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/*
* Copyright (C) 2002, 2003 The Karbon Developers
* Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
* Copyright (C) 2006, 2007 Rob Buis <buis@kde.org>
* Copyright (C) 2007, 2009 Apple Inc. All rights reserved.
* Copyright (C) Research In Motion Limited 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
* 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.
*/
#include "config.h"
#if ENABLE(SVG)
#include "SVGPathParser.h"
#include "AffineTransform.h"
#include <wtf/MathExtras.h>
static const float gOneOverThree = 1 / 3.f;
namespace WebCore {
SVGPathParser::SVGPathParser()
: m_consumer(0)
{
}
void SVGPathParser::parseClosePathSegment()
{
// Reset m_currentPoint for the next path.
if (m_pathParsingMode == NormalizedParsing)
m_currentPoint = m_subPathPoint;
m_closePath = true;
m_consumer->closePath();
}
bool SVGPathParser::parseMoveToSegment()
{
FloatPoint targetPoint;
if (!m_source->parseMoveToSegment(targetPoint))
return false;
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates)
m_currentPoint += targetPoint;
else
m_currentPoint = targetPoint;
m_subPathPoint = m_currentPoint;
m_consumer->moveTo(m_currentPoint, m_closePath, AbsoluteCoordinates);
} else
m_consumer->moveTo(targetPoint, m_closePath, m_mode);
m_closePath = false;
return true;
}
bool SVGPathParser::parseLineToSegment()
{
FloatPoint targetPoint;
if (!m_source->parseLineToSegment(targetPoint))
return false;
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates)
m_currentPoint += targetPoint;
else
m_currentPoint = targetPoint;
m_consumer->lineTo(m_currentPoint, AbsoluteCoordinates);
} else
m_consumer->lineTo(targetPoint, m_mode);
return true;
}
bool SVGPathParser::parseLineToHorizontalSegment()
{
float toX;
if (!m_source->parseLineToHorizontalSegment(toX))
return false;
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates)
m_currentPoint.move(toX, 0);
else
m_currentPoint.setX(toX);
m_consumer->lineTo(m_currentPoint, AbsoluteCoordinates);
} else
m_consumer->lineToHorizontal(toX, m_mode);
return true;
}
bool SVGPathParser::parseLineToVerticalSegment()
{
float toY;
if (!m_source->parseLineToVerticalSegment(toY))
return false;
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates)
m_currentPoint.move(0, toY);
else
m_currentPoint.setY(toY);
m_consumer->lineTo(m_currentPoint, AbsoluteCoordinates);
} else
m_consumer->lineToVertical(toY, m_mode);
return true;
}
bool SVGPathParser::parseCurveToCubicSegment()
{
FloatPoint point1;
FloatPoint point2;
FloatPoint targetPoint;
if (!m_source->parseCurveToCubicSegment(point1, point2, targetPoint))
return false;
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates) {
point1 += m_currentPoint;
point2 += m_currentPoint;
targetPoint += m_currentPoint;
}
m_consumer->curveToCubic(point1, point2, targetPoint, AbsoluteCoordinates);
m_controlPoint = point2;
m_currentPoint = targetPoint;
} else
m_consumer->curveToCubic(point1, point2, targetPoint, m_mode);
return true;
}
bool SVGPathParser::parseCurveToCubicSmoothSegment()
{
FloatPoint point2;
FloatPoint targetPoint;
if (!m_source->parseCurveToCubicSmoothSegment(point2, targetPoint))
return false;
if (m_lastCommand != PathSegCurveToCubicAbs
&& m_lastCommand != PathSegCurveToCubicRel
