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Collision Data In Sonic 2 SMS I didn't see it documented anywhere...

#1 User is offline Ravenfreak 

Posted 01 January 2012 - 01:19 AM

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  • Project:Hacking some 8-bit Sonic game
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Happy new year everyone! So I'm going through the collision arrays that are in the wiki disassembly of Sonic 2 SMS, and decided to document what I come across. Since I can't access the SVN to check if the current notes are updated with collision data, and I don't recall reading any documentation anywhere else I decided to post them here. Forgive me if they have been documented... :v:
Collision Notes:
Collision data is set up in 32 byte arrays. Before the array pointer, there's 2 bytes. 
The first one determines the type of block such as if it's a breakable block, a solid block, etc. The second one seems to determine the 
collision type. Each collision offset points to 3 separate arrays with the last one only consisting of 16 bytes that marks the end of the array.
Block values are bellow:
$00- Same as 86 
Values $20- $50 are all invalid, and crashes the game.
$81- Solid
$82- Not Solid
$83- Tube (from bottom to top)
$84- Same as $83
$85- Damaging Block
$86- Conveyor Belt?
$87- Same as $86
$88- Slippery Slope (Unused?) 
$89- Spring
$8A- Same as $83
$8B- Same as $81
$8C- Collapsing Bridge
$8D- Breakable Block
$8E- Conveyor Belt (Moves Sonic to the Right)
$8F- Same as $81
$90- Same as $81
$91- Same As $81

That's all I have atm, and maybe someone can use this.

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