[webkit-changes] [WebKit/WebKit] f7f897: [SVG] Add approximate stroke-bounding-box computat...

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: f7f897982b66445d96622a5b67145280e2ba2d81
      https://github.com/WebKit/WebKit/commit/f7f897982b66445d96622a5b67145280e2ba2d81
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2023-10-18 (Wed, 18 Oct 2023)

  Changed paths:
    M Source/WebCore/rendering/svg/RenderSVGContainer.cpp
    M Source/WebCore/rendering/svg/RenderSVGEllipse.cpp
    M Source/WebCore/rendering/svg/RenderSVGPath.cpp
    M Source/WebCore/rendering/svg/RenderSVGPath.h
    M Source/WebCore/rendering/svg/RenderSVGRect.cpp
    M Source/WebCore/rendering/svg/RenderSVGRoot.cpp
    M Source/WebCore/rendering/svg/RenderSVGShape.cpp
    M Source/WebCore/rendering/svg/RenderSVGShape.h
    M Source/WebCore/rendering/svg/SVGBoundingBoxComputation.cpp
    M Source/WebCore/rendering/svg/SVGRenderSupport.cpp
    M Source/WebCore/rendering/svg/SVGRenderSupport.h
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGContainer.cpp
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGContainer.h
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGPath.cpp
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGRoot.cpp
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGRoot.h
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGShape.cpp
    M Source/WebCore/rendering/svg/legacy/LegacyRenderSVGShape.h

  Log Message:
  -----------
  [SVG] Add approximate stroke-bounding-box computation for repainting
https://bugs.webkit.org/show_bug.cgi?id=263184
rdar://116999242

Reviewed by Cameron McCormack.

This is one step of the patch series implementing approximate repainting rect for SVG path, derived from blink's work[1].

This patch adds approximate stroke-bounding-box (basically repaint bounding box) implementation. The core concept is that, for very compute costly element (like, path),
for repaint bounding box, we just report approximate repaint bounding box. This can be computed from stroke width etc. Like, let's
assume that stroke exists at the edge of fill bounding box. Then we can compute approximate repaint bounding box which is always larger-or-equal
to stroke bounding box.

Important thing in this patch is that we are not using approximate stroke-bounding-box computation yet. We will switch
it in the next patch with a few lines of changes. This patch is adding the implementation separately from enablement.

One of the hard thing is that our current implementation is relying on the computation order of this in the tree because of existence of
recursive / circular references of the repaint bounding box via markers. For example, LayoutTests/svg/custom/circular-marker-reference-4.svg
shows how markers can refer to the other marker in a circular manner. And in this case, our current implementation is just using stale
repaint bounding box for one of them, so probably the implementation is wrong already. But in this patch, we do not want to change the behavior.
As a result, we workaround the issue by eagerly compute stroke bounding box when markers exist in LegacyRenderSVGPath. This does not become
a problem in accuracy of stroke bounding box in LBSE since it is implementing SVG2, and SVG2 stroke bounding box does not include markers.

[1]: https://bugs.chromium.org/p/chromium/issues/detail?id=435097

* Source/WebCore/rendering/svg/RenderSVGContainer.cpp:
(WebCore::RenderSVGContainer::strokeBoundingBox const):
* Source/WebCore/rendering/svg/RenderSVGEllipse.cpp:
(WebCore::RenderSVGEllipse::updateShapeFromElement):
* Source/WebCore/rendering/svg/RenderSVGPath.cpp:
(WebCore::RenderSVGPath::updateShapeFromElement):
* Source/WebCore/rendering/svg/RenderSVGRect.cpp:
(WebCore::RenderSVGRect::updateShapeFromElement):
* Source/WebCore/rendering/svg/RenderSVGRoot.cpp:
(WebCore::RenderSVGRoot::strokeBoundingBox const):
* Source/WebCore/rendering/svg/RenderSVGShape.cpp:
(WebCore::RenderSVGShape::strokeBoundingBox const):
(WebCore::RenderSVGShape::approximateStrokeBoundingBox const):
(WebCore::RenderSVGShape::calculateApproximateScalingStrokeBoundingBox const):
(WebCore::RenderSVGShape::calculateApproximateNonScalingStrokeBoundingBox const):
(WebCore::RenderSVGShape::calculateApproximateStrokeBoundingBox const):
* Source/WebCore/rendering/svg/RenderSVGShape.h:
* Source/WebCore/rendering/svg/SVGBoundingBoxComputation.cpp:
(WebCore::SVGBoundingBoxComputation::handleShapeOrTextOrInline const):
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGContainer.cpp:
(WebCore::LegacyRenderSVGContainer::updateCachedBoundaries):
(WebCore::LegacyRenderSVGContainer::strokeBoundingBox const):
(WebCore::LegacyRenderSVGContainer::repaintRectInLocalCoordinates const):
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGContainer.h:
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGPath.cpp:
(WebCore::LegacyRenderSVGPath::updateShapeFromElement):
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGRoot.cpp:
(WebCore::LegacyRenderSVGRoot::updateCachedBoundaries):
(WebCore::LegacyRenderSVGRoot::strokeBoundingBox const):
(WebCore::LegacyRenderSVGRoot::repaintRectInLocalCoordinates const):
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGRoot.h:
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGShape.cpp:
(WebCore::LegacyRenderSVGShape::strokeBoundingBox const):
(WebCore::LegacyRenderSVGShape::calculateApproximateScalingStrokeBoundingBox const):
(WebCore::LegacyRenderSVGShape::calculateApproximateNonScalingStrokeBoundingBox const):
(WebCore::LegacyRenderSVGShape::calculateApproximateStrokeBoundingBox const):
(WebCore::LegacyRenderSVGShape::updateRepaintBoundingBox):
(WebCore::LegacyRenderSVGShape::repaintRectInLocalCoordinates const):
* Source/WebCore/rendering/svg/legacy/LegacyRenderSVGShape.h:

Canonical link: https://commits.webkit.org/269492@main