Remove SVGPathElement.pathSegList and related interfaces

third_party/WebKit/Source/core/svg/SVGPathData.h

+/*
+ * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
+ * Copyright (C) 2004, 2005, 2006, 2008 Rob Buis <buis@kde.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef SVGPathData_h
+#define SVGPathData_h
+
+#include "platform/geometry/FloatPoint.h"
+#include "wtf/Allocator.h"
+
+namespace blink {
+
+enum SVGPathSegType {
+    PathSegUnknown = 0,
+    PathSegClosePath = 1,
+    PathSegMoveToAbs = 2,
+    PathSegMoveToRel = 3,
+    PathSegLineToAbs = 4,
+    PathSegLineToRel = 5,
+    PathSegCurveToCubicAbs = 6,
+    PathSegCurveToCubicRel = 7,
+    PathSegCurveToQuadraticAbs = 8,
+    PathSegCurveToQuadraticRel = 9,
+    PathSegArcAbs = 10,
+    PathSegArcRel = 11,
+    PathSegLineToHorizontalAbs = 12,
+    PathSegLineToHorizontalRel = 13,
+    PathSegLineToVerticalAbs = 14,
+    PathSegLineToVerticalRel = 15,
+    PathSegCurveToCubicSmoothAbs = 16,
+    PathSegCurveToCubicSmoothRel = 17,
+    PathSegCurveToQuadraticSmoothAbs = 18,
+    PathSegCurveToQuadraticSmoothRel = 19
+};
+
+static inline SVGPathSegType toAbsolutePathSegType(const SVGPathSegType type)
+{
+    // Clear the LSB to get the absolute command.
+    return type >= PathSegMoveToAbs ? static_cast<SVGPathSegType>(type & ~1u) : type;
+}
+
+static inline bool isAbsolutePathSegType(const SVGPathSegType type)
+{
+    // For commands with an ordinal >= PathSegMoveToAbs, and odd number => relative command.
+    return type < PathSegMoveToAbs || type % 2 == 0;
+}
+
+struct PathSegmentData {
+    STACK_ALLOCATED();
+    PathSegmentData()
+        : command(PathSegUnknown)
+        , arcSweep(false)
+        , arcLarge(false)
+    {
+    }
+
+    const FloatPoint& arcRadii() const { return point1; }
+    float arcAngle() const { return point2.x(); }
+
+    float r1() const { return arcRadii().x(); }
+    float r2() const { return arcRadii().y(); }
+
+    bool largeArcFlag() const { return arcLarge; }
+    bool sweepFlag() const { return arcSweep; }
+
+    float x() const { return targetPoint.x(); }
+    float y() const { return targetPoint.y(); }
+
+    float x1() const { return point1.x(); }
+    float y1() const { return point1.y(); }
+
+    float x2() const { return point2.x(); }
+    float y2() const { return point2.y(); }
+
+    SVGPathSegType command;

[pdr., 2015/10/23 04:40:55]

Could we get better packing by moving this next to arcSweep and arcLarge?

[fs, 2015/10/23 09:12:33]

Just moving it will not gain us anything (FloatPoints should only require 4-byte
alignment). If we were to store these structures "more persistently", then
something like:

unsigned command : 8;
unsigned arcSweep : 1;
unsigned arcLarge : 1;

might be useful (to save 4 bytes; 32 -> 28; still assuming alignof(FloatPoint)
== 4).

+    FloatPoint targetPoint;
+    FloatPoint point1;
+    FloatPoint point2;
+    bool arcSweep;
+    bool arcLarge;
+};
+
+} // namespace blink
+
+#endif // SVGPathData_h