diff --git a/inc/hgl/2d/TGA.h b/inc/hgl/2d/TGA.h
index 3a44b88..a06e270 100644
--- a/inc/hgl/2d/TGA.h
+++ b/inc/hgl/2d/TGA.h
@@ -44,7 +44,7 @@ namespace hgl
         };
 #pragma pack(pop)
 
-        constexpr size_t TGAHeaderSize=sizeof(TGAHeader);
+        constexpr size_t TGAHeaderSize=sizeof(TGAHeader);       ///<TGA文件头，必须等于18
 
         bool FillTGAHeader(TGAHeader *header,const uint16 width,const uint16 height,const uint8 channels,const uint8 single_channel_bits=8);
     }//namespace imgfmt