/* ==========================================================================
                          MAKE_FACE_C
=============================================================================

    FUNCTION NAMES

    face_reset			-- reset the face to neutral.
    create_face                 -- creates the face data
    create_face			-- returns a pointer to the head datastructure.
    make_face			-- makes a face from the two input files.
    add_polygon_to_face		-- adds a polygon to the face data structure.
    reflect_polygon 		-- reflect a polygon in the Y axis.
    void averaged_vertex_normals - compute the average vertex normals.
    data_struct 		-- create the datastructure for the face.

    C SPECIFICATIONS

    void face_reset 	( HEAD *face )
    HEAD *create_face 	( char *f1, char *f2 )	
    HEAD *create_face 	( f1, f2 )
    make_face 		( HEAD *face ) 
    add_polygon_to_face ( POLYGON *p, HEAD *face )
    reflect_polygon 	( POLYGON *poly, HEAD *face ) 
    void averaged_vertex_normals ( HEAD *face, int p, 
                                   float *n1, float *n2, float *n3 ) 
    data_struct 	( HEAD *face )

    DESCRIPTION

	This module is where the face data structures are created.
	T his module comes as is with no warranties.  

    HISTORY
	16-Dec-94  Keith Waters (waters) at DEC's Cambridge Research Lab
	Created.
	Modified 22-Nov-96 Sing Bing Kang (sbk@crl.dec.com)
	  Added function expressions() to enable changing facial expression

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

#include <math.h>           /* C header for any math functions               */
#include <stdio.h>          /* C header for standard I/O                     */
#include <string.h>         /* For String compare                            */
#include <stdlib.h>
#ifndef WIN32
#include <sys/types.h>
#include <sys/file.h>
#endif

#include "memory.h"         /* Local memory allocation macros                */
#include "head.h"	    /* local header for the face		     */

void reflect_polygon ( POLYGON *poly, HEAD *face );
void add_polygon_to_face ( POLYGON *p, HEAD *face );
void make_face ( HEAD *face );

/* ========================================================================= */  
/* face_reset	                                                             */
/* ========================================================================= */  
/*
** Resets the geometry of the face to neutral.
**
*/

void face_reset ( HEAD *face )
{
  int i,j,k ;

  
  for ( i=0; i<face->npolygons; i++ ) {

    for ( j=0; j<3; j++ ) {

      for ( k=0; k<3; k++ ) {
	face->polygon[i]->vertex[j]->xyz[k] = 
	  face->polygon[i]->vertex[j]->nxyz[k] ;
      }
    }
  }
}


/* ========================================================================= 
   expressions                                                            
   Written by: Sing Bing Kang
   Date: 11/22/96
   ========================================================================= */  
/*
** Produces the facial expressions as indicated by the muscle contraction
** vector
**
*/

void
expressions ( HEAD *face, int e )
{
    int m;

    fprintf( stderr, "Expression: %s\n", face->expression[e]->name );

    for (m=0; m<face->nmuscles; m++) {
	float m_val = face->expression[e]->m[m],
              m_diff = m_val - face->muscle[m]->mstat;

	face->muscle[m]->mstat = m_val;
        activate_muscle ( face,
                         face->muscle[m]->head,
                         face->muscle[m]->tail,
                         face->muscle[m]->fs,
                         face->muscle[m]->fe,
                         face->muscle[m]->zone,
                         m_diff ) ;
    }

}

/* ========================================================================= */  
/* create_face	                                                             */
/* ========================================================================= */  
/*
** create the default structures for the face and retrun a pointer.
**
*/

HEAD *create_face ( char *f1, char *f2 )
{
  HEAD *h ;
  
  h = _new ( HEAD ) ;
  
  h->npolygons		= 0 ;
  h->npindices		= 0 ;
  h->npolylinenodes	= 0 ;

  read_polygon_indices ( f1, h ) ;
  read_polygon_line    ( f2, h ) ;

  make_face ( h ) ;
  
  return ( h ) ;

