Save the trees, flowers, etc.

[Vash]

I figured it's time for another one of my theory posts. Keep in mind, my last post like this turned into the Real-Time World Edit code. Here it goes.

AC:WW uses a series of bytes that read either 00 or 01 to decide if an item on the world map is buried. Why not apply the same idea to save the current position of all of your trees, or all of your flowers, or a rock maze? Before I go into detail, I'd like to answer the question as to how this would be helpful? Like I said above, you could create and destroy massive mazes with the press of an activator. You could save your town from being destroyed by visitors by simply saving the position of your trees and re-creating them after your visitors leave. The same goes for flowers.

Now, what would we need to make this happen? 4,096 bytes of free ram, to be exact. Luckily for us, the DS version of AC has plenty of free ram. 256 free lines in a debugger is easy to spot. What would we need to do? Write an ASM routine to search through the world map for a given hex (0xF1FF for example). When it finds it, it'll change the 00 to a 01 at that slot's corresponding spot in the free ram. How would we do this? By creating an equation that would take the address of each slot on the world map and correspond it to one of the free bytes of ram. It will be in a series, so we can also write the opposite of this equation to go through the series of bytes and find any that are set to 01. When it finds one, it'll change that free byte's address back to the actual map slot address and place the item there. Complicated, but it's definitely possible. Much easier than the RTWE, accomplished by Toenailed.

So, who's up for the challenge?

EDIT: We can use 0x022BF200 to 0x022C1200. Starting at the first slot, it's 0x021E3124 + DC0DCh to get to the first byte we're using. Really we just need to write an ASM routine to subtract 1h from the number we're adding (DC0DC) each time it runs through the loop. This will get you to each of the free ram slots. For example:

0x021E3124 -World Slot 1
+DC0DC
__________
0x022BF200 -Free Slot 1

Then

0x021E3126 -World Slot 2
+DC0DB
__________
0x022BF201 -Free Slot 2

[Maniac]

Sounds easy enough to adapt something of mine >__> Meh I'll ask a few question on msn and maybe work on it.

Edit:
This what you want? :P (If you want me to note it more I can >_>)
It currently can only do one item, it may be able to be adapted to do several... just depends :\ Anyways doing the reverse of this should be simple so I won't post it now.


EDIT2: Please not the below code it not the up to date one.

ldr r0, Map
add r1, r0, #0x2000
ldr r4, AddVal
ldrh r8, SearchFor
ldrb r5,  One @Pointless, I know but it wont let me do streqb #0x1,[r3], it wants a register...

Loop:
cmp r0, r1
bxeq lr
ldrh r2, [r0], #0x2 @r2 = 16 bits from Map, r0 + 2 -> r0
add r3, r0, r4 @Our open byte = r3
sub r4, r4, #0x1 @r4 - 1 -> r4
cmp r2, r8
streqb r5,[r3]
b Loop

Map:
.long 0x21e3124
AddVal:
.long 0xDC0DC
SearchFor:
.short 0xF1FF
One:
.byte 0x01

[Area51_Hacker2]

Shouldn't that have an activator? There aren't any conditionals...

[Vash]

That's just a routine. It's not the entire code.

[Maniac]

Its also not the up to date routine >_> i.e. it has bugs.

[dragonboy269]

Just wondering, has anything new happened with this code?

[Maniac]

yes and no >_>

[Vash]

Sort of...

[dragonboy269]

Wow, now that I look back at this it looks extremely easy
I may make something like this for AC:CF soon, if there's free space like that in the game
I Still don't have a USBGecko though so I don't really know much about the inner workings of the game
Anyway so long everyone