解决圆角问题

src/qelmt/arc.rs

@@ -99,6 +99,19 @@ impl From<&Arc> for XMLElement {
 }
 
 impl Arc {
+    pub fn new(x: f64, y: f64, width: f64, height: f64, start: f64, angle: f64, style: String) -> Self {
+        Arc {
+            x,
+            y,
+            width,
+            height,
+            start,
+            angle,
+            style,
+            antialias: false,
+        }
+    }
+
     pub fn update_line_style<F>(&mut self, update_fn: F) 
     where 
         F: FnOnce(&mut String),

src/qelmt/line.rs

@@ -174,6 +174,21 @@ impl From<&Line> for XMLElement {
 }
 
 impl Line {
+    pub fn new(x1: f64, y1: f64, x2: f64, y2: f64, style: String) -> Self {
+        Line {
+            length2: 1.5,
+            end2: LineEnd::None,
+            length1: 1.5,
+            x1,
+            y1,
+            x2,
+            y2,
+            style,
+            end1: LineEnd::None,
+            antialias: false,
+        }
+    }
+
     pub fn update_line_style<F>(&mut self, update_fn: F) 
     where 
         F: FnOnce(&mut String),

src/qelmt/mod.rs

@@ -860,6 +860,29 @@ impl<'a> ObjectsBuilder<'a> {
                         ellipse.y -= self.offset.y;
 
                         Ok(Objects::Ellipse(ellipse))
+                    } else if polygon::is_rounded_rectangle(lwpolyline) {
+                        // 拆分圆角四边形为圆弧和直线段
+                        let mut decomposed_objects = polygon::decompose_rounded_rectangle(lwpolyline);
+
+                        // 对每个对象应用缩放和偏移
+                        for obj in &mut decomposed_objects {
+                            obj.scale(self.scale_fact.x, self.scale_fact.y);
+                            match obj {
+                                Objects::Arc(ref mut arc) => {
+                                    arc.x += self.offset.x;
+                                    arc.y -= self.offset.y;
+                                }
+                                Objects::Line(ref mut line) => {
+                                    line.x1 += self.offset.x;
+                                    line.y1 -= self.offset.y;
+                                    line.x2 += self.offset.x;
+                                    line.y2 -= self.offset.y;
+                                }
+                                _ => {}
+                            }
+                        }
+                        
+                        Ok(Objects::Group(decomposed_objects))
                     } else {
                             let mut poly: Polygon = lwpolyline.into();
 
@@ -1638,3 +1661,4 @@ enum TextEntity<'a> {
     MText(&'a dxf::entities::MText),
     Attrib(&'a AttributeDefinition),
 }
+

