解决多线段lowpolyline圆圈问题

src/qelmt/ellipse.rs

@@ -100,7 +100,9 @@ impl TryFrom<&LwPolyline> for Ellipse {
     type Error = &'static str; //add better error later
 
     fn try_from(poly: &LwPolyline) -> Result<Self, Self::Error> {
-        if !poly.is_circular() {
+        let is_bugle_circle = poly.is_circular_with_bulge();
+
+        if !is_bugle_circle&&!poly.is_circular() {
             return Err("Polyline has poor circularity, can't convert");
         }
 
@@ -126,8 +128,12 @@ impl TryFrom<&LwPolyline> for Ellipse {
 
         Ok(Ellipse {
             x,
-            y: -max_y,
-            height: max_y - y,
+            y: if is_bugle_circle {-max_y-(max_x - x)/2.0} else {-max_y},
+            height: if is_bugle_circle {
+                max_x - x
+            } else {
+                max_y - y
+            },
             width: max_x - x,
 
             //in the original code antialias is always set to false...I'm guessing for performance

src/qelmt/mod.rs

@@ -100,6 +100,9 @@ trait Circularity {
         //for a specific type
         0.98..=1.02
     }
+
+    // 考虑bugle圆形判断
+    fn is_circular_with_bulge(&self) -> bool;
 }
 
 // 为 Polyline 类型实现圆形检测，有点类似函数定义
@@ -137,6 +140,10 @@ impl Circularity for Polyline {
 
         Self::match_range().contains(&t_ratio)
     }
+
+    fn is_circular_with_bulge(&self) -> bool{
+        false
+    }
 }
 
 // 为 LwPolyline 类型实现相同的圆形检测逻辑
@@ -165,10 +172,32 @@ impl Circularity for LwPolyline {
             poly_area /= 2.0;
             poly_area.abs()
         };
+        
         let t_ratio = 4.0 * PI * poly_area / poly_perim.powf(2.0);
-
         Self::match_range().contains(&t_ratio)
     }
+
+    fn is_circular_with_bulge(&self) -> bool {
+        // 检查是否有显著的bulge值
+        let has_bulge = self.vertices.iter().any(|v| v.bulge.abs() > 0.5);
+        if !has_bulge {
+            return false;
+        }
+
+        let all_quarter_arcs = self.vertices.iter()
+            .all(|v| (v.bulge.abs() - 1.0).abs() < 0.05);
+        
+        if all_quarter_arcs {
+            // 检查是否闭合
+            if self.vertices.len() >= 3 {
+                let first = &self.vertices[0];
+                let last = &self.vertices[self.vertices.len() - 1];
+                let distance = ((last.x - first.x).powf(2.0) + (last.y - first.y).powf(2.0)).sqrt();
+                return distance < 0.1; // 起点终点接近
+            }
+        }
+        false
+    }
 }
 
 // 实现Definition的方法