Sonic R/Technical information/Windows PC

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Fixing startup crash

Sonic R's startup code attempts to divide a value by the time elapsed for a given function. On reasonably fast computers (basically anything with a CPU newer than Pentium 4), this results in a division by zero. This can be fixed with a simple binary edit.

[source]

(Note: This hack assumes you're using the original executable without network support. The network version doesn't seem to work on NT-based Windows systems to begin with.)

In a hex editor, go to offset 0x70584. Replace these bytes:

2e ff 15 8c 05 95 00

with these bytes:

b8 31 00 00 00 90 90

Next, go to offset 0x705A0. Replace these bytes:

2e ff 15 8c 05 95 00

with these bytes:

b8 01 00 00 00 90 90

What this does is it disables the function calls to get the system time and replaces them with known values that are guaranteed to work on modern systems.

RAM locations

These values are absolute from base of RAM; a value of 0x400001 is equal to sonicr.exe+0x000001.

Global variables

TODO: Find and add the remaining 2004 variables.

Address (2004)	Address (1998)	Data Type	Description	Notes
	0x504278	Dword	CD Check	1 if CD present, 0 if not. Largely useless after game boots.
	0x540064	Dword Pointer	AI RAM Location	Memory address of the current level's AI data (copied into RAM from the AI file.)
	0x625BFC	Word	Current File	Used by fread()
0x5EDD24	0x630144	Dword	Windowed	Crashes the game when not 0 on the 1998 release.
	0x630148	Dword	Native Software Render Mode	Probably related to ancient software 3D drivers for Windows 95.
	0x675907	Array (10 bytes)	Function Key States	Array of F1-F10, 0 being unpressed and 0x80 being pressed.
	0x68AF34	Dword	Sound Test Selection	Selection for the Sound Test option on the Options menu.
	0x68AF38	Dword	Music Test Selection	Selection for the Music Test option on the Options menu.
	0x68AFB8	Dword	1P Ready	Controls whether or not the player has selected their character. If less than 4 players, the unused players are automatically set to 1.
	0x68AFBC	Dword	2P Ready
	0x68AFC0	Dword	3P Ready
	0x68AFC4	Dword	4P Ready
	0x6d9A38	Dword	Seconds Since Race Start	Used to control camera position, and "READY SET GO!" indicators, among other things.
0x75349C	0x6DD860	Dword	Render Mode	0 if ? (makes D3D not load new textures), 1 if standard D3D, 2 if DDraw
0x461520	0x6E9898	Dword	X Resolution	Sometimes forcing this to a value w/ Cheat Engine and toggling the resolution back and forth will make this resolution stick. It usually does not.
0x461524	0x6E989C	Word	Y Resolution
	0x6E98B4	Dword	Color Depth	Possible values 8 and 16. D3D is always 16.
	0x6E98DC	Dword	Visible Screen Width	Width of screen excluding borders added in options.
0x7AF280	0x6E9908	Dword	No. of Game Windows	Number of windows to show. Don't set to higher than there is screen space for; exit level, set, and reenter level instead.
0x7344EC	0x6E991C	Dword	2P HUD Split style	0 is horizontal, 1 is vertical. Doesn't seem to effect anything besides HUD elements and borders, actual window positions are determined by something else.
	0x6E9958	Float	Camera Angle Float?	A float of some sort determining some sort of camera angle.
	0x6E9C90	Dword	Viewport X	X-position of camera.
	0x6E9C94	Dword	Viewport Y	Y-position of camera.
	0x6E9C98	Dword	Viewport Z	Z-position of camera.
N/A	0x6E9CDC	Dword	Current FPS	How many frames the game renders in a second. Does not count frames skipped by user choice. (2004 version uses kernel32:sleep() for waiting instead so it doesn't use this.)
	0x6E9D00	Dword	Frames Rendered Lifetime	Probably the frames rendered since the game first starts.
	0x6EAD30	Dword	# Parts in course	Range 0-until it crashes. Tells the game how many level parts it should render. Typical values ~500-~1000, depending on the complexity of the level.
0x753504	0x713060	Dword	Model Count	Number of character models. Should be 10 on vanilla copies of the game.
