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CSS style declaration bytecode
==============================
Format
------
<opcode+flags> [<parameters>]
<opcode+flags> is 32 bits wide.
The bottom 16 bits contain the opcode and the top 16 bits contain flags.
The 16 bits of flag data are defined as follows:
bit 0 : !important
bit 1-15: MBZ
Parameters are opcode-specific. Each parameter must begin on a 4 byte boundary.
Datatype storage
----------------
8 and 16 bit integers are stored as 32bit values.
32 and 64 bit integers are stored in their natural format.
Floats and doubles are stored in their natural format.
Strings are stored unterminated UTF8, preceded by 32bits of byte length, and
followed by 0-3 bytes of padding for alignment. The padding bytes must be
zero. The padding is not included in the byte length.
CSS dimensions are stored as two 32bit values: <length, units>.
Length is a 32bit integer and unit is as follows:
bit 8 clear => length unit
bits 9-31: MBZ
bits 0-7 :
00000000 => px
00000001 => ex
00000010 => em
00000011 => in
00000100 => cm
00000101 => mm
00000110 => pt
00000111 => pc
bit 8 set => percentage unit
bits 9-31: MBZ
bits 0-7 : MBZ
bit 9 set => angle unit
bits 10-31: MBZ
bit 8 : MBZ
bits 0-7 :
00000000 => deg
00000001 => grad
00000010 => rad
bit 10 set => time unit
bits 11-31: MBZ
bits 8-9 : MBZ
bits 0-7 :
00000000 => ms
00000001 => s
bit 11 set => frequency unit
bits 12-31: MBZ
bits 8-10 : MBZ
bits 0-7 :
00000000 => Hz
00000001 => kHz
CSS colours are stored as one 32bit value:
bits 24-31: Red component
bits 16-23: Green component
bits 8-15 : Blue component
bits 0-7 : Alpha component
CSS shapes are stored as one 32bit value followed by n CSS dimensions:
bits 1-31: MBZ
bit 0 : clear => rect, 4 dimensions follow
set => reserved for future expansion
TODO: how to handle "auto"?
Opcodes
-------
00 - azimuth
<value> (32bits) :
bits 8-31: MBZ
bit 7 set => angle or inherit:
bits 0-6: 0000000 => signed angle unit follows,
1111111 => inherit,
other => Reserved for future expansion.
bit 6 set => relative movement:
bit 7 : MBZ
bits 1-5: MBZ
bit 0 : set => rightwards, clear => leftwards
bits 6 & 7 clear => keyword position:
bit 5 : set => behind, clear => in front
bits 0-4:
0000 => left-side
0001 => far-left
0010 => left
0011 => center-left
0100 => center
0101 => center-right
0110 => right
0111 => far-right
1000 => right-side
other => Reserved for future expansion.
01 - background-attachment
<value> (32bits) :
0 => fixed
1 => scroll
0xff => inherit
other => Reserved for future expansion.
02 - background-color
<value> (32bits) :
bit 8-31: MBZ
bit 7 set => color or inherit:
bits 0-6: 0000000 => colour follows,
1111111 => inherit,
other => Reserved for future expansion.
bit 7 clear => keyword color:
bits 1-6: MBZ
bit 0 : clear => transparent, set => rffe.
03 - background-image
<value> (32bits) :
bits 8-31: MBZ
bit 7 set => uri or inherit:
bits 0-6: 0000000 => uri string follows,
1111111 => inherit,
other => Reserved for future expansion.
bit 7 clear => keyword:
bits 1-6: MBZ
bit 0 : clear => none, set => rffe.
04 - background-position
<value> (32bits) :
bits 8-31: MBZ
bits 0-7 :
11111111 => inherit
otherwise:
bit 7: set => percentage or length unit follows
bits 4-6: MBZ
clear => keywords:
bits 4-6:
000 => right
001 => center
010 => left
other => rffe
bit 3: set => percentage or length unit follows
bits 0-2: MBZ
clear => keywords:
bits 0-2:
000 => bottom
001 => center
010 => top
other => rffe
05 - background-repeat
<value> (32bits) :
0 => no-repeat
1 => repeat-x
2 => repeat-y
3 => repeat
0xff => inherit
other => Reserved for future expansion.
06 - border-collapse
<value> (32bits) :
0 => separate
1 => collapse
0xff => inherit
other => Reserved for future expansion.
07 - border-spacing
<value> (32bits) :
bits 8-31: MBZ
bits 0-7 : 00000000 => two lengths follow,
11111111 => inherit,
other => Reserved for future expansion.
08 - border-{top,right,bottom,left}-color
<value> (32bits) :
bits 10-31: MBZ
bits 8-9 :
00 => top
01 => right
10 => bottom
11 => left
bits 0-7 : 00000000 => colour follows,
00000001 => transparent,
11111111 => inherit,
other => Reserved for future expansion.
09 - border-{top,right,bottom,left}-style
<value> (32bits) :
bits 10-31: MBZ
bits 8-9 :
00 => top
01 => right
10 => bottom
11 => left
bits 0-7 :
00000000 => none,
00000001 => hidden,
00000010 => dotted,
00000011 => dashed,
00000100 => solid,
00000101 => double,
00000110 => groove,
00000111 => ridge,
00001000 => inset,
00001001 => outset,
11111111 => inherit,
other => Reserved for future expansion.
0a - border-{top,right,bottom,left}-width
<value> (32bits) :
bits 10-31: MBZ
bits 8-9 :
00 => top
01 => right
10 => bottom
11 => left
bits 0-7 :
11111111 => inherit,
otherwise:
bit 7 set => length follows
bits 0-6: MBZ
bit 7 clear => keywords:
bits 0-6: 0000000 => thin,
0000001 => medium,
0000010 => thick,
other => rffe.
0b - bottom
0c - caption-side
0d - clear
0e - clip
0f - color
10 - content
11 - counter-increment
12 - counter-reset
13 - cue-after
14 - cue-before
15 - cursor
16 - direction
17 - display
18 - elevation
19 - empty-cells
1a - float
1b - font-family
1c - font-size
1d - font-style
1e - font-variant
1f - font-weight
20 - height
21 - left
22 - letter-spacing
23 - line-height
24 - list-style-image
25 - list-style-position
26 - list-style-type
27 - margin-{top,right,bottom,left}
28 - max-height
29 - max-width
2a - min-height
2b - min-width
2c - orphans
2d - outline-color
2e - outline-style
2f - outline-width
30 - overflow
31 - padding-{top,right,bottom,left}
32 - page-break-after
33 - page-break-before
34 - page-break-inside
35 - pause-after
36 - pause-before
37 - pitch-range
38 - pitch
39 - play-during
3a - position
3b - quotes
3c - richness
3d - speak-header
3e - speak-numeral
3f - speak-punctuation
40 - speak
41 - speech-rate
42 - stress
43 - table-layout
44 - text-align
45 - text-decoration
46 - text-indent
47 - text-transform
48 - top
49 - unicode-bidi
4a - vertical-align
4b - visibility
4c - voice-family
4d - volume
4e - white-space
4f - widows
50 - width
51 - word-spacing
52 - z-index
53-ffff - Reserved for future expansion.
|
