(Or rather, bring offsetLeft and offsetTop closer to spec, and implement
the previously-missing offsetParent)
This makes mouse inputs on https://nerget.com/fluidSim/ work properly.
Sizing already worked correctly, but before this change, we were too
aggressive with inserting line breaks when negative margins would
still an atomic inline to fit on the line.
The css-backgrounds.html ref test file only tests the most basic usage
of this, which failed to catch some regressions, so let's add a more
extensive test. :^)
Given that we have a glyph run where the position of each glyph is
calculated for text fragments during layout, we can reuse it to avoid
this work during painting.
If one profile uses PCSXYZ and the other PCSLAB as connection space,
we now do the necessary XYZ/LAB conversion.
With this and the previous commits, we can now convert from profiles
that use PCSLAB with mAB, such as stress.jpeg from
https://littlecms.com/blog/2020/09/09/browser-check/ :
% Build/lagom/icc --name sRGB --reencode-to serenity-sRGB.icc
% Build/lagom/bin/image -o out.png \
--convert-to-color-profile serenity-sRGB.icc \
~/src/jpegfiles/stress.jpeg
After commit ff48b7333c, we remove shadow
roots from elements that are removed from the DOM. Setting a node's
shadow root to null also sets that shadow root's host to null. Thus, the
comment in Node::is_shadow_including_descendant_of that assumes the host
is always non-null is not true.
The test added here would previously crash when interacting with a node
that is a descendant of a removed shadow root.
Previously we would calculate the index of the first parent node as
heap.size() (which is initialized to non_zero_freqs), so in the edge
case in which all symbols had a non-zero frequency, we would use the
Size-index entry in the array for both the first symbol's leaf node,
and the first parent node.
The result would either be a non-optimal huffman code (bad), or an
illegal huffman code that would then go on to crash due to an error
check in CanonicalCode::from_bytes. (worse)
We now store parent nodes starting at heap.size() - 1, which eliminates
the potential overlap, and resolves the issue.
Previously, we determined the positions of glyphs for each text run at
the time of painting, which constituted a significant portion of the
painting process according to profiles. However, since we already go
through each glyph to figure out the width of each fragment during
layout, we can simultaneously gather data about the position of each
glyph in the layout phase and utilize this information in the painting
phase.
I had to update expectations for a couple of reference tests. These
updates are due to the fact that we now measure glyph positions during
layout using a 1x font, and then linearly scale each glyph's position
to device pixels during painting. This approach should be acceptable,
considering we measure a fragment's width and height with an unscaled
font during layout.
