// ----------------------------------------------------------------------------
// Blitz-Irrlicht 1.8.3 Wrapper by Ed Musolino 2015
// Based off of Frank Dodd's Irrlicht 1.7 Freebasic Wrapper (2006-2010)
// ----------------------------------------------------------------------------

//  This software is provided 'as-is', without any express Or implied
//  warranty.  In no event will the authors be held liable For any damages
//  arising from the use of this software.

//  Permission is granted To anyone To use this software For any purpose,
//  including commercial applications, And To alter it And redistribute it
//  freely, subject To the following restrictions:

//  1. The Origin of this software must Not be misrepresented; you must not
//     claim that you wrote the original software. If you use this software
//     in a product, an acknowledgement in the product documentation would be
//     appreciated but is Not required.
//  2. Altered source versions must be clearly marked as such, And must Not be
//     misrepresented as being the original software.
//  3. This notice may Not be removed Or altered from any source distribution.
//
// /////////////////////////////////////////////////////////////////////////////

// Copyright (C) 2002-2007 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

// The code for the TerrainSceneNode is based on the GeoMipMapSceneNode
// developed by Spintz. He made it available for Irrlicht and allowed it to be
// distributed under this licence. I only modified some parts. A lot of thanks go to him.

#ifndef __C_TERRAIN_SCENE_NODE_H__
#define __C_TERRAIN_SCENE_NODE_H__

#include "ISceneManager.h"
#include "SMesh.h"
#include "IReadFile.h"
#include "ITextSceneNode.h"
#include "ETerrainElements.h"
#include "ISceneNode.h"
#include "SMeshBufferLightMap.h"
#include "irrArray.h"
#include "ITexture.h"


#define CUBE_FACES 6


namespace irr
{
namespace io
{
	class IFileSystem;
}
namespace scene
{
	class IMesh;

	//! A scene node for displaying terrain using the geo mip map algorithm.
	/** The code for the TerrainSceneNode is based on the Terrain renderer by Soconne and
	 * the GeoMipMapSceneNode developed by Spintz. They made their code available for Irrlicht
	 * and allowed it to be distributed under this licence. I only modified some parts.
	 * A lot of thanks go to them.
	 *
	 * This scene node is capable of very quickly loading
	 * terrains and updating the indices at runtime to enable viewing very large terrains. It uses a
	 * CLOD ( Continuous Level of Detail ) algorithm which updates the indices for each patch based on
	 * a LOD ( Level of Detail ) which is determined based on a patch's distance from the camera.
	 *
	 * The Patch Size of the terrain must always be a size of ( 2^N+1, i.e. 8+1(9), 16+1(17), etc. ).
	 * The MaxLOD available is directly dependent on the patch size of the terrain. LOD 0 contains all
	 * of the indices to draw all the triangles at the max detail for a patch. As each LOD goes up by 1
	 * the step taken, in generating indices increases by - 2^LOD, so for LOD 1, the step taken is 2, for
	 * LOD 2, the step taken is 4, LOD 3 - 8, etc. The step can be no larger than the size of the patch,
	 * so having a LOD of 8, with a patch size of 17, is asking the algoritm to generate indices every
	 * 2^8 ( 256 ) vertices, which is not possible with a patch size of 17. The maximum LOD for a patch
	 * size of 17 is 2^4 ( 16 ). So, with a MaxLOD of 5, you'll have LOD 0 ( full detail ), LOD 1 ( every
	 * 2 vertices ), LOD 2 ( every 4 vertices ), LOD 3 ( every 8 vertices ) and LOD 4 ( every 16 vertices ).
	 **/
	class ITerrainSphereNode : public ISceneNode
	{
	public:

		//! Constructor
		ITerrainSphereNode(ISceneNode* parent, ISceneManager* mgr, s32 id,
			const core::vector3df& position = core::vector3df(0.0f, 0.0f, 0.0f),
			const core::vector3df& rotation = core::vector3df(0.0f, 0.0f, 0.0f),
			const core::vector3df& scale = core::vector3df(1.0f, 1.0f, 1.0f) )
			: ISceneNode (mgr->getRootSceneNode(), mgr, id) {}
//			: ISceneNode (parent, mgr, id, position, rotation, scale) {}

		//! Destructor
		virtual ~ITerrainSphereNode() {}

		//! Get the bounding box of the terrain.
		/** \return The bounding box of the entire terrain. */
		virtual const core::aabbox3d<f32>& getBoundingBox() const = 0;

		//! Get the bounding box of a patch
		/** \return The bounding box of the chosen patch. */
		virtual const core::aabbox3d<f32>& getBoundingBox(s32 patchX, s32 patchZ, s32 face ) const = 0;

