From c4ea89ef8cb104fb6f9f9edd4f4bf55e7984a51f Mon Sep 17 00:00:00 2001
From: sparky4 <sparky4@cock.li>
Date: Thu, 2 Jul 2015 00:27:18 -0500
Subject: [PATCH] going to portover the cache system before extenting the 16_mm
 library! 	new file:   src/lib/16_ca.c 	new file:   src/lib/16_ca.h

---
 src/lib/16_ca.c | 2190 +++++++++++++++++++++++++++++++++++++++++++++++
 src/lib/16_ca.h |  124 +++
 2 files changed, 2314 insertions(+)
 create mode 100644 src/lib/16_ca.c
 create mode 100644 src/lib/16_ca.h

diff --git a/src/lib/16_ca.c b/src/lib/16_ca.c
new file mode 100644
index 00000000..bacb7181
--- /dev/null
+++ b/src/lib/16_ca.c
@@ -0,0 +1,2190 @@
+/* Catacomb Apocalypse Source Code
+ * Copyright (C) 1993-2014 Flat Rock Software
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+// ID_CA.C
+
+/*
+=============================================================================
+
+Id Software Caching Manager
+---------------------------
+
+Must be started BEFORE the memory manager, because it needs to get the headers
+loaded into the data segment
+
+=============================================================================
+*/
+
+#include "ID_HEADS.H"
+#pragma hdrstop
+#include "ID_STRS.H"
+
+#pragma warn -pro
+#pragma warn -use
+
+#define THREEBYTEGRSTARTS
+
+/*
+=============================================================================
+
+						 LOCAL CONSTANTS
+
+=============================================================================
+*/
+
+typedef struct
+{
+  unsigned bit0,bit1;	// 0-255 is a character, > is a pointer to a node
+} huffnode;
+
+
+typedef struct
+{
+	unsigned	RLEWtag;
+	long		headeroffsets[100];
+	byte		tileinfo[];
+} mapfiletype;
+
+
+/*
+=============================================================================
+
+						 GLOBAL VARIABLES
+
+=============================================================================
+*/
+
+byte 		_seg	*tinf;
+int			mapon;
+
+unsigned	_seg	*mapsegs[3];
+maptype		_seg	*mapheaderseg[NUMMAPS];
+byte		_seg	*audiosegs[NUMSNDCHUNKS];
+void		_seg	*grsegs[NUMCHUNKS];
+
+byte		far	grneeded[NUMCHUNKS];
+byte		ca_levelbit,ca_levelnum;
+
+int			profilehandle,debughandle;
+
+void	(*drawcachebox)		(char *title, unsigned numcache);
+void	(*updatecachebox)	(void);
+void	(*finishcachebox)	(void);
+
+/*
+=============================================================================
+
+						 LOCAL VARIABLES
+
+=============================================================================
+*/
+
+extern	long	far	CGAhead;
+extern	long	far	EGAhead;
+extern	byte	CGAdict;
+extern	byte	EGAdict;
+extern	byte	far	maphead;
+extern	byte	mapdict;
+extern	byte	far	audiohead;
+extern	byte	audiodict;
+
+
+long		_seg *grstarts;	// array of offsets in egagraph, -1 for sparse
+long		_seg *audiostarts;	// array of offsets in audio / audiot
+
+#ifdef GRHEADERLINKED
+huffnode	*grhuffman;
+#else
+huffnode	grhuffman[255];
+#endif
+
+#ifdef AUDIOHEADERLINKED
+huffnode	*audiohuffman;
+#else
+huffnode	audiohuffman[255];
+#endif
+
+
+int			grhandle;		// handle to EGAGRAPH
+int			maphandle;		// handle to MAPTEMP / GAMEMAPS
+int			audiohandle;	// handle to AUDIOT / AUDIO
+
+long		chunkcomplen,chunkexplen;
+
+SDMode		oldsoundmode;
+
+
+
+void	CAL_DialogDraw (char *title,unsigned numcache);
+void	CAL_DialogUpdate (void);
+void	CAL_DialogFinish (void);
+void	CAL_CarmackExpand (unsigned far *source, unsigned far *dest,
+		unsigned length);
+
+
+#ifdef THREEBYTEGRSTARTS
+#define FILEPOSSIZE	3
+//#define	GRFILEPOS(c) (*(long far *)(((byte far *)grstarts)+(c)*3)&0xffffff)
+long GRFILEPOS(int c)
+{
+	long value;
+	int	offset;
+
+	offset = c*3;
+
+	value = *(long far *)(((byte far *)grstarts)+offset);
+
+	value &= 0x00ffffffl;
+
+	if (value == 0xffffffl)
+		value = -1;
+
+	return value;
+};
+#else
+#define FILEPOSSIZE	4
+#define	GRFILEPOS(c) (grstarts[c])
+#endif
+
+/*
+=============================================================================
+
+					   LOW LEVEL ROUTINES
+
+=============================================================================
+*/
+
+/*
+============================
+=
+= CA_OpenDebug / CA_CloseDebug
+=
+= Opens a binary file with the handle "debughandle"
+=
+============================
+*/
+
+void CA_OpenDebug (void)
+{
+	unlink ("DEBUG.TXT");
+	debughandle = open("DEBUG.TXT", O_CREAT | O_WRONLY | O_TEXT);
+}
+
+void CA_CloseDebug (void)
+{
+	close (debughandle);
+}
+
+
+
+/*
+============================
+=
+= CAL_GetGrChunkLength
+=
+= Gets the length of an explicit length chunk (not tiles)
+= The file pointer is positioned so the compressed data can be read in next.
