#include <glib.h>
#include <math.h>
#include <stdlib.h>
+#include <zlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
#include "dem.h"
#include "file.h"
}
}
-static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename)
+/* return size of unzip data or 0 if failed */
+/* can be made generic to uncompress zip, gzip, bzip2 data */
+static guint uncompress_data(void *uncompressed_buffer, guint uncompressed_size, void *compressed_data, guint compressed_size)
+{
+ z_stream stream;
+ int err;
+
+ stream.next_in = compressed_data;
+ stream.avail_in = compressed_size;
+ stream.next_out = uncompressed_buffer;
+ stream.avail_out = uncompressed_size;
+ stream.zalloc = (alloc_func)0;
+ stream.zfree = (free_func)0;
+ stream.opaque = (voidpf)0;
+
+ /* negative windowBits to inflateInit2 means "no header" */
+ if ((err = inflateInit2(&stream, -MAX_WBITS)) != Z_OK) {
+ g_warning("%s(): inflateInit2 failed", __PRETTY_FUNCTION__);
+ return 0;
+ }
+
+ err = inflate(&stream, Z_FINISH);
+ if ((err != Z_OK) && (err != Z_STREAM_END) && stream.msg) {
+ g_warning("%s() inflate failed err=%d \"%s\"", __PRETTY_FUNCTION__, err, stream.msg == NULL ? "unknown" : stream.msg);
+ inflateEnd(&stream);
+ return 0;
+ }
+
+ inflateEnd(&stream);
+ return(stream.total_out);
+}
+
+static void *unzip_hgt_file(gchar *zip_file, gulong *unzip_size)
+{
+ void *unzip_data = NULL;
+ gchar *zip_data;
+ struct _lfh {
+ guint32 sig;
+ guint16 extract_version;
+ guint16 flags;
+ guint16 comp_method;
+ guint16 time;
+ guint16 date;
+ guint32 crc_32;
+ guint32 compressed_size;
+ guint32 uncompressed_size;
+ guint16 filename_len;
+ guint16 extra_field_len;
+ } __attribute__ ((__packed__)) *local_file_header = NULL;
+
+
+ local_file_header = (struct _lfh *) zip_file;
+ if (local_file_header->sig != 0x04034b50) {
+ g_warning("%s(): wrong format\n", __PRETTY_FUNCTION__);
+ g_free(unzip_data);
+ goto end;
+ }
+
+ zip_data = zip_file + sizeof(struct _lfh) + local_file_header->filename_len + local_file_header->extra_field_len;
+ unzip_data = g_malloc(local_file_header->uncompressed_size);
+ gulong uncompressed_size = local_file_header->uncompressed_size;
+
+ if (!(*unzip_size = uncompress_data(unzip_data, uncompressed_size, zip_data, local_file_header->compressed_size))) {
+ g_free(unzip_data);
+ unzip_data = NULL;
+ goto end;
+ }
+
+end:
+ return(unzip_data);
+}
+
+static VikDEM *vik_dem_read_srtm_hgt(FILE *f, const gchar *basename, gboolean zip)
{
- gint16 elev;
gint i, j;
VikDEM *dem;
-
+ struct stat stat;
+ off_t file_size;
+ gint16 *dem_mem = NULL;
+ gint16 *dem_file = NULL;
+ const gint num_rows_3sec = 1201;
+ const gint num_rows_1sec = 3601;
+ gint num_rows;
+ int fd = fileno(f);
+ gint arcsec;
dem = g_malloc(sizeof(VikDEM));
dem->horiz_units = VIK_DEM_HORIZ_LL_ARCSECONDS;
dem->orig_vert_units = VIK_DEM_VERT_DECIMETERS;
- dem->east_scale = dem->north_scale = 3;
/* TODO */
dem->min_north = atoi(basename+1) * 3600;
dem->columns = g_ptr_array_new();
dem->n_columns = 0;
- for ( i = 0; i < 1201; i++ ) {
+ 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 (zip) {
+ void *unzip_mem = NULL;
+ gulong ucsize;
+
+ if ((unzip_mem = unzip_hgt_file((gchar *)dem_file, &ucsize)) == NULL) {
+ munmap(dem_file, file_size);
+ g_ptr_array_free(dem->columns, TRUE);
+ g_free(dem);
+ return NULL;
+ }
+
+ dem_mem = unzip_mem;
+ file_size = ucsize;
+ }
+
+ if (file_size == (num_rows_3sec * num_rows_3sec * sizeof(gint16)))
+ arcsec = 3;
+ 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_free(dem);
+ return NULL;
+ }
+
+ num_rows = (arcsec == 3) ? num_rows_3sec : num_rows_1sec;
+ dem->east_scale = dem->north_scale = arcsec;
+
+ for ( i = 0; i < num_rows; i++ ) {
dem->n_columns++;
g_ptr_array_add ( dem->columns, g_malloc(sizeof(VikDEMColumn)) );
- GET_COLUMN(dem,i)->east_west = dem->min_east + 3*i;
+ GET_COLUMN(dem,i)->east_west = dem->min_east + arcsec*i;
GET_COLUMN(dem,i)->south = dem->min_north;
- GET_COLUMN(dem,i)->n_points = 1201;
- GET_COLUMN(dem,i)->points = g_malloc(sizeof(gint16)*1201);
+ GET_COLUMN(dem,i)->n_points = num_rows;
+ GET_COLUMN(dem,i)->points = g_malloc(sizeof(gint16)*num_rows);
}
- for ( i = 1200; i >= 0; i-- ) {
- for ( j = 0; j < 1201; j++ ) {
- if ( feof(f) ) {
- g_warning("Incorrect SRTM file: unexpected EOF");
- g_print("%d %d\n", i, j);
- return dem;
- }
- fread(&elev, sizeof(elev), 1, f);
- gchar *x = (gchar *) &elev;
- gchar tmp;
- tmp=x[0];
- x[0]=x[1];
- x[1]=tmp;
- GET_COLUMN(dem,j)->points[i] = elev;
+ int ent = 0;
+ for ( i = (num_rows - 1); i >= 0; i-- ) {
+ for ( j = 0; j < num_rows; j++ ) {
+ GET_COLUMN(dem,j)->points[i] = GINT16_FROM_BE(dem_mem[ent++]);
}
}
+ if (zip)
+ g_free(dem_mem);
+ munmap(dem_file, stat.st_size);
return dem;
}
if ( !f )
return NULL;
- if ( strlen(basename)==11 && basename[7]=='.' && basename[8]=='h' && basename[9]=='g' && basename[10]=='t' &&
- (basename[0] == 'N' || basename[0] == 'S') && (basename[3] == 'E' || basename[3] =='W'))
- return vik_dem_read_srtm_hgt(f, basename);
+ 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);
+ return(rv);
+ }
/* Create Structure */
rv = g_malloc(sizeof(VikDEM));
projects / andy / viking.git / blobdiff