Add a Drafting page for the rotation angle and the polar increment

Two drafting preferences had no proper home. The Drafting Settings dialog
displays the drafting rotation and offers only a Reset button — there was no
way to type an angle short of `SETVAR SNAPANG`. The polar tracking increment
existed in exactly one place: a pop-up hanging off the status-bar pill.

The rotation is a text field over an edit buffer rather than the value
itself, so clearing it to retype does not snap the crosshair to zero on the
way through; the buffer is reseeded whenever the value is restored from
behind it. Angles render without a trailing `.0`, matching how the polar
pop-up has always shown them — same kind of number, same reader.

Snap modes, grid spacing and object snap stay in Drafting Settings, where
they belong; the page links to it.

Co-Authored-By: Claude Opus 5 <[email protected]>

src/app/mod.rs

@@ -517,6 +517,9 @@ pub(super) struct OpenCADStudio {
     crosshair_color: Option<[u8; 3]>,
     /// Editable Options buffer for the crosshair colour.
     crosshair_color_input: String,
+    /// Edit buffer for the SNAPANG field on the Options Drafting page. Kept
+    /// separate from `snap_angle_deg` so a half-typed angle is not parsed.
+    snap_angle_input: String,
     /// Model-space lineweight preview scale, in percent (25..=200).
     lineweight_display_scale: i32,
     /// Isometric drafting state and active axis pair.
@@ -2029,6 +2032,10 @@ pub enum Message {
     QdimSnapPriorityChanged(u8),
     /// Change which annotative objects pick up a new scale (ANNOAUTOSCALE).
     AnnoAutoScaleChanged(i8),
+    /// Edit the drafting rotation field; parsed when it holds a valid angle (SNAPANG).
+    SnapAngleInputChanged(String),
+    /// Change the polar tracking increment in degrees.
+    PolarIncrementChanged(f32),
     /// Restore Model Space display/canvas appearance to defaults.
     RestoreModelSpaceDisplayDefaults,
     /// Restore Selection visual effect settings to defaults.
@@ -3429,6 +3436,7 @@ impl OpenCADStudio {
             cursor_type: settings::CursorType::Crosshair,
             crosshair_color: None,
             crosshair_color_input: String::new(),
+            snap_angle_input: "0".to_string(),
             lineweight_display_scale: 100,
             isometric_drafting: false,
             iso_plane: settings::IsoPlane::Left,

src/app/settings.rs

@@ -145,6 +145,18 @@ pub(crate) fn snaps_from_osmode(osmode: i32) -> (Vec<SnapType>, bool) {
     (modes, osmode & OSMODE_SUPPRESS == 0)
 }
 
+/// Render a drafting angle without a trailing `.0`, so `22.5` but `30`.
+///
+/// The polar pop-up formats its presets the same way; both are showing the
+/// same kind of number to the same person.
+pub fn format_snap_angle(deg: f32) -> String {
+    if (deg - deg.round()).abs() < 1e-4 {
+        format!("{}", deg.round() as i32)
+    } else {
+        format!("{deg}")
+    }
+}
+
 /// GRIPOBJLIMIT default: past this many selected objects, no grips are drawn.
 pub const DEFAULT_GRIP_OBJECT_LIMIT: i32 = 100;
 

src/app/update/file.rs

@@ -452,6 +452,9 @@ impl OpenCADStudio {
         } else {
             0.0
         };
+        // The Options field edits a buffer rather than the value, so it has to
+        // be reseeded whenever the value is restored from behind it.
+        self.snap_angle_input = crate::app::settings::format_snap_angle(self.snap_angle_deg);
         // Ortho + running OSNAP are per-drawing (adopted from the header on
         // open / tab switch), not app-global, so they are not applied here.
         self.snapper.otrack_enabled = s.otrack;

src/app/update/mod.rs

@@ -6266,6 +6266,27 @@ impl OpenCADStudio {
                 Task::none()
             }
 
+            // Typed into freely; only committed when it parses, so clearing
+            // the field to retype does not snap the crosshair back to zero.
+            Message::SnapAngleInputChanged(value) => {
+                self.snap_angle_input = value;
+                if let Ok(angle) = self.snap_angle_input.trim().parse::<f32>() {
+                    if angle.is_finite() {
+                        self.snap_angle_deg = angle.rem_euclid(360.0);
+                        self.persist_settings_if_changed();
+                    }
+                }
+                Task::none()
+            }
+
+            Message::PolarIncrementChanged(deg) => {
+                if deg.is_finite() && deg > 0.0 {
+                    self.polar_increment_deg = deg;
+                    self.persist_settings_if_changed();
+                }
+                Task::none()
+            }
+
             Message::PickDragRectToggled(rectangle) => {
                 self.pick_drag_rect = rectangle;
                 self.persist_settings_if_changed();

