#ifndef UTILITY_PACK_H
#define UTILITY_PACK_H
/*
**	$Id: pack.h,v 39.2 92/04/09 03:05:00 mks Exp $
**
**	Control attributes for Pack/UnpackStructureTags()
**
**	(C) Copyright 1992 Commodore-Amiga Inc.
**	All Rights Reserved
*/

/*****************************************************************************/


#ifndef EXEC_TYPES_H
#include <exec/types.h>
#endif

#ifndef UTILITY_TAGITEM_H
#include <utility/tagitem.h>
#endif


/*****************************************************************************/


/* PackTable definition:
 *
 * The PackTable is a simple array of LONGWORDS that are evaluated by
 * PackStructureTags() and UnpackStructureTags().
 *
 * The table contains compressed information such as the tag offset from
 * the base tag. The tag offset has a limited range so the base tag is
 * defined in the first longword.
 *
 * After the first longword, the fields look as follows:
 *
 *	+--------- 1 = signed, 0 = unsigned (for bits, 1=inverted boolean)
 *	|
 *	|  +------ 00 = Pack/Unpack, 10 = Pack, 01 = Unpack, 11 = special
 *	| / \
 *	| | |  +-- 00 = Byte, 01 = Word, 10 = Long, 11 = Bit
 *	| | | / \
 *	| | | | | /----- For bit operations: 1 = TAG_EXISTS is TRUE
 *	| | | | | |
 *	| | | | | | /-------------------- Tag offset from base tag value
 *	| | | | | | |                 \
 *	m n n o o p q q q q q q q q q q r r r s s s s s s s s s s s s s
 *	                                \   | |                       |
 *	Bit offset (for bit operations) ----/ |                       |
 *	                                      \                       |
 *	Offset into data structure -----------------------------------/
 *
 * A -1 longword signifies that the next longword will be a new base tag
 *
 * A 0 longword signifies that it is the end of the pack table.
 *
 * What this implies is that there are only 13-bits of address offset
 * and 10 bits for tag offsets from the base tag.  For most uses this
 * should be enough, but when this is not, either multiple pack tables
 * or a pack table with extra base tags would be able to do the trick.
 * The goal here was to make the tables small and yet flexible enough to
 * handle most cases.
 */

#define	PSTB_SIGNED 31
#define PSTB_UNPACK 30	  /* Note that these are active low... */
#define PSTB_PACK   29	  /* Note that these are active low... */
#define	PSTB_EXISTS 26    /* Tag exists bit true flag hack...  */

#define	PSTF_SIGNED (1L << PSTB_SIGNED)
#define PSTF_UNPACK (1L << PSTB_UNPACK)
#define PSTF_PACK   (1L << PSTB_PACK)

#define	PSTF_EXISTS (1L << PSTB_EXISTS)

/*****************************************************************************/


#define PKCTRL_PACKUNPACK 0x00000000
#define PKCTRL_PACKONLY   0x40000000
#define PKCTRL_UNPACKONLY 0x20000000

#define PKCTRL_BYTE       0x80000000
#define PKCTRL_WORD       0x88000000
#define PKCTRL_LONG       0x90000000

#define PKCTRL_UBYTE      0x00000000
#define PKCTRL_UWORD      0x08000000
#define PKCTRL_ULONG      0x10000000

#define PKCTRL_BIT        0x18000000
#define PKCTRL_FLIPBIT    0x98000000


/*****************************************************************************/


/* Macros used by the next batch of macros below. Normally, you don't use
 * this batch directly. Then again, some folks are wierd
 */

#define PK_BITNUM1(flg) ((flg) == 0x01 ? 0 : (flg) == 0x02 ? 1 : (flg) == 0x04 ? 2 : (flg) == 0x08 ? 3 : (flg) == 0x10 ? 4 : (flg) == 0x20 ? 5 : (flg) == 0x40 ? 6 : 7)
#define PK_BITNUM2(flg) ((flg < 0x100 ? PK_BITNUM1(flg) : 8+PK_BITNUM1(flg >> 8)))
#define PK_BITNUM(flg) ((flg < 0x10000 ? PK_BITNUM2(flg) : 16+PK_BITNUM2(flg >> 16)))
#define PK_WORDOFFSET(flg) ((flg) < 0x100 ? 1 : 0)
#define PK_LONGOFFSET(flg) ((flg) < 0x100  ? 3 : (flg) < 0x10000 ? 2 : (flg) < 0x1000000 ? 1 : 0)
#define PK_CALCOFFSET(type,field) ((ULONG)(&((struct type *)0)->field))