+=
+============================
+*/
+
+void CAL_GetGrChunkLength (int chunk)
+{
+	lseek(grhandle,GRFILEPOS(chunk),SEEK_SET);
+	read(grhandle,&chunkexplen,sizeof(chunkexplen));
+	chunkcomplen = GRFILEPOS(chunk+1)-GRFILEPOS(chunk)-4;
+}
+
+
+/*
+==========================
+=
+= CA_FarRead
+=
+= Read from a file to a far pointer
+=
+==========================
+*/
+
+boolean CA_FarRead (int handle, byte far *dest, long length)
+{
+	if (length>0xffffl)
+		Quit ("CA_FarRead doesn't support 64K reads yet!");
+
+asm		push	ds
+asm		mov	bx,[handle]
+asm		mov	cx,[WORD PTR length]
+asm		mov	dx,[WORD PTR dest]
+asm		mov	ds,[WORD PTR dest+2]
+asm		mov	ah,0x3f				// READ w/handle
+asm		int	21h
+asm		pop	ds
+asm		jnc	good
+	errno = _AX;
+	return	false;
+good:
+asm		cmp	ax,[WORD PTR length]
+asm		je	done
+	errno = EINVFMT;			// user manager knows this is bad read
+	return	false;
+done:
+	return	true;
+}
+
+
+/*
+==========================
+=
+= CA_SegWrite
+=
+= Write from a file to a far pointer
+=
+==========================
+*/
+
+boolean CA_FarWrite (int handle, byte far *source, long length)
+{
+	if (length>0xffffl)
+		Quit ("CA_FarWrite doesn't support 64K reads yet!");
+
+asm		push	ds
+asm		mov	bx,[handle]
+asm		mov	cx,[WORD PTR length]
+asm		mov	dx,[WORD PTR source]
+asm		mov	ds,[WORD PTR source+2]
+asm		mov	ah,0x40			// WRITE w/handle
+asm		int	21h
+asm		pop	ds
+asm		jnc	good
+	errno = _AX;
+	return	false;
+good:
+asm		cmp	ax,[WORD PTR length]
+asm		je	done
+	errno = ENOMEM;				// user manager knows this is bad write
+	return	false;
+
+done:
+	return	true;
+}
+
+
+/*
+==========================
+=
+= CA_ReadFile
+=
+= Reads a file into an allready allocated buffer
+=
+==========================
+*/
+
+boolean CA_ReadFile (char *filename, memptr *ptr)
+{
+	int handle;
+	long size;
+
+	if ((handle = open(filename,O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		return false;
+
+	size = filelength (handle);
+	if (!CA_FarRead (handle,*ptr,size))
+	{
+		close (handle);
+		return false;
+	}
+	close (handle);
+	return true;
+}
+
+
+
+/*
+==========================
+=
+= CA_LoadFile
+=
+= Allocate space for and load a file
+=
+==========================
+*/
+
+boolean CA_LoadFile (char *filename, memptr *ptr)
+{
+	int handle;
+	long size;
+
+	if ((handle = open(filename,O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		return false;
+
+	size = filelength (handle);
+	MM_GetPtr (ptr,size);
+	if (!CA_FarRead (handle,*ptr,size))
+	{
+		close (handle);
+		return false;
+	}
+	close (handle);
+	return true;
+}
+
+/*
+============================================================================
+
+		COMPRESSION routines, see JHUFF.C for more
+
+============================================================================
+*/
+
+
+
+/*
+===============
+=
+= CAL_OptimizeNodes
+=
+= Goes through a huffman table and changes the 256-511 node numbers to the
+= actular address of the node.  Must be called before CAL_HuffExpand
+=
+===============
+*/
+
+void CAL_OptimizeNodes (huffnode *table)
+{
+  huffnode *node;
+  int i;
+
+  node = table;
+
+  for (i=0;i<255;i++)
+  {
+	if (node->bit0 >= 256)
+	  node->bit0 = (unsigned)(table+(node->bit0-256));
+	if (node->bit1 >= 256)
+	  node->bit1 = (unsigned)(table+(node->bit1-256));
+	node++;
+  }
+}
+
+
+
+/*
+======================
+=
+= CAL_HuffExpand
+=
+= Length is the length of the EXPANDED data
+=
+======================
+*/
+
+void CAL_HuffExpand (byte huge *source, byte huge *dest,
+  long length,huffnode *hufftable)
+{
+//  unsigned bit,byte,node,code;
+  unsigned sourceseg,sourceoff,destseg,destoff,endoff;
+  huffnode *headptr;
+//  huffnode *nodeon;
+
+  headptr = hufftable+254;	// head node is allways node 254
+
+  source++;	// normalize
+  source--;
+  dest++;
+  dest--;
+
+  sourceseg = FP_SEG(source);
+  sourceoff = FP_OFF(source);
+  destseg = FP_SEG(dest);
+  destoff = FP_OFF(dest);
+  endoff = destoff+length;
+
+//
+// ds:si source
+// es:di dest
+// ss:bx node pointer
+//
+
+	if (length <0xfff0)
+	{
+
+//--------------------------
+// expand less than 64k of data
+//--------------------------
+
+asm mov	bx,[headptr]
+
+asm	mov	si,[sourceoff]
+asm	mov	di,[destoff]
+asm	mov	es,[destseg]
+asm	mov	ds,[sourceseg]
+asm	mov	ax,[endoff]
+
+asm	mov	ch,[si]				// load first byte
+asm	inc	si
+asm	mov	cl,1
+
+expandshort:
+asm	test	ch,cl			// bit set?
+asm	jnz	bit1short
+asm	mov	dx,[ss:bx]			// take bit0 path from node
+asm	shl	cl,1				// advance to next bit position
+asm	jc	newbyteshort
+asm	jnc	sourceupshort
+
+bit1short:
+asm	mov	dx,[ss:bx+2]		// take bit1 path
+asm	shl	cl,1				// advance to next bit position
+asm	jnc	sourceupshort
+
+newbyteshort:
+asm	mov	ch,[si]				// load next byte
+asm	inc	si
+asm	mov	cl,1				// back to first bit
+
+sourceupshort:
+asm	or	dh,dh				// if dx<256 its a byte, else move node
+asm	jz	storebyteshort
+asm	mov	bx,dx				// next node = (huffnode *)code
+asm	jmp	expandshort
+
+storebyteshort:
+asm	mov	[es:di],dl
+asm	inc	di					// write a decopmpressed byte out
+asm	mov	bx,[headptr]		// back to the head node for next bit
+
+asm	cmp	di,ax				// done?
+asm	jne	expandshort
+	}
+	else
+	{
+
+//--------------------------
+// expand more than 64k of data
+//--------------------------
+
+  length--;
+
+asm mov	bx,[headptr]
+asm	mov	cl,1
+
+asm	mov	si,[sourceoff]
+asm	mov	di,[destoff]
+asm	mov	es,[destseg]
+asm	mov	ds,[sourceseg]
+
+asm	lodsb			// load first byte
+
+expand:
+asm	test	al,cl		// bit set?
+asm	jnz	bit1
+asm	mov	dx,[ss:bx]	// take bit0 path from node
+asm	jmp	gotcode
+bit1:
+asm	mov	dx,[ss:bx+2]	// take bit1 path
+
+gotcode:
+asm	shl	cl,1		// advance to next bit position
+asm	jnc	sourceup
+asm	lodsb
+asm	cmp	si,0x10		// normalize ds:si
+asm  	jb	sinorm
+asm	mov	cx,ds
+asm	inc	cx
+asm	mov	ds,cx
+asm	xor	si,si
+sinorm:
+asm	mov	cl,1		// back to first bit
+
+sourceup:
+asm	or	dh,dh		// if dx<256 its a byte, else move node
+asm	jz	storebyte
+asm	mov	bx,dx		// next node = (huffnode *)code
+asm	jmp	expand
+
+storebyte:
+asm	mov	[es:di],dl
+asm	inc	di		// write a decopmpressed byte out
+asm	mov	bx,[headptr]	// back to the head node for next bit
+
+asm	cmp	di,0x10		// normalize es:di
+asm  	jb	dinorm
