qpixmap_x11.cpp

奇趣公司比较新的qt/emd版本

                        ++p;
                    }
                    )
                    break;
            case BPP16_555:
                CYCLE(
                    quint16* dst16 = (quint16*)dst;
                    for (int x=0; x<w; x++) {
                        *dst16++ = ((*p >> 9) & 0x7c00)
                                   | ((*p >> 6) & 0x3e0)
                                   | ((*p >> 3) & 0x1f);
                        ++p;
                    }
                    )
                    break;
            case BPP16_MSB:                        // 16 bit MSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        GET_PIXEL
                            *dst++ = (pixel >> 8);
                        *dst++ = pixel;
                    }
                    )
                    break;
            case BPP16_LSB:                        // 16 bit LSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        GET_PIXEL
                            *dst++ = pixel;
                        *dst++ = pixel >> 8;
                    }
                    )
                    break;
            case BPP24_888:                        // 24 bit MSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        *dst++ = qRed  (*p);
                        *dst++ = qGreen(*p);
                        *dst++ = qBlue (*p++);
                    }
                    )
                    break;
            case BPP24_MSB:                        // 24 bit MSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        GET_PIXEL
                            *dst++ = pixel >> 16;
                        *dst++ = pixel >> 8;
                        *dst++ = pixel;
                    }
                    )
                    break;
            case BPP24_LSB:                        // 24 bit LSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        GET_PIXEL
                            *dst++ = pixel;
                        *dst++ = pixel >> 8;
                        *dst++ = pixel >> 16;
                    }
                    )
                    break;
            case BPP32_8888:
                CYCLE(
                    memcpy(dst, p, w * 4);
                    )
                    break;
            case BPP32_MSB:                        // 32 bit MSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        GET_PIXEL
                            *dst++ = pixel >> 24;
                        *dst++ = pixel >> 16;
                        *dst++ = pixel >> 8;
                        *dst++ = pixel;
                    }
                    )
                    break;
            case BPP32_LSB:                        // 32 bit LSB
                CYCLE(
                    for (int x=0; x<w; x++) {
                        GET_PIXEL
                            *dst++ = pixel;
                        *dst++ = pixel >> 8;
                        *dst++ = pixel >> 16;
                        *dst++ = pixel >> 24;
                    }
                    )
                    break;
            default:
                qFatal("Logic error 2");
            }
        }
        xi->data = (char *)newbits;
    }

    if (d == 8 && !trucol) {                        // 8 bit pixmap
        int  pop[256];                                // pixel popularity

        if (image.numColors() == 0)
            image.setNumColors(1);

        const QImage &cimage = image;
        memset(pop, 0, sizeof(int)*256);        // reset popularity array
        for (int i = 0; i < h; i++) {                        // for each scanline...
            const uchar* p = cimage.scanLine(i);
            const uchar *end = p + w;
            while (p < end)                        // compute popularity
                pop[*p++]++;
        }

        newbits = (uchar *)malloc(nbytes);        // copy image into newbits
        Q_CHECK_PTR(newbits);
        if (!newbits)                                // no memory
            return QPixmap();
        uchar* p = newbits;
        memcpy(p, cimage.bits(), nbytes);        // copy image data into newbits

        /*
         * The code below picks the most important colors. It is based on the
         * diversity algorithm, implemented in XV 3.10. XV is (C) by John Bradley.
         */

        struct PIX {                                // pixel sort element
            uchar r,g,b,n;                        // color + pad
            int          use;                                // popularity
            int          index;                        // index in colormap
            int          mindist;
        };
        int ncols = 0;
        for (int i=0; i< cimage.numColors(); i++) { // compute number of colors
            if (pop[i] > 0)
                ncols++;
        }
        for (int i = cimage.numColors(); i < 256; i++) // ignore out-of-range pixels
            pop[i] = 0;

        // works since we make sure above to have at least
        // one color in the image
        if (ncols == 0)
            ncols = 1;

