add black border

src-tauri/src/lib.rs

@@ -35,15 +35,9 @@ fn generate_thumbnail(original_path: &Path) -> Option<String> {
     }
 
     // Generate
-    // Use image reader to be faster? open is fine.
     if let Ok(img) = image::open(original_path) {
-        // Resize to height 200, preserve ratio
         let thumb = img.thumbnail(u32::MAX, 200);
-        // Save as jpeg with quality 80
-        let mut file = fs::File::create(&thumb_path).ok()?;
-        // thumb.write_to(&mut file, image::ImageOutputFormat::Jpeg(80)).ok()?; 
-        // write_to might be slow due to encoding, but parallel execution helps.
-        // save directly
+        let _file = fs::File::create(&thumb_path).ok()?;
         thumb.save_with_format(&thumb_path, image::ImageFormat::Jpeg).ok()?;
         
         return Some(thumb_path.to_string_lossy().to_string());
@@ -165,30 +159,28 @@ async fn export_batch(images: Vec<ExportImageTask>, watermark: WatermarkSettings
             
             // 2. Measure Text
             let scaled_font = PxScale::from(scale_px);
-            let (t_width, t_height) = imageproc::drawing::text_size(scaled_font, &font, &watermark.text);
+            let (t_width, _t_height) = imageproc::drawing::text_size(scaled_font, &font, &watermark.text);
             
             // 3. Ensure it fits width (Padding 5%)
             let max_width = (width as f32 * 0.95) as u32;
             if t_width > max_width {
                  let ratio = max_width as f32 / t_width as f32;
                  scale_px *= ratio;
-                 // Re-measure isn't strictly necessary for center calc if we assume linear scaling,
-                 // but let's be safe for variable width fonts? Actually text_size scales linearly.
             }
             let final_scale = PxScale::from(scale_px);
             let (final_t_width, final_t_height) = imageproc::drawing::text_size(final_scale, &font, &watermark.text);
 
             // 4. Determine Position (Center based)
-            let (mut pos_x_pct, mut pos_y_pct) = if watermark.manual_override {
+            let (pos_x_pct, pos_y_pct) = if watermark.manual_override {
                  (watermark.manual_position.x, watermark.manual_position.y)
             } else {
                  match calculate_zca_internal(&dynamic_img) {
                      Ok(res) => (res.x, res.y),
-                     Err(_) => (0.5, 0.96), // Default fallback lowered
+                     Err(_) => (0.5, 0.96),
                  }
             };
 
-            // Calculate top-left coordinate for draw_text_mut (it expects top-left, not center)
+            // Calculate top-left coordinate for draw_text_mut
             let center_x = width as f64 * pos_x_pct;
             let center_y = height as f64 * pos_y_pct;
 
@@ -203,7 +195,21 @@ async fn export_batch(images: Vec<ExportImageTask>, watermark: WatermarkSettings
             x = x.clamp(padding, max_x);
             y = y.clamp(padding, max_y);
             
-            // 6. Draw
+            // 6. Draw Stroke (Simple 4-direction offset for black outline)
+            let stroke_color = image::Rgba([0, 0, 0, text_color[3]]);
+            for offset in [(-1, -1), (-1, 1), (1, -1), (1, 1)] {
+                draw_text_mut(
+                    &mut base_img,
+                    stroke_color,
+                    x + offset.0,
+                    y + offset.1,
+                    final_scale,
+                    &font,
+                    &watermark.text,
+                );
+            }
+
+            // 7. Draw Main Text
             draw_text_mut(
                 &mut base_img,
                 text_color,