}

/* ========================================================================= */  
/* make_face                                                                 */
/* ========================================================================= */  
/*
** makes the face from the two input files.
**
*/

void
make_face ( HEAD *face ) 
{
  POLYGON  *p ;
  int i, ii, j, k,
      p1, p2, p3, p4 ;
  int parray[4] ;

  for ( i=0, ii=0; i < face->npindices; i++,ii+=4 ) {

    p1 = face->indexlist[ii]   -1 ;
    p2 = face->indexlist[ii+1] -1 ;
    p3 = face->indexlist[ii+2] -1 ;
    p4 = face->indexlist[ii+3] -1 ;

    for (j=0; j<4; j++)
      parray[j] = face->indexlist[ii+j] -1;

    if ( p1 == 999 ) {

      p = _new ( POLYGON ) ;
      for (j=0; j<3; j++) {
	p->vertex[j] = _new ( VERTEX ) ;
	p->vertex[j]->np = 0 ;
      }

      for (j=0; j<3; j++) 
	p->vertex[0]->nxyz[j] = 
	p->vertex[0]->xyz[j]  = face->polyline[ p2*3 + j ] ;
      
      for (j=0; j<3; j++) 
	p->vertex[1]->nxyz[j] = 
        p->vertex[1]->xyz[j]  = face->polyline[ p3*3 + j ] ;
      
      for (j=0; j<3; j++) 
	p->vertex[2]->nxyz[j] = 
        p->vertex[2]->xyz[j]  = face->polyline[ p4*3 + j ] ;

      add_polygon_to_face ( p, face ) ;
      reflect_polygon     ( p, face ) ;
    }
    else {
      p = _new ( POLYGON ) ;
      for (j=0; j<3; j++) {
	p->vertex[j] = _new ( VERTEX ) ;
	p->vertex[j]->np = 0 ;
      }

      for (k=0; k<3; k++) {
	for (j=0; j<3; j++) 
	  p->vertex[k]->nxyz[j] =
	  p->vertex[k]->xyz[j]  = face->polyline[ parray[k]*3 + j ] ;
      }

      add_polygon_to_face ( p, face ) ;
      reflect_polygon     ( p, face ) ;

      p = _new ( POLYGON ) ;
      for (j=0; j<3; j++) {
	p->vertex[j] = _new ( VERTEX ) ;
	p->vertex[j]->np = 0 ;
      }

      for (j=0; j<3; j++) 
	p->vertex[0]->nxyz[j] = 
	p->vertex[0]->xyz[j]  = face->polyline[ p1*3 + j ] ;
      
      for (j=0; j<3; j++) 
	p->vertex[1]->nxyz[j] =
	p->vertex[1]->xyz[j]  = face->polyline[ p3*3 + j ] ;
      
      for (j=0; j<3; j++) 
	p->vertex[2]->nxyz[j] = 
	p->vertex[2]->xyz[j]  = face->polyline[ p4*3 + j ] ;

      add_polygon_to_face ( p, face ) ;
      reflect_polygon     ( p, face ) ;
      }
  }

}

/* ========================================================================= */  
/* add_polygon_to_face                                                       */
/* ========================================================================= */  
/*
** add a polygon to the face structure.
**
*/

void
add_polygon_to_face ( POLYGON *p, HEAD *face )
{
  int nn ;

  if(face->npolygons == 0)
      face->polygon = _new_array(POLYGON *, 500) ;
  else if(face->npolygons % 500 == 0)
      face->polygon = _resize_array(face->polygon,POLYGON *,face->npolygons+500) ;

  nn = face->npolygons ;
  face->polygon[nn] = p ;

  face->npolygons++ ;

}


/* ========================================================================= */  
/* reflect_polygon                                                           */
/* ========================================================================= */  
/*
**  Reflects all the polygons in the half-face and adds them to
**  the data structure.
**
*/

void
reflect_polygon ( POLYGON *poly, HEAD *face ) 
{
  POLYGON *newp ;
  float   temp[3] ;
  int      i, j ;
  
  /* 
   * Allocate memory for the new polygon. 
  */
  newp = _new ( POLYGON ) ;
  for (j=0; j<3; j++) {
    newp->vertex[j] = _new ( VERTEX ) ;
    newp->vertex[j]->np = 0 ;
  }

  /* 
   * Load the old polygon values. 
  */
  for (i=0; i<3; i++) 
    for (j=0; j<3; j++)
      newp->vertex[i]->nxyz[j] = 
      newp->vertex[i]->xyz[j]  = poly->vertex[i]->xyz[j] ;

  /* 
   * flip the X component.         
  */
  for (i=0; i<3; i++) 
    newp->vertex[i]->nxyz[0] = 
    newp->vertex[i]->xyz[0]  = -newp->vertex[i]->xyz[0] ;
  