+asm	mov	dx,es
+asm	inc	dx
+asm	mov	es,dx
+asm	xor	di,di
+dinorm:
+
+asm	sub	[WORD PTR ss:length],1
+asm	jnc	expand
+asm  	dec	[WORD PTR ss:length+2]
+asm	jns	expand		// when length = ffff ffff, done
+
+	}
+
+asm	mov	ax,ss
+asm	mov	ds,ax
+
+}
+
+
+/*
+======================
+=
+= CAL_CarmackExpand
+=
+= Length is the length of the EXPANDED data
+=
+======================
+*/
+
+#define NEARTAG	0xa7
+#define FARTAG	0xa8
+
+void CAL_CarmackExpand (unsigned far *source, unsigned far *dest, unsigned length)
+{
+	unsigned	ch,chhigh,count,offset;
+	unsigned	far *copyptr, far *inptr, far *outptr;
+
+	length/=2;
+
+	inptr = source;
+	outptr = dest;
+
+	while (length)
+	{
+		ch = *inptr++;
+		chhigh = ch>>8;
+		if (chhigh == NEARTAG)
+		{
+			count = ch&0xff;
+			if (!count)
+			{				// have to insert a word containing the tag byte
+				ch |= *((unsigned char far *)inptr)++;
+				*outptr++ = ch;
+				length--;
+			}
+			else
+			{
+				offset = *((unsigned char far *)inptr)++;
+				copyptr = outptr - offset;
+				length -= count;
+				while (count--)
+					*outptr++ = *copyptr++;
+			}
+		}
+		else if (chhigh == FARTAG)
+		{
+			count = ch&0xff;
+			if (!count)
+			{				// have to insert a word containing the tag byte
+				ch |= *((unsigned char far *)inptr)++;
+				*outptr++ = ch;
+				length --;
+			}
+			else
+			{
+				offset = *inptr++;
+				copyptr = dest + offset;
+				length -= count;
+				while (count--)
+					*outptr++ = *copyptr++;
+			}
+		}
+		else
+		{
+			*outptr++ = ch;
+			length --;
+		}
+	}
+}
+
+
+
+/*
+======================
+=
+= CA_RLEWcompress
+=
+======================
+*/
+
+long CA_RLEWCompress (unsigned huge *source, long length, unsigned huge *dest,
+  unsigned rlewtag)
+{
+  long complength;
+  unsigned value,count,i;
+  unsigned huge *start,huge *end;
+
+  start = dest;
+
+  end = source + (length+1)/2;
+
+//
+// compress it
+//
+  do
+  {
+	count = 1;
+	value = *source++;
+	while (*source == value && source<end)
+	{
+	  count++;
+	  source++;
+	}
+	if (count>3 || value == rlewtag)
+	{
+    //
+    // send a tag / count / value string
+    //
+      *dest++ = rlewtag;
+      *dest++ = count;
+      *dest++ = value;
+    }
+    else
+    {
+    //
+    // send word without compressing
+    //
+      for (i=1;i<=count;i++)
+	*dest++ = value;
+	}
+
+  } while (source<end);
+
+  complength = 2*(dest-start);
+  return complength;
+}
+
+
+/*
+======================
+=
+= CA_RLEWexpand
+= length is EXPANDED length
+=
+======================
+*/
+
+void CA_RLEWexpand (unsigned huge *source, unsigned huge *dest,long length,
+  unsigned rlewtag)
+{
+//  unsigned value,count,i;
+  unsigned huge *end;
+  unsigned sourceseg,sourceoff,destseg,destoff,endseg,endoff;
+
+
+//
+// expand it
+//
+#if 0
+  do
+  {
+	value = *source++;
+	if (value != rlewtag)
+	//
+	// uncompressed
+	//
+	  *dest++=value;
+	else
+	{
+	//
+	// compressed string
+	//
+	  count = *source++;
+	  value = *source++;
+	  for (i=1;i<=count;i++)
+	*dest++ = value;
+	}
+  } while (dest<end);
+#endif
+
+  end = dest + (length)/2;
+  sourceseg = FP_SEG(source);
+  sourceoff = FP_OFF(source);
+  destseg = FP_SEG(dest);
+  destoff = FP_OFF(dest);
+  endseg = FP_SEG(end);
+  endoff = FP_OFF(end);
+
+
+//
+// ax = source value
+// bx = tag value
+// cx = repeat counts
+// dx = scratch
+//
+// NOTE: A repeat count that produces 0xfff0 bytes can blow this!
+//
+
+asm	mov	bx,rlewtag
+asm	mov	si,sourceoff
+asm	mov	di,destoff
+asm	mov	es,destseg
+asm	mov	ds,sourceseg
+
+expand:
+asm	lodsw
+asm	cmp	ax,bx
+asm	je	repeat
+asm	stosw
+asm	jmp	next
+
+repeat:
+asm	lodsw
+asm	mov	cx,ax		// repeat count
+asm	lodsw			// repeat value
+asm	rep stosw
+
+next:
+
+asm	cmp	si,0x10		// normalize ds:si
+asm  	jb	sinorm
+asm	mov	ax,si
+asm	shr	ax,1
+asm	shr	ax,1
+asm	shr	ax,1
+asm	shr	ax,1
+asm	mov	dx,ds
+asm	add	dx,ax
+asm	mov	ds,dx
+asm	and	si,0xf
+sinorm:
+asm	cmp	di,0x10		// normalize es:di
+asm  	jb	dinorm
+asm	mov	ax,di
+asm	shr	ax,1
+asm	shr	ax,1
+asm	shr	ax,1
+asm	shr	ax,1
+asm	mov	dx,es
+asm	add	dx,ax
+asm	mov	es,dx
+asm	and	di,0xf
+dinorm:
+
+asm	cmp     di,ss:endoff
+asm	jne	expand
+asm	mov	ax,es
+asm	cmp	ax,ss:endseg
+asm	jb	expand
+
+asm	mov	ax,ss
+asm	mov	ds,ax
+
+}
+
+
+
+/*
+=============================================================================
+
+					 CACHE MANAGER ROUTINES
+
+=============================================================================
+*/
+
+/*
+======================
+=
+= CAL_SetupGrFile
+=
+======================
+*/
+
+void CAL_SetupGrFile (void)
+{
+	int handle;
+	memptr compseg;
+
+#ifdef GRHEADERLINKED
+
+#if GRMODE == EGAGR
+	grhuffman = (huffnode *)&EGAdict;
+	grstarts = (long _seg *)FP_SEG(&EGAhead);
+#endif
+#if GRMODE == CGAGR
+	grhuffman = (huffnode *)&CGAdict;
+	grstarts = (long _seg *)FP_SEG(&CGAhead);
+#endif
+
+	CAL_OptimizeNodes (grhuffman);
+
+#else
+
+//
+// load ???dict.ext (huffman dictionary for graphics files)
+//
+
+	if ((handle = open(GREXT"DICT."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open "GREXT"DICT."EXT"!");
+
+	read(handle, &grhuffman, sizeof(grhuffman));
+	close(handle);
+	CAL_OptimizeNodes (grhuffman);
+//
+// load the data offsets from ???head.ext
+//
+	MM_GetPtr (&(memptr)grstarts,(NUMCHUNKS+1)*FILEPOSSIZE);
+
+	if ((handle = open(GREXT"HEAD."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open "GREXT"HEAD."EXT"!");
+
+	CA_FarRead(handle, (memptr)grstarts, (NUMCHUNKS+1)*FILEPOSSIZE);
+
+	close(handle);
+
+
+#endif
+
+//
+// Open the graphics file, leaving it open until the game is finished
+//
+	grhandle = open(GREXT"GRAPH."EXT, O_RDONLY | O_BINARY);
+	if (grhandle == -1)
+		Quit ("Cannot open "GREXT"GRAPH."EXT"!");
+
+
+//
+// load the pic and sprite headers into the arrays in the data segment
+//
+#if NUMPICS>0
+	MM_GetPtr(&(memptr)pictable,NUMPICS*sizeof(pictabletype));
+	CAL_GetGrChunkLength(STRUCTPIC);		// position file pointer
+	MM_GetPtr(&compseg,chunkcomplen);
+	CA_FarRead (grhandle,compseg,chunkcomplen);
+	CAL_HuffExpand (compseg, (byte huge *)pictable,NUMPICS*sizeof(pictabletype),grhuffman);
+	MM_FreePtr(&compseg);
+#endif
+
+#if NUMPICM>0
+	MM_GetPtr(&(memptr)picmtable,NUMPICM*sizeof(pictabletype));
