Issue #2737 - Part 1: Base implementation of SVGGeometryElement.

Mostly mechanical changes to generalize path geometry for all SVG draw
elements. No user-exposed changes.

dom/svg/SVGPolyElement.cpp

@@ -0,0 +1,158 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "SVGPolyElement.h"
+#include "DOMSVGPointList.h"
+#include "mozilla/gfx/2D.h"
+#include "SVGContentUtils.h"
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+
+//----------------------------------------------------------------------
+// nsISupports methods
+
+NS_IMPL_ADDREF_INHERITED(SVGPolyElement,SVGPolyElementBase)
+NS_IMPL_RELEASE_INHERITED(SVGPolyElement,SVGPolyElementBase)
+
+NS_INTERFACE_MAP_BEGIN(SVGPolyElement)
+NS_INTERFACE_MAP_END_INHERITING(SVGPolyElementBase)
+
+//----------------------------------------------------------------------
+// Implementation
+
+SVGPolyElement::SVGPolyElement(already_AddRefed<mozilla::dom::NodeInfo>& aNodeInfo)
+  : SVGPolyElementBase(aNodeInfo)
+{
+}
+
+SVGPolyElement::~SVGPolyElement()
+{
+}
+
+already_AddRefed<DOMSVGPointList>
+SVGPolyElement::Points()
+{
+  void *key = mPoints.GetBaseValKey();
+  RefPtr<DOMSVGPointList> points = DOMSVGPointList::GetDOMWrapper(key, this, false);
+  return points.forget();
+}
+
+already_AddRefed<DOMSVGPointList>
+SVGPolyElement::AnimatedPoints()
+{
+  void *key = mPoints.GetAnimValKey();
+  RefPtr<DOMSVGPointList> points = DOMSVGPointList::GetDOMWrapper(key, this, true);
+  return points.forget();
+}
+
+
+//----------------------------------------------------------------------
+// nsIContent methods
+
+NS_IMETHODIMP_(bool)
+SVGPolyElement::IsAttributeMapped(const nsIAtom* name) const
+{
+  static const MappedAttributeEntry* const map[] = {
+    sMarkersMap
+  };
+  
+  return FindAttributeDependence(name, map) ||
+    SVGPolyElementBase::IsAttributeMapped(name);
+}
+
+//----------------------------------------------------------------------
+// nsSVGElement methods
+
+/* virtual */ bool
+SVGPolyElement::HasValidDimensions() const
+{
+  return !mPoints.GetAnimValue().IsEmpty();
+}
+
+//----------------------------------------------------------------------
+// SVGGeometryElement methods
+
+bool
+SVGPolyElement::AttributeDefinesGeometry(const nsIAtom *aName)
+{
+  if (aName == nsGkAtoms::points)
+    return true;
+
+  return false;
+}
+
+void
+SVGPolyElement::GetMarkPoints(nsTArray<nsSVGMark> *aMarks)
+{
+  const SVGPointList &points = mPoints.GetAnimValue();
+
+  if (!points.Length())
+    return;
+
+  float px = points[0].mX, py = points[0].mY, prevAngle = 0.0;
+
+  aMarks->AppendElement(nsSVGMark(px, py, 0, nsSVGMark::eStart));
+
+  for (uint32_t i = 1; i < points.Length(); ++i) {
+    float x = points[i].mX;
+    float y = points[i].mY;
+    float angle = atan2(y-py, x-px);
+
+    // Vertex marker.
+    if (i == 1) {
+      aMarks->ElementAt(0).angle = angle;
+    } else {
+      aMarks->ElementAt(aMarks->Length() - 1).angle =
+        SVGContentUtils::AngleBisect(prevAngle, angle);
+    }
+
+    aMarks->AppendElement(nsSVGMark(x, y, 0, nsSVGMark::eMid));
+
+    prevAngle = angle;
+    px = x;
+    py = y;
+  }
+
+  aMarks->LastElement().angle = prevAngle;
+  aMarks->LastElement().type = nsSVGMark::eEnd;
+}
+
+bool
+SVGPolyElement::GetGeometryBounds(Rect* aBounds,
+                                  const StrokeOptions& aStrokeOptions,
+                                  const Matrix& aToBoundsSpace,
+                                  const Matrix* aToNonScalingStrokeSpace)
+{
+  const SVGPointList &points = mPoints.GetAnimValue();
+
+  if (!points.Length()) {
+    // Rendering of the element is disabled
+    aBounds->SetEmpty();
+    return true;
+  }
+
+  if (aStrokeOptions.mLineWidth > 0 || aToNonScalingStrokeSpace) {
+    // We don't handle non-scaling-stroke or stroke-miterlimit etc. yet
+    return false;
+  }
+
+  if (aToBoundsSpace.IsRectilinear()) {
+    // We can avoid transforming each point and just transform the result.
+    // Important for large point lists.
+    Rect bounds(points[0], Size());
+    for (uint32_t i = 1; i < points.Length(); ++i) {
+      bounds.ExpandToEnclose(points[i]);
+    }
+    *aBounds = aToBoundsSpace.TransformBounds(bounds);
+  } else {
+    *aBounds = Rect(aToBoundsSpace.TransformPoint(points[0]), Size());
+    for (uint32_t i = 1; i < points.Length(); ++i) {
+      aBounds->ExpandToEnclose(aToBoundsSpace.TransformPoint(points[i]));
+    }
+  }
+  return true;
+}
+