flightgear/Stripe_w/bands.c

/********************************************************************/
/*   STRIPE: converting a polygonal model to triangle strips    
     Francine Evans, 1996.
     SUNY @ Stony Brook
     Advisors: Steven Skiena and Amitabh Varshney
*/
/********************************************************************/

/*---------------------------------------------------------------------*/
/*   STRIPE: bands.c
     This file contains the main procedure code that will read in the
     object and then call the routines that produce the triangle strips.
*/
/*---------------------------------------------------------------------*/


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif
  
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "global.h"
#include "polverts.h"
#include "triangulate.h"
#include "ties.h"
#include "outputex.h"
#include "options.h"
#include "local.h"
#include "init.h"
#include "free.h"
#include "add.h"

/*   TIMING for Windows */
#ifdef WIN32
#include <sys/timeb.h>
#include <time.h>
/*   TIMING for UNIX */
#else
#include <sys/types.h>
#include <sys/param.h>
#include <sys/times.h>
extern long times( );
long elapsed()
{
  static long total = 0;
  long cpu_time, dummy;
  struct tms buffer;
  times(&buffer);
  dummy    = buffer.tms_utime  + buffer.tms_stime +
             buffer.tms_cutime + buffer.tms_cstime;
  cpu_time = ((dummy - total) * 1000) / HZ;
  total    = dummy;
  return(cpu_time);
}
#endif


int     norms[STRIP_MAX];
int     *vert_norms;
int     *vert_texture;


void get_time()
{
  /*   For timing */
#ifdef WIN32
  struct timeb timebuffer;
  char *timeline;
#else
  long timer;
#endif


#ifdef WIN32
  ftime( &timebuffer );
  timeline = ctime( & ( timebuffer.time ) );
  printf( "The time is %.19s.%hu %s", timeline, timebuffer.millitm, &timeline[20] );
#else
  timer = elapsed();
  printf("The time is %ld\n",timer);
#endif
}

/*
** 
     Here the main program begins. It will start by loading in a .obj file
     then it will convert the polygonal model into triangle strips.
**  
*/

int main (int argc,char *argv[])
{
  char	*fname,*all,buff[255], *ptr, *ptr2;
	FILE	*file, *bands;
	int face_id=0;
  int vert_count=0;
  int loop=0;
  int num=0;
  int num2=0;

	float center[3];
  int temp[STRIP_MAX],vertex,strips, swaps,tempi,cost,triangles;
  int f,t,tr,g;
  char *file_open;
	int	num_vert	= 0,
		num_faces	= 0,
		num_nvert	= 0,
		num_edges	= 0,
    num_texture = 0,
    num_tris = 0;
  double fra = 0.0;
  BOOL texture, normal, normal_and_texture,quads = FALSE;

  /*   Options variables */
  double norm_difference;

	/*   Structures for the object */
  struct vert_struct	*vertices	= NULL,
    *nvertices	= NULL,
		*pvertices	= NULL,
		*pnvertices	= NULL;

  get_time();

  /*   File that will contain the triangle strip data */
  bands = fopen("stripe.objf","w");

  /*
	Scan the file once to find out the number of vertices,
	vertice normals, and faces so we can set up some memory
	structures 
	*/
	/* Interpret the options specified */
	norm_difference = get_options(argc,argv,&f,&t,&tr,&g);
  if (f == BINARY)
    file_open = "rb";
  else
    file_open = "r";

	fname = argv[argc-1];

  printf ("File: %s\n",fname);
	printf ("Scanning...%s ",file_open);

	    
  /*   File can be in binary for faster reading */
  if (file = fopen (fname,file_open))
	{
	  while (!feof (file))
		{
			/*   Read a line */
      if (f == BINARY)
        fread (buff,sizeof(char) * 255,1, file);
			else
        fgets (buff, sizeof(char) * 255, file);
      num++;
      
      printf("%d\r",num);

