forked from ExternalVendorCode/Signal-Server
723 lines
14 KiB
C
723 lines
14 KiB
C
/**************************************************************\
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** Created originally by Jonathan Naylor, G4KLX. **
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** Later embellished by John Magliacane, KD2BD to **
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** detect and handle voids found in the SRTM data, **
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** SRTM-3 data in .BIL and .HGT format, and high **
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** resolution SRTM-1 one arc-second topography data. **
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**************************************************************
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** Compile like this: **
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** cc -Wall -O3 -s -lbz2 srtm2sdf.c -o srtm2sdf **
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** Last modification: 20-Jan-2011 **
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\**************************************************************/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <bzlib.h>
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#define BZBUFFER 65536
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char sdf_filename[30], sdf_path[255], replacement_flag, opened=0,
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hgt=0, bil=0;
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int srtm[3601][3601], usgs[1201][1201], max_north, max_west, n,
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min_north, min_west, merge=0, min_elevation, bzerror, ippd, mpi;
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int ReadSRTM(char *filename)
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{
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int x, y, infile, byte=0, bytes_read;
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unsigned char error, buffer[2];
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char north[3], west[4], *base=NULL, blw_filename[255];
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double cell_size, deg_north, deg_west;
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FILE *fd=NULL;
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if (strstr(filename, ".zip")!=NULL)
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{
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fprintf(stderr, "*** Error: \"%s\" must be uncompressed\n",filename);
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return -1;
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}
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if (strstr(filename, ".tgz")!=NULL)
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{
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fprintf(stderr, "*** Error: \"%s\" must be uncompressed\n",filename);
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return -1;
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}
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if ((strstr(filename, ".hgt")==NULL) && (strstr(filename, ".bil")==NULL))
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{
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fprintf(stderr, "*** Error: \"%s\" does not have the correct extension (.hgt or .bil)\n",filename);
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return -1;
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}
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if (strstr(filename, ".hgt")!=NULL)
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hgt=1;
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if (strstr(filename, ".bil")!=NULL)
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bil=1;
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base=strrchr(filename, '/');
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if (base==NULL)
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base=filename;
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else
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base+=1;
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if (hgt)
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{
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/* We obtain coordinates from the base of the .HGT filename */
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north[0]=base[1];
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north[1]=base[2];
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north[2]=0;
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west[0]=base[4];
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west[1]=base[5];
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west[2]=base[6];
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west[3]=0;
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if ((base[0]!='N' && base[0]!='S') || (base[3]!='W' && base[3]!='E'))
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{
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fprintf(stderr, "*** Error: \"%s\" doesn't look like a valid .hgt SRTM filename.\n", filename);
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return -1;
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}
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max_west=atoi(west);
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if (base[3]=='E')
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max_west=360-max_west;
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min_west=max_west-1;
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if (max_west==360)
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max_west=0;
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if (base[0]=='N')
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min_north=atoi(north);
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else
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min_north=-atoi(north);
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max_north=min_north+1;
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}
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if (bil)
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{
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/* We obtain .BIL file coordinates
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from the corresponding .BLW file */
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strncpy(blw_filename,filename,250);
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x=strlen(filename);
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if (x>3)
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{
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blw_filename[x-2]='l';
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blw_filename[x-1]='w';
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blw_filename[x]=0;
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fd=fopen(blw_filename,"rb");
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if (fd!=NULL)
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{
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n=fscanf(fd,"%lf",&cell_size);
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if ((cell_size<0.0008) || (cell_size>0.0009))
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{
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printf("\n*** .BIL file's cell size is incompatible with SPLAT!!\n");
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exit(1);
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}
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n=fscanf(fd,"%lf",°_west);
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n=fscanf(fd,"%lf",°_west);
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n=fscanf(fd,"%lf",°_west);
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n=fscanf(fd,"%lf",°_west);
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n=fscanf(fd,"%lf",°_north);
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fclose(fd);
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}
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min_north=(int)(deg_north);
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max_north=max_north+1;
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if (deg_west<0.0)
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deg_west=-deg_west;
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else
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deg_west=360.0-deg_west;
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min_west=(int)(deg_west);
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if (min_west==360)
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min_west=0;
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max_west=min_west+1;
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}
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}
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infile=open(filename, O_RDONLY);
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if (infile==0)
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{
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fprintf(stderr, "*** Error: Cannot open \"%s\"\n", filename);
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return -1;
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}
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n=read(infile,&buffer,2);
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if ((buffer[0]=='P') && (buffer[1]=='K'))
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{
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fprintf(stderr, "*** Error: \"%s\" still appears to be compressed!\n",filename);
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close(infile);
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return -1;
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}
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lseek(infile,0L,SEEK_SET);
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if (ippd==3600)
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sprintf(sdf_filename, "%d:%d:%d:%d-hd.sdf", min_north, max_north, min_west, max_west);
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else
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sprintf(sdf_filename, "%d:%d:%d:%d.sdf", min_north, max_north, min_west, max_west);
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error=0;
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replacement_flag=0;
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printf("Reading %s... ", filename);
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fflush(stdout);
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for (x=0; (x<=ippd && error==0); x++)
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for (y=0; (y<=ippd && error==0); y++)
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{
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bytes_read=read(infile,&buffer,2);
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if (bytes_read==2)
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{
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if (bil)
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{
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/* "little-endian" structure */
