Merge pull request #202 from 0xlillith/feat/173-immediate-wheel-zoom

feat(ui): allow disabling wheel zoom smoothing

crates/ui-egui/src/prefs.rs

@@ -58,6 +58,8 @@ pub struct Prefs {
     pub ui_scale: f32,
     /// The wheel zooms toward the point under the cursor (else toward the view's centre).
     pub zoom_to_cursor: bool,
+    /// Spread discrete wheel input across frames (off: apply each event immediately).
+    pub smooth_wheel_zoom: bool,
     /// View changes (axis view, Look At, Home) animate; `look_at_speed` scales how fast.
     pub look_at_anim: bool,
     pub look_at_speed: f32,
@@ -84,6 +86,7 @@ impl Default for Prefs {
             language: "en".into(),
             ui_scale: 1.0,
             zoom_to_cursor: true,
+            smooth_wheel_zoom: true,
             look_at_anim: true,
             look_at_speed: 1.0,
             up_axis: "z".into(),
@@ -184,6 +187,7 @@ fn defaults(app: &mut SolveApp, page: usize) {
             p.radial_context_menu = d.radial_context_menu;
             p.zoom_reverse = d.zoom_reverse;
             p.zoom_to_cursor = d.zoom_to_cursor;
+            p.smooth_wheel_zoom = d.smooth_wheel_zoom;
             p.orbit_cursor = d.orbit_cursor;
             p.space_mouse_enabled = d.space_mouse_enabled;
             p.space_mouse_speed = d.space_mouse_speed;
@@ -577,6 +581,10 @@ fn page(app: &mut SolveApp, ui: &mut egui::Ui, t: &Tokens) {
             ui.checkbox(&mut app.preferences.zoom_to_cursor, "")
                 .on_hover_text("The wheel zooms toward the point under the cursor (off: toward the view's centre)");
             ui.end_row();
+            ui.label("Smooth wheel zoom");
+            ui.checkbox(&mut app.preferences.smooth_wheel_zoom, "")
+                .on_hover_text("Turn off to apply each wheel event immediately, without a smoothing tail");
+            ui.end_row();
             ui.label("Orbit around");
             ui.horizontal(|ui| {
                 ui.radio_value(&mut app.preferences.orbit_cursor, false, "View centre");
@@ -782,6 +790,26 @@ mod tests {
         assert!(h.app.preferences.radial_context_menu, "Cancel restores the last Apply");
     }
 
+    #[test]
+    fn wheel_smoothing_persists_and_follows_dialog_buttons() {
+        assert!(serde_json::from_value::<Prefs>(json!({})).unwrap().smooth_wheel_zoom);
+        let mut app = SolveApp::new(solvecraft_engine::Session::default(), Default::default());
+        control(&mut app, &json!({"open":"Navigation", "smooth_wheel_zoom":false})).unwrap();
+        control(&mut app, &json!({"button":"cancel"})).unwrap();
+        assert!(app.preferences.smooth_wheel_zoom);
+        control(&mut app, &json!({"open":"Navigation", "smooth_wheel_zoom":false})).unwrap();
+        control(&mut app, &json!({"button":"apply"})).unwrap();
+        control(&mut app, &json!({"smooth_wheel_zoom":true, "button":"cancel"})).unwrap();
+        assert!(!app.preferences.smooth_wheel_zoom);
+        let mut other = SolveApp::new(solvecraft_engine::Session::default(), Default::default());
+        other.load_prefs(&app.prefs());
+        assert!(!other.preferences.smooth_wheel_zoom);
+        control(&mut app, &json!({"open":"Navigation", "button":"defaults"})).unwrap();
+        assert!(app.preferences.smooth_wheel_zoom);
+        control(&mut app, &json!({"button":"cancel"})).unwrap();
+        assert!(!app.preferences.smooth_wheel_zoom);
+    }
+
     #[test]
     fn presets_map_the_mouse_and_prefs_round_trip() {
         let mut app = SolveApp::new(solvecraft_engine::Session::default(), Default::default());

