1 : /**********************************************************************
2 : *
3 : * geo_get.c -- Public routines for GEOTIFF GeoKey access.
4 : *
5 : * Written By: Niles D. Ritter.
6 : *
7 : * copyright (c) 1995 Niles D. Ritter
8 : *
9 : * Permission granted to use this software, so long as this copyright
10 : * notice accompanies any products derived therefrom.
11 : *
12 : * Revision History;
13 : *
14 : * 20 June, 1995 Niles D. Ritter New
15 : * 3 July, 1995 Greg Martin Fix strings and index
16 : * 6 July, 1995 Niles D. Ritter Unfix indexing.
17 : *
18 : **********************************************************************/
19 :
20 : #include "geotiff.h" /* public interface */
21 : #include "geo_tiffp.h" /* external TIFF interface */
22 : #include "geo_keyp.h" /* private interface */
23 :
24 : /* return the Header info of this geotiff file */
25 :
26 896 : void GTIFDirectoryInfo(GTIF *gtif, int version[3], int *keycount)
27 : {
28 896 : if (version)
29 : {
30 896 : version[0] = gtif->gt_version;
31 896 : version[1] = gtif->gt_rev_major;
32 896 : version[2] = gtif->gt_rev_minor;
33 : }
34 896 : if (keycount) *keycount = gtif->gt_num_keys;
35 896 : }
36 :
37 :
38 0 : int GTIFKeyInfo(GTIF *gtif, geokey_t key, int *size, tagtype_t* type)
39 : {
40 0 : int index = gtif->gt_keyindex[ key ];
41 : GeoKey *keyptr;
42 :
43 0 : if (!index) return 0;
44 :
45 0 : keyptr = gtif->gt_keys + index;
46 0 : if (size) *size = (int) keyptr->gk_size;
47 0 : if (type) *type = keyptr->gk_type;
48 :
49 0 : return keyptr->gk_count;
50 : }
51 :
52 : /**
53 :
54 : This function reads the value of a single GeoKey from a GeoTIFF file.
55 :
56 : @param gtif The geotiff information handle from GTIFNew().
57 :
58 : @param thekey The geokey_t name (such as ProjectedCSTypeGeoKey).
59 : This must come from the list of legal geokey_t values
60 : (an enumeration) listed below.
61 :
62 : @param val The <b>val</b> argument is a pointer to the
63 : variable into which the value should be read. The type of the variable
64 : varies depending on the geokey_t given. While there is no ready mapping
65 : of geokey_t values onto types, in general code values are of type <i>short</i>,
66 : citations are strings, and everything else is of type <i>double</i>. Note
67 : that pointer's to <i>int</i> should never be passed to GTIFKeyGet() for
68 : integer values as they will be shorts, and the int's may not be properly
69 : initialized (and will be grossly wrong on MSB systems).
70 :
71 : @param index Indicates how far into the list of values
72 : for this geokey to offset. Should normally be zero.
73 :
74 : @param count Indicates how many values
75 : to read. At this time all keys except for strings have only one value,
76 : so <b>index</b> should be zero, and <b>count</b> should be one.
77 :
78 : @return The GTIFKeyGet() function returns the number of values read. Normally
79 : this would be one if successful or zero if the key doesn't exist for this
80 : file.
81 :
82 : From geokeys.inc we see the following geokey_t values are possible:<p>
83 :
84 : <pre>
85 : -- 6.2.1 GeoTIFF Configuration Keys --
86 :
87 : ValuePair( GTModelTypeGeoKey, 1024) -- Section 6.3.1.1 Codes --
88 : ValuePair( GTRasterTypeGeoKey, 1025) -- Section 6.3.1.2 Codes --
89 : ValuePair( GTCitationGeoKey, 1026) -- documentation --
90 :
91 : -- 6.2.2 Geographic CS Parameter Keys --
92 :
93 : ValuePair( GeographicTypeGeoKey, 2048) -- Section 6.3.2.1 Codes --
94 : ValuePair( GeogCitationGeoKey, 2049) -- documentation --
95 : ValuePair( GeogGeodeticDatumGeoKey, 2050) -- Section 6.3.2.2 Codes --
96 : ValuePair( GeogPrimeMeridianGeoKey, 2051) -- Section 6.3.2.4 codes --