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byte=buffer[0]+(buffer[1]<<8);
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if (buffer[1]&128)
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byte-=0x10000;
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}
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if (hgt)
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{
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/* "big-endian" structure */
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byte=buffer[1]+(buffer[0]<<8);
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if (buffer[0]&128)
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byte-=0x10000;
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}
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/* Flag problem elevations here */
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if (byte<-32768)
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byte=-32768;
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if (byte>32767)
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byte=32767;
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if (byte<=min_elevation)
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replacement_flag=1;
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srtm[x][y]=byte;
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}
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else
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error=1;
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}
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if (error)
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{
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fprintf(stderr,"\n*** Error: Premature EOF detected while reading \"%s\"! :-(\n",filename);
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}
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close(infile);
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return 0;
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}
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int LoadSDF_SDF(char *name)
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{
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/* This function reads uncompressed
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SPLAT Data Files (.sdf) into memory. */
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int x, y, n, dummy;
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char sdf_file[255], path_plus_name[512];
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FILE *infile;
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for (x=0; name[x]!='.' && name[x]!=0 && x<250; x++)
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sdf_file[x]=name[x];
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sdf_file[x]='.';
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sdf_file[x+1]='s';
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sdf_file[x+2]='d';
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sdf_file[x+3]='f';
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sdf_file[x+4]=0;
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strncpy(path_plus_name,sdf_path,255);
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strncat(path_plus_name,sdf_file,254);
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infile=fopen(path_plus_name,"rb");
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if (infile==NULL)
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return 0;
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n=fscanf(infile,"%d", &dummy);
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n=fscanf(infile,"%d", &dummy);
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n=fscanf(infile,"%d", &dummy);
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n=fscanf(infile,"%d", &dummy);
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printf("\nReading %s... ",path_plus_name);
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fflush(stdout);
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for (x=0; x<1200; x++)
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for (y=0; y<1200; y++)
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n=fscanf(infile,"%d",&usgs[x][y]);
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fclose(infile);
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return 1;
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}
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char *BZfgets(BZFILE *bzfd, unsigned length)
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{
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/* This function returns at most one less than 'length' number
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of characters from a bz2 compressed file whose file descriptor
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is pointed to by *bzfd. In operation, a buffer is filled with
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uncompressed data (size = BZBUFFER), which is then parsed
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and doled out as NULL terminated character strings every time
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this function is invoked. A NULL string indicates an EOF
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or error condition. */
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static int x, y, nBuf;
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static char buffer[BZBUFFER+1], output[BZBUFFER+1];
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char done=0;
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if (opened!=1 && bzerror==BZ_OK)
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{
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/* First time through. Initialize everything! */
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x=0;
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y=0;
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nBuf=0;
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opened=1;
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output[0]=0;
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}
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do
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{
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if (x==nBuf && bzerror!=BZ_STREAM_END && bzerror==BZ_OK && opened)
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{
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/* Uncompress data into a static buffer */
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nBuf=BZ2_bzRead(&bzerror, bzfd, buffer, BZBUFFER);
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buffer[nBuf]=0;
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x=0;
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}
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/* Build a string from buffer contents */
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output[y]=buffer[x];
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if (output[y]=='\n' || output[y]==0 || y==(int)length-1)
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{
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output[y+1]=0;
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done=1;
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y=0;
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}
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else
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y++;
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x++;
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} while (done==0);
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if (output[0]==0)
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opened=0;
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return (output);
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}
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int LoadSDF_BZ(char *name)
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{
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/* This function reads .bz2 compressed
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SPLAT Data Files into memory. */
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int x, y, dummy;
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char sdf_file[255], path_plus_name[255];
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FILE *fd;
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BZFILE *bzfd;
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for (x=0; name[x]!='.' && name[x]!=0 && x<247; x++)
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sdf_file[x]=name[x];
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sdf_file[x]='.';
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sdf_file[x+1]='s';
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sdf_file[x+2]='d';
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sdf_file[x+3]='f';
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sdf_file[x+4]='.';
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sdf_file[x+5]='b';
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sdf_file[x+6]='z';
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sdf_file[x+7]='2';
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sdf_file[x+8]=0;
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strncpy(path_plus_name,sdf_path,255);
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strncat(path_plus_name,sdf_file,254);
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fd=fopen(path_plus_name,"rb");
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bzfd=BZ2_bzReadOpen(&bzerror,fd,0,0,NULL,0);
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if (fd!=NULL && bzerror==BZ_OK)
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{
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printf("\nReading %s... ",path_plus_name);
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fflush(stdout);
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sscanf(BZfgets(bzfd,255),"%d",&dummy);
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sscanf(BZfgets(bzfd,255),"%d",&dummy);
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sscanf(BZfgets(bzfd,255),"%d",&dummy);
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sscanf(BZfgets(bzfd,255),"%d",&dummy);
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for (x=0; x<1200; x++)
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for (y=0; y<1200; y++)
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sscanf(BZfgets(bzfd,20),"%d",&usgs[x][y]);
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fclose(fd);
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BZ2_bzReadClose(&bzerror,bzfd);
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return 1;
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}
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else
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return 0;
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}
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char LoadSDF(char *name)
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{
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/* This function loads the requested SDF file from the filesystem.
