Game Window Cursor Clipping

Summary

This implementation allows you to clip the cursor to the game window such as in DOOM and DOOM Eternal (id Tech 6 - 7), also brings some fixes to various bugs on VGUI.

 Note: This works only when the window is active, otherwise, the cursor will be unlocked automatically just as in the games specified above.

 Note: This is an incomplete sample. When the resolution gets changed, this will get broken. It will be updated as soon as possible.

• 

  Example of cursor clipping

• 

  Example of cursor clipping while moving a VGUI panel

Requirements

• Knowledge of C++
• Knowledge of Source Engine
• Source SDK Base 2013 - Currently tested on Source SDK Base 2013 Multiplayer

Getting the Implementation/Code

First of all, you'll need the following files from the following GitHub repository:

• source-engine-examples-cursor-clipping

Which you will copy to src/game/client/. You can also create a subfolder if you wish to, and copy these files there.

Implementation

Now head over to cdll_client_int.cpp' and include

#include "CCursorClipManagement.h"

Anywhere before

// memdbgon must be the last include file in a .cpp file!!!
#include "tier0/memdbgon.h"

 Note: Note that if you copy the header to a subfolder, you gotta specify that in your #include

In the same cpp, find CHLClient::PostInit() and add this to the end:

CCursorClipManagement::Init();

Lastly, find void OnRenderEnd() and add this to the end:

g_pCursorClipManager->Think();

Conclusion

You're all set! Compile your client project and check if it works.

Notes

• If you start the game with -tools, -dev, -developer, and -nocursorclipping the cursor clipping will be disabled and won't work by default.
• If you're compiling into a different platform, else than WIN32, the cursor clipping will be disabled and won't work by default.
• You can also add a ConVar to enable or disable this dynamically in-game, all you'll need to do is adding one more check on CCursorClipManagement::Think().
• If you do not want to check whether the window is active or not every time OnRenderEnd() gets called, you can also do this by hooking into window events/messages. Check SetWindowsHookExA.