      
      /*   At a vertex */
      if (*buff == 'v')
			{
				/*   At a normal */
        if (*(buff+1)=='n')
					num_nvert++;
				else if (*(buff+1)=='t')
          num_texture++;
        /*   At a regular vertex */
        else
				  num_vert++;
			}
			/*   At a face */
      else if (*buff == 'f')
			{  
        num_faces++;
			  strtok(buff, " ");
			  tempi = 0;
			  while (strtok(NULL, " ") != NULL) tempi++;
			  num_tris += tempi - 2;
      }
		}
		fclose (file);
  }
	else
  {
    printf("Error in the file name\n");
    exit(1);
  }
	
  printf("%s pass 1\n",fname);
	
	/* Allocate structures for the information */
	Start_Face_Struct(num_faces);
	vertices = (struct vert_struct *)
			malloc (sizeof (struct vert_struct) * num_vert);

	if (num_nvert > 0) {
    nvertices = (struct vert_struct *)
		malloc (sizeof (struct vert_struct) * num_nvert);
    vert_norms = (int *) malloc (sizeof (int) * num_vert);
    /*   
    Initialize entries to zero, in case there are 2 hits
    to the same vertex we will know it - used for determining
    the normal difference
    */
    init_vert_norms(num_vert);
  } else {
		nvertices = NULL;
  }

  if (num_texture > 0) {
    vert_texture = (int *) malloc (sizeof(int) * num_vert);
    init_vert_texture(num_vert);
  }
     
	/*
  Set up the temporary 'p' pointers 
  */
	pvertices = vertices;
	pnvertices = nvertices;

	/* Load the object into memory */
	/*printf (" Loading...");*/
 
   fprintf(bands,"#%s: a triangle strip representation created by STRIPE.\n#This is a .objf file\n#by Francine Evans\n",fname);
 
  /*  File will be put in a list for faster execution if file is in binary */   
  if (file = fopen(fname,file_open)) {
    if (f == BINARY) {
      all = (char *) malloc (sizeof(char) * 255 * num);
      fread(all,sizeof(char) * 255 * num, 1, file);
      ptr = all;
    } else {
      ptr = (char *) malloc (sizeof(char) * 255 * num);
    }
  }

   
  while (num > 0) {
    num--;

    printf("%d\r",num);

		if (f == ASCII) {
      fgets (ptr, sizeof(char) * 255, file);
    } else {
      ptr = ptr + 255;
    }

    /* Load in vertices/normals */
		if (*ptr == 'v') {
			if (*(ptr+1)=='n') {
				sscanf (ptr+3,"%lf%lf%lf",
					&(pnvertices->x),
					&(pnvertices->y),
					&(pnvertices->z));
	   			fprintf(bands,"vn %f %f %f\n",
					pnvertices->x,pnvertices->y,pnvertices->z); 
     			++pnvertices;
			} else if (*(ptr+1)=='t') {
				sscanf (ptr+3,"%f%f%f",&center[0],&center[1],&center[2]);
	   		fprintf(bands,"vt %f %f %f\n",center[0],center[1],center[2]); 
      } else {
				sscanf (ptr+2,"%lf%lf%lf",
					&(pvertices->x), 
					&(pvertices->y), 
					&(pvertices->z));
     			fprintf(bands,"v %f %f %f\n",
					pvertices->x,pvertices->y,pvertices->z); 
				++pvertices;
      }
		} else if (*ptr == 'f') {
			/* Read in faces */
			num2 = 0;
			face_id++;
      ptr2 = ptr+1;
      normal = FALSE; texture = FALSE, normal_and_texture = FALSE;
      while (*ptr2) {
			  if (*ptr2 >='0' && *ptr2 <='9') {
				  num2++;
				  ++ptr2;
				  while (*ptr2 && (*ptr2!=' ' && *ptr2!='/')) {
					  ptr2++;
          }
          /*   There are normals in this line */
          if (*ptr2 == '/') {
            if (*(ptr2+1) == '/') {
              normal = TRUE;
            } else {
              texture = TRUE;
            }
			    } else if (*ptr2 == ' ') {
            if ((num2 == 3) && (texture)) {
              normal_and_texture = TRUE;
            }
          }
        } else {
				  ++ptr2;
        }
			}

      ptr2 = ptr+1;
			