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First, it tries to invoke the LoadSDF_SDF() function to load an
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uncompressed SDF file (since uncompressed files load slightly
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faster). Failing that, it tries to load a compressed SDF file
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by invoking the LoadSDF_BZ() function. */
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int return_value=-1;
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/* Try to load an uncompressed SDF first. */
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return_value=LoadSDF_SDF(name);
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/* If that fails, try loading a compressed SDF. */
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if (return_value==0 || return_value==-1)
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return_value=LoadSDF_BZ(name);
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return return_value;
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}
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int ReadUSGS()
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{
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char usgs_filename[15];
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/* usgs_filename is a minimal filename ("40:41:74:75").
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Full path and extentions are added later though
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subsequent function calls. */
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sprintf(usgs_filename, "%d:%d:%d:%d", min_north, max_north, min_west, max_west);
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return (LoadSDF(usgs_filename));
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}
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void average_terrain(y,x,z)
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int x, y, z;
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{
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long accum;
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int temp=0, count, bad_value;
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double average;
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bad_value=srtm[y][x];
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accum=0L;
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count=0;
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if (y>=2)
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{
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temp=srtm[y-1][x];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if (y<=mpi)
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{
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temp=srtm[y+1][x];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if ((y>=2) && (x<=(mpi-1)))
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{
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temp=srtm[y-1][x+1];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if (x<=(mpi-1))
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{
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temp=srtm[y][x+1];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if ((x<=(mpi-1)) && (y<=mpi))
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{
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temp=srtm[y+1][x+1];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if ((x>=1) && (y>=2))
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{
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temp=srtm[y-1][x-1];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if (x>=1)
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{
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temp=srtm[y][x-1];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if ((y<=mpi) && (x>=1))
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{
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temp=srtm[y+1][x-1];
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if (temp>bad_value)
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{
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accum+=temp;
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count++;
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}
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}
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if (count!=0)
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{
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average=(((double)accum)/((double)count));
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temp=(int)(average+0.5);
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}
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if (temp>min_elevation)
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srtm[y][x]=temp;
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else
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srtm[y][x]=min_elevation;
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}
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void WriteSDF(char *filename)
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{
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/* Like the HGT files, the extreme southwest corner
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* provides the point of reference for the SDF file.
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* The SDF file extends from min_north degrees to
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* the south to min_north+(mpi/ippd) degrees to
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* the north, and max_west degrees to the west to
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* max_west-(mpi/ippd) degrees to the east. The
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* overlapping edge redundancy present in the HGT
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* and earlier USGS files is not necessary, nor
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* is it present in SDF files.