        PIX pixarr[256];                        // pixel array
        PIX pixarr_sorted[256];                        // pixel array (sorted)
        memset(pixarr, 0, ncols*sizeof(PIX));
        PIX *px                   = &pixarr[0];
        int  maxpop = 0;
        int  maxpix = 0;
        uint j = 0;
        QVector<QRgb> ctable = cimage.colorTable();
        for (int i = 0; i < 256; i++) {                // init pixel array
            if (pop[i] > 0) {
                px->r = qRed  (ctable[i]);
                px->g = qGreen(ctable[i]);
                px->b = qBlue (ctable[i]);
                px->n = 0;
                px->use = pop[i];
                if (pop[i] > maxpop) {        // select most popular entry
                    maxpop = pop[i];
                    maxpix = j;
                }
                px->index = i;
                px->mindist = 1000000;
                px++;
                j++;
            }
        }
        pixarr_sorted[0] = pixarr[maxpix];
        pixarr[maxpix].use = 0;

        for (int i = 1; i < ncols; i++) {                // sort pixels
            int minpix = -1, mindist = -1;
            px = &pixarr_sorted[i-1];
            int r = px->r;
            int g = px->g;
            int b = px->b;
            int dist;
            if ((i & 1) || i<10) {                // sort on max distance
                for (int j=0; j<ncols; j++) {
                    px = &pixarr[j];
                    if (px->use) {
                        dist = (px->r - r)*(px->r - r) +
                               (px->g - g)*(px->g - g) +
                               (px->b - b)*(px->b - b);
                        if (px->mindist > dist)
                            px->mindist = dist;
                        if (px->mindist > mindist) {
                            mindist = px->mindist;
                            minpix = j;
                        }
                    }
                }
            } else {                                // sort on max popularity
                for (int j=0; j<ncols; j++) {
                    px = &pixarr[j];
                    if (px->use) {
                        dist = (px->r - r)*(px->r - r) +
                               (px->g - g)*(px->g - g) +
                               (px->b - b)*(px->b - b);
                        if (px->mindist > dist)
                            px->mindist = dist;
                        if (px->use > mindist) {
                            mindist = px->use;
                            minpix = j;
                        }
                    }
                }
            }
            pixarr_sorted[i] = pixarr[minpix];
            pixarr[minpix].use = 0;
        }

        QColormap cmap = QColormap::instance(pixmap.data->xinfo.screen());
        uint pix[256];                                // pixel translation table
        px = &pixarr_sorted[0];
        for (int i = 0; i < ncols; i++) {                // allocate colors
            QColor c(px->r, px->g, px->b);
            pix[px->index] = cmap.pixel(c);
            px++;
        }

        p = newbits;
        for (int i = 0; i < nbytes; i++) {                // translate pixels
            *p = pix[*p];
            p++;
        }
    }

    if (!xi) {                                // X image not created
        xi = XCreateImage(dpy, visual, dd, ZPixmap, 0, 0, w, h, 32, 0);
        if (xi->bits_per_pixel == 16) {        // convert 8 bpp ==> 16 bpp
            ushort *p2;
            int            p2inc = xi->bytes_per_line/sizeof(ushort);
            ushort *newerbits = (ushort *)malloc(xi->bytes_per_line * h);
            Q_CHECK_PTR(newerbits);
            if (!newerbits)                                // no memory
                return QPixmap();
            uchar* p = newbits;
            for (int y = 0; y < h; y++) {                // OOPS: Do right byte order!!
                p2 = newerbits + p2inc*y;
                for (int x = 0; x < w; x++)
                    *p2++ = *p++;
            }
            free(newbits);
            newbits = (uchar *)newerbits;
        } else if (xi->bits_per_pixel != 8) {
            qWarning("QPixmap::fromImage: Display not supported "
                     "(bpp=%d)", xi->bits_per_pixel);
        }
        xi->data = (char *)newbits;
    }

    pixmap.data->hd = (Qt::HANDLE)XCreatePixmap(X11->display,
                                                RootWindow(X11->display, pixmap.data->xinfo.screen()),
                                                w, h, dd);