crates/ui-egui/src/viewport.rs

@@ -62,6 +62,8 @@ pub struct ViewportState {
     pub orbit_pivot: Option<Vec3>,
     /// Continuous orbit: the view turns about the vertical until the next click or key.
     pub spin: bool,
+    /// After immediate zoom, ignore egui's outstanding smoothing until the gesture ends.
+    wheel_zoom_raw_until_idle: bool,
     /// A primary press on the axis gizmo: the pointer position used by its last orbit step.
     pub axis_drag: Option<Pos2>,
     /// Unsnapped camera while Shift-orbit previews a standard or diagonal view.
@@ -1471,6 +1473,34 @@ pub fn delete_selection(app: &mut SolveApp) {
     crate::delete::delete_selection(app);
 }
 
+/// Match egui's wheel units and modifier routing, without its temporal smoothing.
+fn immediate_wheel_delta(input: &egui::InputState, options: egui::InputOptions, page_height: f32) -> f32 {
+    input
+        .events
+        .iter()
+        .filter_map(|event| {
+            let egui::Event::MouseWheel { unit, delta, modifiers, phase: egui::TouchPhase::Move } = event else { return None };
+            if modifiers.matches_any(options.zoom_modifier) {
+                return None;
+            }
+            let delta = match unit {
+                egui::MouseWheelUnit::Point => *delta,
+                egui::MouseWheelUnit::Line => *delta * options.line_scroll_speed,
+                egui::MouseWheelUnit::Page => *delta * page_height,
+            };
+            let horizontal = modifiers.matches_any(options.horizontal_scroll_modifier);
+            let vertical = modifiers.matches_any(options.vertical_scroll_modifier);
+            Some(if horizontal && !vertical {
+                0.0
+            } else if vertical && !horizontal {
+                delta.x + delta.y
+            } else {
+                delta.y
+            })
+        })
+        .sum()
+}
+
 pub fn show(app: &mut SolveApp, ui: &mut egui::Ui) {
     let t = Tokens::get();
     let rect = ui.max_rect();
@@ -1499,6 +1529,18 @@ pub fn show(app: &mut SolveApp, ui: &mut egui::Ui) {
     crate::drag_snap::set_suppressed(mods.ctrl || mods.alt || mods.command);
 
     // ---- navigation ----
+    if !app.preferences.smooth_wheel_zoom {
+        app.viewport.wheel_zoom_raw_until_idle = true;
+    } else if !ui.input(|i| i.is_scrolling()) {
+        app.viewport.wheel_zoom_raw_until_idle = false;
+    }
+    let scroll = if app.viewport.wheel_zoom_raw_until_idle {
+        let options = ui.ctx().options(|o| o.input_options);
+        let page_height = ui.ctx().viewport_rect().height();
+        ui.input(|i| immediate_wheel_delta(i, options, page_height))
+    } else {
+        scroll
+    };
     let h = rect.height().max(1.0) as f64;
     if inside && scroll != 0.0 {
         app.viewport.orbit_snap = None;
@@ -3113,72 +3155,144 @@ mod tests {
         }
     }
 
