Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 48a050966d899df1be64b7b2d1860267742769cf
https://github.com/WebKit/WebKit/commit/48a050966d899df1be64b7b2d1860267742769cf
Author: Nikolas Zimmermann <[email protected]>
Date: 2026-07-17 (Fri, 17 Jul 2026)
Changed paths:
M Source/WebCore/platform/graphics/skia/SkiaCompositingLayer.cpp
M Source/WebCore/platform/graphics/skia/SkiaCompositingLayer.h
M Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp
M Source/WebCore/platform/graphics/texmap/TextureMapperLayer.h
M
Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/AcceleratedSurface.cpp
M Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/AcceleratedSurface.h
M Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp
M
Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/ThreadedCompositor.cpp
M Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/ThreadedCompositor.h
Log Message:
-----------
[Damage][Skia] Composite only the damage
https://bugs.webkit.org/show_bug.cgi?id=315990
Reviewed by Alejandro G. Castro.
Wire the pieces together and start painting from the damage, if the feature
'UseDamagingInformationForCompositing' is turned on (not yet on by default).
Each frame's damage is recorded for the platform and into every swap-chain
target,
and the target, the frame is drawn into, brings its own record of what changed
since
it was last current. The two together are the region the frame is painted
against:
everything when there is no record or it covers the surface, nothing when the
target
already holds the frame, and otherwise the clear and every draw are limited to
its rects.
paint() collects and draws in one call, so the compositor reads the target's
record
before painting and passes it as priorTargetDamage, to be folded there with this
frame's freshly collected damage. Recording into the swap chain happens after
paint()
returns, which is the same as recording before it, since paint() only reads the
target
it draws into.
Debug borders and repaint counters are painted by the layer tree, but their
setters
stored the new state without damaging, unlike every other layer setter. Nothing
repainted them when they appeared or changed, and the frame that switched them
off
reported no damage for them at all, so they stayed on the targets. They now
damage the
layer like any other state change, on both the Skia and the TextureMapper side,
which
is what lets a frame stay restricted to its damage while they show.
The FPS counter is drawn on top of the layer tree, so no layer damages it
either, but
it is a fixed box in the corner rather than something that can be anywhere. It
damages
its own box on the frames the count changes, together with the box drawn
before, which
is larger when the count gets shorter. Its geometry therefore has to be
computed before
the frame is painted rather than while it is drawn. A counter that repainted
more than
its box would hide the cost it is there to measure - so we need to avoid that.
The damage visualizer and the overlay below cannot do the same, because they
draw over
the damage itself: damaging what they drew would feed their own rects back into
what
they show next, until it covers the surface. They repaint the frame in full
instead,
and the platform is told the whole surface changed - that's okay, since it's
debug-only.
WEBKIT_SHOW_DAMAGE keeps its name on the Skia path, so one variable shows the
damage
whichever compositor is in use. It now draws a target's whole accumulated
damage as a
translucent green overlay, rather than the frame damage the compositor no
longer paints
from. Since it repaints in full, it shows what the damage is, not the compositor
honouring it.
* Source/WebCore/platform/graphics/skia/SkiaCompositingLayer.cpp:
(WebCore::SkiaCompositingLayer::paintedLayerRect const):
(WebCore::SkiaCompositingLayer::setDebugIndicators):
(WebCore::SkiaCompositingLayer::paint):
* Source/WebCore/platform/graphics/skia/SkiaCompositingLayer.h:
* Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp:
(WebCore::TextureMapperLayer::setShowDebugBorder):
(WebCore::TextureMapperLayer::setDebugBorderColor):
(WebCore::TextureMapperLayer::setDebugBorderWidth):
(WebCore::TextureMapperLayer::setShowRepaintCounter):
(WebCore::TextureMapperLayer::setRepaintCount):
* Source/WebCore/platform/graphics/texmap/TextureMapperLayer.h:
(WebCore::TextureMapperLayer::setShowDebugBorder): Deleted.
(WebCore::TextureMapperLayer::setDebugBorderColor): Deleted.
(WebCore::TextureMapperLayer::setDebugBorderWidth): Deleted.
(WebCore::TextureMapperLayer::setShowRepaintCounter): Deleted.
(WebCore::TextureMapperLayer::setRepaintCount): Deleted.
* Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/AcceleratedSurface.cpp:
(WebKit::AcceleratedSurface::SwapChainDamageTracker::didPresent):
(WebKit::AcceleratedSurface::backgroundColor):
(WebKit::AcceleratedSurface::skiaClearColor):
(WebKit::AcceleratedSurface::clear):
(WebKit::clearCanvas): Deleted.
* Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/AcceleratedSurface.h:
* Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp:
(WebKit::damageOverlayForcesPropagation):
(WebKit::LayerTreeHost::LayerTreeHost):
(WebKit::LayerTreeHost::attachLayer):
* Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/ThreadedCompositor.cpp:
(WebKit::m_renderTimer):
(WebKit::ThreadedCompositor::setDamagePropagationSettings):
(WebKit::ThreadedCompositor::damageUsedForCompositing const):
(WebKit::ThreadedCompositor::drawsOverlay const):
(WebKit::ThreadedCompositor::paintToCurrentGLContext):
(WebKit::ThreadedCompositor::paintToTextureMapper):
(WebKit::ThreadedCompositor::recordFrameDamage):
(WebKit::drawDamageOverlay):
(WebKit::ThreadedCompositor::paintToSkiaCanvas):
(WebKit::ThreadedCompositor::renderLayerTree):
(WebKit::fpsCounterFont):
(WebKit::fpsCounterPadding):
(WebKit::ThreadedCompositor::fpsCounterRect const):
(WebKit::ThreadedCompositor::updateFPSCounterGeometry):
(WebKit::ThreadedCompositor::takeFPSCounterDamage):
(WebKit::ThreadedCompositor::drawFPSCounter):
(WebKit::ThreadedCompositor::drawSkiaDamage): Deleted.
* Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/ThreadedCompositor.h:
Canonical link: https://commits.webkit.org/317400@main
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