Windows-4.7.4/src/3rdparty/webkit/WebCore/platform/graphics/qt/PathQt.cpp - platform/external/qt - Git at Google

 /*
  * Copyright (C) 2006 Zack Rusin   <zack@kde.org>
  *               2006 Rob Buis     <buis@kde.org>
  *               2009, 2010 Dirk Schulze <krit@webkit.org>
  *
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "Path.h"

 #include "AffineTransform.h"
 #include "FloatRect.h"
 #include "GraphicsContext.h"
 #include "ImageBuffer.h"
 #include "PlatformString.h"
 #include "StrokeStyleApplier.h"
 #include <QPainterPath>
 #include <QTransform>
 #include <QString>
 #include <wtf/OwnPtr.h>

 #define _USE_MATH_DEFINES
 #include <math.h>

 #ifndef M_PI
 #   define M_PI 3.14159265358979323846
 #endif

 namespace WebCore {

 Path::Path()
 {
 }

 Path::~Path()
 {
 }

 Path::Path(const Path& other)
     : m_path(other.m_path)
 {
 }

 Path& Path::operator=(const Path& other)
 {
     m_path = other.m_path;
     return *this;
 }

 static inline bool areCollinear(const QPointF& a, const QPointF& b, const QPointF& c)
 {
     // Solved from comparing the slopes of a to b and b to c: (ay-by)/(ax-bx) == (cy-by)/(cx-bx)
     return qFuzzyCompare((c.y() - b.y()) * (a.x() - b.x()), (a.y() - b.y()) * (c.x() - b.x()));
 }

 static inline bool withinRange(qreal p, qreal a, qreal b)
 {
     return (p >= a && p <= b) || (p >= b && p <= a);
 }

 // Check whether a point is on the border
 static bool isPointOnPathBorder(const QPolygonF& border, const QPointF& p)
 {
     QPointF p1 = border.at(0);
     QPointF p2;

     for (int i = 1; i < border.size(); ++i) {
         p2 = border.at(i);
         if (areCollinear(p, p1, p2)
                 // Once we know that the points are collinear we
                 // only need to check one of the coordinates
                 && (qAbs(p2.x() - p1.x()) > qAbs(p2.y() - p1.y()) ?
                         withinRange(p.x(), p1.x(), p2.x()) :
                         withinRange(p.y(), p1.y(), p2.y()))) {
             return true;
         }
         p1 = p2;
     }
     return false;
 }

 bool Path::contains(const FloatPoint& point, WindRule rule) const
 {
     Qt::FillRule savedRule = m_path.fillRule();
     const_cast<QPainterPath*>(&m_path)->setFillRule(rule == RULE_EVENODD ? Qt::OddEvenFill : Qt::WindingFill);

     bool contains = m_path.contains(point);

     if (!contains) {
         // check whether the point is on the border
         contains = isPointOnPathBorder(m_path.toFillPolygon(), point);
     }

     const_cast<QPainterPath*>(&m_path)->setFillRule(savedRule);
     return contains;
 }

 bool Path::strokeContains(StrokeStyleApplier* applier, const FloatPoint& point) const
 {
     ASSERT(applier);

     // FIXME: We should try to use a 'shared Context' instead of creating a new ImageBuffer
     // on each call.
     OwnPtr<ImageBuffer> scratchImage = ImageBuffer::create(IntSize(1, 1));
     GraphicsContext* gc = scratchImage->context();
     QPainterPathStroker stroke;
     applier->strokeStyle(gc);

     QPen pen = gc->pen();
     stroke.setWidth(pen.widthF());
     stroke.setCapStyle(pen.capStyle());
     stroke.setJoinStyle(pen.joinStyle());
     stroke.setMiterLimit(pen.miterLimit());
     stroke.setDashPattern(pen.dashPattern());
     stroke.setDashOffset(pen.dashOffset());

     return stroke.createStroke(m_path).contains(point);
 }

 void Path::translate(const FloatSize& size)
 {
     QTransform matrix;
     matrix.translate(size.width(), size.height());
     m_path = m_path * matrix;
 }

