3D mouse: invert and speed for each of the cap's six axes (#1814)

Thanks @NecroKote.

README.md

@@ -218,7 +218,8 @@ Windows builds: `cargo xwin build --release --target x86_64-pc-windows-msvc -p s
 On Windows and Linux, SolidCraft detects a connected 3Dconnexion SpaceNavigator or SpaceMouse through its
 multi-axis HID interface. Move the cap to pan and zoom, and tilt or twist it to rotate the 3D view.
 While editing a sketch, the cap pans and zooms without changing the sketch view. The Navigation
-page in Preferences has an on/off switch and a speed control for the 3D mouse. The web app reads
+page in Preferences has an on/off switch, a speed control and, for each of the cap's six axes, an
+invert switch and a speed for the 3D mouse. The web app reads
 it too, through the browser; Firefox needs a 3DxWare setting first (see
 [Getting started › 3D mouse in the browser](docs/book/src/guide/getting-started.md#3d-mouse-in-the-browser)).
 

crates/ui-egui/src/prefs.rs

@@ -273,6 +273,11 @@ pub struct Prefs {
     pub space_mouse_enabled: bool,
     /// Speed multiplier for 3D mouse navigation.
     pub space_mouse_speed: f32,
+    /// Per physical axis of the cap (push X, Y, Z, then tilt X, Y, Z), whether it moves the view
+    /// the other way.
+    pub space_mouse_reverse: [bool; 6],
+    /// Per physical axis of the cap, a multiplier on top of `space_mouse_speed`; 0 switches it off.
+    pub space_mouse_axis_speed: [f32; 6],
     /// Anti-aliasing samples (applies on restart).
     pub msaa: u32,
     /// How finely the viewport tessellates curved faces and edges: `coarse`, `normal`, `fine` or
@@ -402,6 +407,8 @@ impl Default for Prefs {
             orbit_cursor: false,
             space_mouse_enabled: true,
             space_mouse_speed: 1.0,
+            space_mouse_reverse: [false; 6],
+            space_mouse_axis_speed: [1.0; 6],
             msaa: 4,
             display_quality: "normal".into(),
             supersampling: 1.0,
@@ -618,6 +625,8 @@ fn defaults(app: &mut SolveApp, page: usize) {
             p.orbit_cursor = d.orbit_cursor;
             p.space_mouse_enabled = d.space_mouse_enabled;
             p.space_mouse_speed = d.space_mouse_speed;
+            p.space_mouse_reverse = d.space_mouse_reverse;
+            p.space_mouse_axis_speed = d.space_mouse_axis_speed;
             p.look_at_anim = d.look_at_anim;
             p.look_at_speed = d.look_at_speed;
             p.middle_double_click = d.middle_double_click;
@@ -1214,6 +1223,20 @@ fn page(app: &mut SolveApp, ui: &mut egui::Ui, t: &Tokens) {
                 egui::Slider::new(&mut app.preferences.space_mouse_speed, 0.25..=3.0).step_by(0.05).custom_formatter(|v, _| format!("{v:.2}×")),
             );
             ui.end_row();
+            for (axis, name) in SPACE_MOUSE_AXES.iter().enumerate() {
+                ui.label(crate::i18n::tr_label(name));
+                ui.horizontal(|ui| {
+                    ui.add_enabled_ui(app.preferences.space_mouse_enabled, |ui| {
+                        if let Some(reverse) = app.preferences.space_mouse_reverse.get_mut(axis) {
+                            ui.checkbox(reverse, crate::i18n::tr_label("Invert"));
+                        }
+                        if let Some(speed) = app.preferences.space_mouse_axis_speed.get_mut(axis) {
+                            ui.add(egui::Slider::new(speed, 0.0..=3.0).step_by(0.05).custom_formatter(|v, _| format!("{v:.2}×")));
+                        }
+                    });
+                });
+                ui.end_row();
+            }
             note(ui, crate::i18n::tr_label("Move and rotate the view together; sketches use pan and zoom only."));
         }
         PAGE_DESIGN => {
@@ -1453,6 +1476,9 @@ pub fn control(app: &mut SolveApp, p: &serde_json::Value) -> Result<serde_json::
 
