I also converted the example demo and translated the Chinese captions to English the best I could (aka I ran them through Google translate and then fixed the grammar.) Both the package and the demo are in the 7Zip file I've attached, in two separate folders. You'll want to modify the build options for each to reflect your platform/CPU architecture, obviously.
I'm on 64-Bit Windows 10 here (win32 widgetset) and everything works perfectly for me, but it would be cool if users of other platforms could confirm that it works on them as well.
EDIT: I guess there are a few Windows-specific types in the code as well, like HBITMAP, e.t.c... If you're on another platform feel free to reupload the file with the appropriate platform-specific defines/changes (I'm not sure what they would be, unfortunately.)
EDIT #2: Ok, it seems that for whatever reason Lazarus needs you to manually orient bitmaps before doing GL stuff with them, so I added a global procedure called CorrectLineOrder that you can/could call from your code as necessary. I thought this made more sense than making it something that was built into the PaintBox drawing procedures, as there may be circumstances where you DIDN'T want to flip a bitmap from its default orientation.
I've attached a 7z file with an updated copy of the main package source, as well as an updated copy of the demo application source that uses the bitmap flipping procedure.