Amiga Plus 2002 #11/Amiga Plus CD - 2002 - No. 11.iso/Tools/Development/PowerD/powerd/modules.lha/modules/utility/pack.m

Text File | 2000-08-04 | 5.5 KB | 129 lines

/*
**    $VER: pack.m 39.3 (10.2.1993)
**    Includes Release 44.1
**
**    Control attributes for Pack/UnpackStructureTags()
**
**    (C) Copyright 1992-1999 Amiga, Inc.
**    All Rights Reserved
*/

MODULE    'utility/tagitem'

/* 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.
 */
FLAG    PST_SIGNED=31,
        PST_UNPACK=30,        /* Note that these are active low... */
        PST_PACK=29,        /* Note that these are active low... */
        PST_EXISTS=26        /* Tag exists bit true flag hack...  */

CONST    PKCTRL_PACKUNPACK=0,
        PKCTRL_PACKONLY=$40000000,
        PKCTRL_UNPACKONLY=$20000000,
        PKCTRL_BYTE=$80000000,
        PKCTRL_WORD=$88000000,
        PKCTRL_LONG=$90000000,
        PKCTRL_UBYTE=0,
        PKCTRL_UWORD=$8000000,
        PKCTRL_ULONG=$10000000,
        PKCTRL_BIT=$18000000,
        PKCTRL_FLIPBIT=$98000000

/* 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)                    (IF (flg)=$01 THEN 0 ELSE IF (flg)=$02 THEN 1 ELSE IF (flg)=$04 THEN 2 ELSE IF (flg)=$08 THEN 3 ELSE IF (flg)=$10 THEN 4 ELSE IF (flg)=$20 THEN 5 ELSE IF (flg)=$40 THEN 6 ELSE 7)
#define PK_BITNUM2(flg)                    (IF (flg)<$100 THEN PK_BITNUM1(flg) ELSE 8+PK_BITNUM1(flg>>8))
#define PK_BITNUM(flg)                    (IF (flg)<$10000 THEN PK_BITNUM2(flg) ELSE 16+PK_BITNUM2(flg>>16))
#define PK_WORDOFFSET(flg)                (IF (flg)<$100 THEN 1 ELSE 0)
#define PK_LONGOFFSET(flg)                (IF (flg)<$100 THEN 3 ELSE IF (flg)<$10000 THEN 2 ELSE IF (flg)<$1000000 THEN 1 ELSE 0)
#define PK_CALCOFFSET(type,field)    (&0::type.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)            (-1),(tagbase)
CONST        PACK_ENDTABLE=0
#define    PACK_ENTRY(tagbase,tag,type,field,control)       (control | ((tag-tagbase) << 16) | PK_CACOFFSET(type,field))
#define    PACK_BYTEBIT(tagbase,tag,type,field,control,flags) (control | ((tag-tagbase) << 16) | PK_CACOFFSET(type,field) | (PK_BITNUM(flags) << 13))
#define    PACK_WORDBIT(tagbase,tag,type,field,control,flags) (control | ((tag-tagbase) << 16) | (PK_CACOFFSET(type,field)+PK_WORDOFFSET(flags)) | ((PK_BITNUM(flags)&7) << 13))
#define    PACK_LONGBIT(tagbase,tag,type,field,control,flags) (control | ((tag-tagbase) << 16) | (PK_CACOFFSET(type,field)+PK_LONGOFFSET(flags)) | ((PK_BITNUM(flags)&7) << 13))