Create MediaWiki page 'Data Types'

Data-Types.mediawiki

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+== Introduction ==
+
+RuneScape uses a number of standard and non-standard data types.
+
+== Byte Order ==
+
+Data types that are two bytes or larger can be stored and ordered in a variety of different ways. Generally people either use big endian or little endian. 
+
+=== Big Endian ===
+
+In big endian order, the most significant byte (MSB) is stored first and the least significant byte (LSB) is stored last.
+
+=== Little Endian ===
+
+In little endian order, the least significant byte (LSB) is stored first and the most significant byte (MSB) is stored last.
+
+=== Byte order in RuneScape ===
+
+RuneScape uses both little and big-endian byte orders throughout the protocol (however, the 194 client only uses big-endian order), presumably to make reverse-engineering of the protocol harder. Some confusion has arisen over the byte order as the data types are named incorrectly in [[Server Winterlove|Winterlove]]'s server where little endian data types are incorrectly named as big endian types.
+
+== Standard data types ==
+These datatypes can also be read/written by a DataWriter/DataReader implementation (DataStreams and Buffers)
+
+Naming conventions:
+{| border=2
+! Official name
+! Datatype name
+! Jagex name
+! Encoding
+|-
+| Byte
+| byte
+| 1,1b
+|-
+| [[Word|WORD]]
+| short
+| 2,2b
+|-
+| [[DWord|DWORD]]
+| int,int32
+| 4,4b
+|-
+| [[QWord|QWORD]]
+| long,int64
+| 8,8b
+|-
+| C style string
+| string,String,char *,char[]
+| str,strbyte
+| text bytes then '\n' or 10
+|-
+| Java style string
+| string,String,char *,char[]
+| strraw
+| WORD length then text bytes
+|}
+
+Note that [[Jagex]] used to use a new line character as string terminator, in more recent versions they use the
+null character \0 or 0 to support multi-line strings.
+
+== Non Standard Data Types ==
+
+{| border=2
+! Winterlove's name
+! Jagex name
+! Read transformation
+! Write transformation
+|-
+| Special A
+| Unknown
+| value - 128
+| value + 128
+|-
+| Special C
+| Unknown
+| 0 - value
+| 0 - value
+|-
+| Special S
+| Unknown
+| 128 - value
+| 128 - value
+|-
+| SpaceSaverA
+| smarts
+| (value[0] < 128) ? (((value[0] - 128)<<8)+value[1]) : value[0]
+| if(value < 128) putword(value+32768) else putbyte(value);
+|-
+| SpaceSaverB
+| smart
+| (value[0] < 128) ? value[0] - 64 | ((value[0]<<8)+value[1]) - 49152
+| if(i < 64 && i >= -64) putbyte(i + 64) else if(i < 16384 && i >= -16384) putword(i + 49152);
+|-
+| tribyte / RGBColour / 3Byte / int3 / medium
+| 3
+| (value[0] << 24) + (value[1] << 16) + value[2]
+| putbyte(value >> 24);putbyte(value >> 16);putbyte(value);
+|-
+| [[RS String|RS_String]]
+| jstr
+| Old engine: read until newline delimiter ("\n") <br />New engine: read until null byte (value 0).
+| Old engine: write and finish with newline delimiter ("\n") <br />New engine: write and finish with null byte (value 0).
+|}
+
+Additionally, RuneScape also uses two integers that are different from a big- or low endian order. Both byte orders are called middle endian. Their orders could be described as following:
+
+Middle endian big int: C3 D4 A1 B2
+
+Middle endian small int: B2 A1 D4 C3
+
+(A1 smallest D4 biggest byte)