#ifndef Tridimensional_H
#define Tridimensional_H

/* Last edited on 2009-02-10 09:24:25 by stolfi */

/* Procedures that Write/Read a tridimensional state (.st3) and
  compute some 3D geometric operations. */
   
#define Tridimensional_H_copyright \
  "Copyright © 2000 Universidade Estadual de Campinas (UNICAMP)"

#include <Octf.h>
#include <Triangulation.h>

#include <r3x3.h>
#include <r4.h>
#include <r3.h>

#define _GNU_SOURCE
#include <stdio.h>

typedef r3_vec_t Coords3D_t;

typedef struct TetraData_t 
  { uint p0, p1, p2, p3;
    r3x3_t A;
    double density, alpha, beta;
  } TetraData_t;
  
vec_typedef(TetraData_vec_t,TetraData_vec,TetraData_t);
  /* A vector of {TetraData_t} */

r3_t Barycenter3D(ElemTableRec_t *too, Coords3D_t *c3);
  /* Returns the barycenter of all existing nodes. */
    
void Displace3D(ElemTableRec_t *top, r3_t *d, Coords3D_t *c3);
  /* Displaces all existing nodes by {d}. */

void Scale3D(ElemTableRec_t *top, double s, Coords3D_t *c3);
  /* Scales the coordinates of all existing nodes by {s}. */

double MeanNodeDistance3D(ElemTableRec_t *top, Coords3D_t *c3);
  /* The average distance of existing nodes from the origin, in the 
     root-mean-square sense; that is, {sqrt(sum(norm(c3[v])^2, v IN VExist))
     /|VExist|)}. */

void NormalizeNodeDistance3D(ElemTableRec_t *top, Coords3D_t *c3);
  /* Shifts and scales all existing nodes so that they have barycenter
     (0,0,0) and unit mean square distance from the origin. */

double TetraDet3D(uint u, uint v, uint w, uint x, Coords3D_t *c3);
  /* Signed determinant of the points {c3[u],c3[v],c3[w],c3[x]},
    padded at the right with a column of {1}s.  The absolute value 
    of {TetraDet3D} is is six times the volume of the tetrahedron {u,v,w,x},
    and the sign gives the handedness of the screw {u->v->w->x}.*/

bool_t WallIsSilhouette(Place_t p, Coords3D_t *c3);
  /* Return TRUE iff the projected wall associated to the {p} 
     is a silhouette wall. */

int EdgeWindingNumber(Place_t p, Coords3D_t *c3);
  /* Returns the winding number of the tetrahedra incident to the edge.
    In a proper embedding, the number should be +1 or -1. */

r4_t ChoosePlaneThroughPoints(r3_t *u, r3_t *v);
  /* Chooses a plane through the points {u} and {v}.
     Returns the plane coefficients, the last one being the 
     independent term. */

void FWriteState3D(FILE *wr, ElemTableRec_t *top, Coords3D_t *c3, char *cmt /* DF " " */);
  /* Writes the 3D geometric coordinates {c3->e[0..c3->nel-1]} to the
    previously opened file {wr}, in a format that can be read back by
    {FReadState3D}. The file {wr} will be flushed but will be left open. */

void WriteState3D(char *name, char *tag, ElemTableRec_t *top, Coords3D_t *c3, char *cmt /* DF { } */);
  /* Similar to {FWriteState3D}, but writes the data to a file "{name}{tag}.st3". */

Coords3D_t FReadState3D(FILE *rd);
  /* Reads from the previously opened file {rd} a vector of 3D
    geometric coordinates, in the format written by {WriteState3D},
    and returns it.  The file is left open. */

Coords3D_t ReadState3D(char *name, char *tag);
  /* Similar to {FReadState3D}, but the data is read from a disk file called
    "{name}{tag}.st3". */

void FWriteTetrahedra(FILE *wr, ElemTableRec_t *top, TetraData_vec_t *cell, char *cmt /* DF " " */);
  /* Writes the tetrahedron data {cell->e[0..dell->nel-1]} to the
    previously opened file {wr}, in a format that can be read back by
    {FReadTetrahedra}. The file {wr} will be flushed but will be left open. */

void WriteTetrahedra(char *name, char *tag, ElemTableRec_t *top, TetraData_vec_t *cell, char *cmt /* DF " " */);
  /* Similar to {}, but writes to a new disk file called
    "{name}{flage}.te". */

void WriteTetrahedron(FILE *wr, TetraData_t *t, uint nbase);
  /* Writes the data record of a single tetrahedron to {wr}. */

void ReadTetrahedron(FILE *rd, TetraData_t *t);
  /* Reads the data record single tetrahedron, produced by {WriteTetrahedron}. */

void FReadVectors(FILE *rd, uint n, Coords3D_t *pos);
  /* Reads a list of coordinates into {*pos}. */

#define Tridimensional_H_author \
  "Created by L.A.P.Lozada ca. 1999.\n" \
  "Some procedures are based on R. L. W. Liesenfeld's tools \n" \
  "/Animação dinâmica de corpos elásticos/, ca. ????.\n" \
  "Modified by L. A. P. lozada on 2000-02-19."

#endif