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#include "qclsampler.h"
#include "qclcontext.h"

QT_BEGIN_NAMESPACE

/*!
    \class QCLSampler
    \brief The QCLSampler class represents an OpenCL sampler object.
    \since 4.7
    \ingroup opencl
*/

class QCLSamplerPrivate
{
public:
    QCLSamplerPrivate()
        : id(0)
        , context(0)
        , normalizedCoordinates(false)
        , addressingMode(QCLSampler::ClampToEdge)
        , filterMode(QCLSampler::Linear)
    {
    }
    QCLSamplerPrivate(const QCLSamplerPrivate *other)
        : id(other->id)
        , context(other->context)
        , normalizedCoordinates(other->normalizedCoordinates)
        , addressingMode(other->addressingMode)
        , filterMode(other->filterMode)
    {
        if (id)
            clRetainSampler(id);
    }

    void assign(const QCLSamplerPrivate *other)
    {
        if (id)
            clReleaseSampler(id);
        id = other->id;
        if (id)
            clRetainSampler(id);
        context = other->context;
        normalizedCoordinates = other->normalizedCoordinates;
        addressingMode = other->addressingMode;
        filterMode = other->filterMode;
    }

    void detach()
    {
        if (id) {
            clReleaseSampler(id);
            id = 0;
        }
    }

    mutable cl_sampler id;
    mutable QCLContext *context;
    bool normalizedCoordinates;
    QCLSampler::AddressingMode addressingMode;
    QCLSampler::FilterMode filterMode;
};

/*!
    Constructs a default OpenCL sampler object, with unnormalized
    co-ordinates, clamp-to-edge addressing, and linear filtering.
*/
QCLSampler::QCLSampler()
    : d_ptr(new QCLSamplerPrivate())
{
}

/*!
    Constructs an OpenCL sampler object from the native identifier \a id.
    This class takes over ownership of \a id and will release it in
    the destructor.  The sampler \a id will be associated with \a context.
*/
QCLSampler::QCLSampler(QCLContext *context, cl_sampler id)
    : d_ptr(new QCLSamplerPrivate())
{
    Q_D(QCLSampler);
    d->id = id;

    // Read the current settings from the OpenCL implementation.
    if (id) {
        cl_bool normalized = CL_FALSE;
        cl_addressing_mode addressing = CL_ADDRESS_CLAMP_TO_EDGE;
        cl_filter_mode filter = CL_FILTER_LINEAR;
        clGetSamplerInfo(id, CL_SAMPLER_NORMALIZED_COORDS,
                         sizeof(normalized), &normalized, 0);
        clGetSamplerInfo(id, CL_SAMPLER_ADDRESSING_MODE,
                         sizeof(addressing), &addressing, 0);
        clGetSamplerInfo(id, CL_SAMPLER_FILTER_MODE,
                         sizeof(filter), &filter, 0);
        d->normalizedCoordinates = (normalized != CL_FALSE);
        d->addressingMode = QCLSampler::AddressingMode(addressing);
        d->filterMode = QCLSampler::FilterMode(filter);
        d->context = context;
    }
}

/*!
    Constructs a copy of \a other.  The \c{clRetainSampler()} function
    will be called to update the reference count on samplerId().
*/
QCLSampler::QCLSampler(const QCLSampler &other)
    : d_ptr(new QCLSamplerPrivate(other.d_ptr.data()))
{
}

/*!
    Releases this OpenCL sampler object by calling \c{clReleaseSampler()}.
*/
QCLSampler::~QCLSampler()
{
    Q_D(QCLSampler);
    d->detach();
}

/*!
    Assigns \a other to this OpenCL sampler object.  The current samplerId()
    will be released with \c{clReleaseSampler()}, and the new samplerId()
    will be retained with \c{clRetainSampler()}.
*/
QCLSampler &QCLSampler::operator=(const QCLSampler &other)
{
    Q_D(QCLSampler);
    if (d != other.d_ptr.data())
        d->assign(other.d_ptr.data());
    return *this;
}

/*!
    \enum QCLSampler::AddressingMode
    This enum specifies how to handle out-of-range image co-ordinates
    when reading from an image in OpenCL.

    \value None No special handling of out-of-range co-ordinates.
    \value ClampToEdge Out-of-range requests clamp to the edge pixel value.
    \value Clamp Out-of-range requests clamp to the image extents.
    \value Repeat Repeats the image in a cycle.
*/

/*!
    \enum QCLSampler::FilterMode
    This enum defines the type of filter to apply when reading from
    an image in OpenCL.

