The Wolfenstein 3D source as originally released.

WOLFSRC/ID_PM.H

@@ -0,0 +1,83 @@
+//
+//	ID_PM.H
+//	Header file for Id Engine's Page Manager
+//
+
+//	NOTE! PMPageSize must be an even divisor of EMSPageSize, and >= 1024
+#define	EMSPageSize		16384
+#define	EMSPageSizeSeg	(EMSPageSize >> 4)
+#define	EMSPageSizeKB	(EMSPageSize >> 10)
+#define	EMSFrameCount	4
+#define	PMPageSize		4096
+#define	PMPageSizeSeg	(PMPageSize >> 4)
+#define	PMPageSizeKB	(PMPageSize >> 10)
+#define	PMEMSSubPage	(EMSPageSize / PMPageSize)
+
+#define	PMMinMainMem	10			// Min acceptable # of pages from main
+#define	PMMaxMainMem	100			// Max number of pages in main memory
+
+#define	PMThrashThreshold	1	// Number of page thrashes before panic mode
+#define	PMUnThrashThreshold	5	// Number of non-thrashing frames before leaving panic mode
+
+typedef	enum
+		{
+			pml_Unlocked,
+			pml_Locked
+		} PMLockType;
+
+typedef	enum
+		{
+			pmba_Unused = 0,
+			pmba_Used = 1,
+			pmba_Allocated = 2
+		} PMBlockAttr;
+
+typedef	struct
+		{
+			longword	offset;		// Offset of chunk into file
+			word		length;		// Length of the chunk
+
+			int			xmsPage;	// If in XMS, (xmsPage * PMPageSize) gives offset into XMS handle
+
+			PMLockType	locked;		// If set, this page can't be purged
+			int			emsPage;	// If in EMS, logical page/offset into page
+			int			mainPage;	// If in Main, index into handle array
+
+			longword	lastHit;	// Last frame number of hit
+		} PageListStruct;
+
+typedef	struct
+		{
+			int			baseEMSPage;	// Base EMS page for this phys frame
+			longword	lastHit;		// Last frame number of hit
+		} EMSListStruct;
+
+extern	boolean			XMSPresent,EMSPresent;
+extern	word			XMSPagesAvail,EMSPagesAvail;
+
+extern	word			ChunksInFile,
+						PMSpriteStart,PMSoundStart;
+extern	PageListStruct	far *PMPages;
+
+#define	PM_GetSoundPage(v)	PM_GetPage(PMSoundStart + (v))
+#define	PM_GetSpritePage(v)	PM_GetPage(PMSpriteStart + (v))
+
+#define	PM_LockMainMem()	PM_SetMainMemPurge(0)
+#define	PM_UnlockMainMem()	PM_SetMainMemPurge(3)
+
+
+extern	char	PageFileName[13];
+
+
+extern	void	PM_Startup(void),
+				PM_Shutdown(void),
+				PM_Reset(void),
+				PM_Preload(boolean (*update)(word current,word total)),
+				PM_NextFrame(void),
+				PM_SetPageLock(int pagenum,PMLockType lock),
+				PM_SetMainPurge(int level),
+				PM_CheckMainMem(void);
+extern	memptr	PM_GetPageAddress(int pagenum),
+				PM_GetPage(int pagenum);		// Use this one to cache page
+
+void PM_SetMainMemPurge(int level);