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50
51 #include <QtWidgets>
52
53 #include "bubble.h"
54
Bubble(const QPointF & position,qreal radius,const QPointF & velocity)55 Bubble::Bubble(const QPointF &position, qreal radius, const QPointF &velocity)
56 : position(position), vel(velocity), radius(radius)
57 {
58 innerColor = randomColor();
59 outerColor = randomColor();
60 cache = 0;
61 updateBrush();
62 }
63
64 //! [0]
updateCache()65 void Bubble::updateCache()
66 {
67 if (cache)
68 delete cache;
69 cache = new QImage(qRound(radius * 2 + 2), qRound(radius * 2 + 2), QImage::Format_ARGB32_Premultiplied);
70 cache->fill(0x00000000);
71 QPainter p(cache);
72 p.setRenderHint(QPainter::Antialiasing);
73 QPen pen(Qt::white);
74 pen.setWidth(2);
75 p.setPen(pen);
76 p.setBrush(brush);
77 p.drawEllipse(1, 1, int(2*radius), int(2*radius));
78 }
79 //! [0]
80
~Bubble()81 Bubble::~Bubble()
82 {
83 if (cache)
84 delete cache;
85 }
86
updateBrush()87 void Bubble::updateBrush()
88 {
89 QRadialGradient gradient(QPointF(radius, radius), radius,
90 QPointF(radius*0.5, radius*0.5));
91
92 gradient.setColorAt(0, QColor(255, 255, 255, 255));
93 gradient.setColorAt(0.25, innerColor);
94 gradient.setColorAt(1, outerColor);
95 brush = QBrush(gradient);
96 updateCache();
97 }
98
99 //! [1]
drawBubble(QPainter * painter)100 void Bubble::drawBubble(QPainter *painter)
101 {
102 painter->save();
103 painter->translate(position.x() - radius, position.y() - radius);
104 painter->setOpacity(0.8);
105 painter->drawImage(0, 0, *cache);
106 painter->restore();
107 }
108 //! [1]
109
randomColor()110 QColor Bubble::randomColor()
111 {
112 int red = int(185 + QRandomGenerator::global()->bounded(70));
113 int green = int(185 + QRandomGenerator::global()->bounded(70));
114 int blue = int(205 + QRandomGenerator::global()->bounded(50));
115 int alpha = int(91 + QRandomGenerator::global()->bounded(100));
116
117 return QColor(red, green, blue, alpha);
118 }
119
move(const QRect & bbox)120 void Bubble::move(const QRect &bbox)
121 {
122 position += vel;
123 qreal leftOverflow = position.x() - radius - bbox.left();
124 qreal rightOverflow = position.x() + radius - bbox.right();
125 qreal topOverflow = position.y() - radius - bbox.top();
126 qreal bottomOverflow = position.y() + radius - bbox.bottom();
127
128 if (leftOverflow < 0.0) {
129 position.setX(position.x() - 2 * leftOverflow);
130 vel.setX(-vel.x());
131 } else if (rightOverflow > 0.0) {
132 position.setX(position.x() - 2 * rightOverflow);
133 vel.setX(-vel.x());
134 }
135
136 if (topOverflow < 0.0) {
137 position.setY(position.y() - 2 * topOverflow);
138 vel.setY(-vel.y());
139 } else if (bottomOverflow > 0.0) {
140 position.setY(position.y() - 2 * bottomOverflow);
141 vel.setY(-vel.y());
142 }
143 }
144
rect()145 QRectF Bubble::rect()
146 {
147 return QRectF(position.x() - radius, position.y() - radius,
148 2 * radius, 2 * radius);
149 }
150