X-Git-Url: https://git.street.me.uk/andy/viking.git/blobdiff_plain/792a7488a46c20a13d91aba2b25a847b482f79f1..78ac928c4967374d4c7ad5b3024f188074eab36b:/src/dem.c diff --git a/src/dem.c b/src/dem.c index 6fa862fc..84c257e9 100644 --- a/src/dem.c +++ b/src/dem.c @@ -1,14 +1,49 @@ +/* + * viking -- GPS Data and Topo Analyzer, Explorer, and Manager + * + * Copyright (C) 2003-2008, Evan Battaglia + * Copyright (C) 2007, Quy Tonthat + * + * 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 + * + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + #include +#ifdef HAVE_STRING_H #include +#endif #include +#ifdef HAVE_MATH_H #include +#endif +#ifdef HAVE_STDLIB_H #include +#endif #include #include #include +#ifdef HAVE_UNISTD_H #include -#include +#endif +#include +#include #include "dem.h" #include "file.h" @@ -22,7 +57,7 @@ static gboolean get_double_and_continue ( gchar **buffer, gdouble *tmp, gboolean *tmp = g_strtod(*buffer, &endptr); if ( endptr == NULL|| endptr == *buffer ) { if ( warn ) - g_warning("Invalid DEM"); + g_warning(_("Invalid DEM")); return FALSE; } *buffer=endptr; @@ -36,7 +71,7 @@ static gboolean get_int_and_continue ( gchar **buffer, gint *tmp, gboolean warn *tmp = strtol(*buffer, &endptr, 10); if ( endptr == NULL|| endptr == *buffer ) { if ( warn ) - g_warning("Invalid DEM"); + g_warning(_("Invalid DEM")); return FALSE; } *buffer=endptr; @@ -78,7 +113,7 @@ static gboolean dem_parse_header ( gchar *buffer, VikDEM *dem ) /* skip numbers 5-19 */ for ( i = 0; i < 15; i++ ) { if ( ! get_double_and_continue(&buffer, &val, FALSE) ) { - g_warning ("Invalid DEM header"); + g_warning (_("Invalid DEM header")); return FALSE; } } @@ -147,7 +182,7 @@ static void dem_parse_block_as_header ( gchar *buffer, VikDEM *dem, gint *cur_co /* 1 x n_rows 1 east_west south x x x DATA */ if ( (!get_double_and_continue(&buffer, &tmp, TRUE)) || tmp != 1 ) { - g_warning("Incorrect DEM Class B record: expected 1"); + g_warning(_("Incorrect DEM Class B record: expected 1")); return; } @@ -160,7 +195,7 @@ static void dem_parse_block_as_header ( gchar *buffer, VikDEM *dem, gint *cur_co n_rows = (guint) tmp; if ( (!get_double_and_continue(&buffer, &tmp, TRUE)) || tmp != 1 ) { - g_warning("Incorrect DEM Class B record: expected 1"); + g_warning(_("Incorrect DEM Class B record: expected 1")); return; } @@ -264,7 +299,7 @@ static void *unzip_hgt_file(gchar *zip_file, gulong *unzip_size) local_file_header = (struct _lfh *) zip_file; if (local_file_header->sig != 0x04034b50) { - g_warning("%s(): wrong format\n", __PRETTY_FUNCTION__); + g_warning("%s(): wrong format", __PRETTY_FUNCTION__); g_free(unzip_data); goto end; } @@ -283,19 +318,19 @@ end: return(unzip_data); } -static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename, gboolean zip) +static VikDEM *vik_dem_read_srtm_hgt(const gchar *file_name, const gchar *basename, gboolean zip) { gint i, j; VikDEM *dem; - struct stat stat; off_t file_size; gint16 *dem_mem = NULL; - gint16 *dem_file = NULL; + gchar *dem_file = NULL; const gint num_rows_3sec = 1201; const gint num_rows_1sec = 3601; gint num_rows; - int fd = fileno(f); + GMappedFile *mf; gint arcsec; + GError *error = NULL; dem = g_malloc(sizeof(VikDEM)); @@ -316,19 +351,21 @@ static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename, gboolean