1 /* This file is part of the KDE project
2 Copyright (C) 2008 Sven Langkamp <sven.langkamp@gmail.com>
3
4 This library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public
6 License as published by the Free Software Foundation; either
7 version 2 of the License, or (at your option) any later version.
8
9 This library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
13
14 You should have received a copy of the GNU Library General Public License
15 along with this library; see the file COPYING.LIB. If not, write to
16 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 */
19
20 #include "KPrClockWipeSubpathHelper.h"
21
22 #include <math.h>
23 #include <float.h>
24 #include <QPainterPath>
25
26
KPrClockWipeSubpathHelper()27 KPrClockWipeSubpathHelper::KPrClockWipeSubpathHelper()
28 {
29 }
30
~KPrClockWipeSubpathHelper()31 KPrClockWipeSubpathHelper::~KPrClockWipeSubpathHelper()
32 {
33 }
34
addSubpathForCircularArc(QPainterPath * clipPath,QRect & boundingRect,double startAngle,double endAngle)35 void KPrClockWipeSubpathHelper::addSubpathForCircularArc(QPainterPath* clipPath, QRect& boundingRect, double startAngle, double endAngle)
36 {
37 if(fabs(startAngle - endAngle) < DBL_EPSILON)
38 return;
39
40 int width = boundingRect.width();
41 int height = boundingRect.height();
42
43 while(startAngle < 0)
44 startAngle += 2*M_PI;
45
46 if(endAngle < startAngle)
47 endAngle += 2*M_PI;
48
49 QPoint center = boundingRect.center();
50 double maxRadius = sqrt(double(width*width/4 + height*height/4));
51
52 double startAngleInQuadrant = fmod(startAngle, 0.5*M_PI);
53 double quadrantAngle = static_cast<int>(startAngle / (0.5*M_PI))*(0.5*M_PI);
54
55 int cornerX = cos(quadrantAngle + 0.5*M_PI) < 0 ? -width/2 : width/2;
56 int cornerY = sin(quadrantAngle + 0.5*M_PI) < 0 ? -height/2 : height/2;
57
58 double cornerAngleInQuadrant;
59 if(cos(quadrantAngle + 0.5*M_PI)*sin(quadrantAngle + 0.5*M_PI) > 0)
60 cornerAngleInQuadrant = fabs(atan(static_cast<double>(cornerY)/cornerX));
61 else
62 cornerAngleInQuadrant = fabs(atan(static_cast<double>(cornerX)/cornerY));
63
64 double cornerAngle;
65 if( startAngleInQuadrant < cornerAngleInQuadrant )
66 cornerAngle = quadrantAngle + cornerAngleInQuadrant;
67 else
68 cornerAngle = quadrantAngle + M_PI - cornerAngleInQuadrant;
69
70 clipPath->moveTo(center);
71 clipPath->lineTo(QPoint(center.x() + maxRadius*cos(startAngle), center.y() - maxRadius*sin(startAngle)));
72
73 while(cornerAngle < endAngle) {
74
75 int cornerX = cos(cornerAngle) < 0 ? 0 : width;
76 int cornerY = sin(cornerAngle) < 0 ? height : 0;
77 clipPath->lineTo(QPoint( boundingRect.x() + cornerX, boundingRect.y() + cornerY));
78
79 quadrantAngle = static_cast<int>(cornerAngle / (0.5*M_PI))*(0.5*M_PI);
80 cornerAngleInQuadrant = cornerAngle - quadrantAngle;
81 cornerAngle = quadrantAngle + M_PI - cornerAngleInQuadrant;
82 }
83 clipPath->lineTo(QPoint(center.x() + maxRadius*cos(endAngle), center.y() - maxRadius*sin(endAngle)));
84
85
86 clipPath->closeSubpath();
87 }
88
89