fix(cursor): restore default geometry

Keep CURSORSIZE 5 and PICKBOX 3 mapped to the pre-option 60 px arms, 15 px box, and 8 px selection aperture.\n\nRefs #413

src/app/mod.rs

@@ -448,9 +448,9 @@ pub(super) struct OpenCADStudio {
     zoom_wheel_reversed: bool,
     /// Mouse-wheel zoom sensitivity, clamped to 3..=100 (ZOOMFACTOR).
     zoom_factor: i32,
-    /// Crosshair reach as a viewport percentage (CURSORSIZE, 1..=100).
+    /// Crosshair size setting (CURSORSIZE, 1..=100).
     cursor_size: i32,
-    /// Selection-box half-size and click aperture in pixels (PICKBOX, 0..=50).
+    /// Selection-box size setting (PICKBOX, 0..=50).
     pick_box: i32,
     /// Drawing viewport cursor style (CURSORTYPE).
     cursor_type: settings::CursorType,

src/app/settings.rs

@@ -156,9 +156,9 @@ pub struct UserSettings {
     pub polar_increment_deg: f32,
     pub zoom_wheel_reversed: bool,
     pub zoom_factor: i32,
-    /// CURSORSIZE: crosshair arm reach as a percentage of the viewport.
+    /// CURSORSIZE: normalized crosshair reach; 5 retains the original 60 px arms.
     pub cursor_size: i32,
-    /// PICKBOX: visible selection-box half-size and click aperture in pixels.
+    /// PICKBOX: normalized visible-box and click-aperture size.
     pub pick_box: i32,
     /// CURSORTYPE: crosshair or the platform pointer over the drawing.
     pub cursor_type: CursorType,

src/app/update/viewport.rs

@@ -1778,7 +1778,7 @@ impl OpenCADStudio {
                     eye,
                     bounds,
                     self.tabs[i].scene.document.header.lineweight_display,
-                    self.pick_box.max(1) as f32,
+                    crate::ui::overlay::pick_box_aperture_px(self.pick_box),
                 )
                 .and_then(|s| Scene::handle_from_wire_name(s))
                 .or_else(|| {
@@ -2941,7 +2941,7 @@ impl OpenCADStudio {
                     view_rot2,
                     eye2,
                     bounds,
-                    self.pick_box.max(1) as f32 * 2.0,
+                    crate::ui::overlay::pick_box_aperture_px(self.pick_box) * 2.0,
                 );
                 let include_fills = self.tabs[i]
                     .active_cmd
@@ -2962,7 +2962,7 @@ impl OpenCADStudio {
                     eye2,
                     bounds,
                     self.tabs[i].scene.document.header.lineweight_display,
-                    self.pick_box.max(1) as f32,
+                    crate::ui::overlay::pick_box_aperture_px(self.pick_box),
                 )
                 .and_then(|s| Scene::handle_from_wire_name(s))
                 .or_else(|| {
@@ -3491,7 +3491,7 @@ impl OpenCADStudio {
                         view_rot,
                         eye,
                         bounds,
-                        self.pick_box.max(1) as f32 * 2.0,
+                        crate::ui::overlay::pick_box_aperture_px(self.pick_box) * 2.0,
                     );
                     let candidate_handles = self.tabs[i]
                         .scene
@@ -3511,7 +3511,7 @@ impl OpenCADStudio {
                             eye,
                             bounds,
                             self.tabs[i].scene.document.header.lineweight_display,
-                            self.pick_box.max(1) as f32,
+                            crate::ui::overlay::pick_box_aperture_px(self.pick_box),
                         )
                         .into_iter()
                         .filter_map(|s| Scene::handle_from_wire_name(s))
@@ -3533,7 +3533,7 @@ impl OpenCADStudio {
                             eye,
                             bounds,
                             self.tabs[i].scene.document.header.lineweight_display,
-                            self.pick_box.max(1) as f32,
+                            crate::ui::overlay::pick_box_aperture_px(self.pick_box),
                         )
                         .and_then(|s| Scene::handle_from_wire_name(s))
                         .or_else(|| {
@@ -3875,7 +3875,7 @@ impl OpenCADStudio {
                     view_rot,
                     eye,
                     bounds,
-                    self.pick_box.max(1) as f32 * 2.0,
+                    crate::ui::overlay::pick_box_aperture_px(self.pick_box) * 2.0,
                 );
                 let candidate_handles = self.tabs[i]
                     .scene
@@ -3890,7 +3890,7 @@ impl OpenCADStudio {
                     eye,
                     bounds,
                     self.tabs[i].scene.document.header.lineweight_display,
-                    self.pick_box.max(1) as f32,
+                    crate::ui::overlay::pick_box_aperture_px(self.pick_box),
                 )
                 .and_then(|s| Scene::handle_from_wire_name(s))
                 .or_else(|| {
@@ -3995,7 +3995,7 @@ impl OpenCADStudio {
                         view_rot,
                         eye,
                         bounds,
-                        self.pick_box.max(1) as f32 * 2.0,
+                        crate::ui::overlay::pick_box_aperture_px(self.pick_box) * 2.0,
                     );
                     scene::pick::hit_test::click_hit(
                         p,
@@ -4004,7 +4004,7 @@ impl OpenCADStudio {
                         eye,
                         bounds,
                         self.tabs[i].scene.document.header.lineweight_display,
-                        self.pick_box.max(1) as f32,
+                        crate::ui::overlay::pick_box_aperture_px(self.pick_box),
                     )
                     .and_then(|s| Scene::handle_from_wire_name(s))
                     .and_then(|h| {
@@ -4410,7 +4410,7 @@ impl OpenCADStudio {
             view_rot,
             eye,
             bounds,
-            self.pick_box.max(1) as f32 * 2.0,
+            crate::ui::overlay::pick_box_aperture_px(self.pick_box) * 2.0,
         );
         let candidate_ms = candidate_started.elapsed().as_secs_f64() * 1000.0;
         let candidate_count = hover_candidates.len();
@@ -4430,7 +4430,7 @@ impl OpenCADStudio {
             eye,
             bounds,
             self.tabs[i].scene.document.header.lineweight_display,
-            self.pick_box.max(1) as f32,
+            crate::ui::overlay::pick_box_aperture_px(self.pick_box),
         )
         .and_then(Scene::handle_from_wire_name);
         let wire_ms = wire_started.elapsed().as_secs_f64() * 1000.0;

