qscreen_qws.cpp

奇趣公司比较新的qt/emd版本

    qrgb::len_green = len_green;
    qrgb::len_blue = len_blue;
    qrgb::len_alpha = len_alpha;
    qrgb::off_red = off_red;
    qrgb::off_green = off_green;
    qrgb::off_blue = off_blue;
    qrgb::off_alpha = off_alpha;
    screen->d_ptr->blit = blit_rgb;
    if (bpp == 16)
        screen->d_ptr->solidFill = solidFill_rgb_16bpp;
    else if (bpp == 32)
        screen->d_ptr->solidFill = solidFill_rgb_32bpp;
}

#endif // QT_QWS_DEPTH_GENERIC

void qt_blit_setup(QScreen *screen, const QImage &image,
                   const QPoint &topLeft, const QRegion &region)
{
    switch (screen->depth()) {
#ifdef QT_QWS_DEPTH_32
    case 32:
        screen->d_ptr->blit = blit_32;
        break;
#endif
#ifdef QT_QWS_DEPTH_24
    case 24:
        screen->d_ptr->blit = blit_template<quint24, quint32>;
        break;
#endif
#ifdef QT_QWS_DEPTH_18
    case 18:
        screen->d_ptr->blit = blit_template<quint18, quint32>;
        break;
#endif
#ifdef QT_QWS_DEPTH_16
    case 16:
#if Q_BYTE_ORDER == Q_BIG_ENDIAN
        if (screen->d_ptr->fb_is_littleEndian)
            screen->d_ptr->blit = blit_16_bigToLittleEndian;
        else
#endif
            screen->d_ptr->blit = blit_16;
        break;
#endif
#ifdef QT_QWS_DEPTH_8
    case 8:
        screen->d_ptr->blit = blit_8;
        break;
#endif
#ifdef QT_QWS_DEPTH_4
    case 4:
        screen->d_ptr->blit = blit_4;
        break;
#endif
#ifdef QT_QWS_DEPTH_1
    case 1:
        screen->d_ptr->blit = blit_1;
        break;
#endif
    default:
        qFatal("blit_setup(): Screen depth %d not supported!",
               screen->depth());
        screen->d_ptr->blit = 0;
        break;
    }
    screen->d_ptr->blit(screen, image, topLeft, region);
}

QScreenPrivate::QScreenPrivate(QScreen *parent)
    :  pixelFormat(QImage::Format_Invalid), q_ptr(parent)
{
    solidFill = qt_solidFill_setup;
    blit = qt_blit_setup;
#if Q_BYTE_ORDER == Q_BIG_ENDIAN
    fb_is_littleEndian = false;
#endif
}

QImage::Format QScreenPrivate::preferredImageFormat() const
{

    if (q_ptr->depth() <= 16)
        return QImage::Format_RGB16;
    else
        return pixelFormat;
}

/*!
    \class QScreen
    \ingroup qws

    \brief The QScreen class is a base class for screen drivers in
    Qtopia Core.

    Note that this class is only available in \l {Qtopia Core}.

    \l {Qtopia Core} provides ready-made drivers for several screen
    protocols, see the \l {Qtopia Core Display Management}{display
    management} documentation for details. Custom screen drivers can
    be implemented by subclassing the QScreen class and creating a
    screen driver plugin (derived from QScreenDriverPlugin). \l
    {Qtopia Core}'s implementation of the QScreenDriverFactory class
    will automatically detect the plugin, and load the driver into the
    server application at runtime using Qt's \l {How to Create Qt
    Plugins}{plugin system}.

    When rendering, \l {Qtopia Core}'s default behavior is for each
    client to render its widgets as well as its decorations into
    memory, while the server copies the memory content to the device's
    framebuffer using the screen driver. See the \l {Qtopia Core
    Architecture} overview for details (note that it is possible for
    the clients to manipulate and control the underlying hardware
    directly as well).

    Starting with \l {Qtopia Core} 4.2, it is also possible to add an
    accelerated graphics driver to take advantage of available
    hardware resources. See the \l {Adding an Accelerated Graphics
    Driver in Qtopia Core} documentation for details.

    \tableofcontents

    \section1 Framebuffer Management

    When a \l {Qtopia Core} application starts running, it calls the
    screen driver's connect() function to map into the framebuffer and
    the accelerated drivers that the graphics card control
    registers. Note that if the application acts as the server, the
    application will call the initDevice() function prior to the
    connect() function, to initialize the framebuffer. The
    initDevice() function can be reimplemented to set up the graphics
    card.

