The main goal is to remove the eval-based interpreter.
In order to have some good performances, the new parser performs some optimizations
on the AST (similar to the ones in the previous implementation),
and the Wasm compiler generates code for the optimized AST.
For now, in case of errors or unsupported features, the Wasm compiler returns null
and the old interpreter is used as a fallback.
Few things are still missing:
- a wasm-based interpreter using a stack (in case the ps code isn't stack-free);
- a better js implementation in case of disabled wasm.
but they will be added in follow-up patches.
This function only has a single call-site (if we ignore the unit-tests), where the colors are split into separate parameters.
Given that all the color components are modified in the exact same way, it seems easier (and shorter) to pass the colors as-is to `applyOpacity` and have it use `Array.prototype.map()` instead.
This code already has an integration-test, however also having a unit-test shouldn't hurt since those are often easier to run and debug (and it nicely complements the existing `outline` unit-tests).
The patch also makes the following smaller changes to the method itself:
- Avoid creating and parsing an empty Array, when doing the `pageRef` search.
- Use `XRef.prototype.fetch` directly, when walking the parent chain, since the check just above ensures that the value is a Reference.
- Use the `lookupRect` helper when parsing the /BBox entry.
This obviously won't matter in practice, however it seems more "correct" to only extract the necessary number of color components rather than slicing off excess ones at the end.
Since this code is quite old parts of it can also be simplified a little bit by using modern string methods, which removes the need for the `pad` helper function.
Looking at the very similar `CssFontInfo.prototype.#readString` and `SystemFontInfo.prototype.#readString` methods they decode using the data as-is, but the `FontInfo.prototype.#readString` method for some reason copies the data into a new `Uint8Array` first; fixes yet another bug/inefficiency in PR 20197.
* add support for directly writing masks into `rgbaBuf` if their size matches
* add support for writing into `rgbaBuf` to `resizeImageMask` to avoid extra
allocs/copies
* respect `actualHeight` to avoid unnecessary work on non-emitted rows
* mark more operations as `internal`
This changes the path for what I believe is the common case for masks:
a mask to add transparency to the accompanying opaque image, both being
equal in size.
The other paths are not meaninfully unchanged.
That increases my confidence as these new paths can be easily tested
with a PNG with transparency.
Some tests were failing and has been fixed:
- "Hello" + Alef + "(" + Bet: the "(" (neutral) was not considered as a part of the group Alef(Bet and the group wasn't reverted;
- some intermediate neutrals were considered as strong.