+    #[test]
+    fn immediate_wheel_zoom_applies_normalized_input_once() {
+        let mut h = crate::scenario::Harness::new();
+        h.app.preferences.smooth_wheel_zoom = false;
+        h.app.preferences.zoom_to_cursor = false;
+        h.call("ui.move", json!({"x":800,"y":500}));
+        let before = h.app.cam;
+        let line = h.ctx.options(|o| o.input_options.line_scroll_speed);
+        for (unit, amount, points) in
+            [(egui::MouseWheelUnit::Point, 120.0, 120.0), (egui::MouseWheelUnit::Line, 1.0, line), (egui::MouseWheelUnit::Page, 0.1, 100.0)]
+        {
+            let height = h.app.cam.half_height();
+            h.app.synthetic.push(egui::Event::MouseWheel {
+                unit,
+                delta: vec2(0.0, amount),
+                modifiers: egui::Modifiers::NONE,
+                phase: egui::TouchPhase::Move,
+            });
+            h.frame();
+            let expected = height * (-f64::from(points) * 0.0015).exp();
+            assert!((h.app.cam.half_height() - expected).abs() < 1e-6);
+            let after = h.app.cam;
+            h.frames(30);
+            assert_eq!(h.app.cam, after, "idle frames must not replay wheel input");
+        }
+        assert_eq!(h.app.cam.target, before.target);
+        h.app.preferences.zoom_reverse = true;
+        let height = h.app.cam.half_height();
+        h.call("ui.scroll", json!({"x":800,"y":500,"delta":120}));
+        assert!((h.app.cam.half_height() - height * 0.18_f64.exp()).abs() < 1e-6);
+    }
+
+    #[test]
+    fn wheel_zoom_setting_changes_do_not_replay_smoothing() {
+        let mut h = crate::scenario::Harness::new();
+        h.app.preferences.zoom_to_cursor = false;
+        h.call("ui.move", json!({"x":800,"y":500}));
+        h.app.synthetic.push(egui::Event::MouseWheel {
+            unit: egui::MouseWheelUnit::Point,
+            delta: vec2(0.0, 120.0),
+            modifiers: egui::Modifiers::NONE,
+            phase: egui::TouchPhase::Move,
+        });
+        h.frame();
+        assert!(h.ctx.input(|i| i.is_scrolling()));
+        h.app.preferences.smooth_wheel_zoom = false;
+        let stopped = h.app.cam;
+        h.frame();
+        assert_eq!(h.app.cam, stopped);
+        h.app.preferences.smooth_wheel_zoom = true;
+        h.frames(90);
+        assert_eq!(h.app.cam, stopped, "re-enabling must not replay the old smoothing tail");
+        assert!(!h.app.viewport.wheel_zoom_raw_until_idle);
+        h.app.preferences.smooth_wheel_zoom = false;
+        for _ in 0..3 {
+            h.app.synthetic.push(egui::Event::MouseWheel {
+                unit: egui::MouseWheelUnit::Point,
+                delta: vec2(0.0, 120.0),
+                modifiers: egui::Modifiers::NONE,
+                phase: egui::TouchPhase::Move,
+            });
+            h.frame();
+        }
+        assert!((h.app.cam.half_height() - stopped.half_height() * (-0.54_f64).exp()).abs() < 1e-6);
+        let after = h.app.cam;
+        h.frames(90);
+        assert_eq!(h.app.cam, after);
+    }
+
     #[test]
     fn shortcuts_window_wheel_does_not_zoom_the_viewport() {
-        let ctx = egui::Context::default();
-        let mut app = SolveApp::new(solvecraft_engine::Session::default(), crate::Services::default());
-        app.viewport.no_pixels = true;
-        crate::help::run(&mut app, &ctx, "shortcuts");
-        let mut time = 0.0;
-        let mut frame = |app: &mut SolveApp, pointer: Option<Pos2>, wheel: f32| {
-            time += 1.0 / 60.0;
-            let mut events = Vec::new();
-            if let Some(p) = pointer {
-                events.push(egui::Event::PointerMoved(p));
+        for smooth in [true, false] {
+            let ctx = egui::Context::default();
+            let mut app = SolveApp::new(solvecraft_engine::Session::default(), crate::Services::default());
+            app.preferences.smooth_wheel_zoom = smooth;
+            app.viewport.no_pixels = true;
+            crate::help::run(&mut app, &ctx, "shortcuts");
+            let mut time = 0.0;
+            let mut frame = |app: &mut SolveApp, pointer: Option<Pos2>, wheel: f32| {
+                time += 1.0 / 60.0;
+                let mut events = Vec::new();
+                if let Some(p) = pointer {
+                    events.push(egui::Event::PointerMoved(p));
+                }
+                if wheel != 0.0 {
+                    events.push(egui::Event::MouseWheel {
+                        unit: egui::MouseWheelUnit::Point,
+                        delta: vec2(0.0, wheel),
+                        modifiers: egui::Modifiers::NONE,
+                        phase: egui::TouchPhase::Move,
+                    });
+                }
