#include <cmath>
#include <iostream>
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Weffc++"
#pragma GCC diagnostic ignored "-Wunused-local-typedefs"
#include <boost/shared_ptr.hpp>
#include <boost/static_assert.hpp>
#include <QApplication>
#include <QBitmap>
#include <QGraphicsPixmapItem>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QTimer>
#pragma GCC diagnostic pop
BOOST_STATIC_ASSERT(sizeof(qreal)==sizeof(double)
&& "Assume use of double is equivalent of qreal");
struct ChangingBackground : public QGraphicsPixmapItem
{
ChangingBackground(const int width, const int height)
: z(0)
{
QPixmap m(width,height);
this->setPixmap(m);
}
void advance(int)
{
QImage i = this->pixmap().toImage();
const int width = i.width();
const int height = i.height();
for (int y=0;y!=height;++y)
{
for (int x=0;x!=width;++x)
{
QPoint pos(x,y);
QColor c((x+z)%256,(y+z)%256,(x+y+z)%256);
i.setPixel(pos,c.rgb());
}
}
this->setPixmap(this->pixmap().fromImage(i));
++z;
}
private:
int z;
};
struct TransparentSprite : public QGraphicsPixmapItem
{
TransparentSprite(
const int width, const int height,
const int r = 255,
const int g = 255,
const int b = 255)
: dx( ((std::rand() >> 4) % 3) - 1), //Random direction
dy( ((std::rand() >> 4) % 3) - 1), //Random direction
maxx(0),
maxy(0)
{
QImage i(width,height,QImage::Format_ARGB32);
const QColor transparency_color = QColor(0,0,0,255);
const double r_real = static_cast<double>(r);
const double g_real = static_cast<double>(g);
const double b_real = static_cast<double>(b);
const double midx = static_cast<double>(width ) / 2.0;
const double midy = static_cast<double>(height) / 2.0;
const double ray = std::min(midx,midy);
for (int y=0;y!=height;++y)
{
const double y_real = static_cast<double>(y);
const double dy = midy - y_real;
const double dy2 = dy * dy;
for (int x=0;x!=width;++x)
{
const double x_real = static_cast<double>(x);
const double dx = midx - x_real;
const double dx2 = dx * dx;
const double dist = std::sqrt(dx2 + dy2);
if (dist < ray)
{
const QColor c(
(1.0 - (dist / ray)) * r_real,
(1.0 - (dist / ray)) * g_real,
(1.0 - (dist / ray)) * b_real);
i.setPixel(x,y,c.rgb());
}
else
{
i.setPixel(x,y,transparency_color.rgb());
}
}
}
this->setPixmap(this->pixmap().fromImage(i));
QPixmap pixmap = this->pixmap();
const QBitmap mask = pixmap.createMaskFromColor(transparency_color);
pixmap.setMask(mask);
this->setPixmap(pixmap);
}
void advance(int)
{
int new_x = this->x();
int new_y = this->y();
new_x+=dx;
new_y+=dy;
if (new_x<0 || new_x>maxx) dx= -dx;
if (new_y<0 || new_y>maxy) dy= -dy;
this->setX(new_x);
this->setY(new_y);
}
void setRect(const int width, const int height)
{
maxx = width - this->pixmap().width();
maxy = height - this->pixmap().height();
}
private:
int dx;
int dy;
double maxx;
double maxy;
};
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QGraphicsScene s;
QGraphicsView v(&s);
ChangingBackground background(512,512);
s.addItem(&background);
std::vector<boost::shared_ptr<TransparentSprite> > sprites;
//Add multiple sprites
const int n_sprites = 50;
for (int i=0; i!=n_sprites; ++i)
{
boost::shared_ptr<TransparentSprite> sprite(
new TransparentSprite(
64,
64,
128 + (std::rand() % 128),
128 + (std::rand() % 128),
128 + (std::rand() % 128)));
const int maxx = background.pixmap().width() - sprite->pixmap().width();
const int maxy = background.pixmap().height() - sprite->pixmap().height();
sprite->setX(std::rand() % maxx);
sprite->setY(std::rand() % maxy);
sprite->setRect(background.pixmap().width(),background.pixmap().height());
s.addItem(sprite.get());
sprites.push_back(sprite);
}
v.show();
boost::shared_ptr<QTimer> timer(new QTimer(&s));
timer->connect(timer.get(), SIGNAL(timeout()), &s, SLOT(advance()));
timer->start(50);
return a.exec();
}
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