--- /dev/null
+/* main.c -- main loop
+ *
+ * Written by Curtis Olson, started February 1998.
+ *
+ * Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id$
+ * (Log is kept at end of this file)
+ */
+
+
+#include <stdio.h>
+#include <string.h>
+
+#include "rawdem.h"
+
+
+int main(int argc, char **argv) {
+ fgRAWDEM raw;
+ char basename[256], output_dir[256], hdr_file[256], dem_file[256];
+ int i;
+
+ if ( argc != 3 ) {
+ printf("Usage: %s <input_file_basename> <output_dir>\n", argv[0]);
+ exit(-1);
+ }
+
+ /* get basename */
+ strcpy(basename, argv[1]);
+
+ /* get output dir */
+ strcpy(output_dir, argv[2]);
+
+ /* generate header file name */
+ strcpy(hdr_file, basename);
+ strcat(hdr_file, ".HDR");
+
+ /* generate input file name (raw dem) */
+ strcpy(dem_file, basename);
+ strcat(dem_file, ".DEM");
+
+ printf("Header file = %s Input file = %s\n", hdr_file, dem_file);
+ printf("Output Directory = %s\n", output_dir);
+
+ /* scan the header file and extract important values */
+ rawReadDemHdr(&raw, hdr_file);
+
+ /* open up the raw data file */
+ rawOpenDemFile(&raw, dem_file);
+
+ for ( i = 41; i <= 90; i++ ) {
+ rawReadStrip(&raw, i);
+ }
+
+ /* close the raw data file */
+ rawCloseDemFile(&raw);
+
+ return(0);
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/03/02 23:31:01 curt
+/* Initial revision.
+/*
+ */
--- /dev/null
+/* rawdem.c -- library of routines for processing raw dem files (30 arcsec)
+ *
+ * Written by Curtis Olson, started February 1998.
+ *
+ * Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id$
+ * (Log is kept at end of this file)
+ */
+
+
+#include <math.h> /* rint() */
+#include <stdio.h>
+#include <stdlib.h> /* atoi() atof() */
+#include <string.h> /* swab() */
+
+#include <sys/types.h> /* open() */
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h> /* close() */
+
+#include "rawdem.h"
+
+
+/* Read the DEM header to determine various key parameters for this
+ * DEM file */
+void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file ) {
+ FILE *hdr;
+ char line[256], key[256], value[256];
+ int i, len, offset;
+ double tmp;
+
+ if ( (hdr = fopen(hdr_file, "r")) == NULL ) {
+ printf("Error opening DEM header file: %s\n", hdr_file);
+ exit(-1);
+ }
+
+ /* process each line */
+ while ( (fgets(line, 256, hdr) != NULL) ) {
+ /* printf("%s", line); */
+ len = strlen(line);
+
+ /* extract key */
+ i = 0;
+ while ( (line[i] != ' ') && (i < len) ) {
+ key[i] = line[i];
+ i++;
+ }
+ key[i] = '\0';
+
+ /* skip middle space */
+ while ( (line[i] == ' ') && (i < len) ) {
+ i++;
+ }
+ offset = i;
+
+ /* extract value */
+ while ( (line[i] != '\n') && (i < len) ) {
+ value[i-offset] = line[i];
+ i++;
+ }
+ value[i-offset] = '\0';
+ /* printf("key='%s' value='%s'\n", key, value); */
+
+ if ( strcmp(key, "NROWS") == 0 ) {
+ raw->nrows = atoi(value);
+ } else if ( strcmp(key, "NCOLS") == 0 ) {
+ raw->ncols = atoi(value);
+ } else if ( strcmp(key, "ULXMAP") == 0 ) {
+ tmp = atof(value);
+ raw->ulxmap = (int)rint(tmp * 3600.0); /* convert to arcsec */
+ } else if ( strcmp(key, "ULYMAP") == 0 ) {
+ tmp = atof(value);
+ raw->ulymap = (int)rint(tmp * 3600.0); /* convert to arcsec */
+ } else if ( strcmp(key, "XDIM") == 0 ) {
+ tmp = atof(value);
+ raw->xdim = (int)rint(tmp * 3600.0); /* convert to arcsec */
+ } else if ( strcmp(key, "YDIM") == 0 ) {
+ tmp = atof(value);
+ raw->ydim = (int)rint(tmp * 3600.0); /* convert to arcsec */
+ } else {
+ /* ignore for now */
+ }
+ }
+
+ raw->rootx = raw->ulxmap - (raw->xdim / 2);