&& m_lastCommand != PathSegCurveToCubicSmoothAbs
&& m_lastCommand != PathSegCurveToCubicSmoothRel)
m_controlPoint = m_currentPoint;
if (m_pathParsingMode == NormalizedParsing) {
FloatPoint point1 = m_currentPoint;
point1.scale(2, 2);
point1.move(-m_controlPoint.x(), -m_controlPoint.y());
if (m_mode == RelativeCoordinates) {
point2 += m_currentPoint;
targetPoint += m_currentPoint;
}
m_consumer->curveToCubic(point1, point2, targetPoint, AbsoluteCoordinates);
m_controlPoint = point2;
m_currentPoint = targetPoint;
} else
m_consumer->curveToCubicSmooth(point2, targetPoint, m_mode);
return true;
}
bool SVGPathParser::parseCurveToQuadraticSegment()
{
FloatPoint point1;
FloatPoint targetPoint;
if (!m_source->parseCurveToQuadraticSegment(point1, targetPoint))
return false;
if (m_pathParsingMode == NormalizedParsing) {
m_controlPoint = point1;
FloatPoint point1 = m_currentPoint;
point1.move(2 * m_controlPoint.x(), 2 * m_controlPoint.y());
FloatPoint point2(targetPoint.x() + 2 * m_controlPoint.x(), targetPoint.y() + 2 * m_controlPoint.y());
if (m_mode == RelativeCoordinates) {
point1.move(2 * m_currentPoint.x(), 2 * m_currentPoint.y());
point2.move(3 * m_currentPoint.x(), 3 * m_currentPoint.y());
targetPoint += m_currentPoint;
}
point1.scale(gOneOverThree, gOneOverThree);
point2.scale(gOneOverThree, gOneOverThree);
m_consumer->curveToCubic(point1, point2, targetPoint, AbsoluteCoordinates);
if (m_mode == RelativeCoordinates)
m_controlPoint += m_currentPoint;
m_currentPoint = targetPoint;
} else
m_consumer->curveToQuadratic(point1, targetPoint, m_mode);
return true;
}
bool SVGPathParser::parseCurveToQuadraticSmoothSegment()
{
FloatPoint targetPoint;
if (!m_source->parseCurveToQuadraticSmoothSegment(targetPoint))
return false;
if (m_lastCommand != PathSegCurveToQuadraticAbs
&& m_lastCommand != PathSegCurveToQuadraticRel
&& m_lastCommand != PathSegCurveToQuadraticSmoothAbs
&& m_lastCommand != PathSegCurveToQuadraticSmoothRel)
m_controlPoint = m_currentPoint;
if (m_pathParsingMode == NormalizedParsing) {
FloatPoint cubicPoint = m_currentPoint;
cubicPoint.scale(2, 2);
cubicPoint.move(-m_controlPoint.x(), -m_controlPoint.y());
FloatPoint point1(m_currentPoint.x() + 2 * cubicPoint.x(), m_currentPoint.y() + 2 * cubicPoint.y());
FloatPoint point2(targetPoint.x() + 2 * cubicPoint.x(), targetPoint.y() + 2 * cubicPoint.y());
if (m_mode == RelativeCoordinates) {
point2 += m_currentPoint;
targetPoint += m_currentPoint;
}
point1.scale(gOneOverThree, gOneOverThree);
point2.scale(gOneOverThree, gOneOverThree);
m_consumer->curveToCubic(point1, point2, targetPoint, AbsoluteCoordinates);
m_controlPoint = cubicPoint;
m_currentPoint = targetPoint;
} else
m_consumer->curveToQuadraticSmooth(targetPoint, m_mode);
return true;
}
bool SVGPathParser::parseArcToSegment()
{
float rx;
float ry;
float angle;
bool largeArc;
bool sweep;
FloatPoint targetPoint;
if (!m_source->parseArcToSegment(rx, ry, angle, largeArc, sweep, targetPoint))
return false;
// If rx = 0 or ry = 0 then this arc is treated as a straight line segment (a "lineto") joining the endpoints.
// http://www.w3.org/TR/SVG/implnote.html#ArcOutOfRangeParameters
// If the current point and target point for the arc are identical, it should be treated as a zero length
// path. This ensures continuity in animations.
