Кроссплатформенное приложение Qt+MAPAPI

void uxMapView::DrawContents(QPainter *p, int cx, int cy, int cw, int ch)
{
    if (!hMap) {
        // Очистить экран
        QBrush brush( Qt::white);
        p->setBrush( brush );
        p->drawRect( cx, cy, cw, ch );
        p->drawText(QRectF(cx, cy, cw, ch),"Карта не открыта",QTextOption(Qt::AlignHCenter | Qt::AlignVCenter));
        return;
    }


    RectDraw.setLeft(cx);
    RectDraw.setTop(cy);
    RectDraw.setRight(cx + cw);
    RectDraw.setBottom(cy + ch);


    VScrollBar->setEnabled(false);
    HScrollBar->setEnabled(false);


    POINT point1;
    point1.x    = 0;
    point1.y    = 0;


    RECT rect;
    rect.left   = VarHorzPos;
    rect.right  = VarHorzPos + mapViewPort->width();
    rect.top    = VarVertPos;
    rect.bottom = VarVertPos + mapViewPort->height();


    // Проверить размеры буфера изображения
    if (mapGetImageWidth(hScreen) < mapViewPort->width() || mapGetImageHeight(hScreen) < mapViewPort->height())
    {
      mapChangeImageSizeEx(hScreen, 1, mapViewPort->width(), mapViewPort->height());
      mapDrawImageMap(hScreen, hMap, &rect, &point1);
    }


/*
    point1.x    = 0;
    point1.y    = 0;
    rect.left   = VarHorzPos;
    rect.right  = VarHorzPos + mapViewPort->width();
    rect.top    = VarVertPos;
    rect.bottom = VarVertPos + mapViewPort->height();
    mapDrawImageMap(hScreen, hMap, &rect, &point1);
*/
    RECT maprect;
    maprect.left     = RectDraw.left() + HScrollBar->value();
    maprect.top      = RectDraw.top() + VScrollBar->value();
    maprect.right    = RectDraw.right() + HScrollBar->value();
    maprect.bottom   = RectDraw.bottom() + VScrollBar->value();


    UpdateScreenImageBuffer(hScreen);
    // Отобразить принятый буфер
    p->drawImage(0, 0, ScreenImageBuffer);




    VScrollBar->setEnabled(true);
    HScrollBar->setEnabled(true);
}


void uxMapView::UpdateScreenImageBuffer(HIMAGE hScreen)
{
    long imageWidth = mapGetImageWidth(hScreen);
    long imageHeight = mapGetImageHeight(hScreen);


    if (ScreenImageBuffer.width() != imageWidth || ScreenImageBuffer.height() != imageHeight)
    {
        // Reallocate image
        ScreenImageBuffer = QImage(imageWidth, imageHeight, QImage::Format_RGB32);
    }


    if (ScreenImageBuffer.isNull() == false)
    {
        XIMAGEDESC ximage;
        ximage.Height = ScreenImageBuffer.height();
        ximage.Width = ScreenImageBuffer.width();
        ximage.RowSize = ScreenImageBuffer.bytesPerLine();
        ximage.Depth = ScreenImageBuffer.depth();
        ximage.CellSize = ScreenImageBuffer.bytesPerLine() / ScreenImageBuffer.width();
        ximage.Point = (char*)ScreenImageBuffer.bits();
        mapViewImageToXImage(hScreen, &ximage, 0, 0);
    }
}

 mapDrawImageMap(hScreen, hMap, &rect, &point1)