  /* 
   * Re-order the vertices, flip 0 and 1.
  */
  for (j=0; j<3; j++)
    temp[j] = newp->vertex[0]->xyz[j] ;

  for (j=0; j<3; j++)
    newp->vertex[0]->nxyz[j] = 
    newp->vertex[0]->xyz[j]  = newp->vertex[1]->xyz[j];

  for (j=0; j<3; j++)
    newp->vertex[1]->nxyz[j] = 
    newp->vertex[1]->xyz[j]  = temp[j] ;

  add_polygon_to_face ( newp, face ) ;

}

/* ========================================================================= */  
/* averaged_vertex_normals                                                   */
/* ========================================================================= */  
/*
** Caculates the averaged polygon normal.
*/

void averaged_vertex_normals ( HEAD *face, int p, float *n1, float *n2, float *n3 ) 
{
  int i,j,np, pt ;
  float norm[3] ;


  for (i=0; i<3; i++)
    norm[i] = 0.0 ;

  np = face->polygon[p]->vertex[0]->np ;

  for ( i=0; i<np; i++) {
    pt = face->polygon[p]->vertex[0]->plist[i] ;

    for ( j=0; j<3; j++)  {
      norm[j] += face->polygon[pt]->vertex[0]->norm[j] ;
    }
  }

  for (i=0; i<3; i++)
    norm[i] = norm[i] / (float)np ;
    
  for (i=0; i<3; i++)
    n1[i] = norm[i] ;

  for (i=0; i<3; i++)
    norm[i] = 0.0 ;

  np = face->polygon[p]->vertex[1]->np ;

  for ( i=0; i<np; i++) {
    pt = face->polygon[p]->vertex[1]->plist[i] ;

    for ( j=0; j<3; j++) {
      norm[j] += face->polygon[pt]->vertex[1]->norm[j] ;
    }
  }

  for (i=0; i<3; i++)
    norm[i] = norm[i] / (float) np ;

  for (i=0; i<3; i++)
    n2[i] = norm[i] ;

  for (i=0; i<3; i++)
    norm[i] = 0.0 ;

  np = face->polygon[p]->vertex[2]->np ;

  for ( i=0; i<np; i++) {
    pt = face->polygon[p]->vertex[2]->plist[i] ;

    for ( j=0; j<3; j++) {
      norm[j] += face->polygon[pt]->vertex[2]->norm[j] ;
    }
  }

  for (i=0; i<3; i++)
    norm[i] = norm[i]/ (float) np ;
    
  for (i=0; i<3; i++)
    n3[i] = norm[i] ;
   
}

/* ========================================================================= */  
/* data_struct	                                                             */
/* ========================================================================= */  
/*
** Create a new data structure for the polygons.
**
*/
#define DATA_STRUCT_DEBUG 0

void
data_struct ( HEAD *face )
{
  int i,j, n ;
  int flag, cptr ;
  float x1,y1,z1, x2, y2, z2, x3, y3, z3 ;
  float tx1, ty1, tz1, tx2, ty2, tz2, tx3, ty3, tz3 ;

  for (i=0; i<face->npolygons; i++ ){

      x1 = face->polygon[i]->vertex[0]->xyz[0] ;
      y1 = face->polygon[i]->vertex[0]->xyz[1] ;
      z1 = face->polygon[i]->vertex[0]->xyz[2] ;

      x2 = face->polygon[i]->vertex[1]->xyz[0] ;
      y2 = face->polygon[i]->vertex[1]->xyz[1] ;
      z2 = face->polygon[i]->vertex[1]->xyz[2] ;

      x3 = face->polygon[i]->vertex[2]->xyz[0] ;
      y3 = face->polygon[i]->vertex[2]->xyz[1] ;
      z3 = face->polygon[i]->vertex[2]->xyz[2] ;
#if DATA_STRUCT_DEBUG
      fprintf (stderr,"BASE polygon: %d\n", i) ;
      fprintf (stderr,"x1: %f y1: %f z1: %f\n", x1,y1,z1) ;
      fprintf (stderr,"x1: %f y1: %f z1: %f\n", x2,y2,z2) ;
      fprintf (stderr,"x1: %f y1: %f z1: %f\n", x3,y3,z3) ;
#endif
      j    = 0 ;
      flag = 0 ;
      while ( !flag  &&
	      j<face->npolygons ) {

	tx1 = face->polygon[j]->vertex[0]->xyz[0] ;
	ty1 = face->polygon[j]->vertex[0]->xyz[1] ;
	tz1 = face->polygon[j]->vertex[0]->xyz[2] ;