+	CAL_GetGrChunkLength(STRUCTPICM);		// position file pointer
+	MM_GetPtr(&compseg,chunkcomplen);
+	CA_FarRead (grhandle,compseg,chunkcomplen);
+	CAL_HuffExpand (compseg, (byte huge *)picmtable,NUMPICS*sizeof(pictabletype),grhuffman);
+	MM_FreePtr(&compseg);
+#endif
+
+#if NUMSPRITES>0
+	MM_GetPtr(&(memptr)spritetable,NUMSPRITES*sizeof(spritetabletype));
+	CAL_GetGrChunkLength(STRUCTSPRITE);	// position file pointer
+	MM_GetPtr(&compseg,chunkcomplen);
+	CA_FarRead (grhandle,compseg,chunkcomplen);
+	CAL_HuffExpand (compseg, (byte huge *)spritetable,NUMSPRITES*sizeof(spritetabletype),grhuffman);
+	MM_FreePtr(&compseg);
+#endif
+
+}
+
+//==========================================================================
+
+
+/*
+======================
+=
+= CAL_SetupMapFile
+=
+======================
+*/
+
+void CAL_SetupMapFile (void)
+{
+	int handle;
+	long length;
+
+//
+// load maphead.ext (offsets and tileinfo for map file)
+//
+#ifndef MAPHEADERLINKED
+	if ((handle = open("MAPHEAD."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open MAPHEAD."EXT"!");
+	length = filelength(handle);
+	MM_GetPtr (&(memptr)tinf,length);
+	CA_FarRead(handle, tinf, length);
+	close(handle);
+#else
+
+	tinf = (byte _seg *)FP_SEG(&maphead);
+
+#endif
+
+//
+// open the data file
+//
+#ifdef MAPHEADERLINKED
+	if ((maphandle = open("GAMEMAPS."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open GAMEMAPS."EXT"!");
+#else
+	if ((maphandle = open("MAPTEMP."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open MAPTEMP."EXT"!");
+#endif
+}
+
+//==========================================================================
+
+
+/*
+======================
+=
+= CAL_SetupAudioFile
+=
+======================
+*/
+
+void CAL_SetupAudioFile (void)
+{
+	int handle;
+	long length;
+
+//
+// load maphead.ext (offsets and tileinfo for map file)
+//
+#ifndef AUDIOHEADERLINKED
+	if ((handle = open("AUDIOHED."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open AUDIOHED."EXT"!");
+	length = filelength(handle);
+	MM_GetPtr (&(memptr)audiostarts,length);
+	CA_FarRead(handle, (byte far *)audiostarts, length);
+	close(handle);
+#else
+	audiohuffman = (huffnode *)&audiodict;
+	CAL_OptimizeNodes (audiohuffman);
+	audiostarts = (long _seg *)FP_SEG(&audiohead);
+#endif
+
+//
+// open the data file
+//
+#ifndef AUDIOHEADERLINKED
+	if ((audiohandle = open("AUDIOT."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open AUDIOT."EXT"!");
+#else
+	if ((audiohandle = open("AUDIO."EXT,
+		 O_RDONLY | O_BINARY, S_IREAD)) == -1)
+		Quit ("Can't open AUDIO."EXT"!");
+#endif
+}
+
+//==========================================================================
+
+
+/*
+======================
+=
+= CA_Startup
+=
+= Open all files and load in headers
+=
+======================
+*/
+
+void CA_Startup (void)
+{
+#ifdef PROFILE
+	unlink ("PROFILE.TXT");
+	profilehandle = open("PROFILE.TXT", O_CREAT | O_WRONLY | O_TEXT);
+#endif
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("AUDIO."EXT,NULL,2))
+		Quit("CA_Startup(): Can't find audio files.");
+//
+// MDM end
+
+#ifndef NOAUDIO
+	CAL_SetupAudioFile ();
+#endif
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("GAMEMAPS."EXT,NULL,1))
+		Quit("CA_Startup(): Can't find level files.");
+//
+// MDM end
+
+#ifndef NOMAPS
+	CAL_SetupMapFile ();
+#endif
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("EGAGRAPH."EXT,NULL,2))
+		Quit("CA_Startup(): Can't find graphics files.");
+//
+// MDM end
+
+#ifndef NOGRAPHICS
+	CAL_SetupGrFile ();
+#endif
+
+	mapon = -1;
+	ca_levelbit = 1;
+	ca_levelnum = 0;
+
+	drawcachebox	= CAL_DialogDraw;
+	updatecachebox  = CAL_DialogUpdate;
+	finishcachebox	= CAL_DialogFinish;
+}
+
+//==========================================================================
+
+
+/*
+======================
+=
+= CA_Shutdown
+=
+= Closes all files
+=
+======================
+*/
+
+void CA_Shutdown (void)
+{
+#ifdef PROFILE
+	close (profilehandle);
+#endif
+
+	close (maphandle);
+	close (grhandle);
+	close (audiohandle);
+}
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_CacheAudioChunk
+=
+======================
+*/
+
+void CA_CacheAudioChunk (int chunk)
+{
+	long	pos,compressed;
+#ifdef AUDIOHEADERLINKED
+	long	expanded;
+	memptr	bigbufferseg;
+	byte	far *source;
+#endif
+
+	if (audiosegs[chunk])
+	{
+		MM_SetPurge (&(memptr)audiosegs[chunk],0);
+		return;							// allready in memory
+	}
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("AUDIO."EXT,NULL,2))
+		Quit("CA_CacheAudioChunk(): Can't find audio files.");
+//
+// MDM end
+
+//
+// load the chunk into a buffer, either the miscbuffer if it fits, or allocate
+// a larger buffer
+//
+	pos = audiostarts[chunk];
+	compressed = audiostarts[chunk+1]-pos;
+
+	lseek(audiohandle,pos,SEEK_SET);
+
+#ifndef AUDIOHEADERLINKED
+
+	MM_GetPtr (&(memptr)audiosegs[chunk],compressed);
+	if (mmerror)
+		return;
+
+	CA_FarRead(audiohandle,audiosegs[chunk],compressed);
+
+#else
+
+	if (compressed<=BUFFERSIZE)
+	{
+		CA_FarRead(audiohandle,bufferseg,compressed);
+		source = bufferseg;
+	}
+	else
+	{
+		MM_GetPtr(&bigbufferseg,compressed);
+		if (mmerror)
+			return;
+		MM_SetLock (&bigbufferseg,true);
+		CA_FarRead(audiohandle,bigbufferseg,compressed);
+		source = bigbufferseg;
+	}
+
+	expanded = *(long far *)source;
+	source += 4;			// skip over length
+	MM_GetPtr (&(memptr)audiosegs[chunk],expanded);
+	if (mmerror)
+		goto done;
+	CAL_HuffExpand (source,audiosegs[chunk],expanded,audiohuffman);
+
+done:
+	if (compressed>BUFFERSIZE)
+		MM_FreePtr(&bigbufferseg);
+#endif
+}
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_LoadAllSounds
+=
+= Purges all sounds, then loads all new ones (mode switch)
+=
+======================
+*/
+
+void CA_LoadAllSounds (void)
+{
+	unsigned	start,i;
+
+	switch (oldsoundmode)
+	{
+	case sdm_Off:
+		goto cachein;
+	case sdm_PC:
+		start = STARTPCSOUNDS;
+		break;
+	case sdm_AdLib:
+		start = STARTADLIBSOUNDS;
+		break;
+	}
+
+	for (i=0;i<NUMSOUNDS;i++,start++)
+		if (audiosegs[start])
+			MM_SetPurge (&(memptr)audiosegs[start],3);		// make purgable
+
+cachein:
+
+	switch (SoundMode)
+	{
+	case sdm_Off:
+		return;
+	case sdm_PC:
+		start = STARTPCSOUNDS;
+		break;
+	case sdm_AdLib:
+		start = STARTADLIBSOUNDS;
