189397 2018-09-06 23:30:05 -0700 Improvements to zooming helper functions 2023-09-02 08:55:43 -0700 1 1 1 Unclassified WebKit WebCore Misc. WebKit Nightly Build Unspecified Unspecified NEW P2 Normal --- 1 fred.wang webkit-unassigned ahmad.saleem792 simon.fraser oldest_to_newest 1457421 0 fred.wang 2018-09-06 23:30:05 -0700 We currently have at least three functions, with similar logic but different types of parameter. Maybe it would be possible to merge them into a single helper function. Some of them increment/decrement the value to workaround truncation and in bug 182230 Simon suggested to just floor/ceil after the division by zoomFactor. Not sure how that would impact accuracy. RenderStyle.h: inline int adjustForAbsoluteZoom(int value, const RenderStyle& style) { double zoomFactor = style.effectiveZoom(); if (zoomFactor == 1) return value; // Needed because computeLengthInt truncates (rather than rounds) when scaling up. if (zoomFactor > 1) { if (value < 0) value--; else value++; } return roundForImpreciseConversion<int>(value / zoomFactor); } Element.cpp: static double adjustForLocalZoom(LayoutUnit value, const RenderElement& renderer, double& zoomFactor) { zoomFactor = localZoomForRenderer(renderer); if (zoomFactor == 1) return value.toDouble(); return value.toDouble() / zoomFactor; } HTMLBodyElement.cpp static int adjustForZoom(int value, const Frame& frame) { double zoomFactor = frame.pageZoomFactor() * frame.frameScaleFactor(); if (zoomFactor == 1) return value; // Needed because of truncation (rather than rounding) when scaling up. if (zoomFactor > 1) value++; return static_cast<int>(value / zoomFactor); } 1975184 1 ahmad.saleem792 2023-09-02 08:55:43 -0700 Some clean-up from Blink's commit: https://chromium.googlesource.com/chromium/src.git/+/ad54bc5824e5901329fd1ab1beb1a63443399a6a