DanmakuServer

A Windows-Composition-Based desktop danmaku renderer, providing a simple HTTP Restful API for clients to send danmaku messages.

Rendering result:

• Topmost, click-through for mouse. You can use it with any preferred video player.
• White danmaku text with Microsoft Yahei font, 28dip size and 5dip-radius blured shadow.
• Right to left linear danmaku marquee animation with 10s duration.

Performance:

• Total WS consumption maybe quite large on some machine, but Private WS is just ~28MB.
• Animation may flicker, because of the limitation of current implementation and Windows Composition itself.
• High-GPU occupation on dwm.exe, nearly inevitable. When your GPU is not powerful enough, you may experience lag on the whole Windows Shell Experience.

Best experience when used with:

• Windows 11
• https://github.com/iceking2nd/real-url (with the git-patch below)
• Daum PotPlayer

diff --git a/danmu/main.py b/danmu/main.py
index be295d3..eb1ac84 100644
--- a/danmu/main.py
+++ b/danmu/main.py
@@ -4,12 +4,25 @@
 
 import asyncio
 import danmaku
-
+import requests
+
+def send_to_danmaku_server(name, content):
+    PORT = 7654
+    try:
+        resps = requests.get(f'http://localhost:{PORT}/danmaku', params={
+            'name': name,
+            'content': content
+        }).json()
+        if resps['code'] != 0:
+            print('[DanmakuServer] error: ', resps['message'])
+    except:
+        pass

 async def printer(q):
     while True:
         m = await q.get()
         if m['msg_type'] == 'danmaku':
+            send_to_danmaku_server(m['name'], m['content'])
             print(f'{m["name"]}：{m["content"]}')

---

Screenshots

2023-08-04.13-11-39.webm

Known Issues

Warning

Due to some limitation of Windows Notify Icon GUID Registry, the icon may not be able to be shown.

	Windows 10	Windows 11
MSIX Packaged	Cannot update	Perfect
Non Packaged	Cannot move path	Cannot move path

• If you are using Windows 10,

  • update MSIX-packaged installations, or
  • move the path of non-packaged installations

• If you are using Windows 11, the second situation still exists, but the combination of Win11 + MSIX Package works perfectly, at least on my machine. However, I cannot find any official document about this, so I'm not sure if it's a bug or a feature.

If you encounter such issue, you can try this workaround to reset your notification settings.

Implementation

Thanks to:

• Windows Composition
  • Windows Composition means Windows.UI.Composition API from WinRT.
  • It's a GPU-accelerated UI rendering engine, which is provided by DWM.
  • The interface is mostly like a 2D graphics library, but bitmap only.
  • Like every window manager, the compositor is responsible for the rendering of layers of windows on the screen. But for Windows Composition, it also performs extra works like animations and visual effects.
  • These features makes it a good choice for rendering danmaku.
• ADeltaX's reverse-engineering efforts on Composition Interop
  • This interop is between Windows.UI.Composition and Direct Composition.
  • This is only responsible for creating a WinRT Compositor for a classic Win32 HWND.
• Composition Interop with DX and D2D
  • This interop is between Windows.UI.Composition and D2D and DWrite.
  • Because Windows Composition only supports bitmap, we have to render text by ourselves. After rendering text to a bitmap, we can use this interop to create a SurfaceBrush, and then use it under SpriteVisual with DropShadow.

This project uses C++/WinRT and C++ 20 features, and is compiled with MSVC 19.37.32820.

Tested under

• Build 22621 with NVIDIA GeForce RTX 3080 Ti.
• Build 25915 with Intel(R) UHD Graphics 630.