Cheat Engine

[Dark Byte]

In this example for the 64-bit tutorial of Cheat Engine 7.3 step 2, I'll show how to call the function MessageBoxA and react on it based on the result the user clicks

It also shows how to modify a single register, and how to access memory pointed at by a pointer

[ragnaroks]

sorry for disturb you,does it have some way to use "label(tag)" or "registersymbol(tag)" in $CCODE?

what i'm think:

[Dark Byte]

ok, there was another issue with that where local symbols didn't get recognized properly, seems a lot got changed after implementing C compiling. (it's fixed on patreon already)

Anyhow, goto is not going to work, as it's in a completely different stackframe, so the jmp that goto would do would mess up the stack.

It's better to use labels inside the c blocks instead and do the editing there, or use a register as a jump destination based on the result

example (step 2 of the tutorial)
I place an infinite loop after the ccode block, but the rcx register gets the address after that infinite loop (originalcode)

[ragnaroks]

"extern void originalcode();" it's new syntax in $CCODE or both in $C?

thanks for your help,my test cheat logic was done,i learned so much.

[Dark Byte]

can also be in {$c}

basically a {$ccode} section is a {$c} section but with a function prologue and epilog

once CE assembles the script all {$c} blocks get combined into one c-file internally and compiled like that, so {$ccode} blocks have access to what is in {$c} blocks above it. (order of the blocks matter)

in the example i posted the "extern void originalcode();" would be local to the function it's in , but if you'd put it in the {$c} blocks it'd be accessible to all the c-blocks under it.

[MMM-304]

[Dark Byte]

yes.

Also, here's another script example for flying around in kings bounty 2 (v1.3)

it makes use of the GetKeyState() function

I could likely clean it up by making a single isKeydown() function in {$c}

[Csimbi]

How do you return value from a call in C code?
I could not find it in the wiki so I figured I would ask.

Is this correct?

I get a crash in the call below (I never get to test rax,rax), I assume I must be doing something wrong.

[Dark Byte]

don't forget to add

[Frouk]

Just leaving here a method to call a function by virtual method table or by an address, AOB, whatever

[tuxlu]

Hi, completely necroposting this thread as one question inside was left unanswered:
is there a method to call LUA methods in {$ccode} blocks?
I'm espacially interested in registerSymbol and getAddressSafe

I tried declaring the methods , but the compiler does not find them

[Dark Byte]

you can mix C and autoassembler, so in a way: yes, using luacode

now the question is, why would luacode crash for you? Sure it's not performant but i'm not sure about the crash as {$ccode} uses the same trampoline as luacode

[tuxlu]

thanks again for your quick and insightful answer Dark Byte
Elegant answer, even if it still resorts to creating LUA code

But for now it seemed to work, it crashes mainly when I do too many "print" calls.
I'm giving a complete random guess, but as I was patching the character position set method, maybe the game expected a certain timing to this method, and adding the LUA delay messed with the rest of the game? not sure.

I still have some issues, like sometimes when I enable/disable my script, I get "not all instruction could be injected", even if I alloc/dealloc the autoassembler functions I alloc. So maybe I'm doing some funky stuff, I'll have to check a bit more, see in the memory viewer how the cheat is cleaned. but the sole code I have is: