sdlwidget.cpp

qt和sdl库的结合 通过sdl库加载图片 并且在qt界面下显示控制

/****************************************************************************
** $Id:  qt/SDLWidget.cpp   3.0.5   edited Oct 12 2001 $
**
** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.
**
** This file is part of an example program for Qt.  This example
** program may be used, distributed and modified without limitation.
**
*****************************************************************************/

#include <stdlib.h>
#include <stdio.h>
#include "SDL.h"
#include "SDLWidget.h"
#if defined(Q_WS_X11)
#include <X11/Xlib.h>
//Added by qt3to4:
#include <QPaintEvent>
#include <QResizeEvent>
#endif

QSDLScreenWidget::QSDLScreenWidget( QWidget *parent) :
    QWidget(parent), screen(NULL)
{
    atexit(SDL_Quit);
}

void QSDLScreenWidget::resizeEvent( QResizeEvent * )
{
    char variable[64];

    // We could get a resize event at any time, so clean previous mode
    screen = NULL;
    SDL_QuitSubSystem(SDL_INIT_VIDEO);

    // Set the new video mode with the new window size
    sprintf(variable, "SDL_WINDOWID=0x%lx", winId());
    putenv(variable);
    if ( SDL_InitSubSystem(SDL_INIT_VIDEO) < 0 ) {
        fprintf(stderr, "Unable to init SDL: %s\n", SDL_GetError());
        return;
    }
    screen = SDL_SetVideoMode(width(), height(), 0, 0);
    if ( ! screen ) {
        fprintf(stderr, "Unable to set video mode: %s\n", SDL_GetError());
        return;
    }
}

void QSDLScreenWidget::paintEvent( QPaintEvent * )
{
#if defined(Q_WS_X11)
    // Make sure we're not conflicting with drawing from the Qt library
    XSync(QPaintDevice::x11Display(), FALSE);
#endif
    if ( screen ) {
        SDL_FillRect(screen, NULL, 0);

        SDL_Surface *image = SDL_LoadBMP("sample.bmp");
        if ( image ) {
            SDL_Rect dst;
            dst.x = (screen->w - image->w)/2;
            dst.y = (screen->h - image->h)/2;
            dst.w = image->w;
            dst.h = image->h;
            SDL_BlitSurface(image, NULL, screen, &dst);
        }
        SDL_Flip(screen);
    }
}