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rotoscoping: allow adding new points to the spline
[kdenlive] / src / onmonitoritems / rotoscoping / splineitem.cpp
1 /***************************************************************************
2  *   Copyright (C) 2011 by Till Theato (root@ttill.de)                     *
3  *   This file is part of Kdenlive (www.kdenlive.org).                     *
4  *                                                                         *
5  *   Kdenlive is free software: you can redistribute it and/or modify      *
6  *   it under the terms of the GNU General Public License as published by  *
7  *   the Free Software Foundation, either version 2 of the License, or     *
8  *   (at your option) any later version.                                   *
9  *                                                                         *
10  *   Kdenlive is distributed in the hope that it will be useful,           *
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
13  *   GNU General Public License for more details.                          *
14  *                                                                         *
15  *   You should have received a copy of the GNU General Public License     *
16  *   along with Kdenlive.  If not, see <http://www.gnu.org/licenses/>.     *
17  ***************************************************************************/
18
19 #include "splineitem.h"
20 #include "bpointitem.h"
21 #include "nearestpoint.h"
22
23 #include <QGraphicsScene>
24 #include <QCursor>
25 #include <QGraphicsSceneMouseEvent>
26
27
28 inline QPointF closestPointInRect(QPointF point, QRectF rect)
29 {
30     QPointF closest;
31     rect = rect.normalized();
32     closest.setX(qBound<qreal>(rect.left(), point.x(), rect.right()));
33     closest.setY(qBound<qreal>(rect.top(), point.y(), rect.bottom()));
34     return closest;
35 }
36
37 void deCasteljau(BPoint *p1, BPoint *p2, BPoint *res, double t)
38 {
39     QPointF ab, bc, cd;
40
41     ab = QLineF(p1->p, p1->h2).pointAt(t);
42     bc = QLineF(p1->h2, p2->h1).pointAt(t);
43     cd = QLineF(p2->h1, p2->p).pointAt(t);
44
45     res->h1 = QLineF(ab, bc).pointAt(t);
46     res->h2 = QLineF(bc, cd).pointAt(t);
47     res->p = QLineF(res->h1, res->h2).pointAt(t);
48
49     p1->h2 = ab;
50     p2->h1 = cd;
51 }
52
53
54 SplineItem::SplineItem(const QList< BPoint >& points, QGraphicsItem* parent, QGraphicsScene *scene) :
55     QGraphicsPathItem(parent, scene)
56 {
57     QPen framepen(Qt::SolidLine);
58     framepen.setColor(Qt::yellow);
59     setPen(framepen);
60     setBrush(Qt::NoBrush);
61     setAcceptHoverEvents(true);
62
63     if (points.isEmpty())
64         return;
65
66     QPainterPath path(points.at(0).p);
67     int j;
68     for (int i = 0; i < points.count(); ++i) {
69         new BPointItem(points.at(i), this);
70         j = (i + 1) % points.count();
71         path.cubicTo(points.at(i).h2, points.at(j).h1, points.at(j).p);
72     }
73     setPath(path);
74 }
75
76 int SplineItem::type() const
77 {
78     return Type;
79 }
80
81 void SplineItem::updateSpline()
82 {
83     QPainterPath path(qgraphicsitem_cast<BPointItem *>(childItems().at(0))->getPoint().p);
84
85     BPoint p1, p2;
86     int j;
87     for (int i = 0; i < childItems().count(); ++i) {
88         j = (i + 1) % childItems().count();
89         p1 = qgraphicsitem_cast<BPointItem *>(childItems().at(i))->getPoint();
90         p2 = qgraphicsitem_cast<BPointItem *>(childItems().at(j))->getPoint();