    GC gc = XCreateGC(dpy, pixmap.data->hd, 0, 0);
    XPutImage(dpy, pixmap.data->hd, gc, xi, 0, 0, 0, 0, w, h);
    XFreeGC(dpy, gc);

    qSafeXDestroyImage(xi);
    pixmap.data->w = w;
    pixmap.data->h = h;
    pixmap.data->d = dd;

#ifndef QT_NO_XRENDER
    if (X11->use_xrender) {
        XRenderPictFormat *format = pixmap.data->d == 1
                                    ? XRenderFindStandardFormat(X11->display, PictStandardA1)
                                    : XRenderFindVisualFormat(X11->display, (Visual *) pixmap.data->xinfo.visual());
        pixmap.data->picture = XRenderCreatePicture(X11->display, pixmap.data->hd, format, 0, 0);
    }
#endif

    if (image.hasAlphaChannel()) {
        QBitmap m = QBitmap::fromImage(image.createAlphaMask(flags));
        pixmap.setMask(m);
    }

    return pixmap;
}


/*!
    \fn QPixmap QPixmap::grabWindow(WId window, int x, int y, int
    width, int height)

    Creates and returns a pixmap constructed by grabbing the contents
    of the given \a window restricted by QRect(\a x, \a y, \a width,
    \a height).

    The arguments (\a{x}, \a{y}) specify the offset in the window,
    whereas (\a{width}, \a{height}) specify the area to be copied.  If
    \a width is negative, the function copies everything to the right
    border of the window. If \a height is negative, the function
    copies everything to the bottom of the window.

    The window system identifier (\c WId) can be retrieved using the
    QWidget::winId() function. The rationale for using a window
    identifier and not a QWidget, is to enable grabbing of windows
    that are not part of the application, window system frames, and so
    on.

    The grabWindow() function grabs pixels from the screen, not from
    the window, i.e. if there is another window partially or entirely
    over the one you grab, you get pixels from the overlying window,
    too. The mouse cursor is generally not grabbed.

    Note on X11that if the given \a window doesn't have the same depth
    as the root window, and another window partially or entirely
    obscures the one you grab, you will \e not get pixels from the
    overlying window.  The contents of the obscured areas in the
    pixmap will be undefined and uninitialized.

    \warning In general, grabbing an area outside the screen is not
    safe. This depends on the underlying window system.

    \sa grabWidget(), {Screenshot Example}
*/

QPixmap QPixmap::grabWindow(WId window, int x, int y, int w, int h)
{
    if (w == 0 || h == 0)
        return QPixmap();

    Display *dpy = X11->display;
    XWindowAttributes window_attr;
    if (! XGetWindowAttributes(dpy, window, &window_attr))
        return QPixmap();

    if (w < 0)
        w = window_attr.width - x;
    if (h < 0)
        h = window_attr.height - y;

    // determine the screen
    int scr;
    for (scr = 0; scr < ScreenCount(dpy); ++scr) {
        if (window_attr.root == RootWindow(dpy, scr))        // found it
            break;
    }
    if (scr >= ScreenCount(dpy))                // sanity check
        return QPixmap();


    // get the depth of the root window
    XWindowAttributes root_attr;
    if (! XGetWindowAttributes(dpy, window_attr.root, &root_attr))
        return QPixmap();

    if (window_attr.depth == root_attr.depth) {
        // if the depth of the specified window and the root window are the
        // same, grab pixels from the root window (so that we get the any
        // overlapping windows and window manager frames)

        // map x and y to the root window
        WId unused;
        if (! XTranslateCoordinates(dpy, window, window_attr.root, x, y,
                                    &x, &y, &unused))
            return QPixmap();

        window = window_attr.root;