/*****************************************************************************
The Dark Mod GPL Source Code

This file is part of the The Dark Mod Source Code, originally based
on the Doom 3 GPL Source Code as published in 2011.

The Dark Mod Source Code is free software: you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3 of the License,
or (at your option) any later version. For details, see LICENSE.TXT.

Project: The Dark Mod (http://www.thedarkmod.com/)

******************************************************************************/

#ifndef __MODEL_H__
#define __MODEL_H__

#include "idlib/bv/Bvh.h"

/*
===============================================================================

	Render Model

===============================================================================
*/

// shared between the renderer, game, and Maya export DLL
#define MD5_VERSION_STRING		"MD5Version"
#define MD5_MESH_EXT			"md5mesh"
#define MD5_ANIM_EXT			"md5anim"
#define MD5_CAMERA_EXT			"md5camera"
#define MD5_VERSION				10

//#include "VertexCache.h"
#define VERTCACHE_FRAMENUM_BITS 15
/**
 * Describes a single entry in the static or dynamic vertex or index cache in 80 bits.
 */
struct vertCacheHandle_t {
	uint32_t	size;
	uint32_t	offset;
	uint16_t	frameNumber : VERTCACHE_FRAMENUM_BITS;
	bool		isStatic : 1;

	bool IsValid() const {
		return size != 0;
	}
	static vertCacheHandle_t Create(uint32_t size, uint32_t offset, uint16_t frameNumber, bool isStatic) {
		vertCacheHandle_t res;
		res.size = size;
		res.offset = offset;
		res.frameNumber = frameNumber;
		res.isStatic = isStatic;
		return res;
	}
	bool operator== (const vertCacheHandle_t &other) const {
		return offset == other.offset && size == other.size && isStatic == other.isStatic && frameNumber == other.frameNumber;
	}
};

// using shorts for triangle indexes can save a significant amount of traffic, but
// to support the large models that renderBump loads, they need to be 32 bits
#if 1

//#define GL_INDEX_TYPE		GL_UNSIGNED_INT
typedef int glIndex_t;

#else

#define GL_INDEX_TYPE		GL_UNSIGNED_SHORT
typedef short glIndex_t;

#endif


typedef struct silEdge_s {
	// NOTE: making this a glIndex is dubious, as there can be 2x the faces as verts
	glIndex_t					p1, p2;					// planes defining the edge
	glIndex_t					v1, v2;					// verts defining the edge
} silEdge_t;

// this is used for calculating unsmoothed normals and tangents for deformed models
typedef struct dominantTri_s {
	glIndex_t					v2, v3;
	float						normalizationScale[3];
} dominantTri_t;

typedef struct shadowCache_s {
	idVec4						xyz;					// we use homogenous coordinate tricks
} shadowCache_t;

const int SHADOW_CAP_INFINITE	= 64;

// our only drawing geometry type
typedef struct srfTriangles_s {
	idBounds					bounds;					// for culling

	int							ambientViewCount;		// if == tr.viewCount, it is visible this view

	bool						generateNormals;		// create normals from geometry, instead of using explicit ones
	bool						tangentsCalculated;		// set when the vertex tangents have been calculated
	bool						facePlanesCalculated;	// set when the face planes have been calculated
	bool						perfectHull;			// true if there aren't any dangling edges
	bool						deformedSurface;		// if true, indexes, silIndexes, mirrorVerts, and silEdges are
														// pointers into the original surface, and should not be freed

	int							numVerts;				// number of vertices
	idDrawVert *				verts;					// vertices, allocated with special allocator

	int							numIndexes;				// for shadows, this has both front and rear end caps and silhouette planes
	glIndex_t *					indexes;				// indexes, allocated with special allocator

	int							numBvhNodes;
	bvhNode_t *					bvhNodes;				// stgatilov #5886: compressed BVH tree on triangles of this surface

	glIndex_t *					silIndexes;				// indexes changed to be the first vertex with same XYZ, ignoring normal and texcoords

	int							numMirroredVerts;		// this many verts at the end of the vert list are tangent mirrors
	int *						mirroredVerts;			// tri->mirroredVerts[0] is the mirror of tri->numVerts - tri->numMirroredVerts + 0

	int							numDupVerts;			// number of duplicate vertexes
	int *						dupVerts;				// pairs of the number of the first vertex and the number of the duplicate vertex

	int							numSilEdges;			// number of silhouette edges
	silEdge_t *					silEdges;				// silhouette edges
	glIndex_t *					adjTris;				// stgatilov #5886: indexes of adjacent triangles opposite to each vertex of a triangle

	idPlane *					facePlanes;				// [numIndexes/3] plane equations

	dominantTri_t *				dominantTris;			// [numVerts] for deformed surface fast tangent calculation

