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

Doom 3 BFG Edition GPL Source Code
Copyright (C) 1993-2012 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 BFG Edition GPL Source Code ("Doom 3 BFG Edition Source Code").  

Doom 3 BFG Edition 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.

Doom 3 BFG Edition Source Code is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Doom 3 BFG Edition Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 BFG Edition Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 BFG Edition Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

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

#pragma hdrstop
#include "../idlib/precompiled.h"

#include "tr_local.h"
#include "Model_local.h"
#include "Model_md3.h"

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

	idMD3Mesh

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

#define	LL(x) x=LittleLong(x)

/*
=================
idRenderModelMD3::InitFromFile
=================
*/
void idRenderModelMD3::InitFromFile( const char *fileName ) {
	int					i, j;
	md3Header_t			*pinmodel;
    md3Frame_t			*frame;
	md3Surface_t		*surf;
	md3Shader_t			*shader;
	md3Triangle_t		*tri;
	md3St_t				*st;
	md3XyzNormal_t		*xyz;
	md3Tag_t			*tag;
	void				*buffer;
	int					version;
	int					size;


	name = fileName;

	size = fileSystem->ReadFile( fileName, &buffer, NULL );
	if (!size || size<0 ) {
		return;
	}

	pinmodel = (md3Header_t *)buffer;

	version = LittleLong (pinmodel->version);
	if (version != MD3_VERSION) {
		fileSystem->FreeFile( buffer );
		common->Warning( "InitFromFile: %s has wrong version (%i should be %i)",
				 fileName, version, MD3_VERSION);
		return;
	}

	size = LittleLong(pinmodel->ofsEnd);
	dataSize += size;
	md3 = (md3Header_t *)Mem_Alloc( size, TAG_MODEL );

	memcpy (md3, buffer, LittleLong(pinmodel->ofsEnd) );

    LL(md3->ident);
    LL(md3->version);
    LL(md3->numFrames);
    LL(md3->numTags);
    LL(md3->numSurfaces);
    LL(md3->ofsFrames);
    LL(md3->ofsTags);
    LL(md3->ofsSurfaces);
    LL(md3->ofsEnd);

	if ( md3->numFrames < 1 ) {
		common->Warning( "InitFromFile: %s has no frames", fileName );
		fileSystem->FreeFile( buffer );
		return;
	}
    
	// swap all the frames
    frame = (md3Frame_t *) ( (byte *)md3 + md3->ofsFrames );
    for ( i = 0 ; i < md3->numFrames ; i++, frame++) {
    	frame->radius = LittleFloat( frame->radius );
        for ( j = 0 ; j < 3 ; j++ ) {
            frame->bounds[0][j] = LittleFloat( frame->bounds[0][j] );
            frame->bounds[1][j] = LittleFloat( frame->bounds[1][j] );
	    	frame->localOrigin[j] = LittleFloat( frame->localOrigin[j] );
        }
	}

	// swap all the tags
    tag = (md3Tag_t *) ( (byte *)md3 + md3->ofsTags );
    for ( i = 0 ; i < md3->numTags * md3->numFrames ; i++, tag++) {
        for ( j = 0 ; j < 3 ; j++ ) {
			tag->origin[j] = LittleFloat( tag->origin[j] );
			tag->axis[0][j] = LittleFloat( tag->axis[0][j] );
			tag->axis[1][j] = LittleFloat( tag->axis[1][j] );
			tag->axis[2][j] = LittleFloat( tag->axis[2][j] );
        }
	}

	// swap all the surfaces
	surf = (md3Surface_t *) ( (byte *)md3 + md3->ofsSurfaces );
	for ( i = 0 ; i < md3->numSurfaces ; i++) {