    Likewise, just before a \l {Qtopia Core} application exits, it
    calls the screen driver's disconnect() function. The server
    application will in addition call the shutdownDevice() function
    before it calls disconnect(). Note that the default implementation
    of the shutdownDevice() function only hides the mouse cursor.

    QScreen also provides the save() and restore() functions, making
    it possible to save and restore the state of the graphics
    card. Note that the default implementations do nothing. Hardware
    screen drivers should reimplement these functions to save (and
    restore) its registers, enabling switching between virtual
    consoles.

    In addition, you can use the base() function to retrieve a pointer
    to the beginning of the framebuffer, and the region() function to
    retrieve the framebuffer's region. Use the onCard() function to
    determine whether the framebuffer is within the graphics card's
    memory, and the totalSize() function to determine the size of the
    available graphics card memory (including the screen). Finally,
    you can use the offset() function to retrieve the offset between
    the framebuffer's coordinates and the application's coordinate
    system.

    \section1 Palette Management

    QScreen provides several functions to retrieve information about
    the color palette: The clut() function returns a pointer to the
    color lookup table (i.e. its color palette). Use the numCols()
    function to determine the number of entries in this table, and the
    alloc() function to retrieve the palette index of the color that
    is the closest match to a given RGB value.

    To determine if the screen driver supports a given color depth,
    use the supportsDepth() function that returns true of the
    specified depth is supported.

    \section1 Drawing on Screen

    When a screen update is required, the \l {Qtopia Core} server runs
    through all the top-level windows that intersect with the region
    that is about to be updated, and ensures that the associated
    clients have updated their memory buffer. Then the server calls
    the exposeRegion() function that composes the window surfaces and
    copies the content of memory to screen by calling the blit() and
    solidFill() functions.

    The blit() function copies a given region in a given image to a
    specified point using device coordinates, while the solidFill()
    function fills the given region of the screen with the specified
    color. Note that normally there is no need to call either of these
    functions explicitly.

    In addition, QScreen provides the blank() function that can be
    reimplemented to prevent any contents from being displayed on the
    screen, and the setDirty() function that can be reimplemented to
    indicate that a given rectangle of the screen has been
    altered. Note that the default implementations of these functions
    do nothing.

    Reimplement the the mapFromDevice() and mapToDevice() functions to
    map objects from the framebuffer coordinate system to the
    coordinate space used by the application, and vice versa. Be aware
    that the default implementations simply return the given objects
    as they are.

    \section1 Properties

    \table
    \header \o Property \o Functions
    \row
    \o Size
    \o

    The size of the screen can be retrieved using the screenSize()
    function. The size is returned in bytes.

    The framebuffer's logical width and height can be retrieved using
    width() and height(), respectively. These functions return values
    are given in pixels. Alternatively, the physicalWidth() and
    physicalHeight() function returns the same metrics in
    millimeters. QScreen also provides the deviceWidth() and
    deviceHeight() functions returning the physical width and height
    of the device in pixels. Note that the latter metrics can differ
    from the ones used if the display is centered within the
    framebuffer.

    \row
    \o Resolution
    \o

    Reimplement the setMode() function to be able to set the
    framebuffer to a new resolution (width and height) and bit depth.

    The current depth of the framebuffer can be always be retrieved
    using the depth() function. Use the pixmapDepth() function to
    obtain the preferred depth for pixmaps.

    \row
    \o Pixmap Alignment
    \o

    Use the pixmapOffsetAlignment() function to retrieve the value to
    which the start address of pixmaps held in the graphics card's
    memory, should be aligned.

    Use the pixmapLinestepAlignment() to retrieve the value to which
    the \e {individual scanlines} of pixmaps should be aligned.

    \row
    \o Image Display
    \o

    The isInterlaced() function tells whether the screen is displaying
    images progressively, and the isTransformed() function whether it
    is rotated. The transformOrientation() function can be
    reimplemented to return the current rotation.

    \row
    \o Scanlines
    \o

    Use the linestep() function to retrieve the length of each
    scanline of the framebuffer.

    \row
    \o Pixel Type
    \o

    The pixelType() function returns the screen's pixel storage format as
    described by the PixelType enum.

    \endtable

    \sa QScreenDriverPlugin, QScreenDriverFactory, {Qtopia Core Display
    Management}
*/

/*!
    \enum QScreen::PixelType

    This enum describes the pixel storage format of the screen,
    i.e. the order of the red (R), green (G) and blue (B) components
    of a pixel.