rx = fabsf(rx);
ry = fabsf(ry);
bool arcIsZeroLength = false;
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates)
arcIsZeroLength = targetPoint == FloatPoint::zero();
else
arcIsZeroLength = targetPoint == m_currentPoint;
}
if (!rx || !ry || arcIsZeroLength) {
if (m_pathParsingMode == NormalizedParsing) {
if (m_mode == RelativeCoordinates)
m_currentPoint += targetPoint;
else
m_currentPoint = targetPoint;
m_consumer->lineTo(m_currentPoint, AbsoluteCoordinates);
} else
m_consumer->lineTo(targetPoint, m_mode);
return true;
}
if (m_pathParsingMode == NormalizedParsing) {
FloatPoint point1 = m_currentPoint;
if (m_mode == RelativeCoordinates)
targetPoint += m_currentPoint;
m_currentPoint = targetPoint;
return decomposeArcToCubic(angle, rx, ry, point1, targetPoint, largeArc, sweep);
}
m_consumer->arcTo(rx, ry, angle, largeArc, sweep, targetPoint, m_mode);
return true;
}
bool SVGPathParser::parsePathDataFromSource(PathParsingMode pathParsingMode)
{
ASSERT(m_source);
ASSERT(m_consumer);
m_pathParsingMode = pathParsingMode;
m_controlPoint = FloatPoint();
m_currentPoint = FloatPoint();
m_subPathPoint = FloatPoint();
m_closePath = true;
// Skip any leading spaces.
if (!m_source->moveToNextToken())
return false;
SVGPathSegType command;
m_source->parseSVGSegmentType(command);
m_lastCommand = PathSegUnknown;
// Path must start with moveto.
if (command != PathSegMoveToAbs && command != PathSegMoveToRel)
return false;
while (true) {
// Skip spaces between command and first coordinate.
m_source->moveToNextToken();
m_mode = AbsoluteCoordinates;
switch (command) {
case PathSegMoveToRel:
m_mode = RelativeCoordinates;
case PathSegMoveToAbs:
if (!parseMoveToSegment())
return false;
break;
case PathSegLineToRel:
m_mode = RelativeCoordinates;
case PathSegLineToAbs:
if (!parseLineToSegment())
return false;
break;
case PathSegLineToHorizontalRel:
m_mode = RelativeCoordinates;
case PathSegLineToHorizontalAbs:
if (!parseLineToHorizontalSegment())
return false;
break;
case PathSegLineToVerticalRel:
m_mode = RelativeCoordinates;
case PathSegLineToVerticalAbs:
if (!parseLineToVerticalSegment())
return false;
break;
case PathSegClosePath:
parseClosePathSegment();
break;
case PathSegCurveToCubicRel:
m_mode = RelativeCoordinates;
case PathSegCurveToCubicAbs:
if (!parseCurveToCubicSegment())
return false;
break;
case PathSegCurveToCubicSmoothRel:
m_mode = RelativeCoordinates;
case PathSegCurveToCubicSmoothAbs:
if (!parseCurveToCubicSmoothSegment())
return false;
break;
case PathSegCurveToQuadraticRel:
m_mode = RelativeCoordinates;
case PathSegCurveToQuadraticAbs:
if (!parseCurveToQuadraticSegment())
return false;
break;
case PathSegCurveToQuadraticSmoothRel:
m_mode = RelativeCoordinates;
case PathSegCurveToQuadraticSmoothAbs:
if (!parseCurveToQuadraticSmoothSegment())
return false;
break;
case PathSegArcRel:
m_mode = RelativeCoordinates;
case PathSegArcAbs:
if (!parseArcToSegment())
return false;
break;
default:
return false;
}
if (!m_consumer->continueConsuming())
return true;
m_lastCommand = command;
if (!m_source->hasMoreData())
return true;
command = m_source->nextCommand(command);
if (m_lastCommand != PathSegCurveToCubicAbs
&& m_lastCommand != PathSegCurveToCubicRel
&& m_lastCommand != PathSegCurveToCubicSmoothAbs
&& m_lastCommand != PathSegCurveToCubicSmoothRel
&& m_lastCommand != PathSegCurveToQuadraticAbs
&& m_lastCommand != PathSegCurveToQuadraticRel
&& m_lastCommand != PathSegCurveToQuadraticSmoothAbs
&& m_lastCommand != PathSegCurveToQuadraticSmoothRel)
m_controlPoint = m_currentPoint;
m_consumer->incrementPathSegmentCount();
}
return false;
}
void SVGPathParser::cleanup()
{
ASSERT(m_source);
ASSERT(m_consumer);
m_consumer->cleanup();
m_source = 0;
m_consumer = 0;
}
// This works by converting the SVG arc to "simple" beziers.