		//! Get the number of indices currently in the meshbuffer
		/** \return The index count. */
		virtual u32 getIndexCount( s32 face ) const = 0;

		//! Get pointer to the mesh
		/** \return Pointer to the mesh. */
		virtual IMesh* getMesh() = 0;

		//! Gets the meshbuffer data based on a specified level of detail.
		/** \param mb A reference to an SMeshBuffer object
		\param LOD The level of detail you want the indices from. */
		virtual void getMeshBufferForLOD(SMeshBufferLightMap& mb, s32 LOD) const = 0;

		//! Gets the indices for a specified patch at a specified Level of Detail.
		/** \param indices A reference to an array of u32 indices.
		\param patchX Patch x coordinate.
		\param patchZ Patch z coordinate.
		\param LOD The level of detail to get for that patch. If -1,
		then get the CurrentLOD. If the CurrentLOD is set to -1,
		meaning it's not shown, then it will retrieve the triangles at
		the highest LOD ( 0 ).
		\return Number if indices put into the buffer. */
		virtual s32 getIndicesForPatch(core::array<u32>& indices,
			s32 patchX, s32 patchZ, s32 face , s32 LOD = 0 ) = 0;

		//! Populates an array with the CurrentLOD of each patch.
		/** \param LODs A reference to a core::array<s32> to hold the
		values
		\return Number of elements in the array */
		virtual s32 getCurrentLODOfPatches(core::array<s32>& LODs) const = 0;

		//! Manually sets the LOD of a patch
		/** \param patchX Patch x coordinate.
		\param patchZ Patch z coordinate.
		\param LOD The level of detail to set the patch to. */
		virtual void setLODOfPatch( s32 patchX, s32 patchZ, s32 face , s32 LOD ) = 0;

		//! Get center of terrain.
		virtual const core::vector3df& getTerrainCenter() const = 0;

		//! Get height of a point of the terrain.
		virtual f32 getHeight( f32 x, f32 y ) const = 0;

		//! Sets the movement camera threshold.
		/** It is used to determine when to recalculate
		indices for the scene node. The default value is 10.0f. */
		virtual void setCameraMovementDelta(f32 delta) = 0;

		//! Sets the rotation camera threshold.
		/** It is used to determine when to recalculate
		indices for the scene node. The default value is 1.0f. */
		virtual void setCameraRotationDelta(f32 delta) = 0;

		//! Sets whether or not the node should dynamically update its associated selector when the geomipmap data changes.
		/** \param bVal: Boolean value representing whether or not to update selector dynamically. */
		virtual void setDynamicSelectorUpdate(bool bVal) = 0;

		//! Override the default generation of distance thresholds.
		/** For determining the LOD a patch is rendered at. If any LOD
		is overridden, then the scene node will no longer apply scaling
		factors to these values. If you override these distances, and
		then apply a scale to the scene node, it is your responsibility
		to update the new distances to work best with your new terrain
		size. */
		virtual bool overrideLODDistance(s32 LOD, f64 newDistance) = 0;

		//! Scales the base texture, similar to makePlanarTextureMapping.
		/** \param scale The scaling amount. Values above 1.0
		increase the number of time the texture is drawn on the
		terrain. Values below 0 will decrease the number of times the
		texture is drawn on the terrain. Using negative values will
		flip the texture, as well as still scaling it.
		\param scale2 If set to 0 (default value), this will set the
		second texture coordinate set to the same values as in the
		first set. If this is another value than zero, it will scale
		the second texture coordinate set by this value. */
		virtual void scaleTexture(f32 scale = 1.0f, f32 scale2 = 0.0f) = 0;
	};


	//! A scene node for displaying terrain using the geo mip map algorithm.
	/** The code for the TerrainSceneNode is based on the GeoMipMapSceneNode
	 * developed by Spintz. He made it available for Irrlicht and allowed it to be
	 * distributed under this licence. I only modified some parts. A lot of thanks go to him.
	 **/
	class CTerrainSphereNode : public ITerrainSphereNode
	{
	public:

		//! constructor
		//! \param parent: The node which this node is a child of.  Making this node a child of another node, or
		//! making it a parent of another node is yet untested and most likely does not work properly.
		//! \param mgr: Pointer to the scene manager.
		//! \param id: The id of the node
		//! \param maxLOD: The maximum LOD ( Level of Detail ) for the node.
		//! \param patchSize: An E_GEOMIPMAP_PATCH_SIZE enumeration defining the size of each patch of the terrain.
		//! \param position: The absolute position of this node.
		//! \param rotation: The absolute rotation of this node. ( NOT YET IMPLEMENTED )
		//! \param scale: The scale factor for the terrain.  If you're using a heightmap of size 128x128 and would like
		//! your terrain to be 12800x12800 in game units, then use a scale factor of ( core::vector ( 100.0f, 100.0f, 100.0f ).
		//! If you use a Y scaling factor of 0.0f, then your terrain will be flat.
		CTerrainSphereNode(ISceneNode* parent, ISceneManager* mgr, io::IFileSystem* fs, s32 id,
			s32 maxLOD = 4, E_TERRAIN_PATCH_SIZE patchSize = ETPS_17,
			const core::vector3df& position = core::vector3df(0.0f, 0.0f, 0.0f),
			const core::vector3df& rotation = core::vector3df(0.0f, 0.0f, 0.0f),
			const core::vector3df& scale = core::vector3df(1.0f, 1.0f, 1.0f));

		virtual ~CTerrainSphereNode();

		//! distort the terrain geometry before the heightmap is applied
		void distort( core::vector3df &v, float scale, int face, bool invX = false, bool invZ = false );

		//! Initializes the terrain data.  Loads the vertices from the heightMapFile.
		virtual bool loadHeightMap(io::IReadFile** file,
			video::SColor vertexColor = video::SColor ( 255, 255, 255, 255 ), s32 smoothFactor = 0 );

		//! Initializes the terrain data.  Loads the vertices from the heightMapFile.
		virtual bool loadHeightMapRAW(io::IReadFile* file, s32 bitsPerPixel = 16,
			video::SColor vertexColor = video::SColor ( 255, 255, 255, 255 ), s32 smoothFactor = 0 );

		//! Returns the material based on the zero based index i. This scene node only uses
		//! 1 material.
		//! \param i: Zero based index i. UNUSED, left in for virtual purposes.
		//! \return Returns the single material this scene node uses.
		virtual video::SMaterial& getMaterial ( u32 i )
		{
			return Mesh.getMeshBuffer(i)->getMaterial();
		}

		//! Returns the material based on the zero based index i. This scene node only uses
		//! 1 material.
		//! \param i: Zero based index i. UNUSED, left in for virtual purposes.
		//! \return Returns the single material this scene node uses.
		virtual void setTextures (
                                    video::ITexture *textureTop,
                                    video::ITexture *textureFront,
                                    video::ITexture *textureBack,
                                    video::ITexture *textureLeft,
                                    video::ITexture *textureRight,
                                    video::ITexture *textureBottom,
                                    u32 materialIndex );

        //! load the vertex colors ,of each of the faces from a series of image files
        //! param 1: an array of six image files
        virtual void loadVertexColor( video::IImage **images );


		//! Returns amount of materials used by this scene node ( always 1 )
		//! \return Returns current count of materials used by this scene node ( always 1 )
		virtual u32 getMaterialCount() const
		{
			return Mesh.getMeshBufferCount();
		}

		//! Gets the last scaling factor applied to the scene node.  This value only represents the
		//! last scaling factor presented to the node.  For instance, if you make create the node
		//! with a scale factor of ( 1.0f, 1.0f, 1.0f ) then call setScale ( 50.0f, 5.0f, 50.0f ),
		//! then make another call to setScale with the values ( 2.0f, 2.0f, 2.0f ), this will return
		//! core::vector3df ( 2.0f, 2.0f, 2.0f ), although the total scaling of the scene node is
		//! core::vector3df ( 100.0f, 10.0f, 100.0f ).
		//! \return Returns the last scaling factor passed to the scene node.
		virtual const core::vector3df& getScale() const
		{
			return TerrainData.Scale;
		}

		//! Scales the scene nodes vertices by the vector specified.
		//! \param scale: Scaling factor to apply to the node.
		virtual void setScale(const core::vector3df& scale);

		//! Gets the last rotation factor applied to the scene node.
		//! \return Returns the last rotation factor applied to the scene node.
		virtual const core::vector3df& getRotation() const
		{
			return TerrainData.Rotation;
		}

		//! Rotates the node. This only modifies the relative rotation of the node.
		//! \param rotation: New rotation of the node in degrees.
		virtual void setRotation(const core::vector3df& rotation);

		//! Sets the pivot point for rotation of this node.  This is useful for the TiledTerrainManager to
		//! rotate all terrain tiles around a global world point.
		//! NOTE: The default for the RotationPivot will be the center of the individual tile.
		virtual void setRotationPivot( const core::vector3df& pivot );

