File indexing completed on 2024-04-28 07:39:35

 /*.
     SPDX-FileCopyrightText: 2007 Vladimir Kuznetsov <ks.vladimir@gmail.com>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "arrow.h"
 
 #include <cmath>
 
 #include <QPainter>
 
 const int ARROW_STROKE = 6;
 
 Arrow::Arrow(const QLineF& line, int width) : QLineF(line), _width(width)
 {
 }
 
 Arrow::Arrow(const QPointF& p1, const QPointF& p2, int width) :
     QLineF(p1, p2), _width(width)
 {
 }
 
 Arrow::Arrow(qreal x1, qreal y1, qreal x2, qreal y2, int width) :
     QLineF(x1, y1, x2, y2), _width(width)
 {
 }
 
 void Arrow::draw(QPainter* painter) const
 {
     const QTransform& transform = painter->worldTransform();
     QLineF transformed = transform.map(*this);
     QLineF real_transformed(floor(transformed.x1()) + 0.5,
                             floor(transformed.y1()) + 0.5,
                             floor(transformed.x2()) + 0.5,
                             floor(transformed.y2()) + 0.5);
     QLineF line_unit = real_transformed.unitVector();
     line_unit.translate(-line_unit.p1());
     QLineF line_normal = line_unit.normalVector();
     
     QPointF arrow_head_base =
         real_transformed.p2() - line_unit.p2() * 0.866 * _width;
     QLineF arrow_line(transformed);
     arrow_line.setLength(arrow_line.length() - 0.5 * _width);
     
     QPolygonF arrow_head(3);
     arrow_head[0] = real_transformed.p2();
     arrow_head[1] = arrow_head_base + line_normal.p2() * 0.5 * _width;
     arrow_head[2] = arrow_head_base - line_normal.p2() * 0.5 * _width;
     
     painter->save();
     painter->setWorldMatrixEnabled(false);
     QPen pen = painter->pen();
     pen.setWidth(0);
     painter->setPen(pen);
     painter->drawLine(arrow_line);
     painter->setRenderHint(QPainter::Antialiasing, true);
     painter->setBrush(pen.color());
     painter->setPen(Qt::NoPen);
     painter->drawPolygon(arrow_head);
     painter->restore();
 }