// Partly adapted from Niko's code in kdelibs/kdecore/svgicons.
// See also SVG implementation notes: http://www.w3.org/TR/SVG/implnote.html#ArcConversionEndpointToCenter
bool SVGPathParser::decomposeArcToCubic(float angle, float rx, float ry, FloatPoint& point1, FloatPoint& point2, bool largeArcFlag, bool sweepFlag)
{
FloatSize midPointDistance = point1 - point2;
midPointDistance.scale(0.5f);
AffineTransform pointTransform;
pointTransform.rotate(-angle);
FloatPoint transformedMidPoint = pointTransform.mapPoint(FloatPoint(midPointDistance.width(), midPointDistance.height()));
float squareRx = rx * rx;
float squareRy = ry * ry;
float squareX = transformedMidPoint.x() * transformedMidPoint.x();
float squareY = transformedMidPoint.y() * transformedMidPoint.y();
// Check if the radii are big enough to draw the arc, scale radii if not.
// http://www.w3.org/TR/SVG/implnote.html#ArcCorrectionOutOfRangeRadii
float radiiScale = squareX / squareRx + squareY / squareRy;
if (radiiScale > 1) {
rx *= sqrtf(radiiScale);
ry *= sqrtf(radiiScale);
}
pointTransform.makeIdentity();
pointTransform.scale(1 / rx, 1 / ry);
pointTransform.rotate(-angle);
point1 = pointTransform.mapPoint(point1);
point2 = pointTransform.mapPoint(point2);
FloatSize delta = point2 - point1;
float d = delta.width() * delta.width() + delta.height() * delta.height();
float scaleFactorSquared = std::max(1 / d - 0.25f, 0.f);
float scaleFactor = sqrtf(scaleFactorSquared);
if (sweepFlag == largeArcFlag)
scaleFactor = -scaleFactor;
delta.scale(scaleFactor);
FloatPoint centerPoint = FloatPoint(0.5f * (point1.x() + point2.x()) - delta.height(),
0.5f * (point1.y() + point2.y()) + delta.width());
float theta1 = atan2f(point1.y() - centerPoint.y(), point1.x() - centerPoint.x());
float theta2 = atan2f(point2.y() - centerPoint.y(), point2.x() - centerPoint.x());
float thetaArc = theta2 - theta1;
if (thetaArc < 0 && sweepFlag)
thetaArc += 2 * piFloat;
else if (thetaArc > 0 && !sweepFlag)
thetaArc -= 2 * piFloat;
pointTransform.makeIdentity();
pointTransform.rotate(angle);
pointTransform.scale(rx, ry);
// Some results of atan2 on some platform implementations are not exact enough. So that we get more
// cubic curves than expected here. Adding 0.001f reduces the count of sgements to the correct count.
int segments = ceilf(fabsf(thetaArc / (piOverTwoFloat + 0.001f)));
for (int i = 0; i < segments; ++i) {
float startTheta = theta1 + i * thetaArc / segments;
float endTheta = theta1 + (i + 1) * thetaArc / segments;
float t = (8 / 6.f) * tanf(0.25f * (endTheta - startTheta));
if (!isfinite(t))
return false;
float sinStartTheta = sinf(startTheta);
float cosStartTheta = cosf(startTheta);
float sinEndTheta = sinf(endTheta);
float cosEndTheta = cosf(endTheta);
point1 = FloatPoint(cosStartTheta - t * sinStartTheta, sinStartTheta + t * cosStartTheta);
point1.move(centerPoint.x(), centerPoint.y());
FloatPoint targetPoint = FloatPoint(cosEndTheta, sinEndTheta);
targetPoint.move(centerPoint.x(), centerPoint.y());
point2 = targetPoint;
point2.move(t * sinEndTheta, -t * cosEndTheta);
m_consumer->curveToCubic(pointTransform.mapPoint(point1), pointTransform.mapPoint(point2),
pointTransform.mapPoint(targetPoint), AbsoluteCoordinates);
}
return true;
}
}
#endif // ENABLE(SVG)
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