Format version: 6
The text form of a PdfDisplayList (or of any interpretation, written straight from the interpreter). It is used for
snapshot tests and is meant to be comparable across implementations: it is plain UTF-8 text, one record per line, with
\n line ends. Any change to what is written bumps the version below and the number in the header line.
Header
The first line is onepdf-display-list 6: the magic word and the format version.
Numbers
Numbers are rounded to four decimals (ties to even), printed in plain decimal with no exponent, no trailing zeros
and no negative zero: 0, 12, -0.5, 3.1416. The rounding and printing use integer arithmetic on the scaled value, so
all platforms print the same text. Non-finite values print as nan, inf, -inf; magnitudes of 1e14 or more print as
huge or -huge.
A matrix is [a b c d e f]. A box is left bottom right top.
Lines
Each line is indented by two spaces per open bracket (page, clip, group, soft mask, marked content, annotation); the indentation is informative. The record keyword is the first word.
| Record | Meaning |
|---|---|
page box=<box> name=<CropBox|MediaBox|BleedBox|TrimBox|ArtBox> rotate=<0|90|180|270> unit=<n> scale=<n> size=<w> <h> base=<matrix> | Start of a page: the selected box in default user space, the rotation and user unit applied, the total scale, the output size and the matrix from default user space to the output (y grows downward). |
end-page | End of the page. |
gs ctm=<matrix> fill=<color> stroke=<color> lw=<n> cap=<n> join=<n> miter=<n> dash=[<n> ...] phase=<n> flat=<n> ri=<name> fa=<n> sa=<n> bm=<name> sm=<id> ais=<0|1> op=<fill><stroke><mode> [tk=0] | The graphics state that applies to the records that follow, written whenever it differs from the last one written. ctm maps the user space of the following paths to the output. fa/sa are the fill and stroke alpha, bm the blend mode, sm the soft mask id (0 = none), op three characters: fill overprint, stroke overprint (0/1) and the overprint mode. tk=0 appears only when the text knockout flag (/TK, ISO 32000-2 9.3.8) is off; it is on by default and then not written. |
fill <nonzero|evenodd> <path> | Fill a path. |
stroke <path> | Stroke a path. |
fillstroke <nonzero|evenodd> <path> | Fill and stroke one path as a single knockout group, from the B, B*, b and b* operators (ISO 32000-2 11.7.4.4); the path is already closed for b and b*. A fill followed by a separate stroke (f then S) stays two records. |
clip <nonzero|evenodd> <path> | Intersect the clip with a path; opens a clip bracket. |
text-clip | Intersect the clip with the glyphs shown in clipping render modes since the last BT; opens a clip bracket. |
pop-clip | Close the most recent clip bracket. |
text font=<name> size=<n> mode=<0-7> tc=<n> tw=<n> th=<n> rise=<n> tm=<matrix> vert=<0|1> adv=<x> <y> codes=<hex> glyphs=[<glyph> ...] | One shown string. th is the horizontal scale as a factor. tm is the text matrix at the start of the string. adv is the total displacement of the text matrix. codes are the string bytes in lower-case hex. Each glyph is <code>@<offsetX>,<offsetY>,<width> optionally followed by :g<glyph id> and :u<UTF-8 hex> when known, and, in a vertical run, :v<vx>,<vy>,<w1> (the position vector and vertical advance in em units; the offsets are those of the glyph origin, ISO 32000-2 9.7.4.3). Outlines are not written. A Type 3 font's run lists its text with no outlines; the glyph procedures follow as begin-glyph brackets. |
image <inline|/Name> bytes=<n> fnv=<hex> data=<finished> dict=<object> | An image drawn into the unit square of the CTM: the length and FNV-1a 64-bit hash of its encoded data (bytes=-1 when unreadable), the finished image and its dictionary. <finished> is decoded:<w>x<h>:<colour space name>:<fnv of the 8-bit samples>, stencil:<w>x<h>:<fnv of the coverage plane>, encoded:<w>x<h> (no decoder for its codec), none (unusable dictionary) or limit (over an image limit); a mask or colour key adds :alpha=<w>x<h>:<fnv>. Decoding uses the default decoder registry, which ships empty. |