+                let mut output = ctx.run_ui(
+                    egui::RawInput {
+                        screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(1100.0, 800.0))),
+                        time: Some(time),
+                        events,
+                        ..Default::default()
+                    },
+                    |ui| {
+                        egui::CentralPanel::default().show(ui, |ui| show(app, ui));
+                        crate::prefs::show(app, ui.ctx());
+                    },
+                );
+                output.textures_delta.clear();
+            };
+            // Let egui establish the floating window's size and hit-test widgets.
+            for _ in 0..4 {
+                frame(&mut app, None, 0.0);
             }
-            if wheel != 0.0 {
-                events.push(egui::Event::MouseWheel {
-                    unit: egui::MouseWheelUnit::Point,
-                    delta: vec2(0.0, wheel),
-                    modifiers: egui::Modifiers::NONE,
-                    phase: egui::TouchPhase::Move,
-                });
-            }
-            let mut output = ctx.run_ui(
-                egui::RawInput {
-                    screen_rect: Some(Rect::from_min_size(Pos2::ZERO, vec2(1100.0, 800.0))),
-                    time: Some(time),
-                    events,
-                    ..Default::default()
-                },
-                |ui| {
-                    egui::CentralPanel::default().show(ui, |ui| show(app, ui));
-                    crate::prefs::show(app, ui.ctx());
-                },
-            );
-            output.textures_delta.clear();
-        };
-        // Let egui establish the floating window's size and hit-test widgets.
-        for _ in 0..4 {
-            frame(&mut app, None, 0.0);
-        }
-        let window = ctx.memory(|m| m.area_rect(egui::Id::new("sc_prefs"))).unwrap();
-        let list = window.center() + vec2(140.0, 0.0);
-        let height = app.cam.half_height();
-        let target = app.cam.target;
-        frame(&mut app, Some(list), 0.0);
-        for n in 0..12 {
-            frame(&mut app, Some(list), if n == 0 { -120.0 } else { 0.0 });
-            assert_eq!(app.cam.half_height(), height, "wheel input over shortcuts must stay in the popup");
-            assert_eq!(app.cam.target, target);
-        }
-        // The window's non-scrolling sidebar must also shield the model.
-        frame(&mut app, Some(window.left_center() + vec2(30.0, 0.0)), -120.0);
-        assert_eq!(app.cam.half_height(), height);
-        // An exposed part of the viewport still accepts wheel navigation with the popup open.
-        let exposed = pos2(40.0, 700.0);
-        assert!(!window.contains(exposed));
-        frame(&mut app, Some(exposed), 0.0);
-        frame(&mut app, Some(exposed), -120.0);
-        assert_ne!(app.cam.half_height(), height);
-        // Closing the popup returns its former area to the viewport.
-        app.prefs_window.open = false;
-        for _ in 0..12 {
+            let window = ctx.memory(|m| m.area_rect(egui::Id::new("sc_prefs"))).unwrap();
+            let list = window.center() + vec2(140.0, 0.0);
+            let height = app.cam.half_height();
+            let target = app.cam.target;
             frame(&mut app, Some(list), 0.0);
+            for n in 0..12 {
+                frame(&mut app, Some(list), if n == 0 { -120.0 } else { 0.0 });
+                assert_eq!(app.cam.half_height(), height, "wheel input over shortcuts must stay in the popup");
+                assert_eq!(app.cam.target, target);
+            }
+            // The window's non-scrolling sidebar must also shield the model.
+            frame(&mut app, Some(window.left_center() + vec2(30.0, 0.0)), -120.0);
+            assert_eq!(app.cam.half_height(), height);
+            // An exposed part of the viewport still accepts wheel navigation with the popup open.
+            let exposed = pos2(40.0, 700.0);
+            assert!(!window.contains(exposed));
+            frame(&mut app, Some(exposed), 0.0);
+            frame(&mut app, Some(exposed), -120.0);
+            assert_ne!(app.cam.half_height(), height);
+            // Closing the popup returns its former area to the viewport.
+            app.prefs_window.open = false;
+            for _ in 0..12 {
+                frame(&mut app, Some(list), 0.0);
+            }
+            let height = app.cam.half_height();
+            frame(&mut app, Some(list), -120.0);
+            assert_ne!(app.cam.half_height(), height);
         }
-        let height = app.cam.half_height();
-        frame(&mut app, Some(list), -120.0);
-        assert_ne!(app.cam.half_height(), height);
     }
 