src/qelmt/polygon.rs

@@ -289,3 +289,168 @@ impl ScaleEntity for Polygon {
         }
     }
 }
+
+
+/// 判断LwPolyline是否为带圆角的四边形
+/// 条件：恰好8个顶点，闭合，每个顶点的bulge值要么为0（直线段）要么非0（圆弧段）
+pub fn is_rounded_rectangle(lwpolyline: &LwPolyline) -> bool {
+    // 检查顶点数量
+    if lwpolyline.vertices.len() != 8 {
+        return false;
+    }
+    
+    // 检查每个顶点的bulge值，确保形成合理的圆角四边形
+    // 圆角四边形应该有交替的直线段和圆弧段，或者4个圆角
+    let bulge_count = lwpolyline.vertices.iter()
+        .filter(|v| v.bulge.abs() > 0.0)
+        .count();
+    
+    // 4个圆角
+    bulge_count == 4
+}
+
+/// 将带圆角的四边形拆分为圆弧和直线段
+pub fn decompose_rounded_rectangle(lwpolyline: &LwPolyline) -> Vec<super::Objects> {
+    let mut objects = Vec::new();
+    let vertices = &lwpolyline.vertices;
+    
+    for i in 0..vertices.len() {
+        let current = &vertices[i];
+        let next = &vertices[(i + 1) % vertices.len()];
+        
+        if current.bulge.abs() > 1e-10 {
+            // 创建圆弧段
+            if let Some(arc) = create_arc_from_bulge(current.x, current.y, next.x, next.y, current.bulge) {
+                objects.push(super::Objects::Arc(arc));
+            }
+        } else {
+            // 创建直线段
+            let style = if lwpolyline.thickness > 0.5 {
+                "line-style:normal;line-weight:normal;filling:none;color:black"
+            } else {
+                "line-style:normal;line-weight:thin;filling:none;color:black"
+            }.to_string();
+            
+            let line = super::Line::new(
+                current.x,
+                -current.y,  // Y轴翻转
+                next.x,
+                -next.y,     // Y轴翻转
+                style,
+            );
+            objects.push(super::Objects::Line(line));
+        }
+    }
+    objects
+}
+
+/// 根据bulge值创建圆弧
+fn create_arc_from_bulge(start_x: f64, start_y: f64, end_x: f64, end_y: f64, bulge: f64) -> Option<super::Arc> {
+    if bulge.abs() <= 1e-10 {
+        return None;
+    }
+
+    // 计算弦长和中点
+    let chord_length = ((end_x - start_x).powi(2) + (end_y - start_y).powi(2)).sqrt();
+    let mid_x = (start_x + end_x) / 2.0;
+    let mid_y = (start_y + end_y) / 2.0;
+
+    // 根据bulge值计算圆弧参数
+    // bulge = tan(angle/4)，其中angle是圆弧的包含角
+    let included_angle = 4.0 * bulge.atan(); // 圆弧包含角（弧度）
+
+    // 计算半径
+    let radius: f64 = chord_length / (2.0 * (included_angle / 2.0).sin());
+
+    // 计算圆心位置
+    // 弦的方向向量
+    let chord_dx = end_x - start_x;
+    let chord_dy = end_y - start_y;
+    
+    // 弦的垂直方向（向左旋转90度）
+    let perp_dx = -chord_dy;
+    let perp_dy = chord_dx;
+    let perp_length: f64 = (perp_dx * perp_dx + perp_dy * perp_dy).sqrt();
+    
+    // 标准化垂直向量
+    let unit_perp_x = perp_dx / perp_length;
+    let unit_perp_y = perp_dy / perp_length;
+
+    // 计算圆心到中点的距离
+    let center_distance: f64 = radius * (included_angle / 2.0).cos();
+    
+    // 根据bulge的符号确定圆心位置
+    let center_x = if bulge > 0.0 {
+        mid_x + center_distance * unit_perp_x
+    } else {
+        mid_x - center_distance * unit_perp_x
+    };
+    let center_y = if bulge > 0.0 {
+        mid_y + center_distance * unit_perp_y
+    } else {
+        mid_y - center_distance * unit_perp_y
+    };
+
+    // 计算起始角度和结束角度
+    let start_angle = (start_y - center_y).atan2(start_x - center_x);
+    let end_angle = (end_y - center_y).atan2(end_x - center_x);
+
+    // 将弧度转换为度数
+    let mut start_angle_deg: f64 = start_angle.to_degrees();
+    let mut end_angle_deg: f64 = end_angle.to_degrees();
+        
+    // 标准化角度到0-360度范围
+    if start_angle_deg < 0.0 {
+        start_angle_deg += 360.0;
+    }
+    if end_angle_deg < 0.0 {
+        end_angle_deg += 360.0;
+    }
+        
+    // 计算角度跨度
+    let arc_angle: f64 = included_angle.to_degrees().abs();
+    
+    // // 计算圆弧参数
+    // let start_x = start_vertex.x;
+    // let start_y = -start_vertex.y;  // Y轴翻转
+    // let end_x = end_vertex.x;
+    // let end_y = -end_vertex.y;      // Y轴翻转
+    
+    // // 弦长
+    // let chord_length = ((end_x - start_x).powi(2) + (end_y - start_y).powi(2)).sqrt();
+    // if chord_length < 1e-10 {
+    //     return None;
+    // }
+    
+    // // 根据bulge计算圆弧的角度
+    // let angle = 4.0 * bulge.atan();
+    // // 计算圆弧的半径
+    // let radius = chord_length / (2.0 * (angle / 2.0).sin());
+    
+    // // 计算中点
+    // let mid_x = (start_x + end_x) / 2.0;
+    // let mid_y = (start_y + end_y) / 2.0;
+    
+    // // 计算弦角
+    // let chord_angle = (end_y - start_y).atan2(end_x - start_x);
+    // let center_offset = radius * (angle / 2.0).cos();
+    
+    // let center_x = mid_x - center_offset * (chord_angle + std::f64::consts::PI / 2.0).sin();
+    // let center_y = mid_y + center_offset * (chord_angle + std::f64::consts::PI / 2.0).cos();
+    
+    // // 计算起始角度和角度跨度
+    // let start_angle = (start_y - center_y).atan2(start_x - center_x).to_degrees();
+    // let angle_span = angle.to_degrees().abs();
+
+    let style = "line-style:normal;line-weight:thin;filling:none;color:black".to_string();
+    
+    Some(super::Arc::new(
+        center_x-radius,
+        -center_y-radius,
+        radius.abs() * 2.0,
+        radius.abs() * 2.0,
+        start_angle_deg,
+        arc_angle,
+        style,
+    ))
+}