Difference between revisions of "Tutorial:CodeInjection Floats"

From Cheat Engine
Jump to navigation Jump to search
(Created page with '<!-- Tutorial:CodeInjection_Floats --> Category:Tutorial Category:Auto Assembler {{DISPLAYTITLE:Code Injection - Working with Floats}} This tutorial builds on the topic o…')
(No difference)

Revision as of 23:58, 6 May 2018


This tutorial builds on the topic of Code Injection:


Let's say you have a float and some code that increases the value.

addss [eax+10],xmm0
Note: SS is for singles and SD is for doubles.

What if what writes to the value is only a MOVSS. Try to find a spot above the write instruction that has an ADDSS (or a SUBSS depending on what you want to do).

addss xmm0,xmm1
//...
movss [eax+10],xmm0


Editable value

We could use a label, giving it some memory. And optionally register it so the label can be used on the table as an address.

//...
alloc(someMem, 0x400)
//...
label(someSymbol)
registerSymbol(someSymbol)
//...
someMem:
  //...
  mov xmm0,[someSymbol]
  addss [eax+10],xmm0
  //...
  jmp return
  //...
  someSymbol:
    dd (float)100
//...


Adding a Multiplier

We could add an editable value like above but use MULSS to add a multiplier to the script.

//...
alloc(someMem, 0x400)
//...
label(someSymbol)
registerSymbol(someSymbol)
//...
someMem:
  //...
  mulss xmm0,[someSymbol]
  addss [eax+10],xmm0
  //...
  jmp return
  //...
  someSymbol:
    dd (float)100
//...


Calculate a value for a Multiplier

Let's say we just can't find an ADDSS or a SUBSS, and all we have is a MOVSS.

movss [eax+10],xmm0

We can just do some math in the script, to calculate a value for a multiplier.

//...
alloc(someMem, 0x400)
//...
label(someSymbol)
registerSymbol(someSymbol)
//...
someMem:
  //...
  subss xmm0,[eax+10]
  mulss xmm0,[someSymbol]
  addss xmm0,[eax+10]
  movss [eax+10],xmm0
  //...
  jmp return
  //...
  someSymbol:
    dd (float)10
//...


Working with doubles

Let's say the game use doubles, we can use ADDSD, SUBSD, MULSD, and MOVSD instead. We just need to also make our scripts value a double.

movsd [eax+10],xmm0

So to calculate a value for a multiplier.

//...
alloc(someMem, 0x400)
//...
label(someSymbol)
registerSymbol(someSymbol)
//...
someMem:
  //...
  subsd xmm0,[eax+10]
  mulsd xmm0,[someSymbol]
  addsd xmm0,[eax+10]
  movsd [eax+10],xmm0
  //...
  jmp return
  //...
  someSymbol:
    dq (double)10
//...


See Also