This is a disassembly where I implement a variety of things onto Red Miso Studios' Sonic 1 in Sonic 3 of small to medium size.
- Drop Dash, from Sonic Mania (the code for which was derived from my own Sonic 2 - Score Rush)
- Fast Air Moves, a feature that disables the vertical speed check that occurs during a jump, and before an air move
- Super Sonic's sprites have been disabled. I intend to address it through an approach distinct from that of the base game.
Original code contributions are free to reuse for the development of Sonic ROM Hacks, and, if applicable, non-commercial projects. Other original asset contributions, as well as unoriginal assets and code, may be subject to separate conditions. You may not use any of the contents of the repository for commercial purposes without the explicit, written permission of giovanni.gen. Due to the fact that this is a derivative of SEGA's Sonic the Hedgehog Mega Drive games, there is a 99.99999% likelihood you will simply not be granted permission to use certain code and assets for commercial purposes anyway, on account of the fact that giovanni.gen does not hold the power to grant you such permission in the first place. It is highly advised you triple check whether any line of code was written specifically for this project, or if it already existed, as there exists the chance you'll pull code directly originating from SEGA's Sonic the Hedgehog Mega Drive games.
Credit is appreciated.
Each mini-project has its own set of credits:
Sprites source: Sample Sprite mod (Sonic 3 - Angel Island Revisited)
Peel-Out fading sound effect: DeltaW May contain code by heyjoeway Original sprites sourced from Sonic 3 - Angel Island Revisited
This is a port of Sonic The Hedgehog (1991) to Sonic Clean Engine (S.C.E.), our heavily modified and improved Sonic 3 & Knuckles engine, which we have been using for a long time for our MD projects (such as Hellfire Saga and Sonic 3 & Knuckles: Epilogue).
Free use. You use it at your own risk. All code is provided “as is”. This source code uses software from other authors. Check their licenses before using it. You assume any and all responsibility for using this content responsibly. I claims no responsibility or warranty. Commercial usage is expressly prohibited.
You can use this source code as a base for your projects, or just as an example for optimizations of your source code.
Screenshots
To build this, use build.bat if you're a Windows user, or build.sh if you're a Linux user. The built ROM will be called 'S1S3.gen'. Use build_debug for debug things. The built ROM will be called 'S1S3.Debug.gen'.
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For editing sprites you can use SonMapEd, ClownMapEd or Flex2 (Read the issues).
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For editing levels you can use official SonLVL or SonLVL-64x64-Compatible. Unfortunately, SonED2 is no longer supported.
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To convert SMPS music to asm format you can use smps2asm.
- S.C.E. uses Kosinski Plus algorithm, but Flex2 program does not support Kosinski Plus Module. Therefore, Flex2.json project file is partially useless. SonMapEd program does not support Kosinski Plus at all. You can only open uncompressed graphics.
- If you want to convert levels from previous Sonic games, you have to use LevelConverter from SonLVL. Then change the layout format using Layout converter.
- If you want to make a different text for Title Card, you need to create a file of letters from List.unc. This will be loaded before the level starts. You don't have to add the letters 'ENOZ' (ZONE) because those letters are already in VRAM. Then you have to create a mapping of your zone name in Map - Title Card.asm.
- If you want to use other SMPS music you can use Valley Bell's SMPS Research or vgm2smps.
- Unfortunately, not all programs support MapMacros, so I wanted to maintain compatibility with older programs. I don't want to just throw away SonMapEd. But there is support for MapMacros here, and you can use it if you want.
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The speed of the ROM build process depends entirely on the power of your computer. A high-performance machine will build the ROM quickly, while a slower one will take significantly more time. If you're a Linux user and you're using Wine and Windows batch script, that will affect build speed too.
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Always specify jump sizes for instructions. Writing code without specifying jump sizes will significantly slow down the ROM build. The Macro Assembler AS will perform multiple passes until it can successfully build the ROM, which increases build time.
Example of problematic code:
beq sub_1234 ; and any other branch instructions
bsr sub_1234
bra sub_1234
jsr sub_1234
jmp sub_1234
lea sub_1234,a1
pea sub_1234
Example of correct code:
beq.s sub_1234 ; and any other branch instructions
bsr.s sub_1234
bra.s sub_1234
jsr (sub_1234).l
jmp (sub_1234).l
lea (sub_1234).l,a1
pea (sub_1234).l
For God's sake, always specify the jump sizes for instructions. Don't try to play around with Macro Assembler AS. Sometimes you may see random and meaningless errors just because you didn't specify the code size. You will try to fix something that wasn't actually broken, but these errors were caused only because you didn't specify the jump size in instruction.
- TheBlad768 -- Project lead, sole programmer, S.C.E. Game Engine
- Nichloya -- Level art and level design edits, sprite art and other things
- pixelcat -- Sprite art, UI art and other things
- FoxConED -- S.C.E. Level Select font art
- Dolphman -- Robotnik head art
- giovanni.gen, KGL, DeltaW, Narcologer, CatswellMeow, Nintorch, FoxConED, lavagaming1, cuberoot, Vladikcomper, ProjectFM, MarkeyJester, VAdaPEGA
- cuberoot
- joshyflip for consulting on the artwork
- Flamewing, devon, RealMalachi and others for bug fixing guides
- Clownacy for work on the disassemblies
- SSRG and Sonic Retro
- Sonic 3 Rebuilt by TomatoWave_0
- Sonic The Hedgehog in Hellfire Saga
- Sonic 3 & Knuckles: Epilogue
- TishaProject (2019)
- Sonic Virtual Adventure (2017) (Cancelled) — In the past I made this source code specifically for this project (: