_d::Key::A => Self::MoveLeft,
            three_d::Key::S => Self::MoveDown,
            three_d::Key::D => Self::MoveRight,
            three_d::Key::Z => Self::MoveForward,
            three_d::Key::X => Self::MoveBackward,
            three_d::Key::Q => Self::RotateCounterClockwise,
            three_d::Key::E => Self::RotateClockwise,
            _ => return None,
        })
    }
}

pub struct Control {
    buttons:      EnumMap<Button, bool>,
    mouse:        CameraControl,
    linear_speed: f32,
    rotate_speed: Radians,
    update_time:  Instant,
}

impl Control {
    pub fn new(
        linear_speed: f32,
        rotate_speed: impl Into<Radians>,
        linear_sensitivity: f32,
        rotate_sensitivity: f32,
    ) -> Self {
        Self {
            buttons: EnumMap::default(),
            mouse: CameraControl {
                left_drag_horizontal:   CameraAction::None,
                left_drag_vertical:     CameraAction::None,
                middle_drag_horizontal: CameraAction::Left { speed: linear_sensitivity },
                middle_drag_vertical:   CameraAction::Up { speed: linear_sensitivity },
                right_drag_horizontal:  CameraAction::Yaw { speed: -rotate_sensitivity },
                right_drag_vertical:    CameraAction::Pitch { speed: -rotate_sensitivity },
                scroll_horizontal:      CameraAction::Roll { speed: rotate_sensitivity },
                scroll_vertical:        CameraAction::Forward { speed: linear_sensitivity },
            },
            linear_speed,
            rotate_speed: rotate_speed.into(),
            update_time: Instant::now(),
        }
    }

    pub fn handle_events(
        &mut self,
        camera: &mut Camera,
        events: &mut [three_d::Event],
    ) -> Result<bool, Box<dyn Error>> {
        let mut redraw = false;

        redraw |= self.mouse.handle_events(camera, events)?;

        for event in events {
            match event {
                three_d::Event::KeyPress { kind, modifiers: _, handled } => {
                    if *handled {
                        continue;
                    }

                    if let Some(button) = Button::from_key(*kind) {
                        self.buttons[button] = true;
                        *handled = true;
                    }
                }
                three_d::Event::KeyRelease { kind, modifiers: _, handled } => {
                    if *handled {
                        continue;
                    }

                    if let Some(button) = Button::from_key(*kind) {
                        self.buttons[button] = false;
                        *handled = true;
                    }
                }
                _ => {}
            }
        }

        let mut translate = three_d::Vec3::new(0.0, 0.0, 0.0);

        if self.buttons[Button::MoveUp] {
            translate += camera.right_direction().cross(camera.view_direction());
        }
        if self.buttons[Button::MoveDown] {
            translate -= camera.right_direction().cross(camera.view_direction());
        }
        if self.buttons[Button::MoveLeft] {
            translate -= camera.right_direction();
        }
        if self.buttons[Button::MoveRight] {
            translate += camera.right_direction();
        }
        if self.buttons[Button::MoveForward] {
            translate += camera.view_direction();
        }
        if self.buttons[Button::MoveBackward] {
            translate -= camera.view_direction();
        }

        let elapsed = self.update_time.elapsed().as_secs_f32();
        self.update_time = Instant::now();

        if translate != three_d::Vec3::new(0.0, 0.0, 0.0) {
            camera.translate(&(translate * self.linear_speed * elapsed))?;
            redraw = true;
        }

        if self.buttons[Button::RotateClockwise] {
            camera.roll(self.rotate_speed * elapsed)?;
            redraw = true;
        }
        if self.buttons[Button::RotateCounterClockwise] {
            camera.roll(-self.rotate_speed * elapsed)?;
            redraw = true;
        }

        Ok(redraw)
    }
}

pub fn handle_pick<'t, K>(
    gl: &three_d::Context,
    camera: &Camera,
    frame_input: &three_d::FrameInput,
    objects: impl Iterator<Item = (K, &'t dyn three_d::Object)>,
) -> Result<Option<K>, Box<dyn Error>> {
    let mut mouse_position = None;

    for event in &frame_input.events {
        if let three_d::Event::MouseMotion { position, .. } = event {
            mouse_position = Some((position.0, position.1));
            break;
        }
    }

    let mouse_position = match mouse_position {
        Some((x, y)) => (
            (frame_input.device_pixel_ratio * x).lossy_float(),
            (frame_input.device_pixel_ratio * y).lossy_float(),
        ),
        None => return Ok(None),
    };

    let mut min = None;

    for (key, object) in objects {
        if camera.in_frustum(&object.aabb()) {
            let pos = three_d::pick(gl, camera, mouse_position, &[object])?;
            if let Some(pos) = pos {
                match min {
                    Some((_, min_pos))
                        if camera.position().distance2(pos)
                            < camera.position().distance2(min_pos) =>
                    {
                        min = Some((key, pos));
                    }
                    None => {
                        min = Some((key, pos));
                    }
                    Some(_) => {}
                }
            }
        }
    }

    Ok(min.map(|(key, _)| key))
}