0x753678	0x713064	Dword	Model Limb Count	Number of movable parts in all character models. Should be 115 in vanilla copies of the game.
0x7BCB70	0x713068	Dword	Model Vertex Count	Number of vertexes in all character models. Should be 3349 in vanilla copies of the game.
0x7AF07C	0x713070	Dword	Model Polygon Count	Number of polygons (tris and quads) in all character models. Should be 1917 in vanilla copies of the game.
0x7535DC	0x713074	Dword	Model Frame Count	Number of total animation frames for all characters. Should be 15974 in vanilla copies of the game.
	0x8F6C28	Dword	Footstep/Shadow texture page	Offset for textures used in character footsteps and shadows.
	0x8F6C38	Dword	Pause Menu/MP Number Texture Page	Offset for textures used in pause menu and multiplayer-specific HUD elements.
	0x8F6C3C	Dword	HUD texture page	Offset for textures used in HUD elements.
	0x8F6C48	Dword	Menu Texture Page	Offset for textures used in menu screens.
	0x8FB35C	Dword	Draw Distance 2	Unknown use
	0x8FB360	Dword	Draw Distance 3	Unknown use
	0x8FB364	Float	Draw Distance Fog	Controls fog distance, but not render distance.
	0x8FB68C	Dword	Frames Rendered Scene	Frames rendered since the start of the race/menu/etc.
	0x8FB690	Dword	Frames Rendered Lifetime	Frames rendered since the start of the game.
	0x8FB80C	Dword	Frame Limiter Multiplier	How many frames to skip before rendering another one. 0 is 30FPS, 1 is 15 FPS, etc.
	0x8FB8E4	Dword	Demo Mode	Tells if the game is currently in demo. 0 - No demo 1 - Title screen demo 2 - Replay demo
0x7AF13C	0x8FB8EC	Word	Current Course	Current course. Changing during gameplay WILL crash game. Note that Factory and Ruin are swapped from their in-game menu order. 0 - Invalid 1 - Resort Island 2 - Radical City 3 - Reactive Factory. 4 - Regal Ruin. 5 - Radiant Emerald.
0x769F24	0x8FB950	Dword	Game Mode	The current HUD/game mode. 0 - GP Mode 1 - Multiplayer 2 - Time Attack 3 - VS. Challenge
0x769F28		Word	Sum Of Emeralds Collected	The emeralds have an assigned value (1 or 2). The sum of the collected emeralds is stored here.
0x7BCB80	0x8FB954	Dword	Time Attack Submode	The current time attack submode 0 - Normal 1 - Reverse 2 - Tag 4 3 - Balloon Hunt
	0x8FD444	Dword	Game Difficulty	Difficulty of game. Range 0-2.
	0x8FD448	Dword	Ghost On/Off	Toggles time attack ghost saving/loading. 0 is off, 1 is on.
	0x8FD44C	Dword	Weather Option	Chosen weather conditions. 0 - Random 1 - Clear 2 - Rain 3 - Snow
	0x8FD450	Dword	Catchup On/Off	Toggles rubber band AI (although it seems largely ignored if difficulty is not on hard.) 0 is off. 1 is on.
	0x8FD454	Dword	Guide On/Off	Toggles the trail of sparkles in time attack mode showing you where to go. 0 is off, 1 is on.
	0x8FD458	Dword	Minimap On/Off	Toggles the minimap in the corner. 0 is off, 1 is on.
	0x8FD45C	Dword	2P Split Option	Changes which way the subscreens in 2 player mode are oriented. 0 is Horizontal, 1 is Vertical.
	0x8FD468	Dword	Screen Y Resolution Option	The number shown on the resolution option. Does not actually modify the resolution.
	0x8FD46A	Dword	Screen X Resolution Option
	0x8FD46C	Dword	Color Depth	Number of bits of color information. Can be 8 or 16. Only option in D3D mode is 16.
	0x8FD470	Dword	Alpha Blending On/Off	DDraw only. Toggles between mesh-style transparency and actual alpha blending
	0x8FD474	Dword	Unused Option	Probably unused, but it is saved/loaded like all the other options.
	0x8FD478	Dword	Interlace On/Off	DDraw mode only. Toggles whether or not to skip every other line. 0 is off, 1 is on.
	0x8FD480	Dword	Draw Distance	Option for the draw distance. In D3D mode this can go up to the max value, but doing go in Ddraw mode will make frames take years to render.
	0x8FD484	Dword	Window	Size of the screen. 4 is full resolution, 0 is smallest size.
	0x8FD488	Dword	Track Shading On/Off	DDraw mode only. Toggles whether or not to tint the track.
	0x8FD490	Dword	Unknown Option	No idea what this does, but it seems to be referred to by everything.
