Generic FileFormat Data Types

Intro

This is a generic list of data types encountered in all file formats. Not all of which will be used in a specific file format.

They are listed here, rather than repetitive typing in each of file format's documentation.

Endian

Little endian byte order, lsb first for numeric values, text is stored in Big endian byte order.

Data Types

Type	Description
byte	unsigned 8 bit (1 byte)
char	signed 8 bit Ascii(utf8)character
char[]	fixed length string
tbool	byte (0 = false).
short	16 bit signed short (2 bytes)
ushort	16 bit unsigned short (2 bytes)
long	32 bit signed integer (4 bytes)
ulong	32 bit unsigned integer (4 bytes)
float	32 bit signed single precision floating point value (4 bytes)
double	64 bit signed single precision floating point value (8 bytes)
asciiz	Null terminated (0x00) variable length ascii string
asciiz...	zero or more concatenated asciiz strings
ascii	fixed length ascii string(UTF-8)

XYPair

XYPair
{
 ulong x,y; // normally associated with cell sizes
}

XYZTriplet

XYZTriplet
{
 float    x,y,z;
}

Normally, this structure is associated with positional information.

RGBAColor

RGBAColor
{
 byte r,g,b,a; // // 0xFF:FF:FF:FF means 'default'
}

• RGBA colors correspond to Microsoft's D3DCOLORVALUE
• They normally come in pairs inside the pew structures to reflect object and outline colors

String

String
{
 ulong  Length;
 Asciiz Characters;// null terminated regardless. 
};

Length always =strlen(Characters)+1;

This is a pre-calculated convenience to reduce load times (and skip over the variable length block).

Note

Note that 'int' is not used in this documentation for the following reasons:

• an 'int' is machine and compiler and language dependent. It is an arbitrary size SIGNED value.
• with exceptions, BI use floats when requiring negative values.
• almost all references to 'integers' in BI file formats are either positive-only offsets into memory, zero based indexes, and counts.
• the incidence of true shorts and true integers in BI is quite rare. Exception -1 is a favourite, to indicate default