 FloatRect Path::boundingRect() const
 {
     return m_path.boundingRect();
 }

 FloatRect Path::strokeBoundingRect(StrokeStyleApplier* applier)
 {
     // FIXME: We should try to use a 'shared Context' instead of creating a new ImageBuffer
     // on each call.
     OwnPtr<ImageBuffer> scratchImage = ImageBuffer::create(IntSize(1, 1));
     GraphicsContext* gc = scratchImage->context();
     QPainterPathStroker stroke;
     if (applier) {
         applier->strokeStyle(gc);

         QPen pen = gc->pen();
         stroke.setWidth(pen.widthF());
         stroke.setCapStyle(pen.capStyle());
         stroke.setJoinStyle(pen.joinStyle());
         stroke.setMiterLimit(pen.miterLimit());
         stroke.setDashPattern(pen.dashPattern());
         stroke.setDashOffset(pen.dashOffset());
     }
     return stroke.createStroke(m_path).boundingRect();
 }

 void Path::moveTo(const FloatPoint& point)
 {
     m_path.moveTo(point);
 }

 void Path::addLineTo(const FloatPoint& p)
 {
     m_path.lineTo(p);
 }

 void Path::addQuadCurveTo(const FloatPoint& cp, const FloatPoint& p)
 {
     m_path.quadTo(cp, p);
 }

 void Path::addBezierCurveTo(const FloatPoint& cp1, const FloatPoint& cp2, const FloatPoint& p)
 {
     m_path.cubicTo(cp1, cp2, p);
 }

 void Path::addArcTo(const FloatPoint& p1, const FloatPoint& p2, float radius)
 {
     FloatPoint p0(m_path.currentPosition());

     if ((p1.x() == p0.x() && p1.y() == p0.y()) || (p1.x() == p2.x() && p1.y() == p2.y()) || radius == 0.f) {
         m_path.lineTo(p1);
         return;
     }

     FloatPoint p1p0((p0.x() - p1.x()), (p0.y() - p1.y()));
     FloatPoint p1p2((p2.x() - p1.x()), (p2.y() - p1.y()));
     float p1p0_length = sqrtf(p1p0.x() * p1p0.x() + p1p0.y() * p1p0.y());
     float p1p2_length = sqrtf(p1p2.x() * p1p2.x() + p1p2.y() * p1p2.y());

     double cos_phi = (p1p0.x() * p1p2.x() + p1p0.y() * p1p2.y()) / (p1p0_length * p1p2_length);

     // The points p0, p1, and p2 are on the same straight line (HTML5, 4.8.11.1.8)
     // We could have used areCollinear() here, but since we're reusing
     // the variables computed above later on we keep this logic.
     if (qFuzzyCompare(qAbs(cos_phi), 1.0)) {
         m_path.lineTo(p1);
         return;
     }

     float tangent = radius / tan(acos(cos_phi) / 2);
     float factor_p1p0 = tangent / p1p0_length;
     FloatPoint t_p1p0((p1.x() + factor_p1p0 * p1p0.x()), (p1.y() + factor_p1p0 * p1p0.y()));

     FloatPoint orth_p1p0(p1p0.y(), -p1p0.x());
     float orth_p1p0_length = sqrt(orth_p1p0.x() * orth_p1p0.x() + orth_p1p0.y() * orth_p1p0.y());
     float factor_ra = radius / orth_p1p0_length;

     // angle between orth_p1p0 and p1p2 to get the right vector orthographic to p1p0
     double cos_alpha = (orth_p1p0.x() * p1p2.x() + orth_p1p0.y() * p1p2.y()) / (orth_p1p0_length * p1p2_length);
     if (cos_alpha < 0.f)
         orth_p1p0 = FloatPoint(-orth_p1p0.x(), -orth_p1p0.y());

     FloatPoint p((t_p1p0.x() + factor_ra * orth_p1p0.x()), (t_p1p0.y() + factor_ra * orth_p1p0.y()));

     // calculate angles for addArc
     orth_p1p0 = FloatPoint(-orth_p1p0.x(), -orth_p1p0.y());
     float sa = acos(orth_p1p0.x() / orth_p1p0_length);
     if (orth_p1p0.y() < 0.f)
         sa = 2 * piDouble - sa;

