qimage.cpp

奇趣公司比较新的qt/emd版本

  \internal
*/
int QImage::devType() const
{
    return QInternal::Image;
}

/*!
   Returns the image as a QVariant.
*/
QImage::operator QVariant() const
{
    return QVariant(QVariant::Image, this);
}

/*!
    \internal

    If multiple images share common data, this image makes a copy of
    the data and detaches itself from the sharing mechanism, making
    sure that this image is the only one referring to the data.

    Nothing is done if there is just a single reference.

    \sa copy(), isDetached(), {Implicit Data Sharing}
*/
void QImage::detach()
{
    if (d) {
        if (qt_image_cleanup_hook_64 && d->ref == 1)
            qt_image_cleanup_hook_64(cacheKey());

        if (d->ref != 1 || d->ro_data)
            *this = copy();
        ++d->detach_no;
    }
}


/*!
    \fn QImage QImage::copy(int x, int y, int width, int height) const
    \overload

    The returned image is copied from the position (\a x, \a y) in
    this image, and will always have the given \a width and \a height.
    In areas beyond this image, pixels are set to 0.

*/

/*!
    \fn QImage QImage::copy(const QRect& rectangle) const

    Returns a sub-area of the image as a new image.

    The returned image is copied from the position (\a
    {rectangle}.x(), \a{rectangle}.y()) in this image, and will always
    have the size of the given \a rectangle.

    In areas beyond this image, pixels are set to 0. For 32-bit RGB
    images, this means black; for 32-bit ARGB images, this means
    transparent black; for 8-bit images, this means the color with
    index 0 in the color table which can be anything; for 1-bit
    images, this means Qt::color0.

    If the given \a rectangle is a null rectangle the entire image is
    copied.

    \sa QImage()
*/
QImage QImage::copy(const QRect& r) const
{
    if (!d)
        return QImage();

    if (r.isNull()) {
        QImage image(d->width, d->height, d->format);
        if (image.isNull())
            return image;

        // Qtopia Core can create images with non-default bpl
        // make sure we don't crash.
        if (image.d->nbytes != d->nbytes) {
            int bpl = image.bytesPerLine();
            for (int i = 0; i < height(); i++)
                memcpy(image.scanLine(i), scanLine(i), bpl);
        } else
            memcpy(image.bits(), bits(), d->nbytes);
        image.d->colortable = d->colortable;
        image.d->dpmx = d->dpmx;
        image.d->dpmy = d->dpmy;
        image.d->offset = d->offset;
        image.d->has_alpha_clut = d->has_alpha_clut;
#ifndef QT_NO_IMAGE_TEXT
        image.d->text = d->text;
#endif
        return image;
    }

    int x = r.x();
    int y = r.y();
    int w = r.width();
    int h = r.height();

    int dx = 0;
    int dy = 0;
    if (w <= 0 || h <= 0)
        return QImage();

    QImage image(w, h, d->format);
    if (image.isNull())
        return image;

    if (x < 0 || y < 0 || x + w > d->width || y + h > d->height) {
        // bitBlt will not cover entire image - clear it.
        image.fill(0);
        if (x < 0) {
            dx = -x;
            x = 0;
        }
        if (y < 0) {
            dy = -y;
            y = 0;
        }
    }

    image.d->colortable = d->colortable;

    int pixels_to_copy = qMax(w - dx, 0);
    if (x > d->width)
        pixels_to_copy = 0;
    else if (pixels_to_copy > d->width - x)
        pixels_to_copy = d->width - x;
    int lines_to_copy = qMax(h - dy, 0);
    if (y > d->height)
        lines_to_copy = 0;
    else if (lines_to_copy > d->height - y)
        lines_to_copy = d->height - y;

    bool byteAligned = true;
    if (d->format == Format_Mono || d->format == Format_MonoLSB)
        byteAligned = !(dx & 7) && !(x & 7) && !(pixels_to_copy & 7);

    if (byteAligned) {
        const uchar *src = d->data + ((x * d->depth) >> 3) + y * d->bytes_per_line;
        uchar *dest = image.d->data + ((dx * d->depth) >> 3) + dy * image.d->bytes_per_line;
        const int bytes_to_copy = (pixels_to_copy * d->depth) >> 3;
        for (int i = 0; i < lines_to_copy; ++i) {
            memcpy(dest, src, bytes_to_copy);
            src += d->bytes_per_line;
            dest += image.d->bytes_per_line;
        }
    } else if (d->format == Format_Mono) {
        const uchar *src = d->data + y * d->bytes_per_line;
        uchar *dest = image.d->data + dy * image.d->bytes_per_line;
        for (int i = 0; i < lines_to_copy; ++i) {
            for (int j = 0; j < pixels_to_copy; ++j) {
                if (src[(x + j) >> 3] & (0x80 >> ((x + j) & 7)))
                    dest[(dx + j) >> 3] |= (0x80 >> ((dx + j) & 7));
                else
                    dest[(dx + j) >> 3] &= ~(0x80 >> ((dx + j) & 7));
            }
            src += d->bytes_per_line;
            dest += image.d->bytes_per_line;
        }
    } else { // Format_MonoLSB
        Q_ASSERT(d->format == Format_MonoLSB);
        const uchar *src = d->data + y * d->bytes_per_line;
        uchar *dest = image.d->data + dy * image.d->bytes_per_line;
        for (int i = 0; i < lines_to_copy; ++i) {
            for (int j = 0; j < pixels_to_copy; ++j) {
                if (src[(x + j) >> 3] & (0x1 << ((x + j) & 7)))
                    dest[(dx + j) >> 3] |= (0x1 << ((dx + j) & 7));
                else
                    dest[(dx + j) >> 3] &= ~(0x1 << ((dx + j) & 7));
            }
            src += d->bytes_per_line;
            dest += image.d->bytes_per_line;
        }
    }

    image.d->dpmx = dotsPerMeterX();
    image.d->dpmy = dotsPerMeterY();
    image.d->offset = offset();
    image.d->has_alpha_clut = d->has_alpha_clut;
#ifndef QT_NO_IMAGE_TEXT
    image.d->text = d->text;
#endif
    return image;
}


/*!
    \fn bool QImage::isNull() const

    Returns true if it is a null image, otherwise returns false.

