Direct Input DDK Annotations

Last Updated Nov 21, 2000

Direct Input DDK

Click here to get the Direct X 5 DDK

- It's part of the Windows 98 DDK.


Click here to get the Direct X 7.0 DDK for Windows 2000

- It's a part of the Windows 2000 DDK


Click here to get the Direct X 7.0 DDK for Windows 98

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I used to have this information in an annotation file, but it is easier to update in HTML format. If people want this to go back to annotation style, please email me.

VJOYD_DeviceUpdateNotify_Service
This service seems to need eax to be set to 0 in order for it to function. So, if you implement your driver in C, the call should look like this:

_asm mov eax, 0
VxDCall( VJOYD_DeviceUpdateNotify_Service );


VJDEVICEDESC
You may be confused on several fronts if you look at the help file for VJDEVICEDESC. According to the help file, the lpHWCaps structure is reserved. Well, it isn't. Direct Input expects that structure to be filled with valid information. To get around that, Windows 95 allowed the pointer to VJDEVICEDESC(lpDeviceDesc)in VJREGDRVINFO to be null. If the pointer to the structure was null, it took all its information from the registry. This worked fine until Windows 98 was given to beta testers. Some versions of Windows 98 (pre RC 4.0) failed when the pointer was null. The device may show up having buttons on the control panel, but games will not be able to access them. (Checking the device caps will have the device listed as 0 buttons) Even though this should be fixed by the final version, the safest method is to fill that structure.

Poll
Poll is different than the DX1-3 PollRoutine. Make sure to return VJ_ERRFAIL if the device is not connected. Also, if the data isn't fresh, return S_FALSE. Normally, return VJ_OK.

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Custom Control Panel
There is an example of this in the D5 ddk. It should be found at (d5ddkloc)\input\samples\cplsvr1. If you compile this dll, and install it through the .inf file, you should have a usable example. But, some people have problems.

If you hit the property button and it immediately crashes, or does nothing, there are two possible reasons.

1. The file cplsvr1.dll didn't get copied to the \windows\system directory. Copy the file by hand and try again.
2. The dll didn't get compiled with the cplsvr1.def file. Without this file, no functions are exported. Make sure that file is listed in the project and compile again.

Once the sample is tested, you will probably modify the example code to use in your own control panel. Make sure that you create your own GUID. If you have Visual C++, you should have a program named "guidgen.exe". This program can create GUIDs. This number should be placed in your .inf file (registry format), and the cplsvr1.h file (static const format).

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