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1 | #include <glib.h> |
2 | ||
3 | #include "dems.h" | |
4 | ||
5 | typedef struct { | |
6 | VikDEM *dem; | |
7 | guint ref_count; | |
8 | } LoadedDEM; | |
9 | ||
10 | GHashTable *loaded_dems = NULL; | |
11 | /* filename -> DEM */ | |
12 | ||
13 | static void loaded_dem_free ( LoadedDEM *ldem ) | |
14 | { | |
15 | vik_dem_free ( ldem->dem ); | |
16 | g_free ( ldem ); | |
17 | } | |
18 | ||
19 | void a_dems_uninit () | |
20 | { | |
21 | if ( loaded_dems ) | |
22 | g_hash_table_destroy ( loaded_dems ); | |
23 | } | |
24 | ||
25 | /* To load a dem. if it was already loaded, will simply | |
26 | * reference the one already loaded and return it. | |
27 | */ | |
28 | VikDEM *a_dems_load(const gchar *filename) | |
29 | { | |
30 | LoadedDEM *ldem; | |
31 | ||
32 | /* dems init hash table */ | |
33 | if ( ! loaded_dems ) | |
34 | loaded_dems = g_hash_table_new_full ( g_str_hash, g_str_equal, g_free, (GDestroyNotify) loaded_dem_free ); | |
35 | ||
36 | ldem = (LoadedDEM *) g_hash_table_lookup ( loaded_dems, filename ); | |
37 | if ( ldem ) { | |
38 | ldem->ref_count++; | |
39 | return ldem->dem; | |
40 | } else { | |
41 | VikDEM *dem = vik_dem_new_from_file ( filename ); | |
42 | if ( ! dem ) | |
43 | return NULL; | |
44 | ldem = g_malloc ( sizeof(LoadedDEM) ); | |
45 | ldem->ref_count = 1; | |
46 | ldem->dem = dem; | |
47 | g_hash_table_insert ( loaded_dems, g_strdup(filename), ldem ); | |
48 | return dem; | |
49 | } | |
50 | } | |
51 | ||
52 | void a_dems_unref(const gchar *filename) | |
53 | { | |
54 | LoadedDEM *ldem = (LoadedDEM *) g_hash_table_lookup ( loaded_dems, filename ); | |
55 | g_assert ( ldem ); | |
56 | ldem->ref_count --; | |
57 | if ( ldem->ref_count == 0 ) | |
58 | g_hash_table_remove ( loaded_dems, filename ); | |
59 | } | |
60 | ||
61 | /* to get a DEM that was already loaded. | |
62 | * assumes that its in there already, | |
63 | * although it could not be if earlier load failed. | |
64 | */ | |
65 | VikDEM *a_dems_get(const gchar *filename) | |
66 | { | |
67 | LoadedDEM *ldem = g_hash_table_lookup ( loaded_dems, filename ); | |
68 | if ( ldem ) | |
69 | return ldem->dem; | |
70 | return NULL; | |
71 | } | |
72 | ||
73 | ||
74 | /* Load a string list (GList of strings) of dems. You have to use get to at them later. | |
75 | * When updating a list as a parameter, this should be bfore freeing the list so | |
76 | * the same DEMs won't be loaded & unloaded. | |
77 | * Modifies the list to remove DEMs which did not load. | |
78 | */ | |
79 | ||
80 | /* TODO: don't delete them when they don't exist. | |
81 | * we need to warn the user, but we should keep them in the GList. | |
82 | * we need to know that they weren't referenced though when we | |
83 | * do the a_dems_list_free(). | |
84 | */ | |
85 | void a_dems_load_list ( GList **dems ) | |
86 | { | |
87 | GList *iter = *dems; | |
88 | while ( iter ) { | |
89 | if ( ! a_dems_load((const gchar *) (iter->data)) ) { | |
90 | GList *iter_temp = iter->next; | |
91 | g_free ( iter->data ); | |
92 | (*dems) = g_list_remove_link ( (*dems), iter ); | |
93 | iter = iter_temp; | |
94 | } else { | |
95 | iter = iter->next; | |
96 | } | |
97 | } | |
98 | } | |
99 | ||
100 | /* Takes a string list (GList of strings) of dems (filenames). | |
101 | * Unrefs all the dems (i.e. "unloads" them), then frees the | |
102 | * strings, the frees the list. | |
103 | */ | |
104 | void a_dems_list_free ( GList *dems ) | |
105 | { | |
106 | GList *iter = dems; | |
107 | while ( iter ) { | |
108 | a_dems_unref ((const gchar *)iter->data); | |
109 | g_free ( iter->data ); | |
110 | iter = iter->next; | |
111 | } | |
112 | g_list_free ( dems ); | |
113 | } | |
114 | ||
115 | GList *a_dems_list_copy ( GList *dems ) | |
116 | { | |