    A null image has all parameters set to zero and no allocated data.
*/
bool QImage::isNull() const
{
    return !d;
}

/*!
    \fn int QImage::width() const

    Returns the width of the image.

    \sa {QImage#Image Information}{Image Information}
*/
int QImage::width() const
{
    return d ? d->width : 0;
}

/*!
    \fn int QImage::height() const

    Returns the height of the image.

    \sa {QImage#Image Information}{Image Information}
*/
int QImage::height() const
{
    return d ? d->height : 0;
}

/*!
    \fn QSize QImage::size() const

    Returns the size of the image, i.e. its width() and height().

    \sa {QImage#Image Information}{Image Information}
*/
QSize QImage::size() const
{
    return d ? QSize(d->width, d->height) : QSize();
}

/*!
    \fn QRect QImage::rect() const

    Returns the enclosing rectangle (0, 0, width(), height()) of the
    image.

    \sa {QImage#Image Information}{Image Information}
*/
QRect QImage::rect() const
{
    return d ? QRect(0, 0, d->width, d->height) : QRect();
}

/*!
    Returns the depth of the image.

    The image depth is the number of bits used to encode a single
    pixel, also called bits per pixel (bpp) or bit planes of an image.

    The supported depths are 1, 8 and 32.

    \sa convertToFormat(), {QImage#Image Formats}{Image Formats},
    {QImage#Image Information}{Image Information}

*/
int QImage::depth() const
{
    return d ? d->depth : 0;
}

/*!
    \fn int QImage::numColors() const

    Returns the size of the color table for the image.

    Notice that numColors() returns 0 for 32-bpp images because these
    images do not use color tables, but instead encode pixel values as
    ARGB quadruplets.

    \sa setNumColors(), {QImage#Image Information}{Image Information}
*/
int QImage::numColors() const
{
    return d ? d->colortable.size() : 0;
}


#ifdef QT3_SUPPORT
/*!
    \fn QImage::Endian QImage::bitOrder() const

    Returns the bit order for the image. If it is a 1-bpp image, this
    function returns either QImage::BigEndian or
    QImage::LittleEndian. Otherwise, this function returns
    QImage::IgnoreEndian.

    Use the format() function instead for the monochrome formats. For
    non-monochrome formats the bit order is irrelevant.
*/

/*!
    Returns a pointer to the scanline pointer table. This is the
    beginning of the data block for the image.

    Use the bits() or scanLine() function instead.
*/
uchar **QImage::jumpTable()
{
    if (!d)
        return 0;
    detach();

    if (!d->jumptable) {
        d->jumptable = (uchar **)malloc(d->height*sizeof(uchar *));
        uchar *data = d->data;
        int height = d->height;
        uchar **p = d->jumptable;
        while (height--) {
            *p++ = data;
            data += d->bytes_per_line;
        }
    }
    return d->jumptable;
}

/*!
    \overload
*/
const uchar * const *QImage::jumpTable() const
{
    if (!d)
        return 0;
    if (!d->jumptable) {
        d->jumptable = (uchar **)malloc(d->height*sizeof(uchar *));
        uchar *data = d->data;
        int height = d->height;
        uchar **p = d->jumptable;
        while (height--) {
            *p++ = data;
            data += d->bytes_per_line;
        }
    }
    return d->jumptable;
}
#endif

/*!
    Sets the color table used to translate color indexes to QRgb
    values, to the specified \a colors.

    \sa colorTable(), setColor(), {QImage#Image Transformations}{Image
    Transformations}
*/
void QImage::setColorTable(const QVector<QRgb> colors)
{
    if (!d)
        return;
    detach();
    d->colortable = colors;
    d->has_alpha_clut = false;
    for (int i = 0; i < d->colortable.size(); ++i)
        d->has_alpha_clut |= (qAlpha(d->colortable.at(i)) != 255);
}

/*!
    Returns a list of the colors contained in the image's color table,
    or an empty list if the image does not have a color table

    \sa setColorTable(), numColors(), color()
*/
QVector<QRgb> QImage::colorTable() const
{
    return d ? d->colortable : QVector<QRgb>();
}


/*!
    Returns the number of bytes occupied by the image data.

    \sa bytesPerLine(), bits(), {QImage#Image Information}{Image
    Information}
*/
int QImage::numBytes() const
{
    return d ? d->nbytes : 0;
}

/*!
    Returns the number of bytes per image scanline.

    This is equivalent to numBytes()/ height().

    \sa scanLine()
*/
int QImage::bytesPerLine() const
{
    return (d && d->height) ? d->nbytes / d->height : 0;
}


/*!
    Returns the color in the color table at index \a i. The first
    color is at index 0.

    The colors in an image's color table are specified as ARGB
    quadruplets (QRgb). Use the qAlpha(), qRed(), qGreen(), and
    qBlue() functions to get the color value components.

    \sa setColor(), pixelIndex(), {QImage#Pixel Manipulation}{Pixel
    Manipulation}
*/
QRgb QImage::color(int i) const
{
    Q_ASSERT(i < numColors());
    return d ? d->colortable.at(i) : QRgb(uint(-1));
}

/*!
    \fn void QImage::setColor(int index, QRgb colorValue)