marrub-- · November 26, 2023 04:33
diff --git a/MarathonData.md b/MarathonData.md
diff --git a/zz_macheader.d b/zz_macheader.d
 // Copyright (c) 2017 Alison Sanderson, all rights reserved.

 // This code is for educational use, it's not usable anyways
 // as it relies on libraries specific to the implementation.

 // These are loaders for MacBin and AppleSingle headers that
 // skip over them into the first resource fork, while also
 // verifying the integrity of the header.

 /// Checks for an AppleSingle header. Returns offset to data if any.
 size_t checkAppleS(VInFile fp)
 {
 	auto origin = fp.tell;
 	ushort num;

 	if(fp.readU32B != 0x51600 || fp.readU32B != 0x20000)
 		goto err;

 	fp.seek(16, SEEK_CUR);

 	num = fp.readU16B;
 	while(num--)
 	{
 		auto fid = fp.readU32B;
 		auto ofs = fp.readS32B;
 		auto len = fp.readS32B;

 		if(fid == 1)
 		{
 			if(ofs + len > fp.size) goto err;
 			fp.seek(ofs);
 			return ofs;
 		}
 	}

 err:
 	fp.seek(origin);
 	return 0;
 }

 /// Checks for a MacBin header. Returns offset to data if any.
 size_t checkMacBin(VInFile fp)
 {
 	auto origin = fp.tell;
 	auto bufu = fp.readU8N(128);
 	ushort crc16;

 	if(bufu[0] || bufu[1] > 63 || bufu[74] || bufu[123] > 0x81)
 		goto err;

 	for(int i; i < 124; i++)
 	{
 		ushort data = cast(ushort)(bufu[i] << 8);

 		for(int j; j < 8; j++)
 		{
 			if((data ^ crc16) & 0x8000) crc16 = cast(ushort)(crc16 << 1) ^ 0x1021;
 			else                        crc16 <<= 1;

 			data <<= 1;
 		}
 	}

 	if(((bufu[124] << 8) | bufu[125]) == crc16)
 		return 128;

 err:
 	fp.seek(origin);
 	return 0;
 }

 /// Reads a MacBin or AppleSingle header if there is one
 /// and returns the offset from the start of the header to
 /// the resource fork (if one is found.)
 size_t tryMacHeader(VInFile fp)
 {
 	if(auto sz = fp.checkMacBin)
 		return sz;
 	else
 		return fp.checkAppleS;
 }
Title	Description
LICENSING	The license this document is under.
CONTENTS	This table of contents.
TERMINAL CODE	Info on terminal definition files.
CHUNK TYPES	Chunk types used throughout Marathon.
STRUCTURES	Structure types used throughout Marathon.
ENUMERATIONS	Names for integers used in Marathon's structures.
FLAGS	Names for bit field flags used in Marathon's structures.
Name	Will display when
`UNFINISHED`	your objective has not been met or no other block exists
`FINISHED`	you have succeeded or failed
`FAILURE`	you have failed your objective
`SUCCESS`	you have succeeded in your objective
$-code	Effect
`I/i`	enables/disables italic text
`B/b`	enables/disables bold text
`U/u`	enables/disables underlined text
`Cn`	changes the text color, where "n" is a number 0 through 9
Name	Description
`PNTS`	Array of Points
`LINS`	Array of Lines
`SIDS`	Array of Sides
`POLY`	Array of Polygons
`LITE`	Array of Lights
`NOTE`	Not analyzed (annotations)
`OBJS`	Array of Objects
`p'th`	No test data (' is $8C) (guardpaths)
`Minf`	Static Map Info
`plac`	Not analyzed (item placement)
`door`	No test data (extra door data)
`plat`	No test data (platform static data)
`EPNT`	Array of Endpoints
`medi`	Not analyzed (media)
`ambi`	Not analyzed (ambient sounds)
`bonk`	No test data (random sounds)
`term`	Array of Terminals
`iidx`	Not analyzed (map indices)
Type	Description	Name
u16	Wad Version	WadVer
u16	Data Version	DataVer
u8[64]	Original filename, null byte terminated	OrigName
u32	Checksum of entire file with this value as 0	CRC
Type	Description	Name
u32	Directory offset	DirOfs
u16	Number of entries in this file	NumEntries
u16	Bytes to skip for each directory entry	AppData
u16	Size of chunks	ChunkSize
u16	Size of directory entries	EntrySize
Type	Description	Name
u32	Offset to start of data (from start of file)	Offset
u32	Length of entry data	Size
Type	Description	Name
u16	Index of entry	Index
u8[N]	Application specified data	AppData
Type	Description	Name
u8[4]	Chunk name (no null byte)	Ident
u32	Absolute file offset of next chunk (-file header)	Offset
u32	Size of chunk (not including the header)	Size
Type	Description	Name
u16	Function index
u16	Period
u16	Delta period
u16	Intensity (high)
u16	Intensity (low)
u16	Delta intensity (high)
u16	Delta intensity (low)