Support 'pathLength' for stroking operations on <path>

third_party/WebKit/Source/core/layout/svg/SVGLayoutSupport.cpp

 /*
  * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 354 matching lines @@
 }
 
 DashArray SVGLayoutSupport::resolveSVGDashArray(const SVGDashArray& svgDashArray, const ComputedStyle& style, const SVGLengthContext& lengthContext)
 {
     DashArray dashArray;
     for (const Length& dashLength : svgDashArray.vector())
         dashArray.append(lengthContext.valueForLength(dashLength, style));
     return dashArray;
 }
 
-void SVGLayoutSupport::applyStrokeStyleToStrokeData(StrokeData& strokeData, const ComputedStyle& style, const LayoutObject& object)
+void SVGLayoutSupport::applyStrokeStyleToStrokeData(StrokeData& strokeData, const ComputedStyle& style, const LayoutObject& object, float dashScaleFactor)
 {
     ASSERT(object.node());
     ASSERT(object.node()->isSVGElement());
 
     const SVGComputedStyle& svgStyle = style.svgStyle();
 
     SVGLengthContext lengthContext(toSVGElement(object.node()));
     strokeData.setThickness(lengthContext.valueForLength(svgStyle.strokeWidth()));
     strokeData.setLineCap(svgStyle.capStyle());
     strokeData.setLineJoin(svgStyle.joinStyle());
     strokeData.setMiterLimit(svgStyle.strokeMiterLimit());
 
     DashArray dashArray = resolveSVGDashArray(*svgStyle.strokeDashArray(), style, lengthContext);
-    strokeData.setLineDash(dashArray, lengthContext.valueForLength(svgStyle.strokeDashOffset(), style));
+    float dashOffset = lengthContext.valueForLength(svgStyle.strokeDashOffset(), style);
+    // Apply scaling from 'pathLength'.
+    if (dashScaleFactor != 1) {
+        ASSERT(dashScaleFactor >= 0);
+        dashOffset *= dashScaleFactor;
+        for (auto& dashItem : dashArray)
+            dashItem *= dashScaleFactor;
+    }
+    strokeData.setLineDash(dashArray, dashOffset);
 }
 
 bool SVGLayoutSupport::isLayoutableTextNode(const LayoutObject* object)
 {
     ASSERT(object->isText());
     // <br> is marked as text, but is not handled by the SVG layout code-path.
     return object->isSVGInlineText() && !toLayoutSVGInlineText(object)->hasEmptyText();
 }
 
 bool SVGLayoutSupport::willIsolateBlendingDescendantsForStyle(const ComputedStyle& style)
@@ skipping 70 matching lines @@
 
     // FIXME: trying to compute a device space transform at record time is wrong. All clients
     // should be updated to avoid relying on this information, and the method should be removed.
     AffineTransform ctm = deprecatedCalculateTransformToLayer(layoutObject) * SubtreeContentTransformScope::currentContentTransformation();
     ctm.scale(layoutObject->document().frameHost()->deviceScaleFactor());
 
     return narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
 }
 
 } // namespace blink