      /* 
      loop on the number of numbers in this line of face data 
      */
			vert_count = 0;
								
			for (loop=0;loop<num2;loop++) {
				/* skip the whitespace */
				while (*ptr2<'0' || *ptr2>'9') {
          if (*ptr2 == '-') {
            break;
          }
          ptr2++;
        }
				vertex = atoi(ptr2)-1;
        if (vertex < 0) {
          vertex = num_vert + vertex;
          *ptr2 = ' ';
          ptr2++;
        }
        /*
        If there are either normals or textures with the vertices
        in this file, the data alternates so we must read it this way 
        */
				if ( (normal) && (!normal_and_texture)) {
					if (loop%2) {
            add_norm_id(vertex,vert_count);
            /*
            Test here to see if we added a new vertex, since the
            vertex has more than one normal and the 2 normals are greater
            than the threshold specified
            */
            if (norm_array(vertex,0,norm_difference,nvertices,num_vert)) {
              /*
              Add a new vertex and change the
              id of the vertex that we just read to the id of the new
              vertex that we just added
              */
              /*
              Put it in the output file, note the added vertices will
              be after the normals and separated from the rest of the 
              vertices. Will not affect our viewer
              */
              fprintf(bands,"v %f %f %f\n",
                (vertices + temp[vert_count - 1])->x,
                (vertices + temp[vert_count - 1])->y,
                (vertices + temp[vert_count - 1])->z); 
              num_vert++;
              temp[vert_count - 1] = num_vert - 1;
              if (!(add_vert_id(num_vert - 1,vert_count))) {
                vert_count--;
              }
            }
          } else {
					  /* the vertex */
						temp[vert_count] = vertex ;
						vert_count++;
            if (!(add_vert_id(vertex,vert_count))) {
                vert_count--;
            }
            norm_array(vertex,1,norm_difference,nvertices,num_vert);
					}
        } else if (normal_and_texture) {                      
          /* Else there are vertices and textures with the data */
          if( !((loop+1)%3)) {
            add_norm_id(vertex,vert_count);
            /*
            Test here to see if we added a new vertex, since the
            vertex has more than one normal and the 2 normals are greater
            than the threshold specified
            */
            if (norm_array(vertex,0,norm_difference,nvertices,num_vert)) {
              /*
              Add a new vertex and change the
              id of the vertex that we just read to the id of the new
              vertex that we just added
              */
              /*
              Put it in the output file, note the added vertices will
              be after the normals and separated from the rest of the 
              vertices. Will not affect our viewer
              */
              fprintf(bands,"v %f %f %f\n",
                (vertices + temp[vert_count - 1])->x,
                (vertices + temp[vert_count - 1])->y,
                (vertices + temp[vert_count - 1])->z); 
              num_vert++;
              temp[vert_count - 1] = num_vert - 1;
              if (!(add_vert_id(num_vert - 1,vert_count))) {
                vert_count--;
              }
            }
          } else if ((loop == 0) || (*(ptr2-1) == ' ')) {
            /*   the vertex */
            temp[vert_count] = vertex ;
            vert_count++;
            if (vert_count == 4) {
              quads = TRUE;
            }
            if (!(add_vert_id(vertex,vert_count))) {
              vert_count--;
            }
            add_texture(vertex,TRUE);
            norm_array(vertex,1,norm_difference,nvertices,num_vert);
					} else {
            /*   The texture */
            add_texture(vertex,FALSE);
          }
        } else if ( texture ) {
					/*   the vertex */
          if (!(loop%2)) {
						temp[vert_count] = vertex ;
						vert_count++;
            if (vert_count == 4)
              quads = TRUE;
            add_texture(vertex,TRUE);
            if (!(add_vert_id(vertex,vert_count)))
              vert_count--;
            norm_array(vertex,1,norm_difference,nvertices,num_vert);
					} else {
            /*   texture */
            add_texture(vertex,FALSE);
          }
        } else {
				  /*** no nvertices ***/
					temp[vert_count] = vertex ;
					vert_count++;
          if (vert_count == 4)
            quads = TRUE;
          if (!(add_vert_id(vertex,vert_count)))
            vert_count--;
				}
				while (*ptr2>='0' && *ptr2<='9')
					ptr2++;
      }
			/* Done with the polygon */
			num_edges += vert_count;
			/* add it to face structure */
			if (vert_count >= 3)
        AddNewFace(ids,vert_count,face_id,norms);
      else
        face_id--;
      if (vert_count == 4)
        quads = TRUE;
    }
    else if ((g == TRUE) && (face_id > 0)
         && ((*ptr == 'g') || (*ptr  == 's') || (*ptr == 'm') || (*ptr == 'o')))
    {
      /*
      The user specified that the strips will be contained in each group
      from the data file, so we just finished a group and will find the
      triangle strips in it.
      */
      Start_Edge_Struct(num_vert);
	    Find_Adjacencies(face_id);
	    if (quads)
      {
        Init_Table_SGI();
	      Build_SGI_Table(num_vert,face_id);
        /* Code for lengths of walks in each direction */
	      /* Save_Walks(face_id,TRUE); */
	      Save_Walks(face_id);

