This tag is required by the specification, but some encoders (at least
Krita) don't write it for images with a single strip.
The test file was generated by opening deflate.tiff in Krita and saving
it with the DEFLATE compression.
In the cases where spec authors have us directly interact with promises
in a task source context, we need to prepare the backup settings object
stack as well as push an actual execution context to the JS VM.
This prevents goal conditions that rely on tasks that are currently in
flight on the task queue (or were just submitted) from blocking the
event loop until an IPC event fires to kick the native event loop.
This involves passing the UserNavigationInvolvement from each form
associated element that triggers a submit through to the methods that
perform the actual navigation. While here, refactor HTMLFormElement to
use the new Bindings::NavigationHistoryBehavior enum.
The one current caller of this function always defers microtask
checkpoints before calling wait_for_all, ensuring that the promise
accept/reject handlers will always be called later in the Web event loop
processing. We need to store all the state for the closures in a heap
allocated object with HeapFunctions to keep it around while there are
still promises to resolve.
We need to make sure that the given target realm is at the top of the
VM's execution context stack before doing any JS object construction
based on the data in our serialized buffer.
Window and other global objects are not technically legacy platform
objects, and have other ways to override their setters and getters.
However, Window does need to share some code with the legacy platform
object paths, and simply adding another bool check to the mix seems
the shortest putt.
Prior to this change, we iterated through all fragments within each
PaintableWithLines to resolve the relative position offset. This
happened before transferring the fragments to their corresponding
inline paintables.
With this change, we significantly reduce amount of work by attempting
to resolve relative position offsets only for those contained within
inline paintables.
Performance improvement on https://html.spec.whatwg.org/
We still don't apply it to the glyph itself, so they don't show up
scaled or rotated, but they're at the right spot now.
One big thing this here hsa going for it is that the final glyph
position is now calculated with just
`ext_rendering_matrix.map(glyph_position)`.
Also, character_spacing and word_spacing are now used unmodified
in the SimpleFont::draw_string() loop. This also means we no longer
have to undo a scale when updating the position in
`Renderer::show_text()`.
Most of the rest stays pretty yucky though. The root cause of many
problems is that ScaledFont has its rendering sized baked into the
object. We want to render fonts at size font_size times scale from
text matrix times scale from current transformation matrix (but
not size from hotizontal_scaling). So we have to make that the
font_size, but then we have to undo that in a bunch of places to
get the actualy font size.
This will eventually get better when LibPDF moves off ScaledFont.
Fonts should have size font_size times total scaling. We tried to
get that by computing text_rendering_matrix.x_scale() * font_size,
but text_rendering_matrix.x_scale() also includes
horizontal_scaling, which shouldn't be part of font size.
Same for character_spacing and word_spacing.
This is all a big mess that's caused by LibPDF using ScaledFont,
which requires scaling to be aprt of the text type. I have an
in-progress local branch that moves LibPDF to directly use VectorFont,
which will hopefully make this (and other things) nicer. But first,
let's get this right, and then make sure we don't regress it when
things change :^)
While PDFFont::draw_string() already returns a position scaled by
horizontal_scaling, the division by text_rendering_matrix.x_scale()
(which also contains the scaling factor) undid it. Reapply it.
Fixes the horizontal layout of the line
"should be the same on all lines: super" in Tests/LibPDF/text.pdf.
PDF spec 1.7 5.3.3 Text Space Details gives the correct multiplication
order: parameters * textmatrix * ctm.
We used to do text * ctm * parameters
(AffineTransform::multiply() does left-multiplication).
This only matters if `text_state().rise` is non-zero. In practice,
it's almost always zero, in which case the paramter matrix is a
diagonal matrix that commutes.
Fixes the horizontal offset of "super" in Tests/LibPDF/text.pdf.
