padding vulkan reflect mode

src/layer/vulkan/shader/padding.comp

@@ -78,6 +78,16 @@ void main()
         x = clamp(x, 0, p.w - 1);
         y = clamp(y, 0, p.h - 1);
 
+        int v_offset = gz * p.cstep + y * p.w + x;
+        top_blob_data[gz * p.outcstep + gy * p.outw + gx] = bottom_blob_data[v_offset];
+    }
+    else if (type == 2)
+    {
+        x = abs(x);
+        y = abs(y);
+        x = (p.w - 1) - abs(x - (p.w - 1));
+        y = (p.h - 1) - abs(y - (p.h - 1));
+
         int v_offset = gz * p.cstep + y * p.w + x;
         top_blob_data[gz * p.outcstep + gy * p.outw + gx] = bottom_blob_data[v_offset];
     }

src/layer/vulkan/shader/padding_pack4.comp

@@ -83,6 +83,16 @@ void main()
         x = clamp(x, 0, p.w - 1);
         y = clamp(y, 0, p.h - 1);
 
+        int v_offset = gz * p.cstep + y * p.w + x;
+        top_blob_data[gz * p.outcstep + gy * p.outw + gx] = bottom_blob_data[v_offset];
+    }
+    else if (type == 2)
+    {
+        x = abs(x);
+        y = abs(y);
+        x = (p.w - 1) - abs(x - (p.w - 1));
+        y = (p.h - 1) - abs(y - (p.h - 1));
+
         int v_offset = gz * p.cstep + y * p.w + x;
         top_blob_data[gz * p.outcstep + gy * p.outw + gx] = bottom_blob_data[v_offset];
     }