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*/
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int x, y, byte, last_good_byte=0;
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FILE *outfile;
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printf("\nWriting %s... ", filename);
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fflush(stdout);
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outfile=fopen(filename,"wb");
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fprintf(outfile, "%d\n%d\n%d\n%d\n", max_west, min_north, min_west, max_north);
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for (y=ippd; y>=1; y--) /* Omit the northern most edge */
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for (x=mpi; x>=0; x--) /* Omit the eastern most edge */
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{
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byte=srtm[y][x];
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if (byte>min_elevation)
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last_good_byte=byte;
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|
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if (byte<min_elevation)
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{
|
|
if (merge)
|
|
{
|
|
if (ippd==3600)
|
|
fprintf(outfile,"%d\n",usgs[1200-(y/3)][1199-(x/3)]);
|
|
else
|
|
fprintf(outfile,"%d\n",usgs[1200-y][1199-x]);
|
|
}
|
|
|
|
else
|
|
{
|
|
average_terrain(y,x,last_good_byte);
|
|
fprintf(outfile,"%d\n",srtm[y][x]);
|
|
}
|
|
}
|
|
else
|
|
fprintf(outfile,"%d\n",byte);
|
|
}
|
|
|
|
printf("Done!\n");
|
|
|
|
fclose(outfile);
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int x, y, z=0;
|
|
char *env=NULL, string[255], *s=NULL;
|
|
FILE *fd;
|
|
|
|
if (strstr(argv[0], "srtm2sdf-hd")!=NULL)
|
|
{
|
|
ippd=3600; /* High Definition (1 arc-sec) Mode */
|
|
strncpy(string,"srtm2sdf-hd\0",12);
|
|
}
|
|
|
|
else
|
|
{
|
|
ippd=1200; /* Standard Definition (3 arc-sec) Mode */
|
|
strncpy(string,"srtm2sdf\0",9);
|
|
}
|
|
|
|
mpi=ippd-1; /* Maximum pixel index per degree */
|
|
|
|
if (argc==1 || (argc==2 && strncmp(argv[1],"-h",2)==0))
|
|
{
|
|
if (ippd==1200)
|
|
fprintf(stderr, "\nsrtm2sdf: Generates SPLAT! elevation data files from unzipped\nSRTM-3 elevation data files, and replaces SRTM data voids with\nelevation data from older usgs2sdf derived SDF files.\n\n");
|
|
|
|
if (ippd==3600)
|
|
fprintf(stderr, "\nsrtm2sdf-hd: Generates SPLAT! elevation data files from unzipped\nSRTM-1 elevation data files, and replaces SRTM data voids with\naverages, or elevation data from older usgs2sdf derived SDF files.\n\n");
|
|
|
|
fprintf(stderr, "\tAvailable Options...\n\n");
|
|
fprintf(stderr, "\t-d directory path of usgs2sdf derived SDF files\n\t (overrides path in ~/.splat_path file)\n\n");
|
|
fprintf(stderr, "\t-n elevation limit (in meters) below which SRTM data is\n\t replaced by USGS-derived .sdf data (default = 0 meters)\n\n");
|
|
fprintf(stderr, "Examples: %s N40W074.hgt\n",string);
|
|
fprintf(stderr, " %s -d /cdrom/sdf N40W074.hgt\n",string);
|
|
fprintf(stderr, " %s -d /dev/null N40W074.hgt (prevents data replacement)\n",string);
|
|
fprintf(stderr, " %s -n -5 N40W074.hgt\n\n",string);
|
|
|
|
return 1;
|
|
}
|
|
|
|
y=argc-1;
|
|
|
|
min_elevation=0;
|
|
|
|
for (x=1, z=0; x<=y; x++)
|
|
{
|
|
if (strcmp(argv[x],"-d")==0)
|
|
{
|
|
z=x+1;
|
|
|
|
if (z<=y && argv[z][0] && argv[z][0]!='-')
|
|
strncpy(sdf_path,argv[z],253);
|
|
}
|
|
|
|
if (strcmp(argv[x],"-n")==0)
|
|
{
|
|
z=x+1;
|
|
|
|
if (z<=y && argv[z][0])
|
|
{
|
|
sscanf(argv[z],"%d",&min_elevation);
|
|
|
|
if (min_elevation<-32767)
|
|
min_elevation=0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* If no SDF path was specified on the command line (-d), check
|
|
for a path specified in the $HOME/.splat_path file. If the
|
|
file is not found, then sdf_path[] remains NULL, and a data
|
|
merge will not be attempted if voids are found in the SRTM file. */
|
|
|
|
if (sdf_path[0]==0)
|
|
{
|
|
env=getenv("HOME");
|
|
|
|
sprintf(string,"%s/.splat_path",env);
|
|
|
|
fd=fopen(string,"r");
|
|
|
|
if (fd!=NULL)
|
|
{
|
|
s=fgets(string,253,fd);
|
|
|
|
/* Remove <CR> and/or <LF> from string */
|
|
|
|
for (x=0; string[x]!=13 && string[x]!=10 && string[x]!=0 && x<253; x++);
|
|
string[x]=0;
|
|
|
|
strncpy(sdf_path,string,253);
|
|
|
|
fclose(fd);
|
|
}
|
|
}
|
|
|
|
/* Ensure a trailing '/' is present in sdf_path */
|
|
|
|
if (sdf_path[0])
|
|
{
|
|
x=strlen(sdf_path);
|
|
|
|
if (sdf_path[x-1]!='/' && x!=0)
|
|
{
|
|
sdf_path[x]='/';
|
|
sdf_path[x+1]=0;
|
|
}
|
|
}
|
|
|
|
if (ReadSRTM(argv[z+1])==0)
|
|
{
|
|
if (replacement_flag && sdf_path[0])
|
|
merge=ReadUSGS();
|
|
|
|
WriteSDF(sdf_filename);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|