There's no specification for that (even if it's possible to have an idea from
the xfa specs) so we just want to hide them in order to avoid to display something
wrong.
When an image has a non-zero SMaskInData it means that the image
has an alpha channel.
With JPX images, the colorspace isn't required (by spec) so when we
don't have it, the JPX decoder will handle the conversion in RGBA
format.
Note that the referenced file is trivially corrupt, since it contains *two* PDF documents placed in the same file which doesn't make sense (and isn't how a PDF document should be updated).
However it's still a good idea to ensure that `loadFont` is able to handle errors when resolving References, since that allows us to invoke the existing fallback font handling.
Fixes issue #16843.
In certain cases, the text layer was misaligned
due to a difference between the `lang` attribute
of the viewer and the canvas. This commit addresses
the problem by adding the `lang` attribute to the canvas.
The issue was caused because PDF.js uses serif/sans-serif
fonts to generate the text layer and relies on system fonts.
The difference in the `lang` attribute led to different fonts
being picked, causing the misalignment.
This also required changing the initial `charCodeToGlyphId`-data to an Object, which seems generally correct since it's consistent with existing code in the `src\core\{cff_font, type1_font}.js` files.
For images that failed to decode once we want to avoid a pointless round-trip to the main-thread, which could otherwise happen for globally cached images.
It fixes issues #14982 and #14724.
The main problem of upscaling a canvas is that it can induces some pixelation
(see issue #14724). So this patch is just removing the limit and as a side
effect it fixes issue #14982.
As far as I can tell, in looking different profiles (especially some memory profile)
in using the Firefox profiler, I don't see any noticeable difference in term of
memory use.
and implement then in using some SVG filters and composition.
Composing in using destination-in in order to multiply RGB components by
the alpha from the mask isn't perfect: it'd be a way better to natively have
alpha masks support, it induces some small rounding errors and consequently
computed RGB are approximatively correct.
In term of performance, it's a real improvement, for example, the pdf in
issue #17779 is now rendered in few seconds.
There are still some room for improvement, but overall it should be a way
better.
*Note:* This borrows a helper function from the viewer, however the code cannot be directly shared since the worker-thread has access to various primitives.
In PR 17428 this functionality was limited to "larger" images, to not affect performance negatively. However it turns out that it's also beneficial to consider more "complex" images, regardless of their size, that contain /SMask or /Mask data; see issue 11518.
The PDF specification states that empty dash arrays, i.e. arrays with
zero elements, are in fact valid. In that case the dash array simply
corresponds to a solid, unbroken line. However, this case was erroneously
being flagged as invalid and therefore the annotation was not drawn
because its width was set to zero. This commit fixes the issue by
allowing dash arrays to have a length of zero.
The following are some highlights of this patch:
- In the Worker we only extract a *subset* of the potential contents of the `Usage` dictionary, to avoid having to implement/test a bunch of code that'd be completely unused in the viewer.
- In order to still allow the user to *manually* override the default visible layers in the viewer, the viewable/printable state is purposely *not* enforced during initialization in the `OptionalContentConfig` constructor.
- Printing will now always use the *default* visible layers, rather than using the same state as the viewer (as was the case previously).
This ensures that the printing-output will correctly take the `Usage` dictionary into account, and in practice toggling of visible layers rarely seem to be necessary except in the viewer itself (if at all).[1]
---
[1] In the unlikely case that it'd ever be deemed necessary to support fine-grained control of optional content visibility during printing, some new (additional) UI would likely be needed to support that case.
When highlighting, the annotation editor layer is disabled to get pointer events
from the text layer, but the annotation layer must be then disabled either in
order to avoid bad interactions.
