/******************************************************************************
 * Copyright 2020 NVIDIA Corporation. All rights reserved.
 *****************************************************************************/
/// \file
/// \brief Scene attribute controlling volume filter mode.

#ifndef NVIDIA_INDEX_IVOLUME_FILTER_MODE_H
#define NVIDIA_INDEX_IVOLUME_FILTER_MODE_H

#include <mi/base/interface_declare.h>

#include <nv/index/iattribute.h>

namespace nv {
namespace index {

/// Scene attribute controlling volume filter mode.
///
/// The volume filter mode specifies what kind of interpolation of volume samples is performed upon
/// rendering a volume primitive directly (using \c IRegular_volume) or indirectly (e.g. mapped on
/// an \c IPlane).
///
/// \note This attribute takes precedence over the global setting from \c
/// IConfig_settings::set_volume_filter().
///
/// \todo Currently this attribute only affects volume data mapped onto an \c IPlane.
///
/// \ingroup nv_index_scene_description_attribute
///
class IVolume_filter_mode :
    public mi::base::Interface_declare<0x7346860a,0x21c6,0x4f71,0xab,0x1d,0x95,0xb4,0xd9,0x07,0xf2,0xd8,
                                       nv::index::IAttribute>
{
public:
    /// Filter modes (interpolation) for volume access. With post-classification the volume data
    /// is filtered before applying the colormap, while with pre-classification the colormap is
    /// applied before filtering.
    /// In GPU rendering mode, all the filters below including those tagged as 'software' are
    /// implemented using CUDA. Those filters that are are tagged 'hardware' leverage the
    /// texture hardware, e.g., linear filters, exposed through CUDA to further optimize
    /// the filtering performance.
    enum Filter_mode
    {
        /// Access a single voxel with nearest filtering (a.k.a. point filtering).
        VOLUME_FILTER_NEAREST                    = 0,
        /// Trilinear interpolation with post-classification, using texture hardware.
        VOLUME_FILTER_TRILINEAR_POST_HW          = 1,
        /// Trilinear interpolation with post-classification, using software filtering.
        VOLUME_FILTER_TRILINEAR_POST_SW          = 2,
        /// Trilinear interpolation with pre-classification, using software filtering.
        VOLUME_FILTER_TRILINEAR_PRE_SW           = 3,
        /// Tricubic Catmull-Rom interpolation with pre-classification, using software filtering.
        VOLUME_FILTER_TRICUBIC_CATMULL           = 4,
        /// Tricubic Catmull-Rom interpolation with pre-classification, using texture hardware.
        VOLUME_FILTER_TRICUBIC_CATMULL_POST_HW   = 5,
        /// Tricubic B-spline interpolation with pre-classification, using software filtering.
        VOLUME_FILTER_TRICUBIC_BSPLINE           = 6,
        /// Tricubic B-spline interpolation with post-classification, using texture hardware.
        VOLUME_FILTER_TRICUBIC_BSPLINE_POST_HW   = 7
    };

    /// Sets the filter mode for volume rendering, which is used when sampling volume data
    /// (default: \c VOLUME_FILTER_NEAREST).
    ///
    /// \param[in] mode Volume filter mode
    virtual void set_filter_mode(Filter_mode mode) = 0;

    /// Returns the current volume filter mode.
    ///
    /// \return volume filter mode
    virtual Filter_mode get_filter_mode() const = 0;
};

} // namespace index
} // namespace nv

#endif // NVIDIA_INDEX_ITEXTURE_FILTER_MODE_H
