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#ifndef SlicedVolume_INCLUDE_ONCE
#define SlicedVolume_INCLUDE_ONCE

#include <vlVolume/link_config.hpp>
#include <vlGraphics/Actor.hpp>
#include <vlGraphics/Geometry.hpp>
#include <vlGraphics/Light.hpp>

namespace vl
{
  class VLVOLUME_EXPORT SlicedVolume: public ActorEventCallback
  {
    VL_INSTRUMENT_CLASS(vl::SlicedVolume, ActorEventCallback)

  public:
    //! Constructor.
    SlicedVolume();

    void onActorRenderStarted(Actor* actor, real frame_clock, const Camera* cam, Renderable* renderable, const Shader* shader, int pass);

    void onActorDelete(Actor*) { mActor = NULL; }

    //! Binds a SlicedVolume to an Actor so that the SlicedVolume can generate the viewport aligned slices' geometry for the Actor as appropriate.
    void bindActor(Actor*);

    //! Updates the uniforms used by the GLSLProgram to render the volume each time the onActorRenderStarted() method is called.
    virtual void updateUniforms(Actor* actor, real clock, const Camera* camera, Renderable* rend, const Shader* shader);

    //! Defines the number of slices used to render the volume: more slices generate a better (and slower) rendering. Default is 0.
    //! If equal to 0 the number of slices is computed automatically as max(viewport.width, viewport.height).
    void setSliceCount(int count) { mSliceCount = count; }

    //! Returns the number of slices used to render the volume.
    //! If equal to 0 the number of slices is computed automatically as max(viewport.width, viewport.height).
    int sliceCount() const { return mSliceCount; }

    //! Returns the Geometry associated to a SlicedVolume and its bound Actor
    Geometry* geometry() { return mGeometry.get(); }

    //! Returns the Geometry associated to a SlicedVolume and its bound Actor
    const Geometry* geometry() const { return mGeometry.get(); }

    //! Defines the dimensions of the box enclosing the volume
    void setBox(const AABB& box);

    //! The dimensions of the box enclosing the volume
    const AABB& box() const { return mBox; }

    //! Returns the texture coordinates assigned to each of the 8 box corners of the volume
    const fvec3* texCoords() const { return mTexCoord; }

    //! Returns the texture coordinates assigned to each of the 8 box corners of the volume
    fvec3* texCoords() { return mTexCoord; }

    //! Generates a default set of texture coordinates for the 8 box corners of the volume based on the given texture dimensions.
    void generateTextureCoordinates(const ivec3& size);

    //! Generates a default set of texture coordinates for the 8 box corners of the volume based on the given texture dimensions.
    //! Use this function to visualize a subset of the volume. The subset is defined by \p min_corner and \p max_corner.
    void generateTextureCoordinates(const ivec3& img_size, const ivec3& min_corner, const ivec3& max_corner);

    //! Returns the currently bound actor
    const Actor* actor() const { return mActor; }
    //! Returns the currently bound actor
    Actor* actor() { return mActor; }

  protected:
    int mSliceCount;
    ref<Geometry> mGeometry;
    AABB mBox;
    fmat4 mCache;
    fvec3 mTexCoord[8];
    // Naked pointer on purpose in order not to create cyclical dependencies and mem leaks: the Actor owns the SlicedVolume
    Actor* mActor;
  };
}

#endif