     #[test]

docs/book/src/guide/ui-tour.md

@@ -39,5 +39,10 @@ Preferences (File › Preferences) hold the theme, the units of new designs, the
 visual style and autosave. Help › Keyboard Shortcuts lists every key, and File › Keyboard
 Shortcuts changes them.
 
+Navigation › **Smooth wheel zoom** is on by default. Turn it off to apply each wheel or
+trackpad event immediately, with no smoothing tail. It is independent of **Animate view
+changes**, which controls axis views, Look At, Home and Fit. Re-enabling smoothing during
+a wheel gesture takes effect after that gesture ends, avoiding leftover zoom being replayed.
+
 Shift-orbit snapping includes 45-degree edge views and isometric corner views, with a
 lightly damped spring transition and a small boundary margin to prevent flicker.

docs/control-protocol.md

@@ -70,7 +70,7 @@ rolls the numbering back with the design), so they can go straight into later co
 | `ui.home` | `open?`: bool; `sample?`: index | the start page: show or hide it, open a built-in sample (once built); returns `open` and the recent designs |
 | `ui.shortcut` | `command`, `key?`, `replace?` | a command's key, or rebinds it (`""` clears; a key another command uses is refused unless `replace`) |
 | `ui.help` | `item?`: `about`, `shortcuts` (read only), `report` (copies diagnostics) | the version, commit, build date and diagnostic text |
-| `ui.prefs` | any of `default_units`, `nav` (`fusion`, `solidworks`, `inventor`, `alias`, `tinkercad`), `zoom_reverse`, `zoom_to_cursor`, `orbit_cursor`, `look_at_anim`, `look_at_speed`, `msaa`, `length_decimals`, `angle_decimals`, `theme` (`dark`, `light`, `system`), `language` (`en`, `ja`; see [localization](localization.md)), `ui_scale`, `up_axis` (`z`, `y`), `offer_stand_up`; `open` (a page: General, Navigation, Keyboard Shortcuts, Design, Graphics, Sketch, Selection) opens the Preferences dialog there; `button`: `ok`, `cancel`, `apply`, `defaults`; `stand_up: true` stands up a just-opened Y-up file | sets preferences (kept between runs), returns them all plus `dialog` (the open page or null), `dark` and `stand_up_offer` |
+| `ui.prefs` | any of `default_units`, `nav` (`fusion`, `solidworks`, `inventor`, `alias`, `tinkercad`), `zoom_reverse`, `zoom_to_cursor`, `smooth_wheel_zoom` (default true), `orbit_cursor`, `look_at_anim`, `look_at_speed`, `msaa`, `length_decimals`, `angle_decimals`, `theme` (`dark`, `light`, `system`), `language` (`en`, `ja`; see [localization](localization.md)), `ui_scale`, `up_axis` (`z`, `y`), `offer_stand_up`; `open` (a page: General, Navigation, Keyboard Shortcuts, Design, Graphics, Sketch, Selection) opens the Preferences dialog there; `button`: `ok`, `cancel`, `apply`, `defaults`; `stand_up: true` stands up a just-opened Y-up file | sets preferences (kept between runs), returns them all plus `dialog` (the open page or null), `dark` and `stand_up_offer` |
 | `ui.capture` | `action?`: `capture`, `revert`, `cancel` | answers the Capture Position question (asked when a command starts or the design is saved while components were moved without capturing); without `action`, what waits |
 | `ui.window` | `action`: minimize, maximize, restore, toggle, close | what the title bar's caption buttons do (on Windows and Linux the application bar is the title bar); close asks about unsaved designs first |
 | `ui.agent_cursor` | `show` (bool), `speed`: a number from 1 to 5 (times the normal speed) or `"instant"` (no animation: the command runs at once and the pointer jumps to where it acted), `follow_camera` (bool); all optional | the settings. While the cursor is shown, `engine.execute` first glides to the command's toolbar button and to each pick, then runs and replies; later requests wait their turn. `"animate": false` on a call skips it |