        LL(surf->ident);
        LL(surf->flags);
        LL(surf->numFrames);
        LL(surf->numShaders);
        LL(surf->numTriangles);
        LL(surf->ofsTriangles);
        LL(surf->numVerts);
        LL(surf->ofsShaders);
        LL(surf->ofsSt);
        LL(surf->ofsXyzNormals);
        LL(surf->ofsEnd);
		
		if ( surf->numVerts > SHADER_MAX_VERTEXES ) {
			common->Error( "InitFromFile: %s has more than %i verts on a surface (%i)",
				fileName, SHADER_MAX_VERTEXES, surf->numVerts );
		}
		if ( surf->numTriangles*3 > SHADER_MAX_INDEXES ) {
			common->Error( "InitFromFile: %s has more than %i triangles on a surface (%i)",
				fileName, SHADER_MAX_INDEXES / 3, surf->numTriangles );
		}
	
		// change to surface identifier
		surf->ident = 0;	//SF_MD3;

		// lowercase the surface name so skin compares are faster
		int slen = (int)strlen( surf->name );
		for( j = 0; j < slen; j++ ) {
			surf->name[j] = tolower( surf->name[j] );
		}

		// strip off a trailing _1 or _2
		// this is a crutch for q3data being a mess
		j = strlen( surf->name );
		if ( j > 2 && surf->name[j-2] == '_' ) {
			surf->name[j-2] = 0;
		}

        // register the shaders
        shader = (md3Shader_t *) ( (byte *)surf + surf->ofsShaders );
        for ( j = 0 ; j < surf->numShaders ; j++, shader++ ) {
            const idMaterial *sh;

            sh = declManager->FindMaterial( shader->name );
			shader->shader = sh;
        }

		// swap all the triangles
		tri = (md3Triangle_t *) ( (byte *)surf + surf->ofsTriangles );
		for ( j = 0 ; j < surf->numTriangles ; j++, tri++ ) {
			LL(tri->indexes[0]);
			LL(tri->indexes[1]);
			LL(tri->indexes[2]);
		}

		// swap all the ST
        st = (md3St_t *) ( (byte *)surf + surf->ofsSt );
        for ( j = 0 ; j < surf->numVerts ; j++, st++ ) {
            st->st[0] = LittleFloat( st->st[0] );
            st->st[1] = LittleFloat( st->st[1] );
        }

		// swap all the XyzNormals
        xyz = (md3XyzNormal_t *) ( (byte *)surf + surf->ofsXyzNormals );
        for ( j = 0 ; j < surf->numVerts * surf->numFrames ; j++, xyz++ ) 
		{
            xyz->xyz[0] = LittleShort( xyz->xyz[0] );
            xyz->xyz[1] = LittleShort( xyz->xyz[1] );
            xyz->xyz[2] = LittleShort( xyz->xyz[2] );

            xyz->normal = LittleShort( xyz->normal );
        }


		// find the next surface
		surf = (md3Surface_t *)( (byte *)surf + surf->ofsEnd );
	}
    
	fileSystem->FreeFile( buffer );
}

/*
=================
idRenderModelMD3::IsDynamicModel
=================
*/
dynamicModel_t idRenderModelMD3::IsDynamicModel() const {
	return DM_CACHED;
}

/*
=================
idRenderModelMD3::LerpMeshVertexes
=================
*/
void idRenderModelMD3::LerpMeshVertexes ( srfTriangles_t *tri, const struct md3Surface_s *surf, const float backlerp, const int frame, const int oldframe ) const {
	short	*oldXyz, *newXyz;
	float	oldXyzScale, newXyzScale;
	int		vertNum;
	int		numVerts;

	newXyz = (short *)((byte *)surf + surf->ofsXyzNormals) + (frame * surf->numVerts * 4);

	newXyzScale = MD3_XYZ_SCALE * (1.0 - backlerp);

	numVerts = surf->numVerts;

	if ( backlerp == 0 ) {
		//
		// just copy the vertexes
		//
		for (vertNum=0 ; vertNum < numVerts ; vertNum++, newXyz += 4 ) {

			idDrawVert *outvert = &tri->verts[tri->numVerts];

			outvert->xyz.x = newXyz[0] * newXyzScale;
			outvert->xyz.y = newXyz[1] * newXyzScale;
			outvert->xyz.z = newXyz[2] * newXyzScale;

			tri->numVerts++;
		}
	} else {
		//
		// interpolate and copy the vertexes
		//
		oldXyz = (short *)((byte *)surf + surf->ofsXyzNormals) + (oldframe * surf->numVerts * 4);

		oldXyzScale = MD3_XYZ_SCALE * backlerp;

		for (vertNum=0 ; vertNum < numVerts ; vertNum++, oldXyz += 4, newXyz += 4 ) {

			idDrawVert *outvert = &tri->verts[tri->numVerts];