+		break;
+	}
+
+	for (i=0;i<NUMSOUNDS;i++,start++)
+		CA_CacheAudioChunk (start);
+
+	oldsoundmode = SoundMode;
+}
+
+//===========================================================================
+
+#if GRMODE == EGAGR
+
+/*
+======================
+=
+= CAL_ShiftSprite
+=
+= Make a shifted (one byte wider) copy of a sprite into another area
+=
+======================
+*/
+
+unsigned	static	sheight,swidth;
+boolean static dothemask;
+
+void CAL_ShiftSprite (unsigned segment,unsigned source,unsigned dest,
+	unsigned width, unsigned height, unsigned pixshift, boolean domask)
+{
+
+	sheight = height;		// because we are going to reassign bp
+	swidth = width;
+	dothemask = domask;
+
+asm	mov	ax,[segment]
+asm	mov	ds,ax		// source and dest are in same segment, and all local
+
+asm	mov	bx,[source]
+asm	mov	di,[dest]
+
+asm	mov	bp,[pixshift]
+asm	shl	bp,1
+asm	mov	bp,WORD PTR [shifttabletable+bp]	// bp holds pointer to shift table
+
+asm	cmp	[ss:dothemask],0
+asm	je		skipmask
+
+//
+// table shift the mask
+//
+asm	mov	dx,[ss:sheight]
+
+domaskrow:
+
+asm	mov	BYTE PTR [di],255	// 0xff first byte
+asm	mov	cx,ss:[swidth]
+
+domaskbyte:
+
+asm	mov	al,[bx]				// source
+asm	not	al
+asm	inc	bx					// next source byte
+asm	xor	ah,ah
+asm	shl	ax,1
+asm	mov	si,ax
+asm	mov	ax,[bp+si]			// table shift into two bytes
+asm	not	ax
+asm	and	[di],al				// and with first byte
+asm	inc	di
+asm	mov	[di],ah				// replace next byte
+
+asm	loop	domaskbyte
+
+asm	inc	di					// the last shifted byte has 1s in it
+asm	dec	dx
+asm	jnz	domaskrow
+
+skipmask:
+
+//
+// table shift the data
+//
+asm	mov	dx,ss:[sheight]
+asm	shl	dx,1
+asm	shl	dx,1				// four planes of data
+
+dodatarow:
+
+asm	mov	BYTE PTR [di],0		// 0 first byte
+asm	mov	cx,ss:[swidth]
+
+dodatabyte:
+
+asm	mov	al,[bx]				// source
+asm	inc	bx					// next source byte
+asm	xor	ah,ah
+asm	shl	ax,1
+asm	mov	si,ax
+asm	mov	ax,[bp+si]			// table shift into two bytes
+asm	or	[di],al				// or with first byte
+asm	inc	di
+asm	mov	[di],ah				// replace next byte
+
+asm	loop	dodatabyte
+
+asm	inc	di					// the last shifted byte has 0s in it
+asm	dec	dx
+asm	jnz	dodatarow
+
+//
+// done
+//
+
+asm	mov	ax,ss				// restore data segment
+asm	mov	ds,ax
+
+}
+
+#endif
+
+//===========================================================================
+
+/*
+======================
+=
+= CAL_CacheSprite
+=
+= Generate shifts and set up sprite structure for a given sprite
+=
+======================
+*/
+
+void CAL_CacheSprite (int chunk, byte far *compressed)
+{
+	int i;
+	unsigned shiftstarts[5];
+	unsigned smallplane,bigplane,expanded;
+	spritetabletype far *spr;
+	spritetype _seg *dest;
+
+#if GRMODE == CGAGR
+//
+// CGA has no pel panning, so shifts are never needed
+//
+	spr = &spritetable[chunk-STARTSPRITES];
+	smallplane = spr->width*spr->height;
+	MM_GetPtr (&grsegs[chunk],smallplane*2+MAXSHIFTS*6);
+	if (mmerror)
+		return;
+	dest = (spritetype _seg *)grsegs[chunk];
+	dest->sourceoffset[0] = MAXSHIFTS*6;	// start data after 3 unsigned tables
+	dest->planesize[0] = smallplane;
+	dest->width[0] = spr->width;
+
+//
+// expand the unshifted shape
+//
+	CAL_HuffExpand (compressed, &dest->data[0],smallplane*2,grhuffman);
+
+#endif
+
+
+#if GRMODE == EGAGR
+
+//
+// calculate sizes
+//
+	spr = &spritetable[chunk-STARTSPRITES];
+	smallplane = spr->width*spr->height;
+	bigplane = (spr->width+1)*spr->height;
+
+	shiftstarts[0] = MAXSHIFTS*6;	// start data after 3 unsigned tables
+	shiftstarts[1] = shiftstarts[0] + smallplane*5;	// 5 planes in a sprite
+	shiftstarts[2] = shiftstarts[1] + bigplane*5;
+	shiftstarts[3] = shiftstarts[2] + bigplane*5;
+	shiftstarts[4] = shiftstarts[3] + bigplane*5;	// nothing ever put here
+
+	expanded = shiftstarts[spr->shifts];
+	MM_GetPtr (&grsegs[chunk],expanded);
+	if (mmerror)
+		return;
+	dest = (spritetype _seg *)grsegs[chunk];
+
+//
+// expand the unshifted shape
+//
+	CAL_HuffExpand (compressed, &dest->data[0],smallplane*5,grhuffman);
+
+//
+// make the shifts!
+//
+	switch (spr->shifts)
+	{
+	case	1:
+		for (i=0;i<4;i++)
+		{
+			dest->sourceoffset[i] = shiftstarts[0];
+			dest->planesize[i] = smallplane;
+			dest->width[i] = spr->width;
+		}
+		break;
+
+	case	2:
+		for (i=0;i<2;i++)
+		{
+			dest->sourceoffset[i] = shiftstarts[0];
+			dest->planesize[i] = smallplane;
+			dest->width[i] = spr->width;
+		}
+		for (i=2;i<4;i++)
+		{
+			dest->sourceoffset[i] = shiftstarts[1];
+			dest->planesize[i] = bigplane;
+			dest->width[i] = spr->width+1;
+		}
+		CAL_ShiftSprite ((unsigned)grsegs[chunk],dest->sourceoffset[0],
+			dest->sourceoffset[2],spr->width,spr->height,4,true);
+		break;
+
+	case	4:
+		dest->sourceoffset[0] = shiftstarts[0];
+		dest->planesize[0] = smallplane;
+		dest->width[0] = spr->width;
+
+		dest->sourceoffset[1] = shiftstarts[1];
+		dest->planesize[1] = bigplane;
+		dest->width[1] = spr->width+1;
+		CAL_ShiftSprite ((unsigned)grsegs[chunk],dest->sourceoffset[0],
+			dest->sourceoffset[1],spr->width,spr->height,2,true);
+
+		dest->sourceoffset[2] = shiftstarts[2];
+		dest->planesize[2] = bigplane;
+		dest->width[2] = spr->width+1;
+		CAL_ShiftSprite ((unsigned)grsegs[chunk],dest->sourceoffset[0],
+			dest->sourceoffset[2],spr->width,spr->height,4,true);
+
+		dest->sourceoffset[3] = shiftstarts[3];
+		dest->planesize[3] = bigplane;
+		dest->width[3] = spr->width+1;
+		CAL_ShiftSprite ((unsigned)grsegs[chunk],dest->sourceoffset[0],
+			dest->sourceoffset[3],spr->width,spr->height,6,true);
+
+		break;
+
+	default:
+		Quit ("CAL_CacheSprite: Bad shifts number!");
+	}
+
+#endif
+}
+
+//===========================================================================
+
+
+/*
+======================
+=
+= CAL_ExpandGrChunk
+=
+= Does whatever is needed with a pointer to a compressed chunk
+=
+======================
+*/
+
+void CAL_ExpandGrChunk (int chunk, byte far *source)
+{
+	long	expanded;
+
+
+	if (chunk >= STARTTILE8 && chunk < STARTEXTERNS)
+	{
+	//
+	// expanded sizes of tile8/16/32 are implicit
+	//
+
+#if GRMODE == EGAGR
+#define BLOCK		32
+#define MASKBLOCK	40
+#endif
+
+#if GRMODE == CGAGR
+#define BLOCK		16
+#define MASKBLOCK	32
+#endif
+
+		if (chunk<STARTTILE8M)			// tile 8s are all in one chunk!