     // anticlockwise logic
     bool anticlockwise = false;

     float factor_p1p2 = tangent / p1p2_length;
     FloatPoint t_p1p2((p1.x() + factor_p1p2 * p1p2.x()), (p1.y() + factor_p1p2 * p1p2.y()));
     FloatPoint orth_p1p2((t_p1p2.x() - p.x()), (t_p1p2.y() - p.y()));
     float orth_p1p2_length = sqrtf(orth_p1p2.x() * orth_p1p2.x() + orth_p1p2.y() * orth_p1p2.y());
     float ea = acos(orth_p1p2.x() / orth_p1p2_length);
     if (orth_p1p2.y() < 0)
         ea = 2 * piDouble - ea;
     if ((sa > ea) && ((sa - ea) < piDouble))
         anticlockwise = true;
     if ((sa < ea) && ((ea - sa) > piDouble))
         anticlockwise = true;

     m_path.lineTo(t_p1p0);

     addArc(p, radius, sa, ea, anticlockwise);
 }

 void Path::closeSubpath()
 {
     m_path.closeSubpath();
 }

 #define DEGREES(t) ((t) * 180.0 / M_PI)
 void Path::addArc(const FloatPoint& p, float r, float sar, float ear, bool anticlockwise)
 {
     qreal xc = p.x();
     qreal yc = p.y();
     qreal radius = r;


     //### HACK
     // In Qt we don't switch the coordinate system for degrees
     // and still use the 0,0 as bottom left for degrees so we need
     // to switch
     sar = -sar;
     ear = -ear;
     anticlockwise = !anticlockwise;
     //end hack

     float sa = DEGREES(sar);
     float ea = DEGREES(ear);

     double span = 0;

     double xs = xc - radius;
     double ys = yc - radius;
     double width  = radius*2;
     double height = radius*2;

     if (!anticlockwise && (ea < sa))
         span += 360;
     else if (anticlockwise && (sa < ea))
         span -= 360;

     // this is also due to switched coordinate system
     // we would end up with a 0 span instead of 360
     if (!(qFuzzyCompare(span + (ea - sa) + 1, 1.0) &&
           qFuzzyCompare(qAbs(span), 360.0))) {
         span += ea - sa;
     }

     // If the path is empty, move to where the arc will start to avoid painting a line from (0,0)
     // NOTE: QPainterPath::isEmpty() won't work here since it ignores a lone MoveToElement
     if (!m_path.elementCount())
         m_path.arcMoveTo(xs, ys, width, height, sa);

     m_path.arcTo(xs, ys, width, height, sa, span);

 }

 void Path::addRect(const FloatRect& r)
 {
     m_path.addRect(r.x(), r.y(), r.width(), r.height());
 }

 void Path::addEllipse(const FloatRect& r)
 {
     m_path.addEllipse(r.x(), r.y(), r.width(), r.height());
 }

 void Path::clear()
 {
     m_path = QPainterPath();
 }

 bool Path::isEmpty() const
 {
     // Don't use QPainterPath::isEmpty(), as that also returns true if there's only
     // one initial MoveTo element in the path.
     return !m_path.elementCount();
 }

 bool Path::hasCurrentPoint() const
 {
     return !isEmpty();
 }

 String Path::debugString() const
 {
     QString ret;
     for (int i = 0; i < m_path.elementCount(); ++i) {
         const QPainterPath::Element &cur = m_path.elementAt(i);

         switch (cur.type) {
             case QPainterPath::MoveToElement:
                 ret += QString(QLatin1String("M%1,%2 ")).arg(cur.x, 0, 'f', 2).arg(cur.y, 0, 'f', 2);
                 break;
             case QPainterPath::LineToElement:
                 ret += QString(QLatin1String("L%1,%2 ")).arg(cur.x, 0, 'f', 2).arg(cur.y, 0, 'f', 2);
                 break;
             case QPainterPath::CurveToElement:
             {
                 const QPainterPath::Element &c1 = m_path.elementAt(i + 1);
                 const QPainterPath::Element &c2 = m_path.elementAt(i + 2);