117 | GList *rv = g_list_copy ( dems ); | |
118 | GList *iter = rv; | |
119 | while ( iter ) { | |
120 | if ( ! a_dems_load((const gchar *) (iter->data)) ) { | |
121 | GList *iter_temp = iter->next; /* delete link, don't bother strdup'ing and free'ing string */ | |
122 | rv = g_list_remove_link ( rv, iter ); | |
123 | iter = iter_temp; | |
124 | } else { | |
125 | iter->data = g_strdup((gchar *)iter->data); /* copy the string too. */ | |
126 | iter = iter->next; | |
127 | } | |
128 | } | |
129 | return rv; | |
130 | } | |
131 | ||
132 | gint16 a_dems_list_get_elev_by_coord ( GList *dems, const VikCoord *coord ) | |
133 | { | |
134 | static struct UTM utm_tmp; | |
135 | static struct LatLon ll_tmp; | |
136 | GList *iter = dems; | |
137 | VikDEM *dem; | |
138 | gint elev; | |
139 | ||
140 | while ( iter ) { | |
141 | dem = a_dems_get ( (gchar *) iter->data ); | |
142 | if ( dem ) { | |
143 | if ( dem->horiz_units == VIK_DEM_HORIZ_LL_ARCSECONDS ) { | |
144 | vik_coord_to_latlon ( coord, &ll_tmp ); | |
145 | ll_tmp.lat *= 3600; | |
146 | ll_tmp.lon *= 3600; | |
147 | elev = vik_dem_get_east_north(dem, ll_tmp.lon, ll_tmp.lat); | |
148 | if ( elev != VIK_DEM_INVALID_ELEVATION ) | |
149 | return elev; | |
150 | } else if ( dem->horiz_units == VIK_DEM_HORIZ_UTM_METERS ) { | |
151 | vik_coord_to_utm ( coord, &utm_tmp ); | |
152 | if ( utm_tmp.zone == dem->utm_zone && | |
153 | (elev = vik_dem_get_east_north(dem, utm_tmp.easting, utm_tmp.northing)) != VIK_DEM_INVALID_ELEVATION ) | |
154 | return elev; | |
155 | } | |
156 | } | |
157 | iter = iter->next; | |
158 | } | |
159 | return VIK_DEM_INVALID_ELEVATION; | |
160 | } | |
55906514 QT |
161 | |
162 | typedef struct { | |
163 | const VikCoord *coord; | |
5ef1d57e | 164 | VikDemInterpol method; |
55906514 QT |
165 | gint elev; |
166 | } CoordElev; | |
167 | ||
168 | static gboolean get_elev_by_coord(gpointer key, LoadedDEM *ldem, CoordElev *ce) | |
169 | { | |
170 | VikDEM *dem = ldem->dem; | |
5ef1d57e | 171 | gdouble lat, lon; |
55906514 QT |
172 | |
173 | if ( dem->horiz_units == VIK_DEM_HORIZ_LL_ARCSECONDS ) { | |
174 | struct LatLon ll_tmp; | |
175 | vik_coord_to_latlon (ce->coord, &ll_tmp ); | |
5ef1d57e QT |
176 | lat = ll_tmp.lat * 3600; |
177 | lon = ll_tmp.lon * 3600; | |
55906514 QT |
178 | } else if (dem->horiz_units == VIK_DEM_HORIZ_UTM_METERS) { |
179 | static struct UTM utm_tmp; | |
5ef1d57e QT |
180 | if (utm_tmp.zone != dem->utm_zone) |
181 | return FALSE; | |
55906514 | 182 | vik_coord_to_utm (ce->coord, &utm_tmp); |
5ef1d57e QT |
183 | lat = utm_tmp.northing; |
184 | lon = utm_tmp.easting; | |
185 | } else | |
186 | return FALSE; | |
187 | ||
188 | switch (ce->method) { | |
189 | case VIK_DEM_INTERPOL_NONE: | |
190 | ce->elev = vik_dem_get_east_north(dem, lon, lat); | |
191 | break; | |
192 | case VIK_DEM_INTERPOL_SIMPLE: | |
193 | ce->elev = vik_dem_get_simple_interpol(dem, lon, lat); | |
194 | break; | |
195 | case VIK_DEM_INTERPOL_BEST: | |
196 | ce->elev = vik_dem_get_shepard_interpol(dem, lon, lat); | |
197 | break; | |
55906514 | 198 | } |
5ef1d57e | 199 | return (ce->elev != VIK_DEM_INVALID_ELEVATION); |
55906514 QT |
200 | } |
201 | ||
202 | /* TODO: keep a (sorted) linked list of DEMs and select the best resolution one */ | |
5ef1d57e | 203 | gint16 a_dems_get_elev_by_coord ( const VikCoord *coord, VikDemInterpol method ) |
55906514 QT |
204 | { |
205 | CoordElev ce; | |
206 | ||
207 | if (!loaded_dems) | |
208 | return VIK_DEM_INVALID_ELEVATION; | |
209 | ||
210 | ce.coord = coord; | |
5ef1d57e | 211 | ce.method = method; |
55906514 QT |
212 | ce.elev = VIK_DEM_INVALID_ELEVATION; |
213 | ||
0654760a | 214 | if(!g_hash_table_find(loaded_dems, (GHRFunc)get_elev_by_coord, &ce)) |
55906514 QT |
215 | return VIK_DEM_INVALID_ELEVATION; |
216 | return ce.elev; | |
217 | } |