jump condition question

[Kalas]

Hey!

I'm kinda new to jump conditions so I wanted to make sure I understand this following code correctly:

Code: Select all

 code:
 pushf
 cmp [r12+20],esi
 jl originalcode
 popf
 jmp return

originalcode:
  popf
  mov [r12+20],esi
  jmp return

The instruction is for Health, It writes when you loose and gain health. (I saw Stephan Chapman video about this but I still don't understand how It works)

[Bloodybone]

jl is jump if less that means jump if [r12+20] is smaler than esi. I watched the tutorial also so what happens is if the player gets hit esi is smaller than [r12+20] so don't jump and if it is bigger like if you use an health potion esi is bigger than [r12+20] so jump.

[Kalas]

Oh I think I got it now, still have doubts.

So if I get hit jump to return which means do nothing, and if I gain health so run the instruction as normal. Thank you so much!

[Bloodybone]

Oh I think I got it now, still have doubts.

So if I get hit jump to return which means do nothing, and if I gain health so run the instruction as normal. Thank you so much!

What doubts do you have?

[Kalas]

I don't get it, If +20 is lower then esi jump to code, shouldn't it jump to return?

[Kalas]

Oh hang on, It's never going to take health but it checks if it is lower then esi it's going to jump to code and allow to gain health.

[Bloodybone]

[r12+20] is the pointer to player health and esi is new player health so if new player health(esi) is smaller then current player health [r12+20] then jump to return and if esi is bigger like current player health is 40 and esi is after drinking the health potion 50 then jump to originalcode

[Bloodybone]

Oh hang on, It's never going to take health but it checks if it is lower then esi it's going to jump to code and allow to gain health.

yes thats it.

[Kalas]

Sweet thanks!