                 Q_ASSERT(c1.type == QPainterPath::CurveToDataElement);
                 Q_ASSERT(c2.type == QPainterPath::CurveToDataElement);

                 ret += QString(QLatin1String("C%1,%2,%3,%4,%5,%6 ")).arg(cur.x, 0, 'f', 2).arg(cur.y, 0, 'f', 2).arg(c1.x, 0, 'f', 2)
                                                                     .arg(c1.y, 0, 'f', 2).arg(c2.x, 0, 'f', 2).arg(c2.y, 0, 'f', 2);
                 i += 2;
                 break;
             }
             case QPainterPath::CurveToDataElement:
                 Q_ASSERT(false);
                 break;
         }
     }

     return ret.trimmed();
 }

 void Path::apply(void* info, PathApplierFunction function) const
 {
     PathElement pelement;
     FloatPoint points[3];
     pelement.points = points;
     for (int i = 0; i < m_path.elementCount(); ++i) {
         const QPainterPath::Element& cur = m_path.elementAt(i);

         switch (cur.type) {
             case QPainterPath::MoveToElement:
                 pelement.type = PathElementMoveToPoint;
                 pelement.points[0] = QPointF(cur);
                 function(info, &pelement);
                 break;
             case QPainterPath::LineToElement:
                 pelement.type = PathElementAddLineToPoint;
                 pelement.points[0] = QPointF(cur);
                 function(info, &pelement);
                 break;
             case QPainterPath::CurveToElement:
             {
                 const QPainterPath::Element& c1 = m_path.elementAt(i + 1);
                 const QPainterPath::Element& c2 = m_path.elementAt(i + 2);

                 Q_ASSERT(c1.type == QPainterPath::CurveToDataElement);
                 Q_ASSERT(c2.type == QPainterPath::CurveToDataElement);

                 pelement.type = PathElementAddCurveToPoint;
                 pelement.points[0] = QPointF(cur);
                 pelement.points[1] = QPointF(c1);
                 pelement.points[2] = QPointF(c2);
                 function(info, &pelement);

                 i += 2;
                 break;
             }
             case QPainterPath::CurveToDataElement:
                 Q_ASSERT(false);
         }
     }
 }

 void Path::transform(const AffineTransform& transform)
 {
     m_path = QTransform(transform).map(m_path);
 }

 }

 // vim: ts=4 sw=4 et
	/*
	* Copyright (C) 2006 Zack Rusin <zack@kde.org>
	* 2006 Rob Buis <buis@kde.org>
	* 2009, 2010 Dirk Schulze <krit@webkit.org>
	*
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "Path.h"

	#include "AffineTransform.h"
	#include "FloatRect.h"
	#include "GraphicsContext.h"
	#include "ImageBuffer.h"
	#include "PlatformString.h"
	#include "StrokeStyleApplier.h"
	#include <QPainterPath>
	#include <QTransform>
	#include <QString>
	#include <wtf/OwnPtr.h>

	#define _USE_MATH_DEFINES
	#include <math.h>

	#ifndef M_PI
	# define M_PI 3.14159265358979323846
	#endif

	namespace WebCore {

	Path::Path()
	{
	}

	Path::~Path()
	{
	}

	Path::Path(const Path& other)
	: m_path(other.m_path)
	{
	}

	Path& Path::operator=(const Path& other)
	{
	m_path = other.m_path;
	return *this;
	}

	static inline bool areCollinear(const QPointF& a, const QPointF& b, const QPointF& c)
	{
	// Solved from comparing the slopes of a to b and b to c: (ay-by)/(ax-bx) == (cy-by)/(cx-bx)
	return qFuzzyCompare((c.y() - b.y()) * (a.x() - b.x()), (a.y() - b.y()) * (c.x() - b.x()));
	}

	static inline bool withinRange(qreal p, qreal a, qreal b)
	{
	return (p >= a && p <= b) \|\| (p >= b && p <= a);
	}