+ raw->rooty = raw->ulymap + (raw->ydim / 2);
+
+ printf("%d %d %d %d %d %d %d %d\n", raw->nrows, raw->ncols,
+ raw->ulxmap, raw->ulymap, raw->rootx, raw->rooty, raw->xdim,
+ raw->ydim);
+}
+
+
+/* Open a raw DEM file. */
+void rawOpenDemFile( fgRAWDEM *raw, char *raw_dem_file ) {
+ printf("Opening Raw DEM file: %s\n", raw_dem_file);
+ if ( (raw->fd = open(raw_dem_file ,O_RDONLY)) == -1 ) {
+ printf("Error opening Raw DEM file: %s\n", raw_dem_file);
+ exit(-1);
+ }
+}
+
+
+/* Close a raw DEM file. */
+void rawCloseDemFile( fgRAWDEM *raw ) {
+ close(raw->fd);
+}
+
+
+/* Advance file pointer position to correct latitude (row) */
+void rawAdvancePosition( fgRAWDEM *raw, int arcsec ) {
+ long offset, result;
+
+ offset = 2 * raw->ncols * ( arcsec / raw->ydim );
+
+ if ( (result = lseek(raw->fd, offset, SEEK_SET)) == -1 ) {
+ printf("Error lseek filed trying to offset by %ld\n", offset);
+ exit(-1);
+ }
+
+ printf("Successful seek ahead of %ld bytes\n", result);
+}
+
+
+/* Read the next row of data */
+void rawReadNextRow( fgRAWDEM *raw, int index ) {
+ char buf[MAX_COLS_X_2];
+ int i, result;
+
+ if ( raw->ncols > MAX_ROWS ) {
+ printf("Error, buf needs to be bigger in rawReadNextRow()\n");
+ exit(-1);
+ }
+
+ /* printf("Attempting to read %d bytes\n", 2 * raw->ncols); */
+ result = read(raw->fd, buf, 2 * raw->ncols);
+ /* printf("Read %d bytes\n", result); */
+
+ /* reverse byte order */
+ /* it would be nice to test in advance some how if we need to do
+ * this */
+ /* swab(frombuf, tobuf, 2 * raw->ncols); */
+
+ for ( i = 0; i < raw->ncols; i++ ) {
+ /* printf("hi = %d lo = %d\n", buf[2*i], buf[2*i + 1]); */
+ raw->strip[index][i] = ( (buf[2*i] + 1) << 8 ) + buf[2*i + 1];
+ }
+}
+
+
+/* Convert from pixel centered values to pixel corner values. This is
+ accomplished by taking the average of the closes center nodes. In
+ the following diagram "x" marks the data point location:
+
+ +-----+ x-----x
+ | | | |
+ | x | ===> | |
+ | | | |
+ +-----+ x-----x
+
+ */
+void rawConvertCenter2Edge( fgRAWDEM *raw ) {
+ int i, j;
+
+ /* derive corner nodes */
+ raw->edge[0][0] = raw->center[0][0];
+ raw->edge[120][0] = raw->center[119][0];
+ raw->edge[120][120] = raw->center[119][119];
+ raw->edge[0][120] = raw->center[0][119];
+
+ /* derive edge nodes */
+ for ( i = 1; i < 120; i++ ) {
+ raw->edge[i][0] = (raw->center[i-1][0] + raw->center[i][0]) / 2.0;
+ raw->edge[i][120] = (raw->center[i-1][119] + raw->center[i][119]) / 2.0;
+ raw->edge[0][i] = (raw->center[0][i-1] + raw->center[0][i]) / 2.0;
+ raw->edge[120][i] = (raw->center[119][i-1] + raw->center[119][i]) / 2.0;
+ }
+
+ /* derive internal nodes */
+ for ( j = 1; j < 120; j++ ) {
+ for ( i = 1; i < 120; i++ ) {
+ raw->edge[i][j] = ( raw->center[i-1][j-1] +
+ raw->center[i] [j-1] +
+ raw->center[i] [j] +
+ raw->center[i-1][j] ) / 4;
+ }
+ }
+}
+
+
+/* Dump out the ascii format DEM file */
+void rawDumpAsciiDEM( fgRAWDEM *raw ) {
+}
+
+
+/* Read a horizontal strip of (1 vertical degree) from the raw DEM
+ * file specified by the upper latitude of the stripe specified in
+ * degrees */
+void rawReadStrip( fgRAWDEM *raw, int lat_degrees ) {
+ int lat, yrange;
+ int i, j, index, row, col;
+ int min = 0, max = 0;
+ int span, num_degrees, tile_width;
+ int xstart, xend;
+
+ /* convert to arcsec */
+ lat = lat_degrees * 3600;
+
+ printf("Max Latitude = %d arcsec\n", lat);
+
+ /* validity check ... */
+ if ( (lat > raw->rooty) ||
+ (lat < (raw->rooty - raw->nrows * raw->ydim + 1)) ) {
+ printf("Latitude out of range for this DEM file\n");
+ return;
+ }