	tx2 = face->polygon[j]->vertex[1]->xyz[0] ;
	ty2 = face->polygon[j]->vertex[1]->xyz[1] ;
	tz2 = face->polygon[j]->vertex[1]->xyz[2] ;

	tx3 = face->polygon[j]->vertex[2]->xyz[0] ;
	ty3 = face->polygon[j]->vertex[2]->xyz[1] ;
	tz3 = face->polygon[j]->vertex[2]->xyz[2] ;
#if DATA_STRUCT_DEBUG
	fprintf (stderr, "COMPARED TO polygon: %d\n", j) ;
	fprintf (stderr,"tx1: %f ty1: %f tz1: %f\n", tx1,ty1,tz1) ;
	fprintf (stderr,"tx1: %f ty1: %f tz1: %f\n", tx2,ty2,tz2) ;
	fprintf (stderr,"tx1: %f ty1: %f tz1: %f\n", tx3,ty3,tz3) ;
#endif	
	if ( x1 == tx1 && y1 == ty1 && z1 == tz1 ||
	     x1 == tx2 && y1 == ty2 && z1 == tz2 ||
	     x1 == tx3 && y1 == ty3 && z1 == tz3) {
	  cptr = j ;
#if DATA_STRUCT_DEBUG
	  fprintf (stderr,"found a vertex match on polygon: %d and %d\n", i,j);
#endif
	  n = face->polygon[i]->vertex[0]->np ;
	  face->polygon[i]->vertex[0]->plist[n] = cptr ;
	  face->polygon[i]->vertex[0]->np++ ;
#if DATA_STRUCT_DEBUG
	  fprintf (stderr,"loaded: %d onto polygon: %d vertex[0]\n", cptr, i) ;
	  fprintf (stderr,"total on vertex: %d\n", face->polygon[i]->vertex[0]->np);
#endif
	}
	j++ ;

      } /* end while */


      j    = 0 ;
      flag = 0 ;
      while ( !flag  &&
	      j<face->npolygons ) {
	tx1 = face->polygon[j]->vertex[0]->xyz[0] ;
	ty1 = face->polygon[j]->vertex[0]->xyz[1] ;
	tz1 = face->polygon[j]->vertex[0]->xyz[2] ;

	tx2 = face->polygon[j]->vertex[1]->xyz[0] ;
	ty2 = face->polygon[j]->vertex[1]->xyz[1] ;
	tz2 = face->polygon[j]->vertex[1]->xyz[2] ;

	tx3 = face->polygon[j]->vertex[2]->xyz[0] ;
	ty3 = face->polygon[j]->vertex[2]->xyz[1] ;
	tz3 = face->polygon[j]->vertex[2]->xyz[2] ;

	if ( x2 == tx1 && y2 == ty1 && z2 == tz1 ||
	     x2 == tx2 && y2 == ty2 && z2 == tz2 ||
	     x2 == tx3 && y2 == ty3 && z2 == tz3) {
	  cptr = j ;

	  n = face->polygon[i]->vertex[1]->np ;
	  face->polygon[i]->vertex[1]->plist[n] = j ;
	  face->polygon[i]->vertex[1]->np++ ;

	}
	j++ ;

      } /* end while */

      j    = 0 ;
      flag = 0 ;
      while ( !flag  &&
	      j<face->npolygons ) {
	tx1 = face->polygon[j]->vertex[0]->xyz[0] ;
	ty1 = face->polygon[j]->vertex[0]->xyz[1] ;
	tz1 = face->polygon[j]->vertex[0]->xyz[2] ;

	tx2 = face->polygon[j]->vertex[1]->xyz[0] ;
	ty2 = face->polygon[j]->vertex[1]->xyz[1] ;
	tz2 = face->polygon[j]->vertex[1]->xyz[2] ;

	tx3 = face->polygon[j]->vertex[2]->xyz[0] ;
	ty3 = face->polygon[j]->vertex[2]->xyz[1] ;
	tz3 = face->polygon[j]->vertex[2]->xyz[2] ;

	if ( x3 == tx1 &&  y3 == ty1 &&  z3 == tz1 ||
	     x3 == tx2 &&  y3 == ty2 &&  z3 == tz2 ||
	     x3 == tx3 &&  y3 == ty3 &&  z3 == tz3) {
	  cptr = j ;

	  n = face->polygon[i]->vertex[2]->np ;
	  face->polygon[i]->vertex[2]->plist[n] = cptr ;
	  face->polygon[i]->vertex[2]->np++ ;

	}
	j++ ;

      } /* end while */
    } /* end for i */
}