	// Check whether a point is on the border
	static bool isPointOnPathBorder(const QPolygonF& border, const QPointF& p)
	{
	QPointF p1 = border.at(0);
	QPointF p2;

	for (int i = 1; i < border.size(); ++i) {
	p2 = border.at(i);
	if (areCollinear(p, p1, p2)
	// Once we know that the points are collinear we
	// only need to check one of the coordinates
	&& (qAbs(p2.x() - p1.x()) > qAbs(p2.y() - p1.y()) ?
	withinRange(p.x(), p1.x(), p2.x()) :
	withinRange(p.y(), p1.y(), p2.y()))) {
	return true;
	}
	p1 = p2;
	}
	return false;
	}

	bool Path::contains(const FloatPoint& point, WindRule rule) const
	{
	Qt::FillRule savedRule = m_path.fillRule();
	const_cast<QPainterPath*>(&m_path)->setFillRule(rule == RULE_EVENODD ? Qt::OddEvenFill : Qt::WindingFill);

	bool contains = m_path.contains(point);

	if (!contains) {
	// check whether the point is on the border
	contains = isPointOnPathBorder(m_path.toFillPolygon(), point);
	}

	const_cast<QPainterPath*>(&m_path)->setFillRule(savedRule);
	return contains;
	}

	bool Path::strokeContains(StrokeStyleApplier* applier, const FloatPoint& point) const
	{
	ASSERT(applier);

	// FIXME: We should try to use a 'shared Context' instead of creating a new ImageBuffer
	// on each call.
	OwnPtr<ImageBuffer> scratchImage = ImageBuffer::create(IntSize(1, 1));
	GraphicsContext* gc = scratchImage->context();
	QPainterPathStroker stroke;
	applier->strokeStyle(gc);

	QPen pen = gc->pen();
	stroke.setWidth(pen.widthF());
	stroke.setCapStyle(pen.capStyle());
	stroke.setJoinStyle(pen.joinStyle());
	stroke.setMiterLimit(pen.miterLimit());
	stroke.setDashPattern(pen.dashPattern());
	stroke.setDashOffset(pen.dashOffset());

	return stroke.createStroke(m_path).contains(point);
	}

	void Path::translate(const FloatSize& size)
	{
	QTransform matrix;
	matrix.translate(size.width(), size.height());
	m_path = m_path * matrix;
	}

	FloatRect Path::boundingRect() const
	{
	return m_path.boundingRect();
	}

	FloatRect Path::strokeBoundingRect(StrokeStyleApplier* applier)
	{
	// FIXME: We should try to use a 'shared Context' instead of creating a new ImageBuffer
	// on each call.
	OwnPtr<ImageBuffer> scratchImage = ImageBuffer::create(IntSize(1, 1));
	GraphicsContext* gc = scratchImage->context();
	QPainterPathStroker stroke;
	if (applier) {
	applier->strokeStyle(gc);

	QPen pen = gc->pen();
	stroke.setWidth(pen.widthF());
	stroke.setCapStyle(pen.capStyle());
	stroke.setJoinStyle(pen.joinStyle());
	stroke.setMiterLimit(pen.miterLimit());
	stroke.setDashPattern(pen.dashPattern());
	stroke.setDashOffset(pen.dashOffset());
	}
	return stroke.createStroke(m_path).boundingRect();
	}

	void Path::moveTo(const FloatPoint& point)
	{
	m_path.moveTo(point);
	}

	void Path::addLineTo(const FloatPoint& p)
	{
	m_path.lineTo(p);
	}

	void Path::addQuadCurveTo(const FloatPoint& cp, const FloatPoint& p)
	{
	m_path.quadTo(cp, p);
	}

	void Path::addBezierCurveTo(const FloatPoint& cp1, const FloatPoint& cp2, const FloatPoint& p)
	{
	m_path.cubicTo(cp1, cp2, p);
	}

	void Path::addArcTo(const FloatPoint& p1, const FloatPoint& p2, float radius)
	{
	FloatPoint p0(m_path.currentPosition());

	if ((p1.x() == p0.x() && p1.y() == p0.y()) \|\| (p1.x() == p2.x() && p1.y() == p2.y()) \|\| radius == 0.f) {
	m_path.lineTo(p1);
	return;
	}

	FloatPoint p1p0((p0.x() - p1.x()), (p0.y() - p1.y()));
	FloatPoint p1p2((p2.x() - p1.x()), (p2.y() - p1.y()));
	float p1p0_length = sqrtf(p1p0.x() * p1p0.x() + p1p0.y() * p1p0.y());
	float p1p2_length = sqrtf(p1p2.x() * p1p2.x() + p1p2.y() * p1p2.y());

	double cos_phi = (p1p0.x() * p1p2.x() + p1p0.y() * p1p2.y()) / (p1p0_length * p1p2_length);