	0x8FD494	Dword	Stereo On/Off	Toggles stereo sound. Considering all the sound effects are mono, this might be an attempt at 3D sound.
	0x8FD498	Dword	Vocals On/Off	Toggles vocals in the soundtrack. This is done by adding 6 to the current sound if it's a song.
	0x8FD49C	Dword	SFX Volume	Volume of the sound effects. Range 0-8, 0 being off (or really quiet, not sure) and 8 being maximum.
0x7AF1B4	0x8FD4A0	Dword	Music Volume	Volume of music in the game. Range for 1998 is 0-1. Range for 2004 is 0-8.
	0x901C10	Dword	Pause Screen Selection	Selection on the Pause menu. 0 - Continue 1 - Retry 2 - Retire
0x7C1BC0	0x901C30	Byte	Game Paused	Whether or not the game is paused. When the game is pause the only thing that happens is that it renders things and checks for input, so it's really useful for debugging.
0x5F388C		Dword	Screen Transition Speed	In units of "Screen Transition Coverage"/frame
0x7BCB28	0x901C44	Dword	Screen Transition Coverage (Maxes out before -255)	How much of the screen the wobbly inverted oval thing covers. In the negative, for some reason.
	0x901C48	Dword	Screen Transition State	State of the screen transitions. 0 - not transitioning 1 - fading out 2 - fading in
	0x901C70	Dword	No. Characters Tagged/Tokens	Range 0-5.
	0x901C78	Dword	Emerald Collected	Number of the last emerald collected by P1.
	0x901C84	Dword	Victory screen timer	Time remaining until the victory screen fades out and kicks you to results. Range 1-infinity, 0 being regular gameplay.
	0x901CC4	Dword	Time Until Race Start	Time remaining until the game starts. Also controls "READY" "SET" "GO" indicators, etc. Counts down.
	0x901CC8	Dword	GO! image size	Size of the "GO" image before the race starts. Setting this too high makes it upside down and small, for some reason.
0x4A3608	0x9020D8	8 bytes (2 bytes * 4 players)	Controls Bitfield	3 - LBrake 6 - Camera 7 - RBrake 8 - Spindash/Accelerate A - Jump B - Start C - Up D - Down E - Left F - Right
	0x902140	Dword	Camera X Position	X-position of camera.
	0x902144	Dword	Camera Elevation	Elevation of camera from water level. Negative values not allowed.
	0x902148	Dword	Camera Z Position	Z position of camera
	0x90214E	Dword	Camera X-Z Rotation	X-Z Rotation of camera from 0-4096.
	0x902152	Word	Camera Tilt	Tilt of camera relative to the player. 0 is forward, - is down. + is up.
0x752828	0x92528C	Dword	Options Screen Selection	Selection on the Options screen and usually anything else vertical, also rotation of main screen icon.
	0x925298	Dword	Character Select Sonic Icon Texture Y Offset	On character select screen, setting this from 0 is 40 changes the Sonic icon to Super Sonic, but not the actual selected character. Setting to 80 changes the icon to Tails, 120 to Knuckles, 160 to Amy, and 200 to a blank. Cannot change value with arrow keys unless the values are set to exactly 0 (Sonic) or 40 (Super Sonic) though.
0x7B7D48	0x9252B4	Dword	Main Menu Option	Selection for the Menu screen and usually anything else horizontal.
	0x9252B8	Dword	Horiz-Menu Screenpos Loc	Current location on screen of the selector on the menu. Range 0 to 320.
0x752858	0x9252BC	Dword	Horiz-Menu Screenpos Dest	Where the selector plans on going.
	0x9252DC	Dword	1P Controller Type	Type of controller used in multiplayer. Format is 0x000A000B, where A is 0 for keyboard and 1 for joystick and B is the port number of joystick or key binding for keyboard.
	0x9252E0	Dword	2P Controller Type
	0x9252E4	Dword	3P Controller Type
	0x9252E8	Dword	4P Controller Type
0x8607BC	0x94BCF4	Dword	Weather	Current weather, regardless of option. Ignored in Time Attack mode for some reason. 0 - clear 1 - rain 2 - snow 3+ - clear
0x85EB78	0x94BCF8	Dword	Time of Day	Time of day. Mostly effects graphics. 0 - sunrise 1 - day. 2 - sunset. 3 - night.
0x5D359C		Array (51 32-bit pointers)	Texture Buffer Pointers	Offsets to malloc'd texture page buffers in RAM. Changes do not effect output until sent to GPU.
	0x6260A4	Dword	No. of texture pages loaded
0x752BE0		Array (10 Dwords)	Character lock array	0 - Unlocked 1 - Locked 2 - Hidden