	int							numShadowIndexesNoFrontCaps;	// shadow volumes with front caps omitted
	int							numShadowIndexesNoCaps;			// shadow volumes with the front and rear caps omitted

	int							shadowCapPlaneBits;		// bits 0-5 are set when that plane of the interacting light has triangles
														// projected on it, which means that if the view is on the outside of that
														// plane, we need to draw the rear caps of the shadow volume
														// turboShadows will have SHADOW_CAP_INFINITE

	shadowCache_t *				shadowVertexes;			// these will be copied to shadowCache when it is going to be drawn.
														// these are NULL when vertex programs are available

	struct srfTriangles_s *		ambientSurface;			// for light interactions, point back at the original surface that generated
														// the interaction, which we will get the ambientCache from

	struct srfTriangles_s *		nextDeferredFree;		// chain of tris to free next frame

	// data in vertex object space, not directly readable by the CPU
	vertCacheHandle_t			indexCache;				// int
	vertCacheHandle_t			ambientCache;			// idDrawVert
	vertCacheHandle_t			shadowCache;			// shadowCache_t
} srfTriangles_t;

typedef idList<srfTriangles_t *> idTriList;

typedef struct modelSurface_s {
	int							id;
	const idMaterial *			material;
	srfTriangles_t *			geometry;
} modelSurface_t;

typedef enum {
	DM_STATIC,		// never creates a dynamic model
	DM_CACHED,		// once created, stays constant until the entity is updated (animating characters)
	DM_CONTINUOUS	// must be recreated for every single view (time dependent things like particles)
} dynamicModel_t;

typedef enum {
	INVALID_JOINT				= -1
} jointHandle_t;

class idMD5Joint {
public:
								idMD5Joint() { parent = NULL; }
	idStr						name;
	const idMD5Joint *			parent;
};


typedef struct modelSamplingParameters_s {
	float areaPerSample;		// number of samples on surface ~= surface area / this value
	int minSamplesPerSurface;	// ... but no less than this number
	int maxSamplesTotal;		// total number of samples should not exceed this (as long as min per surface is satisfied)
	bool poisson;				// true => try to maximize distance between samples (slower)
} modelSamplingParameters_t;

// model sampling: persistent information about point
// does not change between frames (unless model is reloaded)
typedef struct samplePointOnModel_s {
	int surfaceIndex;		// index in idRenderModelStatic::surfaces / idRenderModelMD5::meshes
	idVec3 staticPosition;	// fixed position (in T-pose if model is MD5)
	int triangleIndex;		// index of triangle point lies on
	idVec3 baryCoords;		// barycentric coords of point on triangle
} samplePointOnModel_t;


// the init methods may be called again on an already created model when
// a reloadModels is issued

class idRenderModel {
public:
	virtual						~idRenderModel() {};

	// Loads static models only, dynamic models must be loaded by the modelManager
	virtual void				InitFromFile( const char *fileName ) = 0;

	// renderBump uses this to load the very high poly count models, skipping the
	// shadow and tangent generation, along with some surface cleanup to make it load faster
	virtual void				PartialInitFromFile( const char *fileName ) = 0;

	// this is used for dynamically created surfaces, which are assumed to not be reloadable.
	// It can be called again to clear out the surfaces of a dynamic model for regeneration.
	virtual void				InitEmpty( const char *name ) = 0;

	// dynamic model instantiations will be created with this
	// the geometry data will be owned by the model, and freed when it is freed
	// the geoemtry should be raw triangles, with no extra processing
	virtual void				AddSurface( modelSurface_t surface ) = 0;

	// cleans all the geometry and performs cross-surface processing
	// like shadow hulls
	// Creates the duplicated back side geometry for two sided, alpha tested, lit materials
	// This does not need to be called if none of the surfaces added with AddSurface require
	// light interaction, and all the triangles are already well formed.
	virtual void				FinishSurfaces() = 0;

	// frees all the data, but leaves the class around for dangling references,
	// which can regenerate the data with LoadModel()
	virtual void				PurgeModel() = 0;

	// resets any model information that needs to be reset on a same level load etc.. 
	// currently only implemented for liquids
	virtual void				Reset() = 0;

	// used for initial loads, reloadModel, and reloading the data of purged models
	// Upon exit, the model will absolutely be valid, but possibly as a default model
	virtual void				LoadModel() = 0;

	// internal use
	virtual bool				IsLoaded() const = 0;
	virtual void				SetLevelLoadReferenced( bool referenced ) = 0;
	virtual bool				IsLevelLoadReferenced() = 0;

	// models that are already loaded at level start time
	// will still touch their data to make sure they
	// are kept loaded
	virtual void				TouchData() = 0;

	// dump any ambient caches on the model surfaces
	virtual void				FreeVertexCache() = 0;