+
+ printf ("Reading strip starting at %d (top and working down)\n", lat);
+
+ /* advance to the correct latitude */
+ rawAdvancePosition(raw, (raw->rooty - lat));
+
+ /* printf("short = %d\n", sizeof(short)); */
+
+ yrange = 3600 / raw->ydim;
+
+ for ( i = 0; i < yrange; i++ ) {
+ index = yrange - i - 1;
+ /* printf("About to read into row %d\n", index); */
+ rawReadNextRow(raw, index);
+
+ for ( j = 0; j < raw->ncols; j++ ) {
+ if ( raw->strip[index][j] == -9999 ) {
+ /* map ocean to 0 for now */
+ raw->strip[index][j] = 0;
+ }
+
+ if ( raw->strip[index][j] < min) {
+ min = raw->strip[index][j];
+ }
+
+ if ( raw->strip[index][j] > max) {
+ max = raw->strip[index][j];
+ }
+ }
+ }
+ printf("min = %d max = %d\n", min, max);
+
+ /* extract individual tiles from the strip */
+ span = raw->ncols * raw->xdim;
+ num_degrees = span / 3600;
+ tile_width = raw->ncols / num_degrees;
+ printf("span = %d num_degrees = %d width = %d\n",
+ span, num_degrees, tile_width);
+
+ for ( i = 0; i < num_degrees; i++ ) {
+ xstart = i * tile_width;
+ xend = xstart + 120;
+
+ for ( row = 0; row < yrange; row++ ) {
+ for ( col = xstart; col < xend; col++ ) {
+ /* Copy from strip to pixel centered tile. Yep,
+ * row/col are reversed here. raw->strip is backwards
+ * for convenience. I am converting to [x,y] now. */
+ raw->center[col-xstart][row] = raw->strip[row][col];
+ }
+ }
+
+ /* Convert from pixel centered to pixel edge values */
+ rawConvertCenter2Edge(raw);
+
+ /* Dump out the ascii format DEM file */
+ rawDumpAsciiDEM(raw);
+ }
+}
+
+
+/* $Log$
+/* Revision 1.1 1998/03/02 23:31:01 curt
+/* Initial revision.
+/*
+ */
--- /dev/null
+/* rawdem.h -- library of routines for processing raw dem files (30 arcsec)
+ *
+ * Written by Curtis Olson, started February 1998.
+ *
+ * Copyright (C) 1998 Curtis L. Olson - curt@me.umn.edu
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id$
+ * (Log is kept at end of this file)
+ */
+
+
+#ifndef _RAWDEM_H
+#define _RAWDEM_H
+
+
+#define MAX_ROWS 6000
+#define MAX_COLS 7200
+#define MAX_COLS_X_2 14400
+
+typedef struct {
+ /* header info */
+ int nrows; /* number of rows */
+ int ncols; /* number of cols */
+ int ulxmap; /* X coord of center of upper left pixel in arcsec */
+ int ulymap; /* Y coord of center of upper left pixel in arcsec */
+ int rootx; /* X coord of upper left *edge* of DEM region in degrees */
+ int rooty; /* Y coord of upper left *edge* of DEM region in degrees */
+ int xdim; /* X dimension of a pixel */
+ int ydim; /* Y dimension of a pixel */
+
+ /* file ptr */
+ int fd; /* Raw DEM file descriptor */
+
+ /* storage area for a 1 degree high strip of data. Note, for
+ * convenience this is in y,x order */
+ short strip[120][MAX_ROWS];
+
+ short center[120][120]; /* tile with data taken at center of pixel */
+ float edge[121][121]; /* tile with data converted to corners */
+} fgRAWDEM;
+
+
+/* Read the DEM header to determine various key parameters for this
+ * DEM file */
+void rawReadDemHdr( fgRAWDEM *raw, char *hdr_file );
+
+/* Open a raw DEM file. */
+void rawOpenDemFile( fgRAWDEM *raw, char *raw_dem_file );
+
+/* Close a raw DEM file. */
+void rawCloseDemFile( fgRAWDEM *raw );
+
+/* Read a horizontal strip of (1 vertical degree) from the raw DEM
+ * file specified by the upper latitude of the stripe specified in
+ * degrees */
+void rawReadStrip( fgRAWDEM *raw, int lat );
+
+
+#endif /* _RAWDEM_H */
+
+
+/* $Log$
+/* Revision 1.1 1998/03/02 23:31:02 curt
+/* Initial revision.
+/*
+ */
projects / flightgear.git / commitdiff