Player struct

Game keeps an array of 5 structs for each of 5 racers. For the 1998 release, this starts at 0x8FD4F4 For the 2004 release, this starts at 0x7B7388

Offset	P1 Address	Data Type	Description	Notes
0	Dword	X Position	0 is center of map. Goes up by large amounts.
4	Dword	Y Position	0 is water level. To go up, subtract. You can't go down.
8	Dword	Z Position	0 is center of map. Goes up by large amounts.
C	Dword	YZ Rotation	Max is 4096. Slowly reverts itself if not locked into extreme values.
10	Dword	XZ Rotation
14	Dword	XY Rotation
18	Dword	Ring Count	Max 999. Adding more makes the game subtract back down.
1C	Dword	Animation Frame?
20	Dword	X Position Mirror [???]	Not sure what these are for.
24	Dword	Y Position Mirror [???]
28	Dword	Z Position Mirror [???]
2C	Dword	X Speed	Higher values = faster speed. Goes negative, too. Given in relation to world, not player.
30	Dword	Y Speed
34	Dword	Z Speed
38	Dword	Ground Height	Y position of ground below you
40	Word	In Water?	0 = No, 1 = Yes.
42	Word	Time Until Sink	The higher this is, the longer it takes Sonic/etc. to sink. Instead they just kind of splash through the top of the water ala the shallow water in Super Mario Kart.
44	Dword	Forwards Speed RO	Momentum in terms of the character.
4C	Dword	Distance on Track [?]	Used to calculate race rankings. As such it isn't calculated in Time Attack mode. Goes up by large amounts the further along the track you go. Does not take lap number into account if you've forced it to another number, weirdly enough.
50	Word	Lap 1 Time	1 is ~1/60 of a second. Causes Game Over once the sum of Laps 1-3 reaches 212400 (1 hour).
54	Word	Lap 2 Time
58	Word	Lap 3 Time
5C	Word	Current Place (Center/Player)	Range 1-5. Game won't yell at you if it isn't so, but it'll crash on results screen if not in range 0-6.
5E	Word	Current Lap (Center/Player)	Range 0-3. Setting to 3 instantly loads results screen.
64	Word	Most Recent Item	Seems to only effect the icons that shows you what item you got. 0 - Nothing 1 - Speed Shoes 2 - 5 Ring 3 - 10 Ring 4 - 20 Ring 5 - Water Shield 6 - Electric Shield Above - Garbage graphics.
66	Word	Item Get Cooldown Time	Affects how long until the item box can be used again, and also how long the icon is on screen.
68	Word	Water splash timer [?]	Setting this and water depth to highish values causes a ôburrowingö effect. Strange.
6A	Word	Depth into water	Range 0-6. 6 is fully submerged, 0 is on land.
6C	Word	Pressing Forward	Changes to 0x0000FFFF when the forward key or the accelerate/back key is pressed.
70	Word	Camera XZ Rotation	Range 0-4096. Not sure what the difference between this and the global one is, as they're both obeyed.
72	Word	Ground Flag	1 = on ground, 0 = in air.
74	Word	Tails/Knuckles flight mode	When Tails/(Metal) Knux, set to 0xFFFF when jumping up in air, 2 when flying/gliding, and 0 when falling/on ground.
96	Word	Time in air	Time spent flying in air. Tails stops flying around 62.
98	Word	Current Animation	Animation sequence being played. Note that some of these animations crash with Amy, Robotnik and some of the metal characters. Also some animations after 7 crash on the character select screen. 0 - Running 1 - Jumping 2 - Standing 3 - Skid right 4 - Skid left 5 - Hit by bomb/Falling 6 - Victory 7 - Lose 8 - Recover from left skid. 9 - Recover from right skid. 10 - Duck 11 - Recover from duck 12 - Alternate running? 13 - Falling forwards? 14 - Falling forwards? 15 - Falling 16 - Springing 17 - Stretching 18+ - Character specific?
9C	Dword	Animation Frame (??)	Frame of the animation being played. May or may not be a pointer.
A0	Dword	Loop Mode	If this is 1 while not on a loop, Sonic will just randomly warp across the terrain until he goes out of bounds and crashes.
A4	Dword	Current Collision Layer	Determines which floors/walls the character should listen to during collision detection.
B0	Word	Above Geometry	Is 1 if the player is above some sort of level geometry, 0 if on flat ground or water.
B2	Word	Above Geometry Mirror
B4	Word	Slope RX	Rotation of the current slope along the global X axis.
B6	Word	Slope Magnitude	Intensity of current slope. Independent of X/Z.
B8	Word	Slope RZ	Rotation of the current slope along the global Z axis.
BC	Dword	Loop ?
C0	Dword	Loop XZ Pos	Location left/right while on a loop.
C4	Dword	Loop Distance	Distance completed on the loop.
C8	Dword	Loop ?
CC	Dword	Loop XZ Momentum	Left/Right movement momemtum.
D0	Dword	Loop Momentum	Forwards/Backwards momentum on the loop.
D4	Word	Drift Direction?	0xFE00 if drifting right, 0x0200 if drifting left. Unknown purpose.
EA	Word	Sound FX	Set this to a SFX ID to play a sound effect only heard by that player
F0	Word	Always 1	Not sure what this is for.
F2	Word	Identity	Effects everything besides the character model, including animations, icons, control, etc. Range 0-9.
11C	0xA4 (164) Bytes	AI Area Start	Wiped at beginning of each round. Seems to be used by AI.
1E0	Dword	Player Model	Range 0-9, 0 being Sonic, 9 being Super Sonic.
1EC	Dword	Running Animation	Animation frame being played. Range 0-maximum frame count for the player. Probably corresponds with the loaded files.
1F4	Word	Number of Balloons	Balloons popped in Time Attack Balloon mode. Range 0-255. Setting to 5 instantly loads results screen.
204	Dword	Last Balloon Timer?	Value is usually zero, but setting to max starts a countdown that is set to zero when a balloon is popped.

