RRM Format (Mythos Software)

The RRM Format is a container for room-specific data in The Lost Files of Sherlock Holmes: The Case of the Serrated Scalpel.

File format

Header

The header has this format:

Data type	Name	Description
char[32]	magicText	"\r\n\nHOLMES RESOURCE FILE V2.1\r\n\n\x1A"
BYTE[7]	magicBytes	The same in all files: 00 14 9C 0E 74 50 05. Unknown meaning.
BYTE	isPacked	09 = unpacked, 0A = packed.
UINT32LE	dirOffset	Offset of the directory, described below.

Animations

The header is followed by zero or more animation offsets and data:

Data type	Name	Description
UINT32LE[nAnims]	animOffsets	Offsets to VGS data for animations.
VGSChunk[nAnims]	anims	Animations in the Visage format.

nAnims is found in the directory that follows. RRM files are not parsed sequentially.

Sprite Definitions

Next comes a table defining the sprites:

Data Type	Name	Description
SPRITEDEF[nObjects]	spriteDefs	See below for SPRITEDEF definition.

Note that there are nObjects SPRITEDEFs not nSprites. There are always at least as many objects as there are sprites, and the table is null-padded.

DataType	Name	Description
UINT32LE	spriteSize	Size of the VGS chunk for this sprite.
UINT8	numFrames	Number of frames in the sprite.
char[9]	spriteName	Internal name of the sprite.

Object Data

Objects are the game's most complex data structure and will be defined later on this page. For now, they will be viewed simply as 569-byte chunks. They and their remaining associated data follow:

DataType	Name	Description
OBJECTDEF[nObjects]	objects	Logical room objects.
char[textSize]	objectText	ASCIIZ descriptions used when looking at an object.
BYTE[sequencesSize]	sequenceBlock	Object sequences, defined later on this page.
VGSChunk[nSprites]	sprites	VGS chunks for sprites defined in the SPRITEDEFs.

The VGS chunks for sprites can be read sequentially using the size field in the SPRITEDEFs.

Animation Structures

Next come structures defining the behaviour of animations:

DataType	Name	Description
ANIMDEF[nAnims]	animDefs	See below.

DataType	Name	Description
char[12]	name	Name of the animation structure.
BYTE[30]	sequence	Sequence defining frame order, etc. Sequences are defined later.
UINT16LE	x	Topleft coordinate for first animation frame.
UINT16LE	y	Topleft coordinate for first animation frame.
UINT32LE	size	Size of VGS chunk in the block near the top of the file.
UINT16LE	state	Related to state field of objects, explained later.
UINT8	drawOptions	Related to drawOptions field of objects, explained later.
HPOS	startPos	Holmes' standing position when the animation begins.
HPOS	endPos	Holmes' standing position when the animation ends.

HPOS is a type also used elsewhere in this file. It defines a 'stance' for Holmes:

DataType	Name	Description
UINT16LE	x	Screen coordinate * 100
UINT16LE	y	Screen coordinate * 100
UINT16LE	loopNum	Index into Holmes' list of lists of frames, to be added here later. Essentially, the direction he is facing and whether he is walking or standing still.

The game does coordinate calculations internally in multiples of 100, for example the centre of the screen would be 16000x10000. This was presumably done to avoid floating point in diagonal move deltas.

Pathing Data

Next comes a number of data structures defining how Holmes moves around the room.

DataType	Name	Description
UINT16LE	boxBlockSize	Size of the following block of BOXDEFs. Let nBoxes = boxBlockSize / 10.
BOXDEF[nBoxes]	boxDefs	Boxes as defined below.

BOXDEF is defined as follows:

DataType	Name	Description
UINT16LE	x	Coordinates defining a walkable area on the screen.
UINT16LE	y
UINT16LE	w
UINT16LE	h
UINT16LE	flags	Unknown purpose.