+			expanded = BLOCK*NUMTILE8;
+		else if (chunk<STARTTILE16)
+			expanded = MASKBLOCK*NUMTILE8M;
+		else if (chunk<STARTTILE16M)	// all other tiles are one/chunk
+			expanded = BLOCK*4;
+		else if (chunk<STARTTILE32)
+			expanded = MASKBLOCK*4;
+		else if (chunk<STARTTILE32M)
+			expanded = BLOCK*16;
+		else
+			expanded = MASKBLOCK*16;
+	}
+	else
+	{
+	//
+	// everything else has an explicit size longword
+	//
+		expanded = *(long far *)source;
+		source += 4;			// skip over length
+	}
+
+//
+// allocate final space, decompress it, and free bigbuffer
+// Sprites need to have shifts made and various other junk
+//
+	if (chunk>=STARTSPRITES && chunk< STARTTILE8)
+		CAL_CacheSprite(chunk,source);
+	else
+	{
+		MM_GetPtr (&grsegs[chunk],expanded);
+		if (mmerror)
+			return;
+		CAL_HuffExpand (source,grsegs[chunk],expanded,grhuffman);
+	}
+}
+
+
+/*
+======================
+=
+= CAL_ReadGrChunk
+=
+= Gets a chunk off disk, optimizing reads to general buffer
+=
+======================
+*/
+
+void CAL_ReadGrChunk (int chunk)
+{
+	long	pos,compressed;
+	memptr	bigbufferseg;
+	byte	far *source;
+	int		next;
+
+//
+// load the chunk into a buffer, either the miscbuffer if it fits, or allocate
+// a larger buffer
+//
+	pos = GRFILEPOS(chunk);
+	if (pos<0)							// $FFFFFFFF start is a sparse tile
+	  return;
+
+	next = chunk +1;
+	while (GRFILEPOS(next) == -1)		// skip past any sparse tiles
+		next++;
+
+	compressed = GRFILEPOS(next)-pos;
+
+	lseek(grhandle,pos,SEEK_SET);
+
+	if (compressed<=BUFFERSIZE)
+	{
+		CA_FarRead(grhandle,bufferseg,compressed);
+		source = bufferseg;
+	}
+	else
+	{
+		MM_GetPtr(&bigbufferseg,compressed);
+		if (mmerror)
+			return;
+		MM_SetLock (&bigbufferseg,true);
+		CA_FarRead(grhandle,bigbufferseg,compressed);
+		source = bigbufferseg;
+	}
+
+	CAL_ExpandGrChunk (chunk,source);
+
+	if (compressed>BUFFERSIZE)
+		MM_FreePtr(&bigbufferseg);
+}
+
+/*
+======================
+=
+= CA_CacheGrChunk
+=
+= Makes sure a given chunk is in memory, loadiing it if needed
+=
+======================
+*/
+
+void CA_CacheGrChunk (int chunk)
+{
+	long	pos,compressed;
+	memptr	bigbufferseg;
+	byte	far *source;
+	int		next;
+
+	grneeded[chunk] |= ca_levelbit;		// make sure it doesn't get removed
+	if (grsegs[chunk])
+	{
+		MM_SetPurge (&grsegs[chunk],0);
+		return;							// allready in memory
+	}
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("EGAGRAPH."EXT,NULL,2))
+		Quit("CA_CacheGrChunk(): Can't find graphics files.");
+//
+// MDM end
+
+//
+// load the chunk into a buffer, either the miscbuffer if it fits, or allocate
+// a larger buffer
+//
+	pos = GRFILEPOS(chunk);
+	if (pos<0)							// $FFFFFFFF start is a sparse tile
+	  return;
+
+	next = chunk +1;
+	while (GRFILEPOS(next) == -1)		// skip past any sparse tiles
+		next++;
+
+	compressed = GRFILEPOS(next)-pos;
+
+	lseek(grhandle,pos,SEEK_SET);
+
+	if (compressed<=BUFFERSIZE)
+	{
+		CA_FarRead(grhandle,bufferseg,compressed);
+		source = bufferseg;
+	}
+	else
+	{
+		MM_GetPtr(&bigbufferseg,compressed);
+		MM_SetLock (&bigbufferseg,true);
+		CA_FarRead(grhandle,bigbufferseg,compressed);
+		source = bigbufferseg;
+	}
+
+	CAL_ExpandGrChunk (chunk,source);
+
+	if (compressed>BUFFERSIZE)
+		MM_FreePtr(&bigbufferseg);
+}
+
+
+
+//==========================================================================
+
+/*
+======================
+=
+= CA_CacheMap
+=
+======================
+*/
+
+void CA_CacheMap (int mapnum)
+{
+	long	pos,compressed;
+	int		plane;
+	memptr	*dest,bigbufferseg;
+	unsigned	size;
+	unsigned	far	*source;
+#ifdef MAPHEADERLINKED
+	memptr	buffer2seg;
+	long	expanded;
+#endif
+
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("GAMEMAPS."EXT,NULL,1))
+		Quit("CA_CacheMap(): Can't find level files.");
+//
+// MDM end
+
+
+//
+// free up memory from last map
+//
+	if (mapon>-1 && mapheaderseg[mapon])
+		MM_SetPurge (&(memptr)mapheaderseg[mapon],3);
+	for (plane=0;plane<MAPPLANES;plane++)
+		if (mapsegs[plane])
+			MM_FreePtr (&(memptr)mapsegs[plane]);
+
+	mapon = mapnum;
+
+
+//
+// load map header
+// The header will be cached if it is still around
+//
+	if (!mapheaderseg[mapnum])
+	{
+		pos = ((mapfiletype	_seg *)tinf)->headeroffsets[mapnum];
+		if (pos<0)						// $FFFFFFFF start is a sparse map
+		  Quit ("CA_CacheMap: Tried to load a non existent map!");
+
+		MM_GetPtr(&(memptr)mapheaderseg[mapnum],sizeof(maptype));
+		lseek(maphandle,pos,SEEK_SET);
+		CA_FarRead (maphandle,(memptr)mapheaderseg[mapnum],sizeof(maptype));
+	}
+	else
+		MM_SetPurge (&(memptr)mapheaderseg[mapnum],0);
+
+//
+// load the planes in
+// If a plane's pointer still exists it will be overwritten (levels are
+// allways reloaded, never cached)
+//
+
+	size = mapheaderseg[mapnum]->width * mapheaderseg[mapnum]->height * 2;
+
+	for (plane = 0; plane<MAPPLANES; plane++)
+	{
+		pos = mapheaderseg[mapnum]->planestart[plane];
+		compressed = mapheaderseg[mapnum]->planelength[plane];
+
+		if (!compressed)
+			continue;		// the plane is not used in this game
+
+		dest = &(memptr)mapsegs[plane];
+		MM_GetPtr(dest,size);
+
+		lseek(maphandle,pos,SEEK_SET);
+		if (compressed<=BUFFERSIZE)
+			source = bufferseg;
+		else
+		{
+			MM_GetPtr(&bigbufferseg,compressed);
+			MM_SetLock (&bigbufferseg,true);
+			source = bigbufferseg;
+		}
+
+		CA_FarRead(maphandle,(byte far *)source,compressed);
+#ifdef MAPHEADERLINKED
+		//
+		// unhuffman, then unRLEW
+		// The huffman'd chunk has a two byte expanded length first
+		// The resulting RLEW chunk also does, even though it's not really
+		// needed
+		//
+		expanded = *source;
+		source++;
+		MM_GetPtr (&buffer2seg,expanded);
+		CAL_CarmackExpand (source, (unsigned far *)buffer2seg,expanded);
+		CA_RLEWexpand (((unsigned far *)buffer2seg)+1,*dest,size,
+		((mapfiletype _seg *)tinf)->RLEWtag);
+		MM_FreePtr (&buffer2seg);
+
+#else
+		//
+		// unRLEW, skipping expanded length
+		//
+		CA_RLEWexpand (source+1, *dest,size,
+		((mapfiletype _seg *)tinf)->RLEWtag);
+#endif
+
+		if (compressed>BUFFERSIZE)
+			MM_FreePtr(&bigbufferseg);
+	}
+}
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_UpLevel
+=
+= Goes up a bit level in the needed lists and clears it out.
