[LBSE] Computation of on-screen font scaling factor ignores page zoom

[nikolaszimmermann]

988fed7

[LBSE] Computation of on-screen font scaling factor ignores page zoom
https://bugs.webkit.org/show_bug.cgi?id=258120

Reviewed by Rob Buis.

For standalone SVG documents the page zoom has to be taken into account when computing the
on-screen font scaling factor. Currently we ignore the effective zoom factor and thus select
a sub-optimal font.

Non-scaling-stroke (webkit.org/b/139322) works properly in LBSE, if this fix is applied as well.
Two tests fail in LBSE without this patch: svg/text/non-scaling-stroke-textRendering-default.svg
and svg/text/non-scaling-stroke-textRendering-geometricPrecision.svg).

Covered by new tests added by webkit.org/b/139322 -- easy to test with non-scaling-stroke.
Without non-scaling-stroke, this is most noticeable in zoom-zoom-coords.html which now
exposes slighly different metrics for <text> since the internal font-size scaling factor
changed (now taking zoom into account, as the legacy SVG engine already does).

zoom-zoom-coords.xhtml now delivers correct results across all platforms and is identical
for legacy SVG engine and LBSE -- get rid of platform specific results, finally.

* LayoutTests/platform/glib/svg/zoom/page/zoom-zoom-coords-expected.txt: Removed.
* LayoutTests/platform/mac-ventura-wk2-lbse-text/svg/zoom/page/zoom-zoom-coords-expected.txt: Removed.
* LayoutTests/platform/mac/svg/zoom/page/zoom-zoom-coords-expected.txt: Removed.
* LayoutTests/svg/zoom/page/zoom-zoom-coords-expected.txt:
Finally a single non-LBSE/LBSE result for all platforms.
* LayoutTests/svg/zoom/page/zoom-zoom-coords.xhtml:
* Source/WebCore/rendering/svg/SVGLayerTransformComputation.h:
(WebCore::SVGLayerTransformComputation::calculateScreenFontSizeScalingFactor const):
Multiply scaling factor by effectiveZoom() (which includes page zoom), but only for non-standalone
SVG documents. For standalone SVG documents the page-zoom induced scaling is already part of the CTM.

Canonical link: https://commits.webkit.org/265208@main

5eed14e

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 469e0f7)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	❌ 🧪 mac-wk1	❌ 🧪 gtk-wk2
	✅ 🧪 api-ios	❌ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim
	✅ 🛠 watch
	✅ 🛠 watch-sim

[nikolaszimmermann]

The 100th LBSE patch (see nikolaszimmermann/WebKitIgalia#1) got a nice PR number: 15000 :-)

[rwlbuis]

Looks good, but it seems zoom-zoom-coords.xhtml needs fixing.

[nikolaszimmermann]

Yop, will take care of it later, thanks @rwlbuis!

[webkit-early-warning-system]

EWS run on current version of this PR (hash 5eed14e)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🛠 gtk
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🧪 api-gtk
	✅ 🛠 tv	🧪 mac-AS-debug-wk2
	✅ 🛠 tv-sim
✅ 🛠 🧪 merge	✅ 🛠 watch
	✅ 🛠 watch-sim

[nikolaszimmermann]

Hah, zoom-zoom-coords.xhtml delivers the same results for LBSE and the legacy SVG engine, both across all platforms! :-) Can finally remove the platform specific results for that tricky test case.

[webkit-commit-queue]

Committed 265208@main (988fed7): https://commits.webkit.org/265208@main

Reviewed commits have been landed. Closing PR #15000 and removing active labels.