wolf3d/ID_PM.H
1995-07-21 00:00:00 +00:00

83 lines
2.3 KiB
C

//
// 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);