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|
#include <QApplication>
#include <QFont>
#include <QPushButton>
#include <QWidget>
#include <QShowEvent>
#ifdef Q_WS_WIN
#include <SDL.h>
#elif defined Q_WS_X11
#include <SDL/SDL.h>
#endif
/* PIEGE: main est redéfini par SDL.h comme SDL_Main.
On retire donc la définition puisque Qt le gère
*/
#undef main
#include <vector>
#include <cstdlib>
#include <ctime>
class SDLWidget : public QWidget
{
Q_OBJECT
public:
SDLWidget()
: windowInitialized(false), screen(0), StarNumbers(100)
{
setAttribute(Qt::WA_PaintOnScreen);
setAttribute(Qt::WA_NoSystemBackground);
starfield.resize(100);
initStarfield();
// Le bon vieux mode 13h (simulé, c'est sûr :p )
resize(320, 200);
}
virtual ~SDLWidget()
{
SDL_Quit();
}
protected:
virtual void showEvent(QShowEvent *e)
{
(void)e;
if(!windowInitialized)
{
// C'est ici qu'on dis à SDL d'utiliser notre widget
char windowid[64];
#ifdef Q_WS_WIN
sprintf(windowid, "SDL_WINDOWID=0x%lx", reinterpret_cast<qlonglong>(winId()));
#elif defined Q_WS_X11
sprintf(windowid, "SDL_WINDOWID=0x%lx", winId());
#else
qFatal("Fatal: cast du winId() inconnu pour votre plate-forme; toute information est la bienvenue!");
#endif
SDL_putenv(windowid);
// Initialisation du système vidéo de SDL
SDL_Init(SDL_INIT_VIDEO);
screen = SDL_SetVideoMode(width(), height(), 32, SDL_SWSURFACE);
windowInitialized = true;
}
}
private:
struct Star
{
float x, y, z;
};
private:
Star generateStar()
{
Star s = {(::rand() / (static_cast<double>(RAND_MAX) + 1.0)) * 20-10,
(::rand() / (static_cast<double>(RAND_MAX) + 1.0)) * 20-10,
(::rand() / (static_cast<double>(RAND_MAX) + 1.0)) * 100};
return s;
}
void initStarfield()
{
for(StarField::iterator it = starfield.begin();
it != starfield.end();
++it)
{
*it = generateStar();
}
}
void updateStarfield()
{
for(StarField::iterator it = starfield.begin();
it != starfield.end();
++it)
{
--it->z;
if(it->z <= 0)
{
*it = generateStar();
}
}
}
void drawStarfield()
{
int w = width();
int hw = w >> 1;
int h = height();
int hh = h >> 1;
for(StarField::iterator it = starfield.begin();
it != starfield.end();
++it)
{
int screenX = static_cast<int>((it->x / it->z) * w + hw);
int screenY = static_cast<int>((it->y / it->z) * h + hh);
// ignore out of view stars
if(screenX < 0 || screenX > 319 || screenY < 0 || screenY > 199)
continue;
putpixel(screen, screenX, screenY, SDL_MapRGBA(screen->format,
0xfe, 0xef, 0xcc, 0xff));
}
}
// ripped off SDL doc
void putpixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
{
int bpp = surface->format->BytesPerPixel;
/* Here p is the address to the pixel we want to set */
Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;
switch(bpp) {
case 1:
*p = pixel;
break;
case 2:
*(Uint16 *)p = pixel;
break;
case 3:
if(SDL_BYTEORDER == SDL_BIG_ENDIAN) {
p[0] = (pixel >> 16) & 0xff;
p[1] = (pixel >> 8) & 0xff;
p[2] = pixel & 0xff;
} else {
p[0] = pixel & 0xff;
p[1] = (pixel >> 8) & 0xff;
p[2] = (pixel >> 16) & 0xff;
}
break;
case 4:
*(Uint32 *)p = pixel;
break;
}
}
private slots:
void onRefresh()
{
if(windowInitialized && screen)
{
SDL_LockSurface(screen);
// Nettoyage de l'écran
SDL_FillRect(screen, NULL, 0);
// Dessin du starfield
drawStarfield();
SDL_UnlockSurface(screen);
// Rafraîchissement...
SDL_UpdateRect(screen, 0, 0, 0, 0);
// Et enfin, mise à jour des positions des étoiles
updateStarfield();
}
}
private:
bool windowInitialized;
SDL_Surface *screen;
typedef std::vector<Star> StarField;
StarField starfield;
const int StarNumbers;
};
int main(int argc, char* argv[])
{
QApplication app(argc, argv);
SDLWidget *sdlw = new SDLWidget;
sdlw->show();
return app.exec();
} |