    \value NormalPixel Red-green-blue (RGB)
    \value BGRPixel Blue-green-red (BGR)

    \sa pixelType()
*/

/*!
    \fn static QScreen* QScreen::instance()

    Returns a pointer to the application's QScreen instance.

    If this screen consists of several subscreens, operations to the
    returned instance will affect all its subscreens. Use the
    subscreens() function to retrieve access to a particular
    subscreen.

    \sa subScreens(), subScreenIndexAt()
*/

/*!
    \fn QList<QScreen*> QScreen::subScreens() const
    \since 4.2

    Returns a list of this screen's subscreens. Use the
    subScreenIndexAt() function to retrieve the index of a screen at a
    given position.

    Note that if \e this screen consists of several subscreens,
    operations to \e this instance will affect all subscreens by
    default.

    \sa instance(), subScreenIndexAt()
*/

/*!
    \fn int QScreen::physicalWidth() const
    \since 4.2

    Returns the physical width of the screen in millimeters.

    \sa width(), deviceWidth(), physicalHeight()
*/

/*!
    \fn int QScreen::physicalHeight() const
    \since 4.2

    Returns the physical height of the screen in millimeters.

    \sa height(), deviceHeight(), physicalWidth()
*/

/*!
    \fn virtual bool QScreen::initDevice() = 0

    This function is called by the \l {Qtopia Core} server to
    initialize the framebuffer. Note that a server application will call the
    connect() function prior to this function.

    Implement this function to make accelerated drivers set up the
    graphics card. Return true to indicate success and false to indicate
    failure.

    \sa shutdownDevice(), connect()
*/

/*!
    \fn virtual bool QScreen::connect(const QString &displaySpec) = 0

    This function is called by every \l {Qtopia Core} application on
    startup, and must be implemented to map in the framebuffer and the
    accelerated drivers that the graphics card control registers.
    Note that it is called \e before the initDevice() function.

    Ensure that the function returns true if a connection to the
    screen device can be made; otherwise return false.

    The \a displaySpec argument is passed by the QWS_DISPLAY
    environment variable or the -display command line parameter, and
    has the following syntax:

    \code
        [screen driver][:driver specific options][:display number]
    \endcode

    For example, to use the mach64 driver on fb1 as display 2:

    \code
        Mach64:/dev/fb1:2
    \endcode

    See \l {Qtopia Core Display Management} for more details.

    \sa disconnect(), initDevice(), {Running Qtopia Core Applications}
*/

/*!
    \fn QScreen::disconnect()

    This function is called by every \l {Qtopia Core} application
    before exiting, and must be implemented to unmap the
    framebuffer. Note that a server application will call the
    shutdownDevice() function prior to this function.

    \sa connect(), shutdownDevice(), {Running Qtopia Core
    Applications}
*/

/*!
    \fn QScreen::setMode(int width, int height, int depth)

    Implement this function to reset the framebuffer's resolution (\a
    width and \a height) and bit \a depth.

    After the resolution has been set, existing paint engines will be
    invalid and the framebuffer should be completely redrawn. In a
    multiple-process situation, all other applications must be
    notified to reset their mode and update themselves accordingly.
*/

/*!
    \fn QScreen::blank(bool on)

    Prevents the screen driver form displaying any content on the
    screen.

    Note that the default implementation does nothing.

    Reimplement this function to prevent the screen driver from
    displaying any contents on the screen if \a on is true; otherwise
    the contents is expected to be shown.

    \sa blit()
*/

/*!
    \fn int QScreen::pixmapOffsetAlignment()

    Returns the value (in bits) to which the start address of pixmaps
    held in the graphics card's memory, should be aligned.

    Note that the default implementation returns 64; reimplement this
    function to override the return value, e.g., when implementing an
    accelerated driver (see the \l {Adding an Accelerated Graphics
    Driver in Qtopia Core}{Adding an Accelerated Graphics Driver}
    documentation for details).

    \sa pixmapLinestepAlignment()
*/

/*!
    \fn int QScreen::pixmapLinestepAlignment()

    Returns the value (in bits) to which individual scanlines of
    pixmaps held in the graphics card's memory, should be
    aligned.

    Note that the default implementation returns 64; reimplement this
    function to override the return value, e.g., when implementing an
    accelerated driver (see the \l {Adding an Accelerated Graphics
    Driver in Qtopia Core}{Adding an Accelerated Graphics Driver}
    documentation for details).

    \sa pixmapOffsetAlignment()
*/

/*!
    \fn QScreen::width() const