A magic byte 0xFE follows, and then a lookup table and waypoints data chunk:

DataType	Name	Description
INT16LE[nBoxes][nBoxes]	lookup	See below for explanation.
UINT16LE	waypointsSize	Size of following waypoints data chunk.
BYTE[waypointsSize]	waypoints	Waypoints data chunk.

This data is used when Holmes tries to walk from one box to another. The boxes may not be connected and require travel through other boxes. Let src be the index of the box he is in, and dest be the index of the destination box. lookup[src][dest] where src is a column in the table will yield an index into the waypoints chunk. A waypoints entry looks like this:

DataType	Name	Description
UINT8	nWaypoints	Number of waypoints that follow.
WAYPOINT[nWaypoints]	waypoints	List of screen coordinates that Holmes should walk towards on his path from `src` to `dest`. Each coordinate is UINT16LE x, UINT8 y.

Note that all entries on the main diagonal of the lookup matrix are 0, and at offset 0 in the waypoints block is a set of 0 waypoints, because there is no path needed from a box to itself. Additionally, all entries below the main diagonal are -1, indicating a redundant entry. This is because paths are reversible and the upper half contains all data needed.

Next come the exit boxes:

DataType	Name	Description
UINT8	nExitDefs	Number of following EXITDEFs.
EXITDEF[nExitDefs]	exitDefs	Exits as defined below.

EXITDEF is defined as follows:

DataType	Name	Description
UINT16LE	x	Coordinates defining a walkable area on the screen.
UINT16LE	y
UINT16LE	w
UINT16LE	h
UINT16LE	roomNum	Destination room number.
UINT16LE	unknown	Always 1.
UINT16LE	destX	Holmes' position on entering the new room.
UINT16LE	destY	Holmes' position on entering the new room.
UINT16LE	destLoop	Holmes' animation loop on entering the new room.

Walking on an EXITDEF area causes Holmes to leave the room.

Concluding the pathing data, Holmes' starting position in the room:

DataType	Name	Description
HPOS	startPos	Holmes' starting position on entering the current room.

Sounds

A list of sound effects follows.

DataType	Name	Description
UINT8	nSoundDefs	Number of sound effect names that follow.
char[nSoundDefs][9]	soundDefs	8-byte sound effect name, padded with nulls, followed by byte 09. The sound effect is found in the LIB archive SND.SND

Room object sequences, defined later on this page, can cause a sound effect to be played by index into this list.

Palette and Background

The remainder of the .RRM consists of a 768-byte VGA Palette and a 320x138 background image.

The palette is required to construct the animations and sprites earlier in the file. The programmer may choose between parsing through the file and constructing the animations and sprites later, or seeking to the end of the file immediately, since the palette is always at the fixed offset of EOF - (320 * 138 + 768).

Object Structure

Objects are logical entities in a room that affect gameplay. They may have an associated sprite, or they may have not and function as an invisible trigger area. Still other objects may have no spatial meaning and represent state transitions.

Objects always occupy 569 bytes. Many fields only have meaning at runtime.

FARPTR in the DataType column refers to a 32-bit memory location composed of UINT16LE offset, UINT16LE segment. These runtime fields are included for completeness.