        /* Code for finding the bands */
	      Find_Bands(face_id,bands,&swaps,&strips,&cost,&triangles,num_nvert,vert_norms,num_texture,vert_texture);

        /*
        Remove the faces that we did  so that we can
        run the strip code on the rest of the faces that are left
        */
        if (cost != 0)
        {
          printf("Total %d triangles with %d cost\n",triangles,cost);
          Save_Rest(&face_id);
          printf("We saved %d .... now doing the local algorithm\n",face_id);
          fprintf(bands,"\n#local\n");
	        End_Edge_Struct(num_vert);
          Start_Edge_Struct(num_vert);
	        Find_Adjacencies(face_id);
        }
      }
	       
      SGI_Strip(num_vert,face_id,bands,t,tr);

      /* Get the total cost */
      Output_TriEx(-1,-2,-3,NULL,-1,-20,cost);

      End_Face_Struct(num_faces);
      End_Edge_Struct(num_vert);
      cost = 0;
      face_id = 0;
      quads = FALSE;
      Start_Face_Struct(num_faces-face_id);
      num_faces = num_faces - face_id;
      Free_Strips();
    }
  }
               
  /*   Done reading in all the information into data structures */
  num_faces = face_id;
  fclose (file);
  
  printf("Input Done.\n\n");

  free(vertices);
  free(nvertices);

  printf ("Vertices:	%d\nNormals:	%d\nFaces:		%d\n",num_vert,num_nvert,num_faces);

  Start_Edge_Struct(num_vert);
  Find_Adjacencies(num_faces);

  /* Initialize it */
  Init_Table_SGI();
  /* Build it */
  Build_SGI_Table(num_vert,num_faces);

  InitStripTable();

  if (quads) {
    /* Code for lengths of walks in each direction */
          /* Save_Walks(num_faces,TRUE); */
	  Save_Walks(num_faces);
	  
    /* Code for finding the bands */
	  Find_Bands(num_faces,bands,&swaps,&strips,&cost,&triangles,num_nvert,vert_norms,num_texture,vert_texture);
    /*printf("Total %d triangles with %d cost\n",triangles,cost);*/

    /*  
    Remove the faces that we did  so that we can
    run the strip code on the rest of the faces that are left
    */
    Save_Rest(&num_faces);
    /*printf("We saved %d .... now doing the local algorithm\n",num_faces);*/
    fprintf(bands,"\n#local\n");
	  End_Edge_Struct(num_vert);
    Start_Edge_Struct(num_vert);
	  Find_Adjacencies(num_faces);
  }
	       
  SGI_Strip(num_vert,num_faces,bands,t,tr);

  /*   Get the total cost */
  Output_TriEx(-1,-2,-3,NULL,-1,-20,cost);

  End_Face_Struct(num_faces);
  End_Edge_Struct(num_vert);
  fclose(bands);

  get_time();

  return(0);
}