feat: 实现圆角矩形填充

src/mscanvas.rs

@@ -727,6 +727,98 @@ impl MSCanvas {
         self.fill_rect_color(x, y, width, height, self.background_color)
     }
 
+    /// 填充一个圆角矩形
+    /// - x, y: 左上角坐标
+    /// - width, height: 尺寸（必须 > 0）
+    /// - radius: 圆角半径（会被 clamp 到合理范围）
+    pub fn fill_round_rect(
+        &mut self,
+        x: f32,
+        y: f32,
+        width: f32,
+        height: f32,
+        radius: f32,
+    ) {
+        if (width as i32) <= 2 * self.line_width
+            || (height as i32) <= 2 * self.line_width
+            || width <= 2.0 * radius
+            || height <= 2.0 * radius
+        {
+            self.fill_rect(x as i32, y as i32, width as i32, height as i32);
+            return;
+        }
+
+        let min_x = x;
+        let max_x = x + width - 1.0;
+        let min_y = y;
+        let max_y = y + height - 1.0;
+
+        // 预计算四个圆角的圆心
+        let corners = [
+            ((x + radius) as i32, (y + radius) as i32),         // 左上
+            ((x + width - 1.0 - radius) as i32, (y + radius) as i32),         // 右上
+            ((x + width - 1.0 - radius) as i32, (y + height - 1.0 - radius) as i32),         // 右下
+            ((x + radius) as i32, (y + height - 1.0 - radius) as i32),         // 左下
+        ];
+
+        let min_x = min_x as i32;
+        let max_x = max_x as i32;
+        let min_y = min_y as i32;
+        let max_y = max_y as i32;
+        let radius_sq = (radius + 0.05) * (radius + 0.05);
+        let radius_int = radius as i32;
+        for py in min_y..=max_y {
+            for px in min_x..=max_x {
+                // 判断是否在“直边区域”（无需检查圆角）
+                if px >= min_x + radius_int && px <= max_x - radius_int {
+                    // 在左右圆角之间的竖直带 → 一定在内部
+                    self.draw_pixel_at1(px, py);
+                    continue;
+                }
+                if py >= min_y + radius_int && py <= max_y - radius_int {
+                    // 在上下圆角之间的水平带 → 一定在内部
+                    self.draw_pixel_at1(px, py);
+                    continue;
+                }
+
+                // 否则，点位于四个角落之一，需检查是否在四分之一圆内
+                let in_corner =
+                    // 左上角区域
+                    (distance_sq1((px, py), corners[0]) <= radius_sq) ||
+                        // 右上角区域
+                        (distance_sq1((px, py), corners[1]) <= radius_sq) ||
+                        // 右下角区域
+                        (distance_sq1((px, py), corners[2]) <= radius_sq) ||
+                        // 左下角区域
+                        (distance_sq1((px, py), corners[3]) <= radius_sq);
+
+                if in_corner {
+                    self.draw_pixel_at1(px, py);
+                }
+            }
+        }
+    }
+
+    pub fn fill_round_rect1(&mut self, p1: Point, p2: Point, radius: f32) {
+        let mut x = p1.x;
+        let mut y = p1.y;
+        let mut width = (p2.x - p1.x);
+        let mut height = (p2.y - p1.y);
+        if width < 0.0 && height < 0.0 {
+            x = p2.x;
+            y = p2.y;
+            width = (p1.x - p2.x);
+            height = (p1.y - p2.y);
+        } else if width < 0.0 {
+            x += width;
+            width = -width;
+        } else if height < 0.0 {
+            y += height;
+            height = -height;
+        }
+        self.fill_round_rect(x, y, width, height, radius);
+    }
+
     pub fn round_rect(&mut self, x: f32, y: f32, width: f32, height: f32, radius: f32) {
         if (width as i32) < 2 * self.line_width
             || (height as i32) < 2 * self.line_width
@@ -812,7 +904,7 @@ impl MSCanvas {
         self.round_rect(x, y, width, height, radius);
     }
 
-    pub fn stroke_rect(&mut self, x: i32, y: i32, width: i32, height: i32) {
+    pub fn rect(&mut self, x: i32, y: i32, width: i32, height: i32) {
         if width < 2 * self.line_width || height < 2 * self.line_width {
             self.fill_rect(x, y, width, height);
             return;
@@ -823,7 +915,7 @@ impl MSCanvas {
         self.fill_rect(x + width - self.line_width, y, self.line_width, height);
     }
 
-    pub fn stroke_rect1(&mut self, p1: Point, p2: Point) {
+    pub fn rect1(&mut self, p1: Point, p2: Point) {
         let mut x = p1.x;
         let mut y = p1.y;
         let mut width = (p2.x - p1.x);
@@ -840,7 +932,7 @@ impl MSCanvas {
             y += height;
             height = -height;
         }
-        self.stroke_rect(x as i32, y as i32, width as i32, height as i32);
+        self.rect(x as i32, y as i32, width as i32, height as i32);
     }
 
     pub fn clear(&mut self) {
@@ -1108,3 +1200,19 @@ fn normalize_radian(radian: f32) -> f32 {
 
     r
 }
+
+#[inline]
+/// 辅助函数：计算两点间距离的平方（避免开方）
+fn distance_sq(a: Point, b: Point) -> f32 {
+    let dx = a.x - b.x;
+    let dy = a.y - b.y;
+    dx * dx + dy * dy
+}
+
+#[inline]
+/// 辅助函数：计算两点间距离的平方（避免开方）
+fn distance_sq1(a: (i32, i32), b: (i32, i32)) -> f32 {
+    let dx = a.0 - b.0;
+    let dy = a.1 - b.1;
+    (dx * dx + dy * dy) as f32
+}