src/ui/overlay.rs

@@ -12,6 +12,51 @@ use crate::scene::SelectionState;
 
 use crate::snap::SnapType;
 
+/// Original crosshair geometry retained at the default setting values.
+pub const CROSSHAIR_SQ: f32 = 7.5;
+pub const CROSSHAIR_ARM: f32 = 60.0;
+const DEFAULT_CURSOR_SIZE: i32 = 5;
+const DEFAULT_PICK_BOX: i32 = 3;
+const DEFAULT_PICK_APERTURE: f32 = 8.0;
+
+/// Convert CURSORSIZE to a screen-space arm length while keeping the original
+/// 60 px cursor at the default value and the full-viewport result at 100.
+pub(crate) fn crosshair_arm_px(bounds: iced::Rectangle, value: i32) -> f32 {
+    let value = value.clamp(1, 100);
+    if value <= DEFAULT_CURSOR_SIZE {
+        return CROSSHAIR_ARM * value as f32 / DEFAULT_CURSOR_SIZE as f32;
+    }
+
+    let full = bounds.width.hypot(bounds.height).max(CROSSHAIR_ARM);
+    let scale = (value - DEFAULT_CURSOR_SIZE) as f32 / (100 - DEFAULT_CURSOR_SIZE) as f32;
+    CROSSHAIR_ARM + (full - CROSSHAIR_ARM) * scale
+}
+
+/// Convert PICKBOX to the visible half-size while retaining the original
+/// 15 x 15 px center box at the default value.
+pub(crate) fn pick_box_half_px(value: i32) -> f32 {
+    let value = value.clamp(0, 50);
+    if value <= DEFAULT_PICK_BOX {
+        return CROSSHAIR_SQ * value as f32 / DEFAULT_PICK_BOX as f32;
+    }
+
+    let scale = (value - DEFAULT_PICK_BOX) as f32 / (50 - DEFAULT_PICK_BOX) as f32;
+    CROSSHAIR_SQ + (50.0 - CROSSHAIR_SQ) * scale
+}
+
+/// Convert PICKBOX to the real click/hover aperture. A zero setting hides the
+/// box but retains the one-pixel minimum needed for direct hits.
+pub(crate) fn pick_box_aperture_px(value: i32) -> f32 {
+    let value = value.clamp(0, 50);
+    let aperture = if value <= DEFAULT_PICK_BOX {
+        DEFAULT_PICK_APERTURE * value as f32 / DEFAULT_PICK_BOX as f32
+    } else {
+        let scale = (value - DEFAULT_PICK_BOX) as f32 / (50 - DEFAULT_PICK_BOX) as f32;
+        DEFAULT_PICK_APERTURE + (50.0 - DEFAULT_PICK_APERTURE) * scale
+    };
+    aperture.max(1.0)
+}
+
 #[derive(Clone, Copy)]
 pub struct CrosshairOptions {
     pub size_percent: i32,
@@ -964,10 +1009,8 @@ impl canvas::Program<Message> for SelectionCanvas {
                     style: canvas::Style::Solid(color),
                     ..Default::default()
                 };
-                let sq = self.crosshair.pick_box.clamp(0, 50) as f32;
+                let sq = pick_box_half_px(self.crosshair.pick_box);
-                let arm = bounds.width.hypot(bounds.height)
+                let arm = crosshair_arm_px(bounds, self.crosshair.size_percent);
-                    * self.crosshair.size_percent.clamp(1, 100) as f32
-                    / 100.0;
                 let base_angles: [f64; 2] = if self.crosshair.isometric {
                     self.crosshair.iso_plane.angles()
                 } else {