src/app/view/modal.rs

@@ -204,7 +204,9 @@ impl OpenCADStudio {
                             dimension_continue_mode: self.dimension_continue_mode,
                             qdim_snap_priority: self.quick_dimension_snap_priority,
                             annotation_auto_scale: self.annotation_auto_scale,
+                            polar_increment_deg: self.polar_increment_deg,
                         },
+                        &self.snap_angle_input,
                         self.double_click_block_refedit,
                         self.double_click_block_attedit,
                         self.cursor_type,

src/ui/window/options.rs

@@ -27,6 +27,7 @@ pub enum OptionsTab {
     General,
     OpenAndSave,
     Display,
+    Drafting,
     Selection,
     UserPreferences,
     Drawing,
@@ -62,6 +63,8 @@ pub struct AppPrefs {
     /// ANNOAUTOSCALE, -4..=4. The sign is on/off; the magnitude selects which
     /// objects a newly added scale reaches.
     pub annotation_auto_scale: i8,
+    /// Polar tracking increment in degrees.
+    pub polar_increment_deg: f32,
 }
 
 /// The Selection-card settings that live on `UserSettings` rather than on the
@@ -105,6 +108,7 @@ pub fn view_window<'a>(
     cursor_size: i32,
     selection: SelectionPrefs,
     prefs: AppPrefs,
+    snap_angle_input: &'a str,
     double_click_block_refedit: bool,
     double_click_block_attedit: bool,
     cursor_type: CursorType,
@@ -1150,11 +1154,83 @@ pub fn view_window<'a>(
     .spacing(0)
     .width(sizing.width);
 
+
+    // Snap modes, grid and object snap stay in the Drafting Settings dialog.
+    // These two have no home: Drafting Settings shows the rotation angle but
+    // offers only Reset, and the polar increment lives solely in a status-bar
+    // pop-up.
+    let polar_options = [90.0f32, 45.0, 30.0, 22.5, 18.0, 15.0, 10.0, 5.0, 1.0]
+        .into_iter()
+        .map(|value| Labelled {
+            label: format!("{}°", crate::app::settings::format_snap_angle(value)),
+            value,
+        })
+        .collect::<Vec<_>>();
+    let selected_polar = polar_options
+        .iter()
+        .find(|choice| (choice.value - prefs.polar_increment_deg).abs() < 1e-4)
+        .cloned()
+        .unwrap_or_else(|| Labelled {
+            value: prefs.polar_increment_deg,
+            label: format!(
+                "{}°",
+                crate::app::settings::format_snap_angle(prefs.polar_increment_deg)
+            ),
+        });
+
+    let drafting = column![
+        text(crate::t!("Drafting")).size(15),
+        Space::new().height(10),
+        row![
+            text(crate::t!("Drafting rotation")).size(12).width(150),
+            text_input("0", snap_angle_input)
+                .on_input(Message::SnapAngleInputChanged)
+                .width(110),
+            text(crate::t!("degrees")).size(11),
+        ]
+        .spacing(10)
+        .align_y(iced::Center),
+        Space::new().height(6),
+        text(crate::t!(
+            "Rotates the crosshair and the snap grid in the active UCS (SNAPANG)."
+        ))
+        .size(11)
+        .width(sizing.width),
+        Space::new().height(14),
+        row![
+            text(crate::t!("Polar tracking increment")).size(12).width(150),
+            iced::widget::pick_list(Some(selected_polar), polar_options, |choice| {
+                choice.label.clone()
+            })
+            .on_select(|choice| Message::PolarIncrementChanged(choice.value))
+            .width(Fill),
+        ]
+        .spacing(10)
+        .align_y(iced::Center),
+        Space::new().height(24),
+        text(crate::t!("Snap and Grid")).size(15),
+        Space::new().height(10),
+        row![
+            text(crate::t!("Snap modes, grid spacing and object snap"))
+                .size(12)
+                .width(Fill),
+            button(text(crate::t!("Drafting Settings…")).size(11))
+                .on_press(Message::ToggleSnapPopup)
+                .padding([4, 10])
+                .style(button::secondary),
+        ]
+        .spacing(10)
+        .align_y(iced::Center),
+    ]
+    .spacing(0)
+    .width(sizing.width);
+
     let content: Element<'a, Message> = match active_tab {
         OptionsTab::General => general.into(),
         OptionsTab::Display => display_element.into(),
         OptionsTab::Selection => selection.into(),
         OptionsTab::OpenAndSave => open_and_save.into(),
+        OptionsTab::Drafting => drafting.into(),
         OptionsTab::UserPreferences => user_prefs.into(),
         OptionsTab::Drawing => drawing.into(),
     };
@@ -1174,6 +1250,7 @@ pub fn view_window<'a>(
         tab_button(crate::t!("General"), OptionsTab::General),
         tab_button(crate::t!("Open and Save"), OptionsTab::OpenAndSave),
         tab_button(crate::t!("Display"), OptionsTab::Display),
+        tab_button(crate::t!("Drafting"), OptionsTab::Drafting),
         tab_button(crate::t!("Selection"), OptionsTab::Selection),
         tab_button(crate::t!("User Preferences"), OptionsTab::UserPreferences),
         tab_button(crate::t!("Drawing"), OptionsTab::Drawing),