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Difference between revisions of "SCUMM/Technical Reference/Script resources"
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SCUMM/Technical Reference/Script resources (view source)
Revision as of 02:18, 16 May 2009
, 02:18, 16 May 2009→Object Scripts in V3/4 (OC): Filled out unknowns based on object.cpp/ScummEngine_v4::resetRoomObject
(Added description of OC block for V3/4 games) |
Jestar jokin (talk | contribs) (→Object Scripts in V3/4 (OC): Filled out unknowns based on object.cpp/ScummEngine_v4::resetRoomObject) |
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Starting with Scumm V5, the blockname contains 4 bytes and the block size is BE including the 8 bytes for the header. Older games just have a 2 bytes blockname and the block size is in LE without the 6 bytes for the header. | Starting with Scumm V5, the blockname contains 4 bytes and the block size is BE including the 8 bytes for the header. Older games just have a 2 bytes blockname and the block size is in LE without the 6 bytes for the header. | ||
<br> | |||
= Global Scripts (SC or SCRP) = | == Global Scripts (SC or SCRP) == | ||
Global scripts are limited to 200 and stored in the '''LF''' or '''LFLF''' container. The id and the offset is stored in the ''directory of scripts'' in the game [[SCUMM/Index File|index file]]. | Global scripts are limited to 200 and stored in the '''LF''' or '''LFLF''' container. The id and the offset is stored in the ''directory of scripts'' in the game [[SCUMM/Index File|index file]]. | ||
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Script code variable | Script code variable | ||
= Local Scripts (LS or LSCR) = | == Local Scripts (LS or LSCR) == | ||
Local scripts are stored within a room. | Local scripts are stored within a room. For games until version 6, the first byte after the blockname contains the id of the script. IDs for local scripts always start at 200. | ||
Block name 2 ("LS") or 4 ("LSCR") bytes | Block name 2 ("LS") or 4 ("LSCR") bytes | ||
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Script code variable | Script code variable | ||
For v7 and v8 games the script id is stored in 2 bytes and starts with 2000. | |||
= Room Entry Scripts (EN or ENCD) = | Block name 4 bytes ("LSCR") | ||
Block size 4 bytes | |||
ID 2 bytes | |||
Script code variable | |||
== Room Entry Scripts (EN or ENCD) == | |||
This block contains special code when a room is entered. | This block contains special code when a room is entered. | ||
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= Room Exit Scripts (EX or EXCD) = | == Room Exit Scripts (EX or EXCD) == | ||
This block contains special code when the player leaves a room | This block contains special code when the player leaves a room | ||
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= Object Scripts (OBCD | == Object Scripts V5+ (OBCD) == | ||
These are scripts that correspond to VERB actions. VERBs are predefined activities at the bottom of the screen, e.g. "Open", "Look", "Give" etc. For each named object in a room, the game designer could define responses to the players actions. Starting with version 5, the whole code can be found in an [[Object resources|Object Resource]]. | These are scripts that correspond to VERB actions. VERBs are predefined activities at the bottom of the screen, e.g. "Open", "Look", "Give" etc. For each named object in a room, the game designer could define responses to the players actions. A single VERB block contains the code for all possible player actions on the object. Starting with version 5, the whole code can be found in an [[Object resources|Object Resource]]. | ||
OBCD | OBCD | ||
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Block name 4 bytes ("VERB") | Block name 4 bytes ("VERB") | ||
Block size 4 bytes | Block size 4 bytes | ||
offset table variable | offset table variable { | ||
verb 1 byte (0xFF is default) | |||
offset 2 bytes | |||
table end 1 byte(must be | } | ||
table end 1 byte (must be 0x00) | |||
object code variable | object code variable | ||
OBNA | |||
Block name 4 bytes ("OBNA") | |||
Block size 4 bytes | |||
object name null-terminated string | |||
== Object Scripts in V3/4 (OC) == | |||
In Version 3 and 4 the code can be found in the '''OC''' block: | In Version 3 and 4 the code can be found in the '''OC''' block: | ||
OC | OC | ||
Block size 4 bytes | Block size 4 bytes (LE) | ||
Block name 2 bytes ("OC") | Block name 2 bytes ("OC") | ||
Object ID 1 byte ( | Object ID 2 bytes (LE) | ||
unknown 1 byte | |||
x pos 1 byte | |||
y pos, par. state 1 byte | |||
image width / 8 1 byte | |||
parent 1 byte | |||
walk_x 2 bytes (LE) | |||
walk_y 2 bytes (LE) | |||
height, actor dir 1 byte | |||
name offset 1 byte | |||
offset table variable { | |||
verb 1 byte (0xFF is default) | |||
offset 2 bytes | |||
} | |||
table end 1 byte (must be 0x00) | |||
object name null-terminated string | |||
object code variable | |||
This block contains all object data except for the actual image bitmap. Compare this to V5+ objects, where metadata is split into seperate CDHD and OBNA blocks. | |||
Image width is given in strips, which are 8 pixels wide. The high bit of y pos is used to store the parent's state (0 or 1). Both x pos and y pos will be multiplied by 8 by the interpreter. The lower three bits (mask 0x07) of height are used to store actor dir. Name offset is the absolute offset of object name (or, if you prefer, the position after table end). | |||
The offset table is a variable block like that used in the VERB block in later games, which contains the verb identifier (1 byte) and the absolute offset (2 bytes). The table end is marked with 0x00. Next is the object's name, which is a standard null-terminated string. After this follows the actual object code. Note that unlike other script types, because there are multiple entry points (one for each supported verb), there are also multiple exit points (or "stopObjectCode" instructions). | |||