 /// Fold a setting an older release kept in its own field into the one this version reads.
 /// `orbit_cursor` (`true` = the point under the cursor) became `orbit_around`.
+/// The cap's physical axes, in the order of `Prefs::space_mouse_reverse`.
+const SPACE_MOUSE_AXES: [&str; 6] = ["Push left / right", "Push forward / back", "Lift / press", "Tilt forward / back", "Tilt left / right", "Twist"];
+
 pub fn migrate(mut p: Prefs) -> Prefs {
     if p.orbit_cursor {
         p.orbit_around = OrbitAround::Cursor;

crates/ui-egui/src/space_mouse.rs

@@ -87,6 +87,16 @@ impl DriverMapping {
         mapping
     }
 
+    /// The mapping with the user's per-axis choices folded in: `reverse` flips and `speed` scales
+    /// each physical axis of the cap. A speed that is not a finite number counts as 1.
+    pub fn with_user_axes(mut self, reverse: [bool; 6], speed: [f32; 6]) -> Self {
+        for ((rule, reverse), speed) in self.axes.iter_mut().zip(reverse).zip(speed) {
+            rule.reversed ^= reverse;
+            rule.scale *= if speed.is_finite() { f64::from(speed).clamp(0.0, 3.0) } else { 1.0 };
+        }
+        self
+    }
+
     pub fn apply(self, axes: Axes) -> Motion {
         let raw = [
             normalized(axes.translation[0]),
@@ -139,7 +149,10 @@ pub fn navigate_frame(app: &mut SolveApp, ctx: &egui::Context, mapping: DriverMa
     app.begin_external_navigation();
     // A long gap (the first frame after a pause) moves as far as a 50 ms one.
     let step = if seconds.is_finite() { seconds.min(0.05) } else { 0.0 };
-    app.viewport.device_motion = Some(DeviceMotion { motion: mapping.apply(axes), seconds: step * speed.clamp(0.1, 5.0) });
+    app.viewport.device_motion = Some(DeviceMotion {
+        motion: mapping.with_user_axes(app.preferences.space_mouse_reverse, app.preferences.space_mouse_axis_speed).apply(axes),
+        seconds: step * speed.clamp(0.1, 5.0),
+    });
     ctx.request_repaint_after(Duration::from_millis(16));
     true
 }
@@ -182,6 +195,22 @@ mod tests {
         app
     }
 
+    #[test]
+    fn per_axis_choices_flip_and_scale_one_physical_axis() {
+        let mapping = DriverMapping::default().with_user_axes([false, true, false, false, false, false], [1.0, 1.0, 1.0, 0.5, f32::NAN, 1.0]);
+        let still = Motion::default();
+        assert_eq!(mapping.apply(Axes { translation: [0, 350, 0], rotation: [0; 3] }).translation[1], -raw(PUSH).translation[1]);
+        assert_eq!(
+            mapping.apply(Axes { translation: [350, 0, 0], rotation: [0; 3] }).translation[0],
+            raw(Axes { translation: [350, 0, 0], rotation: [0; 3] }).translation[0]
+        );
+        assert_eq!(mapping.apply(Axes { translation: [0; 3], rotation: [350, 0, 0] }).rotation[0], 0.5);
+        assert_eq!(mapping.apply(Axes { translation: [0; 3], rotation: [0, 350, 0] }).rotation[1], 1.0);
+        assert_eq!(mapping.apply(Axes::default()), still);
+        let off = DriverMapping::default().with_user_axes([false; 6], [0.0; 6]);
+        assert_eq!(off.apply(PUSH), still);
+    }
+
     const PUSH: Axes = Axes { translation: [0, 350, 0], rotation: [0; 3] };
 
     fn wheel(dy: f32) -> egui::Event {