Total length: 0x71C bytes

Character models

Model format

File alternates between vertices, triangles and quads until a vertex count of 0xFFFF is reached. In the event there are no tris or quads in a section, the section is simply skipped. Stored as CHARNAME_?.BIN in /BIN/OBJECTS/CHARNAME

Description	Length
Vertices
Number of Vertices in Part	Word
For each vertex...
X	Word
Y	Word
Z	Word
Unknown	9 bytes
EOL (always 0x80)	Byte
Total:	16 bytes
Triangles
Number of Tris in Part	Word
For each tri...
Vertex No. of Point A	Word
Vertex No. of Point B	Word
Vertex No. of Point C	Word
Texture Point TA-X	Byte
Texture Point TA-Y	Byte
Texture Point TB-X	Byte
Texture Point TB-Y	Byte
Texture Point TC-X	Byte
Texture Point TC-Y	Byte
Null	Dword
Total:	16 bytes
Quads
Number of Quads in Part	Word
For each quad...
Vertex No. of Point A	Word
Vertex No. of Point B	Word
Vertex No. of Point C	Word
Vertex No. of Point D	Word
Texture Point TA-X	Byte
Texture Point TA-Y	Byte
Texture Point TB-X	Byte
Texture Point TB-Y	Byte
Texture Point TC-X	Byte
Texture Point TC-Y	Byte
Texture Point TD-X	Byte
Texture Point TD-Y	Byte
Null	Dword
Total:	20 bytes
End of File (0xFFFF)	Word

Animation format

Stored as ?AN#.BIN in /BIN/OBJECTS/CHARNAME

Description	Length
# of parts to move (global)	Dword
For each part until EOF...
Transformation TX	Dword
Transformation TY	Dword
Transformation TZ	Dword
Rotation RX	Dword
Rotation RY	Dword
Rotation RZ	Dword
Total	24 bytes

Texture format

Tools for editing textures can be found here, with source code here.

RAW files, PLY files

These files only contain raw image data, in RGB888, without any information about width or height. The file size can be one of the following values.

File Size	Width	Height
21504	32	224
23040	96	80
49152	128	128
196608	256	256
368640	320	384
638976	1664	128
921600	640	480

256 files

These files begin with 256 palette entries, in RGB888. Then there are two 2 byte values indicating the width and height.

Following that is the image data, in 8bpp.

Track format

Research incomplete.

Geometry file

Stores track geometry, starting position for each character, the finish line location, results screen stuff, the time trials guide path, and presumably the accelerator path as well. Shares same format as 3D icons on menu/title screen.

The geometry portion is split up into two parts: the track parts and the decoration parts. The track parts can contain rings. I'm not entirely sure why this distinction exists.

Faces on the track portion seem to simply assume that it uses 4 vertices in order. (EX: Part 1 uses vertices 1-4, Part 2 uses 5-8, etc.)

After all the visible parts come 7 sections of X/Y/Z coordinates used by the game for various purposes.

