Cheat Engine

[SwaggaJackin']

I've never written a hook and I have a basic knowledge of C++, I've never actually done anything as advanced as this in C++.

Basically I want to make a jump at Direct3D 9's present() function and have it jump to my own code that will draw items in the game based on memory values retrieved from the game

E.G. Read all of the enemy positions in the game, and read their life. Then draw their remaining life above their coordinates.

My problem lies in the actual hook, I have the address where I want to inject so how do I achieve patching it in C++ and how do I draw on to the game itself. Should I be using dll injection for this? Would that be the easiest method? I've never worked with DirectX, but I won't need to draw anything more advanced then a transparent rectangle.

So how should I go about this? I know how to find the process, just enumerate the process list and check the results of the process name against a string I specify. But how do I make the actual hook?

I've googled samples and a lot are either outdated or broken links. Would really appreciate some help on this. Trying to take it one step at a time. So I wanna first make a successful hook. After I verified I can do this. I want to then see if reading the memory brings in the results I desire. Finally I want to draw to the screen and jump back to the games actual present() function.

So I've got the process PID I want to attach my code to. What do I need to do now?

Thanks!

[atom0s]

You can either wrap the entire interface or specifically hook the single function. Inline patching or vtable hooking will be what you are wanting to do for a single function hook. You are better off hooking the vtable as its typically the most undetected method in most cases.

There are a ton of examples of how to hook onto Direct3D's vtable on the net so you should be able to find some examples easily. If you have any problems feel free to post for more assistance.

[SwaggaJackin']

[atom0s]

[Dark Byte]

Just one thing: Don't do the vtable hook method as calling certain methods (Like serRenderstate) will undo the hooks

[atom0s]

[Dark Byte]

I think it's new. Perhaps an update in DX.
I saw it last time I was playing with the direct3d sdk samples, the pointers in the vtable changed back

Could be it's for DX10+ only, or windows 7

edit: I tested it on the multianimation sample which uses DX9, so could be an updated d3dx library, or it's windows 7

[atom0s]

[Dark Byte]

june 2010
hooking the vtable is of course still possible if you hook enough functions and make sure it keeps hooked (in my personal version of dxmess for example I added a rehook call right after the routines that tend to restore it)

and it could of course be an anti virus or the display driver itself (no idea why they would do that, but who knows...)

[atom0s]