		//! Gets the last positioning vector applied to the scene node.
		//! \return Returns the last position vector applied to the scene node.
		virtual const core::vector3df& getPosition() const
		{
			return TerrainData.Position;
		}

		//! Moves the scene nodes vertices by the vector specified.
		//! \param newpos: Vector specifying how much to move each vertex of the scene node.
		virtual void setPosition(const core::vector3df& newpos);

		//! Updates the scene nodes indices if the camera has moved or rotated by a certain
		//! threshold, which can be changed using the SetCameraMovementDeltaThreshold and
		//! SetCameraRotationDeltaThreshold functions.  This also determines if a given patch
		//! for the scene node is within the view frustum and if it's not the indices are not
		//! generated for that patch.
		virtual void OnRegisterSceneNode();

		//! Render the scene node
		virtual void render();

		//! Return the bounding box of the entire terrain.
		virtual const core::aabbox3d<f32>& getBoundingBox() const;

		//! Return the bounding box of a patch
		virtual const core::aabbox3d<f32>& getBoundingBox(s32 patchX, s32 patchZ, s32 face ) const;

		//! Return the number of indices currently used to draw the scene node.
		virtual u32 getIndexCount( s32 face ) const { return IndicesToRender[face]; }

		//! Returns the mesh
		virtual IMesh* getMesh() { return &Mesh; }

		//! Gets the meshbuffer data based on a specified Level of Detail.
		//! \param mb: A reference to an SMeshBufferLightMap object
		//! \param LOD: The Level Of Detail you want the indices from.
		virtual void getMeshBufferForLOD(SMeshBufferLightMap& mb, s32 LOD ) const;

		//! Gets the indices for a specified patch at a specified Level of Detail.
		//! \param indices: A reference to an array of u32 indices.
		//! \param patchX: Patch x coordinate.
		//! \param patchZ: Patch z coordinate.
		//! \param LOD: The level of detail to get for that patch.  If -1, then get
		//! the CurrentLOD.  If the CurrentLOD is set to -1, meaning it's not shown,
		//! then it will retrieve the triangles at the highest LOD ( 0 ).
		//! \return: Number if indices put into the buffer.
		virtual s32 getIndicesForPatch(core::array<u32>& indices,
			s32 patchX, s32 patchZ, s32 face, s32 LOD = 0 );

		//! Populates an array with the CurrentLOD of each patch.
		//! \param LODs: A reference to a core::array<s32> to hold the values
		//! \return Returns the number of elements in the array
		virtual s32 getCurrentLODOfPatches(core::array<s32>& LODs) const;

		//! Manually sets the LOD of a patch
		//! \param patchX: Patch x coordinate.
		//! \param patchZ: Patch z coordinate.
		//! \param LOD: The level of detail to set the patch to.
		virtual void setLODOfPatch( s32 patchX, s32 patchZ, s32 patchFace, s32 LOD );

		//! Returns center of terrain.
		virtual const core::vector3df& getTerrainCenter() const
		{
			return TerrainData.Center;
		}

		//! Returns the height of a point on the terrain.
		virtual f32 getHeight( f32 x, f32 y ) const;

        //! Gets a surface position
        virtual void getSurfacePosition( s32 face, f32 x, f32 z, core::vector3df &pos ) const;

		//! Sets the movement camera threshold which is used to determine when to recalculate
		//! indices for the scene node.  The default value is 10.0f.
		virtual void setCameraMovementDelta(f32 delta)
		{
			CameraMovementDelta = delta;
		}

		//! Sets the rotation camera threshold which is used to determine when to recalculate
		//! indices for the scene node.  The default value is 1.0f.
		virtual void setCameraRotationDelta(f32 delta)
		{
			CameraRotationDelta = delta;
		}

		//! Sets whether or not the node should dynamically update it's associated selector when
		//! the geomipmap data changes.
		//! param bVal: Boolean value representing whether or not to update selector dynamically.
		//! NOTE: Temporarily disabled while working out issues with DynamicSelectorUpdate
		virtual void setDynamicSelectorUpdate(bool bVal ) { DynamicSelectorUpdate = false; }
		//virtual void setDynamicSelectorUpdate ( bool bVal ) { DynamicSelectorUpdate = bVal; }

		//! Override the default generation of distance thresholds for determining the LOD a patch
		//! is rendered at.  If any LOD is overridden, then the scene node will no longer apply
		//! scaling factors to these values.  If you override these distances, and then apply
		//! a scale to the scene node, it is your responsibility to update the new distances to
		//! work best with your new terrain size.
		virtual bool overrideLODDistance( s32 LOD, f64 newDistance );

		//! Scales the two textures
		virtual void scaleTexture(f32 scale = 1.0f, f32 scale2 = 0.0f);