Offset	DataType	Name	Description
0	char[12]	name	Internal ASCIIZ object name.
12	char[41]	hoverText	ASCIIZ text shown on the status line when the player hovers over the object.
53	FARPTR	textPtr	runtime: pointer to ASCIIZ text description.
57	FARPTR	seqPtr	Initially, the first UINT16LE in this field holds the offset of this object's sequence data in the room sequenceBlock. runtime: afterwards, the field is used as a FARPTR to the sequence.
61	FARPTR	spritePtr	runtime: pointer to VGS sprite for the object.
65	FARPTR	framePtr	runtime: pointer to current sprite frame.
69	BYTE	unknown	always 0
70	BYTE	unknown	always 0
71	UINT16LE	seqIndex	runtime: current position in the object's sequence.
73	UINT16LE	unknown	always 0
75	UINT16LE	x	Topleft screen coordinate of the object.
77	UINT16LE	y	Topleft screen coordinate of the object.
79	INT16LE	deltaX	runtime: position delta for moving object.
81	INT16LE	deltaY	runtime: position delta for moving object.
83	UINT16LE	state	These values occur in the `.RRM`: 4: active, with sprite 6: active, without sprite 7: inactive
85	UINT16LE	frameX	runtime: dimensions of the current sprite frame.
87	UINT16LE	frameY
89	UINT16LE	frameWidth
91	UINT16LE	frameHeight
93	BYTE[4]	unknown	always 0
97	UINT8	intBehave	encodes various things that happen when the user interacts with the object.
98	UINT8	defBehave	default interaction, as an index into the menu commands (1=Look, 2=Talk, 3=Move, etc.)
99	INT16LE[3]	flags	story progress flags, to be described elsewhere.
105	UINT16LE	hoverX	Area occupied by an object with no sprite. 0,0 for objects with sprites.
107	UINT16LE	hoverY
109	UINT16LE	unknown	always 0
111	UINT8	spriteNum	If 0, the object has no sprite. If > 0, subtract 1 and use as index into room sprite list.
112	UINT16LE	spriteFrames	Number of frames in the object's sprite.
114	BYTE	drawOptions	Bitfield controlling drawing of the object's sprite. The following bits are known so far: 0 and 2: OR these bits together and interpret as a number from 0..3 representing drawing layer, with 0 as backmost and 3 as frontmost. 1: if 1, the sprite is mirrored.
115	ACTIONDEF	openAction	Behaviour when opening the object. See below for ACTIONDEF.
165	BYTE	onCollision	Unknown value encoding what to do when Holmes collides with the object.
166	BYTE	unknown	unknown purpose
167	BYTE	seqRepCounter	runtime: counts how many times the object's sequence's current loop has repeated.
168	UINT16LE	approachX	Holmes walks to this position when approaching an object to interact with it.
170	UINT8	approachY
171	UINT8	approachLoop
172	BYTE	unknown	unknown purpose
173	ACTIONDEF	closeAction	Behaviour when closing the object. See below for ACTIONDEF.
223	UINT8	seqPrevIndex	runtime: previous sequence loop position, saved by sequence call command.
224	UINT8	seqFinalFrame	runtime: final frame of sequence shorthand iterator, to be defined later in sequence section.
225	UINT16LE	textOffset	Offset of object's ASCIIZ description text in room textBlock, used when Holmes uses Look interaction on the object.
227	UINT8	seqLoopCounter	runtime: number of times a called sequence loop has repeated.
228	UINT16LE	seqSize	Size of object's sequence data in the room sequenceBlock.
230	BYTE	unknown	always 0
231	ACTIONDEF	moveAction	Behaviour when moving the object. See below for ACTIONDEF.
281	BYTE[8]	unknown	always 0
289	ACTIONDEF2[4]	extraActions	See below for ACTIONDEF2.

ACTIONDEF handles open, close, move actions. It is defined as follows:

DataType	Name	Description
BYTE	animNum	Animation number to play when interacting. 99 means a TLK script is to be loaded.
BYTE	unknown	unknown purpose
char[4][12]	names	Names of other room objects to toggle or TLK scripts to load.

ACTIONDEF2 handles other actions like pickup. It is defined as follows:

DataType	Name	Description
BYTE	animNum	Animation number to play when interacting. 99 means a TLK script is to be loaded.
BYTE	unknown	unknown purpose
char[4][12]	names	Names of other room objects to toggle or TLK scripts to load.
INT16LE	flag	story progress flag, either a prerequisite for or result of the action.
BYTE[6]	unknown	always 0
char[12]	lastName	Always contains either a TLK script name, or special tags like SELF, PICKUP.

Sequence Structure

Coming soon.

Credits

This file format was reverse engineered by Ceidwad. If you find this information helpful in a project you're working on, please give credit where credit is due. (A link back to this wiki would be nice too!)