	// The points p0, p1, and p2 are on the same straight line (HTML5, 4.8.11.1.8)
	// We could have used areCollinear() here, but since we're reusing
	// the variables computed above later on we keep this logic.
	if (qFuzzyCompare(qAbs(cos_phi), 1.0)) {
	m_path.lineTo(p1);
	return;
	}

	float tangent = radius / tan(acos(cos_phi) / 2);
	float factor_p1p0 = tangent / p1p0_length;
	FloatPoint t_p1p0((p1.x() + factor_p1p0 * p1p0.x()), (p1.y() + factor_p1p0 * p1p0.y()));

	FloatPoint orth_p1p0(p1p0.y(), -p1p0.x());
	float orth_p1p0_length = sqrt(orth_p1p0.x() * orth_p1p0.x() + orth_p1p0.y() * orth_p1p0.y());
	float factor_ra = radius / orth_p1p0_length;

	// angle between orth_p1p0 and p1p2 to get the right vector orthographic to p1p0
	double cos_alpha = (orth_p1p0.x() * p1p2.x() + orth_p1p0.y() * p1p2.y()) / (orth_p1p0_length * p1p2_length);
	if (cos_alpha < 0.f)
	orth_p1p0 = FloatPoint(-orth_p1p0.x(), -orth_p1p0.y());

	FloatPoint p((t_p1p0.x() + factor_ra * orth_p1p0.x()), (t_p1p0.y() + factor_ra * orth_p1p0.y()));

	// calculate angles for addArc
	orth_p1p0 = FloatPoint(-orth_p1p0.x(), -orth_p1p0.y());
	float sa = acos(orth_p1p0.x() / orth_p1p0_length);
	if (orth_p1p0.y() < 0.f)
	sa = 2 * piDouble - sa;

	// anticlockwise logic
	bool anticlockwise = false;

	float factor_p1p2 = tangent / p1p2_length;
	FloatPoint t_p1p2((p1.x() + factor_p1p2 * p1p2.x()), (p1.y() + factor_p1p2 * p1p2.y()));
	FloatPoint orth_p1p2((t_p1p2.x() - p.x()), (t_p1p2.y() - p.y()));
	float orth_p1p2_length = sqrtf(orth_p1p2.x() * orth_p1p2.x() + orth_p1p2.y() * orth_p1p2.y());
	float ea = acos(orth_p1p2.x() / orth_p1p2_length);
	if (orth_p1p2.y() < 0)
	ea = 2 * piDouble - ea;
	if ((sa > ea) && ((sa - ea) < piDouble))
	anticlockwise = true;
	if ((sa < ea) && ((ea - sa) > piDouble))
	anticlockwise = true;

	m_path.lineTo(t_p1p0);

	addArc(p, radius, sa, ea, anticlockwise);
	}

	void Path::closeSubpath()
	{
	m_path.closeSubpath();
	}

	#define DEGREES(t) ((t) * 180.0 / M_PI)
	void Path::addArc(const FloatPoint& p, float r, float sar, float ear, bool anticlockwise)
	{
	qreal xc = p.x();
	qreal yc = p.y();
	qreal radius = r;


	//### HACK
	// In Qt we don't switch the coordinate system for degrees
	// and still use the 0,0 as bottom left for degrees so we need
	// to switch
	sar = -sar;
	ear = -ear;
	anticlockwise = !anticlockwise;
	//end hack

	float sa = DEGREES(sar);
	float ea = DEGREES(ear);

	double span = 0;

	double xs = xc - radius;
	double ys = yc - radius;
	double width = radius*2;
	double height = radius*2;

	if (!anticlockwise && (ea < sa))
	span += 360;
	else if (anticlockwise && (sa < ea))
	span -= 360;

	// this is also due to switched coordinate system
	// we would end up with a 0 span instead of 360
	if (!(qFuzzyCompare(span + (ea - sa) + 1, 1.0) &&
	qFuzzyCompare(qAbs(span), 360.0))) {
	span += ea - sa;
	}