zi dem->columns = g_ptr_array_new(); dem->n_columns = 0; - if (fstat(fd, &stat) == -1) - g_error("%s(): fstat failed on %s\n", __PRETTY_FUNCTION__, basename); - if ((dem_file = mmap(NULL, stat.st_size, PROT_READ, MAP_PRIVATE, fd, 0)) == (void *) -1) - g_error("%s(): mmap failed on %s\n", __PRETTY_FUNCTION__, basename); - - file_size = stat.st_size; - dem_mem = dem_file; + if ((mf = g_mapped_file_new(file_name, FALSE, &error)) == NULL) { + g_error(_("Couldn't map file %s: %s"), file_name, error->message); + g_error_free(error); + g_free(dem); + return NULL; + } + file_size = g_mapped_file_get_length(mf); + dem_file = g_mapped_file_get_contents(mf); + if (zip) { void *unzip_mem = NULL; gulong ucsize; - if ((unzip_mem = unzip_hgt_file((gchar *)dem_file, &ucsize)) == NULL) { - munmap(dem_file, file_size); + if ((unzip_mem = unzip_hgt_file(dem_file, &ucsize)) == NULL) { + g_mapped_file_free(mf); g_ptr_array_free(dem->columns, TRUE); g_free(dem); return NULL; @@ -343,9 +380,8 @@ static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename, gboolean zi else if (file_size == (num_rows_1sec * num_rows_1sec * sizeof(gint16))) arcsec = 1; else { - g_warning("%s(): file %s does not have right size\n", __PRETTY_FUNCTION__, basename); - munmap(dem_file, file_size); - g_ptr_array_free(dem->columns, TRUE); + g_warning("%s(): file %s does not have right size", __PRETTY_FUNCTION__, basename); + g_mapped_file_free(mf); g_free(dem); return NULL; } @@ -373,7 +409,7 @@ static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename, gboolean zi if (zip) g_free(dem_mem); - munmap(dem_file, stat.st_size); + g_mapped_file_free(mf); return dem; } @@ -381,7 +417,7 @@ static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename, gboolean zi VikDEM *vik_dem_new_from_file(const gchar *file) { - FILE *f; + FILE *f=NULL; VikDEM *rv; gchar buffer[DEM_BLOCK_SIZE+1]; @@ -390,17 +426,14 @@ VikDEM *vik_dem_new_from_file(const gchar *file) gint cur_row = -1; const gchar *basename = a_file_basename(file); - /* FILE IO */ - f = fopen(file, "r"); - if ( !f ) + if ( g_access ( file, R_OK ) != 0 ) return NULL; if ( (strlen(basename)==11 || ((strlen(basename) == 15) && (basename[11] == '.' && basename[12] == 'z' && basename[13] == 'i' && basename[14] == 'p'))) && basename[7]=='.' && basename[8]=='h' && basename[9]=='g' && basename[10]=='t' && (basename[0] == 'N' || basename[0] == 'S') && (basename[3] == 'E' || basename[3] =='W')) { gboolean is_zip_file = (strlen(basename) == 15); - rv = vik_dem_read_srtm_hgt(f, basename, is_zip_file); - fclose(f); + rv = vik_dem_read_srtm_hgt(file, basename, is_zip_file); return(rv); } @@ -408,9 +441,15 @@ VikDEM *vik_dem_new_from_file(const gchar *file) rv = g_malloc(sizeof(VikDEM)); /* Header */ + f = g_fopen(file, "r"); + if ( !f ) { + g_free ( rv ); + return NULL; + } buffer[fread(buffer, 1, DEM_BLOCK_SIZE, f)] = '\0'; if ( ! dem_parse_header ( buffer, rv ) ) { g_free ( rv ); + fclose(f); return NULL; } /* TODO: actually use header -- i.e. GET # OF COLUMNS EXPECTED */ @@ -439,6 +478,7 @@ VikDEM *vik_dem_new_from_file(const gchar *file) /* TODO - class C records (right now says 'Invalid' and dies) */ fclose(f); + f = NULL; /* 24k scale */ if ( rv->horiz_units == VIK_DEM_HORIZ_UTM_METERS && rv->n_columns >= 2 ) @@ -485,6 +525,120 @@ gint16 vik_dem_get_east_north ( VikDEM *dem, gdouble east, gdouble north ) return vik_dem_get_xy ( dem, col, row ); } +static gboolean dem_get_ref_points_elev_dist(VikDEM *dem, + gdouble east, gdouble north, /* in seconds */ + gint16 *elevs, gint16 *dists) +{ + int i; + int cols[4], rows[4]; + struct LatLon ll[4]; + struct LatLon pos; + + if ( east > dem->max_east || east < dem->min_east || + north > dem->max_north || north < dem->min_north ) + return FALSE; /* got nothing */ + + pos.lon = east/3600; + pos.lat = north/3600; + + /* order of the data: sw, nw, ne, se */ + /* sw */ + cols[0] = (gint) floor((east - dem->min_east) / dem->east_scale); + rows[0] = (gint) floor((north - dem->min_north) / dem->north_scale); + ll[0].lon = (dem->min_east + dem->east_scale*cols[0])/3600; + ll[0].lat = (dem->min_north + dem->north_scale*rows[0])/3600; + /* nw */ + cols[1] = cols[0]; + rows[1] = rows[0] + 1; + ll[1].lon = ll[0].lon; + ll[1].lat = ll[0].lat + (gdouble)dem->north_scale/3600; + /* ne */ + cols[2] = cols[0] + 1; + rows[2] = rows[0] + 1; + ll[2].lon = ll[0].lon + (gdouble)dem->east_scale/3600; + ll[2].lat = ll[0].lat + (gdouble)dem->north_scale/3600; + /* se */ + cols[3] = cols[0] + 1; + rows[3] = rows[0]; + ll[3].lon = ll[0].lon + (gdouble)dem->east_scale/3600; + ll[3].lat = ll[0].lat; + + for (i = 0; i < 4; i++) { + if ((elevs[i] = vik_dem_get_xy(dem, cols[i], rows[i])) == VIK_DEM_INVALID_ELEVATION) + return FALSE; + dists[i] = a_coords_latlon_diff(&pos, &ll[i]); + } + +#if 0 /* debug */ + for (i = 0; i < 4; i++) + fprintf(stderr, "%f:%f:%d:%d ", ll[i].lat, ll[i].lon, dists[i], elevs[i]); + fprintf(stderr, " north_scale=%f\n", dem->north_scale); +#endif + + return TRUE; /* all OK */ +} + +gint16 vik_dem_get_simple_interpol ( VikDEM *dem, gdouble east, gdouble north ) +{ + int i; + gint16 elevs[4], dists[4]; + + if (!dem_get_ref_points_elev_dist(dem, east, north, elevs, dists)) + return VIK_DEM_INVALID_ELEVATION; + + for (i = 0; i < 4; i++) { + if (dists[i] < 1) { + return(elevs[i]); + } + } + + gdouble t = (gdouble)elevs[0]/dists[0] + (gdouble)elevs[1]/dists[1] + (gdouble)elevs[2]/dists[2] + (gdouble)elevs[3]/dists[3]; + gdouble b = 1.0/dists[0] + 1.0/dists[1] + 1.0/dists[2] + 1.0/dists[3]; + + return(t/b); +} + +gint16 vik_dem_get_shepard_interpol ( VikDEM *dem, gdouble east, gdouble north ) +{ + int i; + gint16 elevs[4], dists[4]; + gint16 max_dist; + gdouble t = 0.0; + gdouble b = 0.0; + + if (!dem_get_ref_points_elev_dist(dem, east, north, elevs, dists)) + return VIK_DEM_INVALID_ELEVATION; + + max_dist = 0; + for (i = 0; i < 4; i++) { + if (dists[i] < 1) { + return(elevs[i]); + } + if (dists[i] > max_dist) + max_dist = dists[i]; + } + + gdouble tmp; +#if 0 /* derived method by Franke & Nielson. Does not seem to work too well here */ + for (i = 0; i < 4; i++) { + tmp = pow((1.0*(max_dist - dists[i])/max_dist*dists[i]), 2); + t += tmp*elevs[i]; + b += tmp; + } +#endif + + for (i = 0; i < 4; i++) { + tmp = pow((1.0/dists[i]), 2); + t += tmp*elevs[i]; + b += tmp; + } + + // fprintf(stderr, "DEBUG: tmp=%f t=%f b=%f %f\n", tmp, t, b, t/b); + + return(t/b); + +} + void vik_dem_east_north_to_xy ( VikDEM *dem, gdouble east, gdouble north, guint *col, guint *row ) { *col = (gint) floor((east - dem->min_east) / dem->east_scale);