	// returns the name of the model
	virtual const char	*		Name() const = 0;

	// prints a detailed report on the model for printModel
	virtual void				Print() const = 0;

	// prints a single line report for listModels
	virtual void				List() const = 0;

	// reports the amount of memory (roughly) consumed by the model
	virtual int					Memory() const = 0;

	// for reloadModels
	virtual ID_TIME_T				Timestamp() const = 0;

	// stgatilov: load version is incremented every time LoadModel is called
	// this allows game code to learn if the model has been reloaded in "pull fashion"
	virtual int					GetLoadVersion() const = 0;

	// returns the number of surfaces
	virtual int					NumSurfaces() const = 0;

	// NumBaseSurfaces will not count any overlays added to dynamic models
	virtual int					NumBaseSurfaces() const = 0;

	// get a pointer to a surface
	virtual const modelSurface_t *Surface( int surfaceNum ) const = 0;

	// Allocates surface triangles.
	// Allocates memory for srfTriangles_t::verts and srfTriangles_t::indexes
	// The allocated memory is not initialized.
	// srfTriangles_t::numVerts and srfTriangles_t::numIndexes are set to zero.
	virtual srfTriangles_t *	AllocSurfaceTriangles( int numVerts, int numIndexes ) const = 0;

	// Frees surfaces triangles.
	virtual void				FreeSurfaceTriangles( srfTriangles_t *tris ) const = 0;

	// created at load time by stitching together all surfaces and sharing
	// the maximum number of edges.  This may be incorrect if a skin file
	// remaps surfaces between shadow casting and non-shadow casting, or
	// if some surfaces are noSelfShadow and others aren't
	virtual srfTriangles_t	*	ShadowHull() const = 0;

	// models of the form "_area*" may have a prelight shadow model associated with it
	virtual bool				IsStaticWorldModel() const = 0;

	// models parsed from inside map files or dynamically created cannot be reloaded by
	// reloadmodels
	virtual bool				IsReloadable() const = 0;

	// md3, md5, particles, etc
	virtual dynamicModel_t		IsDynamicModel() const = 0;

	// if the load failed for any reason, this will return true
	virtual bool				IsDefaultModel() const = 0;

	// dynamic models should return a fast, conservative approximation
	// static models should usually return the exact value
	virtual idBounds			Bounds( const struct renderEntity_s *ent = NULL ) const = 0;

	// returns value != 0.0f if the model requires the depth hack
	virtual float				DepthHack() const = 0;

	// returns a static model based on the definition and view
	// currently, this will be regenerated for every view, even though
	// some models, like character meshes, could be used for multiple (mirror)
	// views in a frame, or may stay static for multiple frames (corpses)
	// The renderer will delete the returned dynamic model the next view
	// This isn't const, because it may need to reload a purged model if it
	// wasn't precached correctly.
	virtual idRenderModel *		InstantiateDynamicModel( const struct renderEntity_s *ent, const struct viewDef_s *view, idRenderModel *cachedModel ) = 0;

	// Returns the number of joints or 0 if the model is not an MD5
	virtual int					NumJoints( void ) const = 0;

	// Returns the MD5 joints or NULL if the model is not an MD5
	virtual const idMD5Joint *	GetJoints( void ) const = 0;

	// Returns the handle for the joint with the given name.
	virtual jointHandle_t		GetJointHandle( const char *name ) const = 0;

	// Returns the name for the joint with the given handle.
	virtual const char *		GetJointName( jointHandle_t handle ) const = 0;

	// stgatilov #6099: k-th element = bounds of all joint-affected vertices in local joint space
	// (NULL if model is not MD5)
	virtual const idBounds *	JointBounds() const = 0;

	// Returns the default animation pose or NULL if the model is not an MD5.
	virtual const idJointQuat *	GetDefaultPose( void ) const = 0;

	// Returns number of the joint nearest to the given triangle.
	virtual int					NearestJoint( int surfaceNum, int a, int c, int b ) const = 0;

	// Writing to and reading from a demo file.
	virtual void				ReadFromDemoFile( class idDemoFile *f ) = 0;
	virtual void				WriteToDemoFile( class idDemoFile *f ) = 0;

	// stgatilov #6546: generating sample points on the model
	virtual void				GenerateSamples( idList<samplePointOnModel_t> &samples, const modelSamplingParameters_t &params, idRandom &rnd ) const = 0;
	virtual idVec3				GetSamplePosition( const struct renderEntity_s *ent, const samplePointOnModel_t &sample ) const = 0;
	virtual const idMaterial *	GetSampleMaterial( const struct renderEntity_s *ent, const samplePointOnModel_t &sample ) const = 0;

};

#endif /* !__MODEL_H__ */