	// If the path is empty, move to where the arc will start to avoid painting a line from (0,0)
	// NOTE: QPainterPath::isEmpty() won't work here since it ignores a lone MoveToElement
	if (!m_path.elementCount())
	m_path.arcMoveTo(xs, ys, width, height, sa);

	m_path.arcTo(xs, ys, width, height, sa, span);

	}

	void Path::addRect(const FloatRect& r)
	{
	m_path.addRect(r.x(), r.y(), r.width(), r.height());
	}

	void Path::addEllipse(const FloatRect& r)
	{
	m_path.addEllipse(r.x(), r.y(), r.width(), r.height());
	}

	void Path::clear()
	{
	m_path = QPainterPath();
	}

	bool Path::isEmpty() const
	{
	// Don't use QPainterPath::isEmpty(), as that also returns true if there's only
	// one initial MoveTo element in the path.
	return !m_path.elementCount();
	}

	bool Path::hasCurrentPoint() const
	{
	return !isEmpty();
	}

	String Path::debugString() const
	{
	QString ret;
	for (int i = 0; i < m_path.elementCount(); ++i) {
	const QPainterPath::Element &cur = m_path.elementAt(i);

	switch (cur.type) {
	case QPainterPath::MoveToElement:
	ret += QString(QLatin1String("M%1,%2 ")).arg(cur.x, 0, 'f', 2).arg(cur.y, 0, 'f', 2);
	break;
	case QPainterPath::LineToElement:
	ret += QString(QLatin1String("L%1,%2 ")).arg(cur.x, 0, 'f', 2).arg(cur.y, 0, 'f', 2);
	break;
	case QPainterPath::CurveToElement:
	{
	const QPainterPath::Element &c1 = m_path.elementAt(i + 1);
	const QPainterPath::Element &c2 = m_path.elementAt(i + 2);

	Q_ASSERT(c1.type == QPainterPath::CurveToDataElement);
	Q_ASSERT(c2.type == QPainterPath::CurveToDataElement);

	ret += QString(QLatin1String("C%1,%2,%3,%4,%5,%6 ")).arg(cur.x, 0, 'f', 2).arg(cur.y, 0, 'f', 2).arg(c1.x, 0, 'f', 2)
	.arg(c1.y, 0, 'f', 2).arg(c2.x, 0, 'f', 2).arg(c2.y, 0, 'f', 2);
	i += 2;
	break;
	}
	case QPainterPath::CurveToDataElement:
	Q_ASSERT(false);
	break;
	}
	}

	return ret.trimmed();
	}

	void Path::apply(void* info, PathApplierFunction function) const
	{
	PathElement pelement;
	FloatPoint points[3];
	pelement.points = points;
	for (int i = 0; i < m_path.elementCount(); ++i) {
	const QPainterPath::Element& cur = m_path.elementAt(i);

	switch (cur.type) {
	case QPainterPath::MoveToElement:
	pelement.type = PathElementMoveToPoint;
	pelement.points[0] = QPointF(cur);
	function(info, &pelement);
	break;
	case QPainterPath::LineToElement:
	pelement.type = PathElementAddLineToPoint;
	pelement.points[0] = QPointF(cur);
	function(info, &pelement);
	break;
	case QPainterPath::CurveToElement:
	{
	const QPainterPath::Element& c1 = m_path.elementAt(i + 1);
	const QPainterPath::Element& c2 = m_path.elementAt(i + 2);

	Q_ASSERT(c1.type == QPainterPath::CurveToDataElement);
	Q_ASSERT(c2.type == QPainterPath::CurveToDataElement);

	pelement.type = PathElementAddCurveToPoint;
	pelement.points[0] = QPointF(cur);
	pelement.points[1] = QPointF(c1);
	pelement.points[2] = QPointF(c2);
	function(info, &pelement);

	i += 2;
	break;
	}
	case QPainterPath::CurveToDataElement:
	Q_ASSERT(false);
	}
	}
	}

	void Path::transform(const AffineTransform& transform)
	{
	m_path = QTransform(transform).map(m_path);
	}

	}

	// vim: ts=4 sw=4 et