feat: 实现曲线功能

src/paint.rs

@@ -207,16 +207,23 @@ struct PaintApp {
 
     canvas: MSCanvas,
 
-    // 是否正在绘制
+    /// 是否正在绘制
     is_drawing: bool,
 
+    /// pencil brush line curve rectangle
     begin_point: Point,
+    /// curve
+    end_point: Point,
 
-    // 用于显示的图像句柄缓存
-    // 每次像素变化后需要重新生成
+    /// 贝塞尔曲线控制
+    is_controlling: bool,
+    control_points: Vec<Point>,
+
+    /// 用于显示的图像句柄缓存
+    /// 每次像素变化后需要重新生成
     image_handle: image::Handle,
 
-    // 标记像素是否被修改，用于优化图像句柄的生成
+    /// 标记像素是否被修改，用于优化图像句柄的生成
     dirty: bool,
 
     config: Config,
@@ -239,6 +246,9 @@ impl PaintApp {
             canvas,
             is_drawing: false,
             begin_point: Point::ORIGIN,
+            end_point: Point::ORIGIN,
+            is_controlling: false,
+            control_points: Vec::with_capacity(2),
             image_handle: image::Handle::from_rgba(width as u32, height as u32, pixels),
             dirty: false,
             config,
@@ -392,6 +402,9 @@ impl PaintApp {
             Tool::Line => {
                 self.update_with_line(message);
             }
+            Tool::Curve => {
+                self.update_with_curve(message);
+            }
             Tool::Rectangle => {
                 self.update_with_rectangle(message);
             }
@@ -471,7 +484,7 @@ impl PaintApp {
             _ => None,
         });
         let tick = time::every(milliseconds(50)).map(Message::Tick);
-        return Subscription::batch(vec![ev, tick]);
+        Subscription::batch(vec![ev, tick])
     }
 
     // endregion
@@ -629,6 +642,54 @@ impl PaintApp {
         }
     }
 
+    pub fn update_with_curve(&mut self, message: Message) {
+        match message {
+            Message::MousePressed(pos) => {
+                if self.is_controlling {
+                    if self.control_points.len() == 0 {
+                        self.canvas.restore_pixels();
+                        self.canvas
+                            .quadratic_bezier(self.begin_point, self.end_point, pos);
+                        self.control_points.push(pos);
+                    } else {
+                        self.canvas.restore_pixels();
+                        self.canvas.cubic_bezier(
+                            self.begin_point,
+                            self.end_point,
+                            self.control_points[0],
+                            pos,
+                        );
+                        self.control_points.push(pos);
+                    }
+                    self.dirty = true;
+                } else {
+                    self.is_drawing = true;
+                    self.canvas.save_pixels();
+                    self.begin_point = pos;
+                }
+            }
+            Message::MouseReleased(pos) => {
+                if self.control_points.len() == 0 {
+                    self.is_drawing = false;
+                    self.end_point = pos;
+                    self.is_controlling = true;
+                } else if self.control_points.len() == 2 {
+                    self.control_points.clear();
+                    self.is_controlling = false;
+                }
+            }
+            Message::MouseMoved(pos) => {
+                if self.is_drawing {
+                    self.canvas.restore_pixels();
+                    self.canvas
+                        .draw_line_with_circle_brush(self.begin_point, pos);
+                    self.dirty = true;
+                }
+            }
+            _ => {}
+        }
+    }
+
     pub fn update_with_rectangle(&mut self, message: Message) {
         match message {
             Message::MousePressed(pos) => {