Looking at `ColorSpace.parseToIR`, it will do one of the following things when called:
1. Return a String.
2. Return an Array.
3. Throw a `FormatError`.
4. In one case, return the result of *another* `ColorSpace.parseToIR` call.
However, under no circumstances will it ever return an `AlternateCS` instance.
Since it's often useful to understand why code, which has become unused, existed in the first place, let's grab a hard hat and a shovel and start digging through the history of this code :-)
The current condition was introduced in commit c198ec4323, in PR 794, but it was actually already obsolete by that time.
The preceeding `instanceof SeparationCS` condition predates commit a7278b7fbc, in PR 700.
That condition was originally introduced all the way back in commit 4e3f87b60c, in PR 692. However, it was made obsolete by commit 9dcefe1efc, which is included in the very same PR!
Hence we're left with the conclusion that not only has this code be unused for *almost* six years, it was basically never used at all save for a few refactoring commits that're part of PR 692.
Bug 1392647 has a PDF where the default width of the font
is 0. It draws some charcodes that don't have glyphs, but
we were wrongly using the 1000 default width for these
charcodes causing some text to be overlapping.
(for issue #6289)
This does the same for 16 bit as the existing 8 bit tiff predictor code, an addition of the last word to this word.
The last two "& 0xFF" may or may not be needed, I see this isn't done in the 8 bit code, but I'm not a JS developer.
Currently `PDFFunction` is implemented (basically) like a class with only `static` methods. Since it's used directly in a number of different `src/core/` files, attempting to pass in `isEvalSupported` would result in code that's *very* messy, not to mention difficult to maintain (since *every* single `PDFFunction` method call would need to include a `isEvalSupported` argument).
Rather than having to wait for a possible re-factoring of `PDFFunction` that would avoid the above problems by design, it probably makes sense to at least set `isEvalSupported` globally for `PDFFunction`.
Please note that there's one caveat with this solution: If `PDFJS.getDocument` is used to open multiple files simultaneously, with *different* `PDFJS.isEvalSupported` values set before each call, then the last one will always win.
However, that seems like enough of an edge-case that we shouldn't have to worry about it. Besides, since we'll also test that `eval` is actually supported, it should be fine.
Fixes 5573.
When looking briefly at using `Number.isInteger`/`Number.isNan` rather than `isInt`/`isNaN`, I noticed that there's a couple of not entirely straightforward cases to consider.
At first I really couldn't understand why `parseInt` is being used like it is in `XRef.fetchUncompressed`, since the `num` and `gen` properties of an object reference should *always* be integers.
However, doing a bit of code archaeology pointed to PR 4348, and it thus seem that this was a very deliberate change. Since I didn't want to inadvertently introduce any regressions, I've kept the `parseInt` calls intact but moved them to occur *only* when actually necessary.[1]
Secondly, I noticed that there's a redundant `isCmd` check for an edge-case of broken operators. Since we're throwing a `FormatError` if `obj3` isn't a command, we don't need to repeat that check.
In practice, this patch could perhaps be considered as a micro-optimization, but considering that `XRef.fetchUncompressed` can be called *many* thousand times when loading larger PDF documents these changes at least cannot hurt.
---
[1] I even ran all tests locally, with an added `assert(Number.isInteger(obj1) && Number.isInteger(obj2));` check, and everything passed with flying colours.
However, since it appears that this was in fact necessary at one point, one possible explanation is that the failing test-case(s) have now been replaced by reduced ones.
Since this patch will now treat (some) `NUL` bytes as "ASCII", the number of `followingBytes` checked are thus increased to (hopefully) reduce the risk of introducing new false positives.
Fixes 8823.
According to the specification, see http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf#page=377, a `Dest` entry in an outline item should *not* contain a dictionary.
Unsurprisingly there's PDF generators that completely ignore this, treating is an `A` entry instead.
The patch also adds a little bit more validation code in `Catalog.parseDestDictionary`.
Since we're now using `Uint8ClampedArray`, rather than `Uint8Array`, doing manual clamping shouldn't be necessary given that that is now handled natively.
This shouldn't have any measurable performance impact, but just to sanity check that I've done some quick benchmarking with the following manifest file:
```json
[
{ "id": "S2-eq",
"file": "pdfs/S2.pdf",
"md5": "d0b6137846df6e0fe058f234a87fb588",
"rounds": 100,
"type": "eq"
}
]
```
which gave the following results against the current `master` (repeated benchmark runs didn't result in any meaningful differences):
```
-- Grouped By browser, stat --
browser | stat | Count | Baseline(ms) | Current(ms) | +/- | % | Result(P<.05)
------- | ------------ | ----- | ------------ | ----------- | --- | ----- | -------------
firefox | Overall | 100 | 592 | 592 | 1 | 0.12 |
firefox | Page Request | 100 | 3 | 3 | 0 | -9.88 |
firefox | Rendering | 100 | 588 | 589 | 1 | 0.18 |
```
This patch removes the `clamp0to255` helper function, as well as manual clamping code in `src/core/jpg.js`.
The adjusted constants in `_convertCmykToRgb` were taken from CMYK to RGB conversion code found in `src/core/colorspace.js`.
*Please note:* There will be some very slight movement in a number of existing test-cases, since `Uint8ClampedArray` appears to use `Math.round` (or equivalent) and the old code used (basically) `Math.floor`.
This appears to simply have been forgotten in the re-factoring in PR 4815, where the `coded` property was renamed to the *much* more descriptive `isType3Font` property.
From looking at blame, it seems that these checks became obsolete with PR 692 (which landed close to six years ago). Note how, after that PR, there's no longer anything being assigned to the `code` property of an Object.
In issue #8707, there's a char code mapped to a non-
existing glyph which shouldn't be drawn. However, we
saw it was missing and tried to then use the post table and
end up mapping it incorrectly.
This illuminated a problem with issue #5704 and bug
893730 where glyphs disappeared after above fix. This was
from the cmap returning the wrong glyph id. Which in turn was
caused because the font had multiple of the same type of cmap
table and we were choosing the last one. Now, we instead
default to the first one. I'm unsure if we should instead be
merging the multiple cmaps, but using only the first one works.
Added unit-tests for DeviceGray, DeviceRGB and DeviceCMYK
Added unit-tests for CalGray
Added unit-tests for CalRGB
Removed redundant code
Added unit-tests for LabCS
Added unit-tests for IndexedCS
Update comment
Change lookup to Uint8Array as mentioned in pdf specs(these tests will pass after PR #8666 is merged).
Added unit-tests for AlternateCS
Resolved code-style issues
Fixed code-style issues
Addressed issues pointed out in https://github.com/mozilla/pdf.js/pull/8611#pullrequestreview-52865469
The initial issue with #8255 was I added a missing glyphs
check to adjustMapping, but this caused us to skip re-mapping
a glyph if the fontCharCode was a missingGlyph which in turn
caused us to overwrite a valid glyph id with an invalid one. While
fixing this, I also added a warning if the private use area is full since
this also accidentally happened when I made a different mistake.
This brought to light a number of issues where we map
missing glyphs to notdef, but often the notdef is actually defined
and then ends up being drawn. Now the glyphs don't get
mapped in toFontChar and so they are not drawn by the canvas.
Fixing the above brought up another issue though in bug1050040.pdf.
In this PDF, the font fails to load by the browser and before we were still
drawing the glyphs because it looked like the font had them, but with the fixes
above the glyphs showed up as missing so we didn't attempt draw them. To
fix this, I now throw an error when the loca table is in really bad shape and
we fall back to trying to use a system font. We now also use this fall back if
there are any format errors during converting fonts.