shading type=<1-7> cs=<final space> fn=<0|1> bbox=<box|none> bg=<(c ...)|none> aa=<0|1> ... | The sh operator, or the shading inside a shading pattern. The shading is decoded and evaluated by OnePDF; the line states what a device receives. Type-specific fields follow: type 1 domain=(x0 x1 y0 y1) matrix=<matrix> at-centre=(c ...); types 2 and 3 coords=(...) domain=(t0 t1) extend=<0|1><0|1> at-start=(c ...) at-mid=(c ...) at-end=(c ...) (the colours the evaluator returns at the start, middle and end of the domain, in the final space); types 4 to 7 vertices=<n> triangles=<n>, for patch meshes also patches=<n> div=<n>, then fnv=<hash> (FNV-1a 64 of the rounded vertex data and the triangle indices) and truncated when data was dropped at a limit. |
pattern-def #<id> /Name tiling paint=<1|2> tile=<1-3> bbox=<box> step=<x> <y> matrix=<matrix> / end-pattern-def | The first use of a tiling pattern in a colour: its definition, followed (indented, between the two records) by the records of its cell, which are written like a page's content with pattern space as user space. matrix maps pattern space to the output. Colours name the pattern as pattern(#<id> ...). |
pattern-def #<id> /Name shading matrix=<matrix> / end-pattern-def | The first use of a shading pattern: one shading record between the two. |
begin-group bbox=<box> isolated=<0|1> knockout=<0|1> cs=<object> / end-group | A transparency group. |
begin-softmask id=<n> type=<luminosity|alpha> bbox=<box> bc=<object> tr=<object> trtable=<hex|none> / end-softmask | A soft mask definition; its content sits between the two records. trtable is the 256-byte transfer table OnePDF evaluated from /TR (ISO 32000-2 11.6.5.2), 512 lower-case hex digits, or none for identity. |
begin-mc /Tag props=<object> / end-mc | A marked-content sequence. props is null without properties. |
begin-glyph font=<name> code=<n> name=<glyph name|none> adv=<n> [u=<UTF-8 hex>] / end-glyph | A Type 3 glyph procedure, run as content after the text record that showed it (not for render mode 3 or a code without a procedure). The records between the two are written like a page's content; the gs line before begin-glyph has a CTM that already includes the font matrix and the text space, so glyph coordinates map straight to the output. |
begin-annot /Subtype rect=<box> flags=<n> / end-annot | An annotation appearance. |
Paths
A path is a space-separated list of M x y, L x y, C x1 y1 x2 y2 x3 y3 and Z, in the user space of the CTM in force.
Colors
gray(g), rgb(r g b), cmyk(c m y k), calgray(g), calrgb(r g b), lab(L a b), icc<N>:<profile length>:<FNV-1a 64 of the profile>(c ...), and for
pattern colors pattern(#<id> /Name) (followed by the base space name and tint components for uncolored patterns); <id> numbers the patterns in order of first use and refers to a pattern-def record written before the gs line that uses it.
Objects
Dictionaries, arrays and other objects print in a canonical form: dictionary keys sorted by ordinal, /Name with
non-regular characters as #xx, strings as <hex>, references as n g R, streams as stream<<...>>, true, false,
null; nesting beyond eight levels prints ....
Versioning
The version is an integer that changes whenever the output for any input could change (new records, new fields, different rounding). Readers must reject a version they do not know.
History: 2 added the data= field to image lines and the calgray/calrgb colour spaces (before, CalGray and CalRGB printed as gray and rgb); an ICC profile that is damaged or does not match its component count now prints as the device space with that many components. Version 3 replaced the unevaluated shading /Name obj= record by the decoded shading type=... record, added pattern-def, and changed pattern colours to pattern(#<id> /Name ...). Version 4 added the begin-glyph bracket for Type 3 glyph procedures and the :v suffix of vertical glyphs; glyph runs now carry real glyph ids, Unicode and widths from the PDF fonts. Version 5 added the fillstroke record (before, B/b wrote a fill and a stroke record) and the tk=0 field of gs. Version 6 added the trtable= field of begin-softmask.