+= Everything is made purgable
+=
+======================
+*/
+
+void CA_UpLevel (void)
+{
+	if (ca_levelnum==7)
+		Quit ("CA_UpLevel: Up past level 7!");
+
+	ca_levelbit<<=1;
+	ca_levelnum++;
+}
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_DownLevel
+=
+= Goes down a bit level in the needed lists and recaches
+= everything from the lower level
+=
+======================
+*/
+
+void CA_DownLevel (void)
+{
+	if (!ca_levelnum)
+		Quit ("CA_DownLevel: Down past level 0!");
+	ca_levelbit>>=1;
+	ca_levelnum--;
+	CA_CacheMarks(NULL);
+}
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_ClearMarks
+=
+= Clears out all the marks at the current level
+=
+======================
+*/
+
+void CA_ClearMarks (void)
+{
+	int i;
+
+	for (i=0;i<NUMCHUNKS;i++)
+		grneeded[i]&=~ca_levelbit;
+}
+
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_ClearAllMarks
+=
+= Clears out all the marks on all the levels
+=
+======================
+*/
+
+void CA_ClearAllMarks (void)
+{
+	_fmemset (grneeded,0,sizeof(grneeded));
+	ca_levelbit = 1;
+	ca_levelnum = 0;
+}
+
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_FreeGraphics
+=
+======================
+*/
+
+void CA_FreeGraphics (void)
+{
+	int	i;
+
+	for (i=0;i<NUMCHUNKS;i++)
+		if (grsegs[i])
+			MM_SetPurge (&(memptr)grsegs[i],3);
+}
+
+
+/*
+======================
+=
+= CA_SetAllPurge
+=
+= Make everything possible purgable
+=
+======================
+*/
+
+void CA_SetAllPurge (void)
+{
+	int i;
+
+	CA_ClearMarks ();
+
+//
+// free cursor sprite and background save
+//
+	VW_FreeCursor ();
+
+//
+// free map headers and map planes
+//
+	for (i=0;i<NUMMAPS;i++)
+		if (mapheaderseg[i])
+			MM_SetPurge (&(memptr)mapheaderseg[i],3);
+
+	for (i=0;i<3;i++)
+		if (mapsegs[i])
+			MM_FreePtr (&(memptr)mapsegs[i]);
+
+//
+// free sounds
+//
+	for (i=0;i<NUMSNDCHUNKS;i++)
+		if (audiosegs[i])
+			MM_SetPurge (&(memptr)audiosegs[i],3);
+
+//
+// free graphics
+//
+	CA_FreeGraphics ();
+}
+
+
+void CA_SetGrPurge (void)
+{
+	int i;
+
+//
+// free graphics
+//
+	for (i=0;i<NUMCHUNKS;i++)
+		if (grsegs[i])
+			MM_SetPurge (&(memptr)grsegs[i],3);
+}
+
+
+//===========================================================================
+
+
+/*
+======================
+=
+= CAL_DialogDraw
+=
+======================
+*/
+
+#define NUMBARS	(17l*8)
+#define BARSTEP	8
+
+unsigned	thx,thy,lastx;
+long		barx,barstep;
+
+void	CAL_DialogDraw (char *title,unsigned numcache)
+{
+	unsigned	homex,homey,x;
+
+	barstep = (NUMBARS<<16)/numcache;
+
+//
+// draw dialog window (masked tiles 12 - 20 are window borders)
+//
+	US_CenterWindow (20,8);
+	homex = PrintX;
+	homey = PrintY;
+
+	US_CPrint ("Loading");
+	fontcolor = F_SECONDCOLOR;
+	US_CPrint (title);
+	fontcolor = F_BLACK;
+
+//
+// draw thermometer bar
+//
+	thx = homex + 8;
+	thy = homey + 32;
+	VWB_DrawTile8(thx,thy,0);		// CAT3D numbers
+	VWB_DrawTile8(thx,thy+8,3);
+	VWB_DrawTile8(thx,thy+16,6);
+	VWB_DrawTile8(thx+17*8,thy,2);
+	VWB_DrawTile8(thx+17*8,thy+8,5);
+	VWB_DrawTile8(thx+17*8,thy+16,8);
+	for (x=thx+8;x<thx+17*8;x+=8)
+	{
+		VWB_DrawTile8(x,thy,1);
+		VWB_DrawTile8(x,thy+8,4);
+		VWB_DrawTile8(x,thy+16,7);
+	}
+
+	thx += 4;		// first line location
+	thy += 5;
+	barx = (long)thx<<16;
+	lastx = thx;
+
+	VW_UpdateScreen();
+}
+
+
+/*
+======================
+=
+= CAL_DialogUpdate
+=
+======================
+*/
+
+void	CAL_DialogUpdate (void)
+{
+	unsigned	x,xh;
+
+	barx+=barstep;
+	xh = barx>>16;
+	if (xh - lastx > BARSTEP)
+	{
+		for (x=lastx;x<=xh;x++)
+#if GRMODE == EGAGR
+			VWB_Vlin (thy,thy+13,x,14);
+#endif
+#if GRMODE == CGAGR
+			VWB_Vlin (thy,thy+13,x,SECONDCOLOR);
+#endif
+		lastx = xh;
+		VW_UpdateScreen();
+	}
+}
+
+/*
+======================
+=
+= CAL_DialogFinish
+=
+======================
+*/
+
+void	CAL_DialogFinish (void)
+{
+	unsigned	x,xh;
+
+	xh = thx + NUMBARS;
+	for (x=lastx;x<=xh;x++)
+#if GRMODE == EGAGR
+		VWB_Vlin (thy,thy+13,x,14);
+#endif
+#if GRMODE == CGAGR
+		VWB_Vlin (thy,thy+13,x,SECONDCOLOR);
+#endif
+	VW_UpdateScreen();
+
+}
+
+//===========================================================================
+
+/*
+======================
+=
+= CA_CacheMarks
+=
+======================
+*/
+#define MAXEMPTYREAD	1024
+
+void CA_CacheMarks (char *title)
+{
+	boolean dialog;
+	int 	i,next,numcache;
+	long	pos,endpos,nextpos,nextendpos,compressed;
+	long	bufferstart,bufferend;	// file position of general buffer
+	byte	far *source;
+	memptr	bigbufferseg;
+
+	dialog = (title!=NULL);
+
+	numcache = 0;
+//
+// go through and make everything not needed purgable
+//
+	for (i=0;i<NUMCHUNKS;i++)
+		if (grneeded[i]&ca_levelbit)
+		{
+			if (grsegs[i])					// its allready in memory, make
+				MM_SetPurge(&grsegs[i],0);	// sure it stays there!