		//! Returns type of the scene node
		virtual ESCENE_NODE_TYPE getType() const {return ESNT_TERRAIN;}

		//! Writes attributes of the scene node.
		virtual void serializeAttributes(io::IAttributes* out,
				io::SAttributeReadWriteOptions* options=0) const;

		//! Reads attributes of the scene node.
		virtual void deserializeAttributes(io::IAttributes* in,
				io::SAttributeReadWriteOptions* options=0);

		//! Creates a clone of this scene node and its children.
		virtual ISceneNode* clone(ISceneNode* newParent,
				ISceneManager* newManager);

	private:

		friend class CTerrainTriangleSelector;
		friend class CTiledTerrainSceneNodeManager;

		struct SPatch
		{
			SPatch()
			: CurrentLOD(-1), DebugText(0),
			Top(0), Bottom(0), Right(0), Left(0)
			{
			}

			s32			CurrentLOD;
			core::aabbox3df		BoundingBox;
			core::vector3df		Center;
			scene::ITextSceneNode*	DebugText;
			SPatch*			Top;
			SPatch*			Bottom;
			SPatch*			Right;
			SPatch*			Left;
		};

		struct STerrainData
		{
			STerrainData()
			: Size(0), PatchSize(0), CalcPatchSize(0),
				PatchCount(0), MaxLOD(0),
				BoundingBox(core::aabbox3df( 99999.9f, 99999.9f, 99999.9f, -99999.9f, -99999.9f, -99999.9f)),
				LODDistanceThreshold(0), Patches(0)
			{
			}

			STerrainData(s32 patchSize, s32 maxLOD, const core::vector3df& position, const core::vector3df& rotation, const core::vector3df& scale)
			: Size(0), Position(position), Rotation(rotation), Scale(scale),
				PatchSize(patchSize), CalcPatchSize(patchSize-1),
				PatchCount(0), MaxLOD(maxLOD),
				BoundingBox(core::aabbox3df( 99999.9f, 99999.9f, 99999.9f, -99999.9f, -99999.9f, -99999.9f)),
				LODDistanceThreshold(0), Patches(0)
			{
			}

			s32		Size;
			core::vector3df	Position;
			core::vector3df	Rotation;
			core::vector3df RotationPivot;
			core::vector3df	Scale;
			core::vector3df Center;
			s32		PatchSize;
			s32		CalcPatchSize;
			s32		PatchCount;
			s32		MaxLOD;
			core::aabbox3df	BoundingBox;
			f64*		LODDistanceThreshold;
			SPatch*		Patches;
		};

		virtual void preRenderLODCalculations();
		virtual void preRenderIndicesCalculations();

		//! get indices when generating index data for patches at varying levels of detail.
		u32 getIndex(const s32& PatchX, const s32& PatchZ, const s32& PatchIndex,
					 u32 vX, u32 vZ) const;

		//! calculate smooth normals
		void calculateNormals(SMeshBufferLightMap* pMeshBuffer, s32 face );

		//! create patches, stuff that needs to only be done once for patches goes here.
		void createPatches();

		//! calculate the patches attached across a side of the cube
		SPatch * cubePatch( s32 face, s32 edge, s32 index );

		//! calculate the internal STerrainData structure
		void calculatePatchData();

		//! calculate or recalculate the distance thresholds
		void calculateDistanceThresholds(bool scalechanged = false);

		//! sets the CurrentLOD of all patches to the specified LOD
		void setCurrentLODOfPatches(s32 i);

		//! sets the CurrentLOD of TerrainData patches to the LODs specified in the array
		void setCurrentLODOfPatches(core::array<s32>& lodarray);

		//! Apply transformation changes( scale, position, rotation )
		void applyTransformation();

		STerrainData TerrainData;
		SMesh Mesh;
		SMeshBufferLightMap RenderBuffer[CUBE_FACES];
		u32 VerticesToRender[CUBE_FACES];
		u32 IndicesToRender[CUBE_FACES];

		bool DynamicSelectorUpdate;
		bool OverrideDistanceThreshold;
		bool UseDefaultRotationPivot;
		bool ForceRecalculation;

		core::vector3df	OldCameraPosition;
		core::vector3df	OldCameraRotation;
		f32 CameraMovementDelta;
		f32 CameraRotationDelta;

		// needed for (de)serialization
		f32 TCoordScale1;
		f32 TCoordScale2;
		core::stringc HeightmapFile;
		io::IFileSystem* FileSystem;
	};


} // end namespace scene
} // end namespace irr

#endif // __C_TERRAIN_SCENE_NODE_H__

