More Data Findings, Map Scripts, and a New Feature

Well, I haven't worked on the editor today except for warp saving fixes, but I have found quite a few pieces of data.

For starts, let me introduce a new feature, patching. Basically, the editor will have a menu with categories of patches and things to add or remove. This is to basically decrease the knowledge needed to remove some of the annoying things that would kill hacking. Most of these patches (all so far) just change one byte. There will be no way to revert them back to normal.

So far, patching includes removing the random forest maps (That annoying game) and all possibilities of it. There is also one to change the map the gate to the Maku Tree is (However I will go on further about this). There will be many map patches, such as changing the animal and volcano town maps, but right now there are only two.

In other news, I've cracked how the Gale Seed Warping works. Actually, it's extremely efficient and just screams "HACK ME!". There are three straight-forward bytes per spot (Although the third one seems kind of useless), and room for about 3 or 4 extra warps at the end of the data (I've tested this and we can easily add or remove them).

The only thing I worry about is area editing, such as editing what makes the minimap say Cresent Island is Cresent Island, and there's a Scent Seed Tree there. I've found other unimportant things, such as the cursor offset, sprite, and palette, but I doubt anyone would care to edit those.

Back on the topic of patches, I want to get into the map changing, or what they're really called, map scripts (Like how the Maku Gate stays forever removed after being opened. This is, of course done by a flag somewhere in the 0xC000 bank, but I mean the other part of it). The way they're done is kind of similar to how interaction script locations are calculated. The CPO (Common pointer operation, which is where you have a base address, add the map group * 2, and calculate the pointer there) is done to address 0x124A7. The date here is in pairs of two. The game reads the first byte as the map. If the byte matches the map you're going in to (Like 48 if you're heading up from the Ring Shop), the next byte (Always read but only matters if the Z flag is set) is a reference to the next procedure (I'm going to call these scripts from now on).

The new script is calculated by taking the script reference byte and multiplying it by 2, adding it to 0x012437, and calculating the pointer there using bank 4.

For example purposes, the generated script address takes us to 0x12673. The only thing done here is a global flag check. The flag it checks is bit 2 of 0xC6D2, which is set if the Maku Gate has been opened. If you're wondering, here's how to find the address of the flag and the bit number. Basically, the upper 5 bits are the value to be added to the memory address and the lower 3 are the value added to 0x0000F8 to be read as the bit AND value.

Calculating Address Flag and Bit Number [C# Syntax]
byte value = 0x12; //This is the one used in the Maku Gate check
byte b = (byte)(((value & 0xF8) >> 3)); //0x2
int memoryAddress = 0xC6D0 + b; //C6D2
b = (byte)(value & 0x07); //2 byte
bit = ROMData[0xF8 + b]; //ROMData being the file buffer

Calculating Address Flag and Bit Checking Value [C# Syntax]
byte value;
int dMemoryAddress = 0xC6D2; //Let's make this as easy as possible
byte dBit = 0x2; //The bit to check
byte b = (byte)(dMemoryAddress - 0xC6D0);
byte final = (byte)((b << 3));

Not too bad, but they probably could've saved more space using two bytes instead of one and not performing the procedure. But anyway, that's how those map-specific entry events work. Pretty handy-dandy if you ask me, and it only makes hacking these games better. See you tomorrow!