+			else
+				numcache++;
+		}
+		else
+		{
+			if (grsegs[i])					// not needed, so make it purgeable
+				MM_SetPurge(&grsegs[i],3);
+		}
+
+	if (!numcache)			// nothing to cache!
+		return;
+
+// MDM begin - (GAMERS EDGE)
+//
+	if (!FindFile("EGAGRAPH."EXT,NULL,2))
+		Quit("CA_CacheMarks(): Can't find graphics files.");
+//
+// MDM end
+
+	if (dialog)
+	{
+#ifdef PROFILE
+		write(profilehandle,title,strlen(title));
+		write(profilehandle,"\n",1);
+#endif
+		if (drawcachebox)
+			drawcachebox(title,numcache);
+	}
+
+//
+// go through and load in anything still needed
+//
+	bufferstart = bufferend = 0;		// nothing good in buffer now
+
+	for (i=0;i<NUMCHUNKS;i++)
+		if ( (grneeded[i]&ca_levelbit) && !grsegs[i])
+		{
+//
+// update thermometer
+//
+			if (dialog && updatecachebox)
+				updatecachebox ();
+
+			pos = GRFILEPOS(i);
+			if (pos<0)
+				continue;
+
+			next = i +1;
+			while (GRFILEPOS(next) == -1)		// skip past any sparse tiles
+				next++;
+
+			compressed = GRFILEPOS(next)-pos;
+			endpos = pos+compressed;
+
+			if (compressed<=BUFFERSIZE)
+			{
+				if (bufferstart<=pos
+				&& bufferend>= endpos)
+				{
+				// data is allready in buffer
+					source = (byte _seg *)bufferseg+(pos-bufferstart);
+				}
+				else
+				{
+				// load buffer with a new block from disk
+				// try to get as many of the needed blocks in as possible
+					while ( next < NUMCHUNKS )
+					{
+						while (next < NUMCHUNKS &&
+						!(grneeded[next]&ca_levelbit && !grsegs[next]))
+							next++;
+						if (next == NUMCHUNKS)
+							continue;
+
+						nextpos = GRFILEPOS(next);
+						while (GRFILEPOS(++next) == -1)	// skip past any sparse tiles
+							;
+						nextendpos = GRFILEPOS(next);
+						if (nextpos - endpos <= MAXEMPTYREAD
+						&& nextendpos-pos <= BUFFERSIZE)
+							endpos = nextendpos;
+						else
+							next = NUMCHUNKS;			// read pos to posend
+					}
+
+					lseek(grhandle,pos,SEEK_SET);
+					CA_FarRead(grhandle,bufferseg,endpos-pos);
+					bufferstart = pos;
+					bufferend = endpos;
+					source = bufferseg;
+				}
+			}
+			else
+			{
+			// big chunk, allocate temporary buffer
+				MM_GetPtr(&bigbufferseg,compressed);
+				if (mmerror)
+					return;
+				MM_SetLock (&bigbufferseg,true);
+				lseek(grhandle,pos,SEEK_SET);
+				CA_FarRead(grhandle,bigbufferseg,compressed);
+				source = bigbufferseg;
+			}
+
+			CAL_ExpandGrChunk (i,source);
+			if (mmerror)
+				return;
+
+			if (compressed>BUFFERSIZE)
+				MM_FreePtr(&bigbufferseg);
+
+		}
+
+//
+// finish up any thermometer remnants
+//
+		if (dialog && finishcachebox)
+			finishcachebox();
+}
+
diff --git a/src/lib/16_ca.h b/src/lib/16_ca.h
new file mode 100644
index 00000000..380ae297
--- /dev/null
+++ b/src/lib/16_ca.h
@@ -0,0 +1,124 @@
+/* Catacomb Apocalypse Source Code
+ * Copyright (C) 1993-2014 Flat Rock Software
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+// ID_CA.H
+
+#ifndef __TYPES__
+#include "ID_TYPES.H"
+#endif
+
+#ifndef __ID_MM__
+#include "ID_MM.H"
+#endif
+
+#ifndef __ID_GLOB__
+#include "ID_GLOB.H"
+#endif
+
+#define __ID_CA__
+
+//===========================================================================
+
+//#define NOMAPS
+//#define NOGRAPHICS
+//#define NOAUDIO
+
+#define MAPHEADERLINKED
+#define GRHEADERLINKED
+#define AUDIOHEADERLINKED
+
+#define NUMMAPS		39
+#define MAPPLANES		3
+
+//===========================================================================
+
+typedef	struct
+{
+	long		planestart[3];
+	unsigned	planelength[3];
+	unsigned	width,height;
+	char		name[16];
+} maptype;
+
+//===========================================================================
+
+extern	byte 		_seg	*tinf;
+extern	int			mapon;
+
+extern	unsigned	_seg	*mapsegs[3];
+extern	maptype		_seg	*mapheaderseg[NUMMAPS];
+extern	byte		_seg	*audiosegs[NUMSNDCHUNKS];
+extern	void		_seg	*grsegs[NUMCHUNKS];
+
+extern	byte		far	grneeded[NUMCHUNKS];
+extern	byte		ca_levelbit,ca_levelnum;
+
+extern	char		*titleptr[8];
+
+extern	int			profilehandle,debughandle;
+
+//
+// hooks for custom cache dialogs
+//
+extern	void	(*drawcachebox)		(char *title, unsigned numcache);
+extern	void	(*updatecachebox)	(void);
+extern	void	(*finishcachebox)	(void);
+
+//===========================================================================
+
+// just for the score box reshifting
+
+void CAL_ShiftSprite (unsigned segment,unsigned source,unsigned dest,
+	unsigned width, unsigned height, unsigned pixshift, boolean domask);
+
+//===========================================================================
+
+void CA_OpenDebug (void);
+void CA_CloseDebug (void);
+boolean CA_FarRead (int handle, byte far *dest, long length);
+boolean CA_FarWrite (int handle, byte far *source, long length);
+boolean CA_ReadFile (char *filename, memptr *ptr);
+boolean CA_LoadFile (char *filename, memptr *ptr);
+
+long CA_RLEWCompress (unsigned huge *source, long length, unsigned huge *dest,
+  unsigned rlewtag);
+
+void CA_RLEWexpand (unsigned huge *source, unsigned huge *dest,long length,
+  unsigned rlewtag);
+
+void CA_Startup (void);
+void CA_Shutdown (void);
+
+void CA_CacheAudioChunk (int chunk);
+void CA_LoadAllSounds (void);
+
+void CA_UpLevel (void);
+void CA_DownLevel (void);
+
+void CA_SetAllPurge (void);
+
+void CA_ClearMarks (void);
+void CA_ClearAllMarks (void);
+
+#define CA_MarkGrChunk(chunk)	grneeded[chunk]|=ca_levelbit
+
+void CA_CacheGrChunk (int chunk);
+void CA_CacheMap (int mapnum);
+
+void CA_CacheMarks (char *title);
+
-- 
2.39.2