The first section appears to be every valid path on the track. Might be used for lap-keeping.

The second section is both the intro camera path and the accelerator path. It consists of 360 x/y/z coordinates, where the first 180 are the camera intro keyframes and the last 180 are the accelerator path.

No clue what the third section is. Made up of 4 points (in Radical City, at least.)

Fourth section is the primary path, excluding shortcuts and ring gate paths. Possibly used for boost and lap-keeping.

Fifth section are the player locations for the start of the race and the victory sequence at the end.

Sixth section appears to be positions for the camera to stay stationary during replay mode.

Seventh section is listed as one byte too long and does not seem to be positional data. It could be some important meta-data like results screen icon.

Description	Length
Length of header	Dword
Header (unused by game)	Length of header * 128 bytes
No. of track parts	Dword
For each track part...
X-position	Dword
Y-position	Dword
Z-position	Dword
Effects viewing angles of parts somehow.	Dword
Number of points	Dword
For each point...
X-position	Word
Y-position	Word
Z-position	Word
Red tint	Word
Green tint	Word
Blue tint	Word
Total	12 bytes
Number of faces
For each face...
Texture page (in order loaded by game)	Byte
Null	Byte
Texture Point TA-X	Byte
Texture Point TA-Y	Byte
Texture Point TB-X	Byte
Texture Point TB-Y	Byte
Texture Point TC-X	Byte
Texture Point TC-Y	Byte
Texture Point TD-X	Byte
Texture Point TD-Y	Byte
Unused	Word
Total:	12 bytes
0x0000 (only if rings are on part)	Word
For each ring (if last word was 0x0000)...
X-position	Dword
Y-position	Dword
Z-position	Dword
Total:	12 bytes
Ends with 0xFFFFFFFF
Number of decoration parts	Dword
For each decoration part...
Effects viewing angles of parts somehow.	16 bytes
X position	Dword
Y position	Dword
Z position	Dword
Unknown	6 bytes
Number of triangles	Dword
For each tri...
Point A	Word
Point B	Word
Point C	Word
Texture Point TA-X	Byte
Texture Point TA-Y	Byte
Texture Point TB-X	Byte
Texture Point TB-Y	Byte
Texture Point TC-X	Byte
Texture Point TC-Y	Byte
Texture page	Dword
Total:	16 bytes
Number of quads	Dword
For each quad...
Point A	Word
Point B	Word
Point C	Word
Point D	Word
Texture Point TA-X	Byte
Texture Point TA-Y	Byte
Texture Point TB-X	Byte
Texture Point TB-Y	Byte
Texture Point TC-X	Byte
Texture Point TC-Y	Byte
Texture Point TD-X	Byte
Texture Point TD-Y	Byte
Texture page	Dword
Total	20 bytes
Number of points	Word
For each point...
X-position	Word
Y-position	Word
Z-position	Word
Red tint	Byte
Green tint	Byte
Blue tint	Byte
Null byte	Byte
Total	10 bytes
Number of track path points	Dword
For each track path point...
X	Dword
Y	Dword
Z	Dword
Total	12 bytes
Number of intro camera keyframes	Dword
For each intro camera keyframe...
X	Dword
Unknown (possibly time)	Dword
Z	Dword
Total	12 bytes
Number of (Unknown part 3)	Dword
For each (Unknown part 3)...
Unk 1 (Possibly X)	Dword
Unk 2 (Possibly Y)	Dword
Unk 3 (Possibly Z)	Dword
Total	12 bytes
Number of primary path points	Dword
For each primary path point...
X	Dword
Y	Dword
Z	Dword
Total	12 bytes
Number of player start/end locations	Dword
For each player start/end location...
X	Dword
Y	Dword
Z	Dword
Total	12 bytes
Number of replay camera positions	Dword
For each replay camera position...
X	Dword
Y	Dword
Z	Dword
Total	12 bytes
Number of (Unknown part 7) + 1	Dword
For each (Unknown part 7)...
Unk 1	Word
Unk 2	Word
Unk 3	Word
Total	6 bytes
No special ending

Collision file

Contains collision data. Located in /BIN/EXTRAS. Massively over engineered.

Notes

There exist only two types of collision objects (not counting loops, ring gate activation points, etc.): floors and walls. Really steep slopes are just really steep floors. Ceilings are just the bottom of floors you can't walk on. (Best example is the big ramp upwards in Regal Ruin; the same collision data is used when you're on top of the ramp as when you're underneath it jumping up.)