91         path.cubicTo(p1.h2, p2.h1, p2.p);
92     }
93     setPath(path);
94
95     emit changed();
96 }
97
98 QList <BPoint> SplineItem::getPoints()
99 {
100     QList <BPoint> points;
101     foreach (QGraphicsItem *child, childItems())
102         points << qgraphicsitem_cast<BPointItem *>(child)->getPoint();
103     return points;
104 }
105
106 void SplineItem::mousePressEvent(QGraphicsSceneMouseEvent* event)
107 {
108     QGraphicsItem::mousePressEvent(event);
109
110     if (!event->isAccepted()) {
111         QRectF r(event->scenePos() - QPointF(6, 6), QSizeF(12, 12));
112         if (path().intersects(r) && !path().contains(r)) {
113             double t = 0;
114             BPointItem *i, *i1, *i2;
115             BPoint p, p1, p2;
116             int ix = getClosestPointOnCurve(event->scenePos(), &t);
117             i1 = qgraphicsitem_cast<BPointItem *>(childItems().at(ix));
118             i2 = qgraphicsitem_cast<BPointItem *>(childItems().at((ix + 1) % childItems().count()));
119             p1 = i1->getPoint();
120             p2 = i2->getPoint();
121
122             deCasteljau(&p1, &p2, &p, t);
123
124             i1->setPoint(p1);
125             i2->setPoint(p2);
126
127             i = new BPointItem(p, this);
128             // TODO: make it work with Qt < 4.6
129 #if QT_VERSION >= 0x040600
130             i->stackBefore(i2);
131 #endif
132         }
133     }
134 }
135
136 void SplineItem::mouseMoveEvent(QGraphicsSceneMouseEvent* event)
137 {
138     QGraphicsItem::mouseMoveEvent(event);
139 }
140
141 void SplineItem::mouseReleaseEvent(QGraphicsSceneMouseEvent* event)
142 {
143     QGraphicsItem::mouseReleaseEvent(event);
144 }
145
146 void SplineItem::hoverMoveEvent(QGraphicsSceneHoverEvent* event)
147 {
148     QGraphicsItem::hoverMoveEvent(event);
149
150     QRectF r(event->scenePos() - QPointF(6, 6), QSizeF(12, 12));
151     if (path().intersects(r) && !path().contains(r))
152         setCursor(QCursor(Qt::PointingHandCursor));
153     else
154         unsetCursor();
155 }
156
157 int SplineItem::getClosestPointOnCurve(QPointF point, double *tFinal)
158 {
159     // TODO: proper minDiff
160     qreal diff = 10000, param = 0;
161     BPoint p1, p2;
162     int curveSegment = 0, j;
163     for (int i = 0; i < childItems().count(); ++i) {
164         j = (i + 1) % childItems().count();
165         p1 = qgraphicsitem_cast<BPointItem *>(childItems().at(i))->getPoint();
166         p2 = qgraphicsitem_cast<BPointItem *>(childItems().at(j))->getPoint();
167         QPolygonF bounding = QPolygonF() << p1.p << p1.h2 << p2.h1 << p2.p;
168         QPointF cl = closestPointInRect(point, bounding.boundingRect());
169         qreal d = (point - cl).manhattanLength();
170
171         if (d > diff)
172             continue;
173
174         Point2 b[4], p;
175         double t;
176
177         b[0].x = p1.p.x();
178         b[0].y = p1.p.y();
179         b[1].x = p1.h2.x();
180         b[1].y = p1.h2.y();
181         b[2].x = p2.h1.x();
182         b[2].y = p2.h1.y();
183         b[3].x = p2.p.x();
184         b[3].y = p2.p.y();
185
186         p.x = point.x();
187         p.y = point.y();
188
189         Point2 n = NearestPointOnCurve(p, b, &t);
190         cl.setX(n.x);
191         cl.setY(n.y);
192
193         d = (point - cl).manhattanLength();
194         if (d < diff) {
195             diff = d;
196             param = t;
197             curveSegment = i;
198         }
199     }
200
201     *tFinal = param;
202     return curveSegment;
203 }
204
205 #include "splineitem.moc"