[webkit-changes] [WebKit/WebKit] bb99bf: Optimize transform operations under GraphicsLayerC...

[Simon Fraser]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: bb99bf09fcfa78c93479bb58f3dd6bcbf4e0b469
      https://github.com/WebKit/WebKit/commit/bb99bf09fcfa78c93479bb58f3dd6bcbf4e0b469
  Author: Simon Fraser <simon.fraser at apple.com>
  Date:   2023-06-22 (Thu, 22 Jun 2023)

  Changed paths:
    M Source/WebCore/platform/graphics/ca/GraphicsLayerCA.cpp
    M Source/WebCore/platform/graphics/transforms/TransformState.h
    M Source/WebCore/platform/graphics/transforms/TransformationMatrix.cpp
    M Source/WebCore/platform/graphics/transforms/TransformationMatrix.h

  Log Message:
  -----------
  Optimize transform operations under GraphicsLayerCA::flushCompositingState()
https://bugs.webkit.org/show_bug.cgi?id=258388
rdar://111141766

Reviewed by Cameron McCormack.

Optimize GraphicsLayerCA::layerTransform() by avoiding default construction of two
TransformationMatrices on the stack, and avoiding work involving currentTransform
if it's known to be identity (i.e. both customTransform and m_transform are null).

Similarly we can avoid construction followed by assignment of a matrix in
GraphicsLayerCA::VisibleAndCoverageRects() via a lambda.

Add a way to construct a TransformationMatrix with a translation.

* Source/WebCore/platform/graphics/ca/GraphicsLayerCA.cpp:
(WebCore::GraphicsLayerCA::layerTransform const):
(WebCore::GraphicsLayerCA::computeVisibleAndCoverageRect const):
* Source/WebCore/platform/graphics/transforms/TransformState.h: Use an initializer.
(WebCore::TransformState::TransformState):
* Source/WebCore/platform/graphics/transforms/TransformationMatrix.cpp:
* Source/WebCore/platform/graphics/transforms/TransformationMatrix.h:
(WebCore::TransformationMatrix::TransformationMatrix):

Canonical link: https://commits.webkit.org/265444@main