Memory variable 0x8FD598 (for player 1) is a variable that lists the current "collision layer" the player is on. This starts (usually, depends on level) at 0. It increments when you walk or jump onto a floor that is on top of another floor. Likewise, it decrements when you fall or walk off a floor on top of another floor. (Example: Rock overhang in Resort Island. The ramp up to the overhang is layer 0. The overhang itself is layer 1, as it's overtop of layer 0 (the path below). The arrow sign on the overhang is layer 2, as it's over both the overhang and the path.)

Unless otherwise noted, all values are 2 byte word values.

Header

The first 0x5C bytes are reserved for a header. In this header are the offsets to 10 sections and 13 variables (in that order), all stored as 4-byte DWORDS. To reach a certain section, one simply reads the Nth DWORD and jumps ahead to that DWORD's value.

Variables

1-5, 7, and 8 are unused in the game apart from (most likely) leftover dead code.

6 is the number of loop objects in the level. This is used when reading data from section 6.

9 is the number of objects in section 9. This is used when reading data from section 10.

10-13 are hard course limits. It is impossible to pass these.

   All maximums are multiplied by 4096 when compared with player XYZ.
   Minimums are multiplied by 32, added to maximum, decremented, and then multiples by 4096. (Why?)
   Also I may have swapped Minimum and Maximum. As they're not real coordinates, it's hard to tell.
   10: Max X
   11: Max Z
   12: Min X
   13: Min Z

Note: The coordinates have the form [block][major][minor][precise]. The levels are split into blocks labelled -2, -1, 0, 1, 2, which correspond to FE,FF,00,01,and 02, and those blocks are further split into 0-255 (left to right), and those blocks are further split into 0-255 (left to right). A coordinate can look like FF1af44e, which would correspond to block -1 (FF/block), at position 26 (1a/major), sub-position 244 (fa/minor), sub-sub-position 78 (4e/precise).

Section 1

Main heightmap. This is used to determine what height the character should be at over a certain point.

Note that there exists some sort of mask to determine what is and isn't valid terrain. If you walk off the mask, you will drop to the water level, regardless of any existing heightmap data. Likewise if the heightmap is below the water level (or missing, not tested) the game will attempt to eject you from the floor at the last valid angle you stood on.

Description	Length
X	Word
Height	Word
Z	Word
Total	6 bytes

To get offset from Section 2, you might be able to use raw Section 2 value and add to Section 1 pointer.

Section 2

Possibly rotation data for the points from section 1. Most likely 4 bytes in length. Unknown contents.

To get offset from Section 3, compute [Sec2 + [Sec3_Val] * 14], where ? is one of 2, 4, or 8.

Section 3

Some sort of 2D point map. Unknown (but important) purpose.

Description	Length
Unk. 1	Word
Unk. 2	Word
X	Word
Z	Word
Total	6 bytes

To get this from Section 9, compute [Sec3 + ([Sec9+?] & 0xFFF) * 0x10 + {2, 4, 8}]. (Not sure what ? is. Choose one of 2, 4, or 8.) Only use highest 2 bytes of result. (right-shift 0x10)

Section 4

Undeniably related to walls in some way, shape, or form.

16 bytes (8 words) in length.

The first two words, when edited, seem to cause walls to disappear from some places and reappear (at seemingly intentional places, such as both ends of the high path around Resort Island's volcano thing) in other places.

3rd word (+04) is 2^(current layer).

+06 and +08 are related to X/4096 and Z/4096, respectively.

+0C is compared to (X-06)^2 + (Z-08)^2 to change code branching path.

To get an offset from Section 9, compute [Sec4 + (Sec9 & 0x0FFF) * 16]

Section 5

Appears to be a wallmap, but I cannot confirm this. It appears (when rendered) to be the outlines of the higher up portions of the level.

Description	Length
X	Word
Height	Word
Z	Word
Total	6 bytes

To get an offset from Section 4, compute [Sec5 + [Sec4_Val]*6 + 6]. The (+6) may be optional.

Section 6

Loop metadata. Unknown format and structure size.

Section 7

Loop point information. Should be X/Y/Z like the others, but rendering it like that causes a lot of garbage data to appear. (Despite this, the loop fits in perfectly with all the other collision data.) Attemping other structure sizes doesn't make the garbage disappear; garbage is possibly metadata read using information from section 6.

Section 8

Structure size is probably 16 bytes or a factor of 16 bytes.

This is a look-up table that converts player X and Z coordinates to Section 9 offsets.

