sparse_disk.c

射线追踪程序

/*
 * This file is part of tomo3d
 *
 * Copyright (C) 2002, 2003, Sebastien Judenherc <[e-mail]>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#include "sparse_disk.h"

#define EPS 1.0e-6

#define OK fprintf(stderr,"FILE %s LINE %d\n",__FILE__,__LINE__);

int save_cnt=0;

int writematrix(f,tmp)
FILE *f;
struct matrix_t * tmp;
{ float *line;
  int i,j;

  fprintf(stderr,"Writing matrix ...");
  fwrite(&(tmp->nl),sizeof(int),1,f);
  fwrite (&(tmp->nc),sizeof(int),1,f);
  fprintf(stderr,"%d:%d...",tmp->nl,tmp->nc);
  line=calloc(tmp->nc,sizeof(float));
  if (!line) {
     free(tmp);
     return(2);
  }
  for (i=0; i<tmp->nl; i++) {
      for (j=0; j<tmp->nc; j++) sparsegetval(tmp, i, j, &(line[j]));
      fwrite(line,sizeof(float),tmp->nc,f);
  }
  free(line);
  fprintf(stderr,"OK\n");
  return(0);
}

struct matrix_t * readmatrix(f)
FILE *f;
{ struct matrix_t * tmp;
  int L,C;

  fprintf(stderr,"Reading matrix ...");
  fread(&L,sizeof(int),1,f);
  fread(&C,sizeof(int),1,f);
  fprintf(stderr,"%d:%d...",L,C);
  tmp=newmatrix(L,C);
  if (!tmp) {
     return(NULL);
  }
  tmp->f=f;
  fseek(tmp->f,L*C*sizeof(float),SEEK_CUR);
  fprintf(stderr,"OK\n");
  return(tmp);
}

struct matrix_t * newmatrix(nl,nc)
int nl, nc;
{ struct matrix_t * tmp;
  tmp=(struct matrix_t *)calloc(1,sizeof(struct matrix_t));
  if (!tmp) return(NULL);

  tmp->nl=nl;
  tmp->nc=nc;
  tmp->lcache=-1;
  tmp->cache=(float*)calloc(nl,sizeof(float));
  if (!tmp->cache) {
     free(tmp);
     return(NULL);
  }
  return(tmp);
}

void sparsefreematrix(mat)
struct matrix_t * mat;
{
  free(mat->cache);
  fclose(mat->f);
  free(mat);
}

int sparsegetval( mat, i, j, val )
struct matrix_t * mat;
int i, j;
float *val;
{
        long dest;
        float v;
        assert(i<mat->nl);
        assert(j<mat->nc);
        if (i!=mat->lcache) {
                /* TESTER OPT */
                if (mat->lcache<0) {
                        mat->offset=ftell(mat->f);
                }
                dest=2*sizeof(int)+i*sizeof(float)*mat->nc;
                assert( fseek(mat->f,dest,SEEK_SET)==0 );
                mat->offset=dest-mat->offset;
                assert(fread(mat->cache,sizeof(float)*mat->nc,1,mat->f));
                mat->lcache=i;
        }
        v=*val=mat->cache[j];
        if (v>EPS) {
                return(1);
        }
        if (v<-EPS) {
                return(1);
        }
        return(0);
}