			// interpolate the xyz
			outvert->xyz.x = oldXyz[0] * oldXyzScale + newXyz[0] * newXyzScale;
			outvert->xyz.y = oldXyz[1] * oldXyzScale + newXyz[1] * newXyzScale;
			outvert->xyz.z = oldXyz[2] * oldXyzScale + newXyz[2] * newXyzScale;

			tri->numVerts++;
		}
   	}
}

/*
=============
idRenderModelMD3::InstantiateDynamicModel
=============
*/
idRenderModel *idRenderModelMD3::InstantiateDynamicModel( const struct renderEntity_s *ent, const viewDef_t *view, idRenderModel *cachedModel ) {
	int				i, j;
	float			backlerp;
	int *			triangles;
	int				indexes;
	int				numVerts;
	md3Surface_t *	surface;
	int				frame, oldframe;
	idRenderModelStatic	*staticModel;

	if ( cachedModel ) {
		delete cachedModel;
		cachedModel = NULL;
	}

	staticModel = new (TAG_MODEL) idRenderModelStatic;
	staticModel->bounds.Clear();

	surface = (md3Surface_t *) ((byte *)md3 + md3->ofsSurfaces);

	// TODO: these need set by an entity
	frame = ent->shaderParms[SHADERPARM_MD3_FRAME];			// probably want to keep frames < 1000 or so
	oldframe = ent->shaderParms[SHADERPARM_MD3_LASTFRAME];
	backlerp = ent->shaderParms[SHADERPARM_MD3_BACKLERP];

	for( i = 0; i < md3->numSurfaces; i++ ) {

		srfTriangles_t *tri = R_AllocStaticTriSurf();
		R_AllocStaticTriSurfVerts( tri, surface->numVerts );
		R_AllocStaticTriSurfIndexes( tri, surface->numTriangles * 3 );
		tri->bounds.Clear();

		modelSurface_t	surf;

		surf.geometry = tri;

		md3Shader_t* shaders = (md3Shader_t *) ((byte *)surface + surface->ofsShaders);
		surf.shader = shaders->shader;

		LerpMeshVertexes( tri, surface, backlerp, frame, oldframe );

		triangles = (int *) ((byte *)surface + surface->ofsTriangles);
		indexes = surface->numTriangles * 3;
		for (j = 0 ; j < indexes ; j++) {
			tri->indexes[j] = triangles[j];
		}
		tri->numIndexes += indexes;

		const idVec2 * texCoords = (idVec2 *) ((byte *)surface + surface->ofsSt);

		numVerts = surface->numVerts;
		for ( j = 0; j < numVerts; j++ ) {
			tri->verts[j].SetTexCoord( texCoords[j] );
		}

		R_BoundTriSurf( tri );

		staticModel->AddSurface( surf );
		staticModel->bounds.AddPoint( surf.geometry->bounds[0] );
		staticModel->bounds.AddPoint( surf.geometry->bounds[1] );

		// find the next surface
		surface = (md3Surface_t *)( (byte *)surface + surface->ofsEnd );
	}

	return staticModel;
}

/*
=====================
idRenderModelMD3::Bounds
=====================
*/

idBounds idRenderModelMD3::Bounds(const struct renderEntity_s *ent) const {
	idBounds		ret;

	ret.Clear();

	if (!ent || !md3) {
		// just give it the editor bounds
		ret.AddPoint(idVec3(-10,-10,-10));
		ret.AddPoint(idVec3( 10, 10, 10));
		return ret;
	}

	md3Frame_t	*frame = (md3Frame_t *)( (byte *)md3 + md3->ofsFrames );

	ret.AddPoint( frame->bounds[0] );
	ret.AddPoint( frame->bounds[1] );

	return ret;
}