To get a Section 9 offset, compute [Sec8 + ((Z/4096 - MaxZ) / MinZ * 32 + ((X/4096 - MaxX) / MinX))]. Add that value to the Section 9 start.

Section 9

Structure size is 4 bytes.

This is the primary look-up table. Most other non-XZ tables are indexed by the contents of this table.

Typically only the last 3 nybbles (& 0x0FFF) are used.

See the descriptions for the other sections for how this is used.

Section 10

Seems to contain ring gate activation points. Possibly contains points for other objects; this is untested.

(Note: this may be wrong)

Description	Length
X	Word
Y	Word
Z	Word
Index	Word
Total	6 bytes

AI files

Contains path data for the computer opponents. Located in /AI. Does not contain anything needed for time trials/multiplayer.

Split up into 5 sections.

(Reporting segment size as how many calls to fread() the code makes per section loop)

Section 1 is 0x2000 2 byte segments. This appears to be the input sequence for every AI. Replacing just this section with the bytes from another level made the AI appear think it was on the other level.

Section 2 is 0x80 4 byte segments. This may be the time to wait between inputs. Zeroing out this section resulted in the AI taking every action needed to move around a level within a smaller area/quicker time.

Section 3 is 0xE00 1 byte segments.

Section 4 is 0x400 1 byte segments.

If the course is Resort Island, Section 5 is 0x320 * 1 byte. If the course is Radiant Emerald, Section 5 is 0xA0 * 1 byte Otherwise, Section 5 is 0x280 * 1 byte.

Contents need additional research.

Save files

These files can be found in the .\save directory with filenames in the format r##.sav
This is an incomplete listing of the locations inside these files:

Offset	Type	Description
4	Byte	Resort Island Unlocked (def. 1) 0 - Locked 1 - Unlocked 2 - 1st Place
8	Byte	Radical City Unlocked (def. 1)
C	Byte	Reactive Factory Unlocked (def. 1)
10	Byte	Regal Ruin Unlocked (def. 1)
14	Byte	Radiant Emerald Unlocked (def. 0)
18	Byte	Sonic Unlocked (def. 2) 0 - Hidden 1 - Locked 2 - Unlocked
1C	Byte	Tails Unlocked (def. 2)
20	Byte	Knuckles Unlocked (def. 2)
24	Byte	Amy Unlocked (def. 2)
28	Byte	Robotnik Unlocked (def. 1)
2C	Byte	Metal Sonic Unlocked (def. 0)
30	Byte	Tails Doll Unlocked (def. 0)
34	Byte	Metal Knuckles Unlocked (def. 0)
38	Byte	Eggrobo Unlocked (def. 0)
3C	Byte	Super Sonic Unlocked (def. 0)
40	Byte	Blue Emerald Collected 0 - Not Collected 2 - Collected
44	Byte	Green Emerald Collected
48	Byte	Purple Emerald Collected
4C	Byte	Yellow Emerald Collected
50	Byte	Orange Emerald Collected
54	Byte	Red Emerald Collected
58	Byte	White Emerald Collected

sonicr.inf

This file, located in the main folder, stores various settings. Note that despite the extension inf, it is not an actual inf file, and should NOT be opened with Notepad.

Offset	Type	Description
0	Byte	Difficulty 00 - Easy 01 - Normal 02 - Hard
4	Byte	Ghost Toggle 00 - Off 01 - On
8	Byte	Weather 00 - Random 01 - Clear 02 - Rain 03 - Snow
C	Byte	Catch Up Toggle 00 - Off 01 - On
10	Byte	Guide Toggle 00 - Off 01 - On
14	Byte	Map Toggle 00 - Off 01 - On
28	Byte	Color 08 - 8-bit 10 - 16-bit
18	Byte	2P Split 00 - Horizontal 01 - Vertical
2C	Byte	Alpha Blending 00 - Off 01 - On
34	Byte	Interlace 00 - Off 01 - On
3C	Byte	Draw Distance 00 - Very Near 01 - Near 02 - Medium 03 - Far 04 - Very Far 10 - Max. Draw Distance
40	Byte	Screen Size 00 - Very Small 01 - Small 02 - Medium 03 - Large 04 - Full Screen
44	Byte	Track Shading 00 - Off 01 - On
50	Byte	Stereo Toggle 00 - Off 01 - On
54	Byte	Vocals Toggle 00 - Off 01 - On
58	Byte	SFX Volume (00-08)
5C	Byte	Music Toggle 00 - Off 01 - On