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