/*****************************************************************************/


/* Some handy dandy macros to easily create pack tables
 *
 * Use PACK_STARTTABLE() at the start of a pack table. You pass it the
 * base tag value that will be handled in the following chunk of the pack
 * table.
 *
 * PACK_ENDTABLE() is used to mark the end of a pack table.
 *
 * PACK_NEWOFFSET() lets you change the base tag value used for subsequent
 * entries in the table
 *
 * PACK_ENTRY() lets you define an entry in the pack table. You pass it the
 * base tag value, the tag of interest, the type of the structure to use,
 * the field name in the structure to affect and control bits (combinations of
 * the various PKCTRL_XXX bits)
 *
 * PACK_BYTEBIT() lets you define a bit-control entry in the pack table. You
 * pass it the same data as PACK_ENTRY, plus the flag bit pattern this tag
 * affects. This macro should be used when the field being affected is byte
 * sized.
 *
 * PACK_WORDBIT() lets you define a bit-control entry in the pack table. You
 * pass it the same data as PACK_ENTRY, plus the flag bit pattern this tag
 * affects. This macro should be used when the field being affected is word
 * sized.
 *
 * PACK_LONGBIT() lets you define a bit-control entry in the pack table. You
 * pass it the same data as PACK_ENTRY, plus the flag bit pattern this tag
 * affects. This macro should be used when the field being affected is longword
 * sized.
 *
 * EXAMPLE:
 *
 *    ULONG packTable[] =
 *    {
 *         PACK_STARTTABLE(GA_Dummy),
 *	   PACK_ENTRY(GA_Dummy,GA_Left,Gadget,LeftEdge,PKCTRL_WORD|PKCTRL_PACKUNPACK),
 *	   PACK_ENTRY(GA_Dummy,GA_Top,Gadget,TopEdge,PKCTRL_WORD|PKCTRL_PACKUNPACK),
 *	   PACK_ENTRY(GA_Dummy,GA_Width,Gadget,Width,PKCTRL_UWORD|PKCTRL_PACKUNPACK),
 *	   PACK_ENTRY(GA_Dummy,GA_Height,Gadget,Height,PKCTRL_UWORD|PKCTRL_PACKUNPACK),
 *	   PACK_WORDBIT(GA_Dummy,GA_RelVerify,Gadget,Activation,PKCTRL_BIT|PKCTRL_PACKUNPACK,GACT_RELVERIFY)
 *	   PACK_ENDTABLE
 *    };
 */

#define PACK_STARTTABLE(tagbase)                           (tagbase)
#define PACK_NEWOFFSET(tagbase)                            (-1L),(tagbase)
#define PACK_ENDTABLE                                      0
#define PACK_ENTRY(tagbase,tag,type,field,control)         (control | ((tag-tagbase) << 16L) | PK_CALCOFFSET(type,field))
#define PACK_BYTEBIT(tagbase,tag,type,field,control,flags) (control | ((tag-tagbase) << 16L) | PK_CALCOFFSET(type,field) | (PK_BITNUM(flags) << 13L))
#define PACK_WORDBIT(tagbase,tag,type,field,control,flags) (control | ((tag-tagbase) << 16L) | (PK_CALCOFFSET(type,field)+PK_WORDOFFSET(flags)) | ((PK_BITNUM(flags)&7) << 13L))
#define PACK_LONGBIT(tagbase,tag,type,field,control,flags) (control | ((tag-tagbase) << 16L) | (PK_CALCOFFSET(type,field)+PK_LONGOFFSET(flags)) | ((PK_BITNUM(flags)&7) << 13L))


/*****************************************************************************/

#endif /* UTILITY_PACK_H */
