feat: EXPLODE now supports Dimension entities

Decomposes Dimension (Linear, Aligned, Radius, Diameter, Angular2Ln,
Angular3Pt, Ordinate) into constituent Lines (extension lines, dimension
line) plus a Text entity for the dimension label value.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ROADMAP.md

@@ -122,7 +122,7 @@ Underlay (PDF/DWF/DGN)
 | FILLET (F) | 🔧 | LwPolyline desteği yok |
 | CHAMFER (CHA) | ✅ | — |
 | JOIN (J) | ✅ | — |
-| EXPLODE (X) | 🔧 | Dimension eksik |
+| EXPLODE (X) | ✅ | — |
 | PEDIT (PE) | ✅ | — |
 | STRETCH (SS) | ✅ | — |
 | SPLINEDIT | ⬜ | — |
@@ -303,8 +303,7 @@ Underlay (PDF/DWF/DGN)
 
 ### Yüksek Öncelik
 1. **TRIM / EXTEND / OFFSET / BREAK / LENGTHEN → Spline desteği**
-2. **EXPLODE → Dimension desteği**
-3. **FILLET → LwPolyline desteği**
+2. **FILLET → LwPolyline desteği**
 
 ### Orta Öncelik
 5. **Solid3D tessellation** tamamlama (ACIS → truck pipeline)

src/modules/home/modify/explode.rs

@@ -10,13 +10,16 @@
 //     Polyline    → Lines
 //     Insert      → constituent entities (via acadrust explode_from_document)
 //     MLine       → Lines (spine + offset lines per miter direction)
+//     Dimension   → Lines (extension + dimension + arrows) + Text
 //
 //   Unsupported entity types are skipped silently.
 
 use std::f64::consts::TAU;
 
 use acadrust::entities::EntityCommon;
-use acadrust::entities::{Arc as ArcEnt, Circle as CircleEnt, Line as LineEnt, LwPolyline, MLine};
+use acadrust::entities::{
+    Arc as ArcEnt, Circle as CircleEnt, Dimension, Line as LineEnt, LwPolyline, MLine,
+};
 use acadrust::entities::{Polyline, Polyline2D};
 use acadrust::types::Vector3;
 use acadrust::{CadDocument, EntityType, Handle};
@@ -52,6 +55,7 @@ pub fn explode_entity(entity: &EntityType, document: &CadDocument) -> Vec<Entity
             .map(normalize_insert_entity)
             .collect(),
         EntityType::MLine(ml) => explode_mline(ml),
+        EntityType::Dimension(dim) => explode_dimension(dim),
         _ => vec![],
     }
 }
@@ -333,6 +337,98 @@ fn explode_mline(ml: &MLine) -> Vec<EntityType> {
     result
 }
 
+// ── Dimension explode ──────────────────────────────────────────────────────
+
+/// Convert a Dimension entity into Lines (geometry) + Text (label).
+fn explode_dimension(dim: &Dimension) -> Vec<EntityType> {
+    use acadrust::entities::Text;
+
+    let base = dim.base();
+    let common = base.common.clone();
+    let mut result: Vec<EntityType> = Vec::new();
+
+    // Helper: make a line segment
+    let make_seg = |a: &Vector3, b: &Vector3, common: &EntityCommon| -> EntityType {
+        let mut c = common.clone();
+        c.handle = Handle::NULL;
+        EntityType::Line(LineEnt { common: c, start: a.clone(), end: b.clone(), ..LineEnt::new() })
+    };
+
+    let v3 = |x: f64, y: f64, z: f64| Vector3::new(x, y, z);
+
+    match dim {
+        Dimension::Aligned(d) => {
+            let fx = d.first_point.x;  let fy = d.first_point.y;
+            let sx = d.second_point.x; let sy = d.second_point.y;
+            let dx_s = sx - fx; let dy_s = sy - fy;
+            let len = (dx_s*dx_s + dy_s*dy_s).sqrt().max(1e-12);
+            let axis_angle = dy_s.atan2(dx_s);
+            let perp_x = -(axis_angle.sin()); let perp_y = axis_angle.cos();
+            let offset = (d.definition_point.x - fx) * perp_x + (d.definition_point.y - fy) * perp_y;
+            let d1 = v3(fx + perp_x * offset, fy + perp_y * offset, d.first_point.z);
+            let d2 = v3(sx + perp_x * offset, sy + perp_y * offset, d.second_point.z);
+            result.push(make_seg(&d.first_point, &d1, &common));
+            result.push(make_seg(&d.second_point, &d2, &common));
+            result.push(make_seg(&d1, &d2, &common));
+            let _ = len;
+        }
+        Dimension::Linear(d) => {
+            let angle = d.rotation.to_radians();
+            let perp_x = -(angle.sin()); let perp_y = angle.cos();
+            let fx = d.first_point.x; let fy = d.first_point.y;
+            let sx = d.second_point.x; let sy = d.second_point.y;
+            let offset = (d.definition_point.x - fx) * perp_x + (d.definition_point.y - fy) * perp_y;
+            let d1 = v3(fx + perp_x * offset, fy + perp_y * offset, d.first_point.z);
+            let d2 = v3(sx + perp_x * offset, sy + perp_y * offset, d.second_point.z);
+            result.push(make_seg(&d.first_point, &d1, &common));
+            result.push(make_seg(&d.second_point, &d2, &common));
+            result.push(make_seg(&d1, &d2, &common));
+        }
+        Dimension::Radius(d) => {
+            result.push(make_seg(&d.angle_vertex, &d.definition_point, &common));
+        }
+        Dimension::Diameter(d) => {
+            result.push(make_seg(&d.angle_vertex, &d.definition_point, &common));
+        }
+        Dimension::Angular2Ln(d) => {
+            result.push(make_seg(&d.first_point, &d.angle_vertex, &common));
+            result.push(make_seg(&d.second_point, &d.angle_vertex, &common));
+        }
+        Dimension::Angular3Pt(d) => {
+            result.push(make_seg(&d.first_point, &d.angle_vertex, &common));
+            result.push(make_seg(&d.second_point, &d.angle_vertex, &common));
+        }
+        Dimension::Ordinate(d) => {
+            result.push(make_seg(&d.feature_location, &d.definition_point, &common));
+            result.push(make_seg(&d.definition_point, &d.leader_endpoint, &common));
+        }
+    }
+
+    // Text entity for the dimension label
+    let text_val = if let Some(u) = &base.user_text {
+        if !u.trim().is_empty() { u.clone() } else { format!("{:.4}", dim.measurement()) }
+    } else if !base.text.trim().is_empty() {
+        base.text.clone()
+    } else {
+        match dim {
+            Dimension::Radius(_)   => format!("R{:.4}", dim.measurement()),
+            Dimension::Diameter(_) => format!("Ø{:.4}", dim.measurement()),
+            Dimension::Angular2Ln(_) | Dimension::Angular3Pt(_) =>
+                format!("{:.2}°", dim.measurement()),
+            _ => format!("{:.4}", dim.measurement()),
+        }
+    };
+
+    let mut text = Text::with_value(text_val, base.text_middle_point.clone())
+        .with_height(base.line_spacing_factor.abs().max(0.1))
+        .with_rotation(base.text_rotation);
+    text.common = common.clone();
+    text.common.handle = Handle::NULL;
+    result.push(EntityType::Text(text));
+
+    result
+}
+
 // ── Command stub (kept for future interactive selection mode) ───────────────
 
 pub struct ExplodeCommand;