    \value Nearest Use the color of the nearest pixel.
    \value Linear Interpolate linearly between pixel colors to generate
    intermediate pixel colors.
*/

/*!
    Returns true if this sampler is using normalized co-ordinates;
    false otherwise.  The default value is false.

    \sa setNormalizedCoordinates()
*/
bool QCLSampler::normalizedCoordinates() const
{
    Q_D(const QCLSampler);
    return d->normalizedCoordinates;
}

/*!
    Enables or disables normalized co-ordinates according to \a value.

    This function will release samplerId() if \a value is different
    than the previous value.

    \sa normalizedCoordinates()
*/
void QCLSampler::setNormalizedCoordinates(bool value)
{
    Q_D(QCLSampler);
    if (d->normalizedCoordinates != value) {
        d->detach();
        d->normalizedCoordinates = value;
    }
}

/*!
    Returns the addressing mode for out-of-range co-ordinates
    when reading from an image in OpenCL.  The default value is
    ClampToEdge.

    \sa setAddressingMode()
*/
QCLSampler::AddressingMode QCLSampler::addressingMode() const
{
    Q_D(const QCLSampler);
    return d->addressingMode;
}

/*!
    Sets the addressing mode for out-of-range co-ordinates
    when reading from an image in OpenCL to \a value.

    This function will release samplerId() if \a value is different
    than the previous value.

    \sa addressingMode()
*/
void QCLSampler::setAddressingMode(QCLSampler::AddressingMode value)
{
    Q_D(QCLSampler);
    if (d->addressingMode != value) {
        d->detach();
        d->addressingMode = value;
    }
}

/*!
    Returns the type of filter to apply when reading from an image
    in OpenCL.  The default value is Linear.

    \sa setFilterMode()
*/
QCLSampler::FilterMode QCLSampler::filterMode() const
{
    Q_D(const QCLSampler);
    return d->filterMode;
}

/*!
    Sets the type of filter to apply when reading from an image
    in OpenCL to \a value.

    This function will release samplerId() if \a value is different
    than the previous value.

    \sa filterMode()
*/
void QCLSampler::setFilterMode(QCLSampler::FilterMode value)
{
    Q_D(QCLSampler);
    if (d->filterMode != value) {
        d->detach();
        d->filterMode = value;
    }
}

/*!
    Returns the native OpenCL identifier for this sampler; or 0 if
    the identifier has not been created.

    The identifier is created when the sampler is set on a kernel
    as an argument with QCLKernel::setArg().
*/
cl_sampler QCLSampler::samplerId() const
{
    Q_D(const QCLSampler);
    return d->id;
}

/*!
    Returns the OpenCL context that this sampler was created for;
    null if not yet created within a context.
*/
QCLContext *QCLSampler::context() const
{
    Q_D(const QCLSampler);
    return d->context;
}

/*!
    Returns true if this OpenCL sampler has the same parameters
    as \a other; false otherwise.

    \sa operator!=()
*/
bool QCLSampler::operator==(const QCLSampler &other) const
{
    return d_ptr->normalizedCoordinates ==
                other.d_ptr->normalizedCoordinates &&
           d_ptr->addressingMode == other.d_ptr->addressingMode &&
           d_ptr->filterMode == other.d_ptr->filterMode;
}

/*!
    \fn bool QCLSampler::operator!=(const QCLSampler &other) const

    Returns true if this OpenCL sampler does not have the same
    parameters as \a other; false otherwise.

    \sa operator==()
*/

/*!
    \internal
*/
void QCLSampler::setKernelArg
    (QCLContext *context, cl_kernel kernel, int index) const
{
    Q_D(const QCLSampler);
    if (!d->id || d->context != context) {
        // Create a new sampler in the kernel's context.
        if (d->id)
            clReleaseSampler(d->id);    // Was created for another context.
        cl_int error;
        d->id = clCreateSampler
            (context->contextId(),
             d->normalizedCoordinates ? CL_TRUE : CL_FALSE,
             cl_addressing_mode(d->addressingMode),
             cl_filter_mode(d->filterMode), &error);
        context->reportError("QCLKernel::setArg(sampler):", error);
        if (d->id)
            d->context = context;
        else
            d->context = 0;
    }
    clSetKernelArg(kernel, index, sizeof(d->id), &(d->id));
}

QT_END_NAMESPACE