97 : ValuePair( GeogLinearUnitsGeoKey, 2052) -- Section 6.3.1.3 Codes --
98 : ValuePair( GeogLinearUnitSizeGeoKey, 2053) -- meters --
99 : ValuePair( GeogAngularUnitsGeoKey, 2054) -- Section 6.3.1.4 Codes --
100 : ValuePair( GeogAngularUnitSizeGeoKey, 2055) -- radians --
101 : ValuePair( GeogEllipsoidGeoKey, 2056) -- Section 6.3.2.3 Codes --
102 : ValuePair( GeogSemiMajorAxisGeoKey, 2057) -- GeogLinearUnits --
103 : ValuePair( GeogSemiMinorAxisGeoKey, 2058) -- GeogLinearUnits --
104 : ValuePair( GeogInvFlatteningGeoKey, 2059) -- ratio --
105 : ValuePair( GeogAzimuthUnitsGeoKey, 2060) -- Section 6.3.1.4 Codes --
106 : ValuePair( GeogPrimeMeridianLongGeoKey, 2061) -- GeoAngularUnit --
107 :
108 : -- 6.2.3 Projected CS Parameter Keys --
109 : -- Several keys have been renamed,--
110 : -- and the deprecated names aliased for backward compatibility --
111 :
112 : ValuePair( ProjectedCSTypeGeoKey, 3072) -- Section 6.3.3.1 codes --
113 : ValuePair( PCSCitationGeoKey, 3073) -- documentation --
114 : ValuePair( ProjectionGeoKey, 3074) -- Section 6.3.3.2 codes --
115 : ValuePair( ProjCoordTransGeoKey, 3075) -- Section 6.3.3.3 codes --
116 : ValuePair( ProjLinearUnitsGeoKey, 3076) -- Section 6.3.1.3 codes --
117 : ValuePair( ProjLinearUnitSizeGeoKey, 3077) -- meters --
118 : ValuePair( ProjStdParallel1GeoKey, 3078) -- GeogAngularUnit --
119 : ValuePair( ProjStdParallelGeoKey,ProjStdParallel1GeoKey) -- ** alias ** --
120 : ValuePair( ProjStdParallel2GeoKey, 3079) -- GeogAngularUnit --
121 : ValuePair( ProjNatOriginLongGeoKey, 3080) -- GeogAngularUnit --
122 : ValuePair( ProjOriginLongGeoKey,ProjNatOriginLongGeoKey) -- ** alias ** --
123 : ValuePair( ProjNatOriginLatGeoKey, 3081) -- GeogAngularUnit --
124 : ValuePair( ProjOriginLatGeoKey,ProjNatOriginLatGeoKey) -- ** alias ** --
125 : ValuePair( ProjFalseEastingGeoKey, 3082) -- ProjLinearUnits --
126 : ValuePair( ProjFalseNorthingGeoKey, 3083) -- ProjLinearUnits --
127 : ValuePair( ProjFalseOriginLongGeoKey, 3084) -- GeogAngularUnit --
128 : ValuePair( ProjFalseOriginLatGeoKey, 3085) -- GeogAngularUnit --
129 : ValuePair( ProjFalseOriginEastingGeoKey, 3086) -- ProjLinearUnits --
130 : ValuePair( ProjFalseOriginNorthingGeoKey, 3087) -- ProjLinearUnits --
131 : ValuePair( ProjCenterLongGeoKey, 3088) -- GeogAngularUnit --
132 : ValuePair( ProjCenterLatGeoKey, 3089) -- GeogAngularUnit --
133 : ValuePair( ProjCenterEastingGeoKey, 3090) -- ProjLinearUnits --
134 : ValuePair( ProjCenterNorthingGeoKey, 3091) -- ProjLinearUnits --
135 : ValuePair( ProjScaleAtNatOriginGeoKey, 3092) -- ratio --
136 : ValuePair( ProjScaleAtOriginGeoKey,ProjScaleAtNatOriginGeoKey) -- ** alias ** --
137 : ValuePair( ProjScaleAtCenterGeoKey, 3093) -- ratio --
138 : ValuePair( ProjAzimuthAngleGeoKey, 3094) -- GeogAzimuthUnit --
139 : ValuePair( ProjStraightVertPoleLongGeoKey, 3095) -- GeogAngularUnit --
140 :
141 : 6.2.4 Vertical CS Keys
142 :
143 : ValuePair( VerticalCSTypeGeoKey, 4096) -- Section 6.3.4.1 codes --
144 : ValuePair( VerticalCitationGeoKey, 4097) -- documentation --
145 : ValuePair( VerticalDatumGeoKey, 4098) -- Section 6.3.4.2 codes --
146 : ValuePair( VerticalUnitsGeoKey, 4099) -- Section 6.3.1 (.x) codes --
147 : </pre>
148 : */
149 :
150 15725 : int GTIFKeyGet(GTIF *gtif, geokey_t thekey, void *val, int index, int count)
151 : {
152 15725 : int kindex = gtif->gt_keyindex[ thekey ];
153 : GeoKey *key;
154 : gsize_t size;
155 : char *data;
156 : tagtype_t type;
157 :
158 15725 : if (!kindex) return 0;
159 :
160 5050 : key = gtif->gt_keys+kindex;
161 5050 : if (!count) count = key->gk_count - index;
162 5050 : if (count <=0) return 0;
163 5050 : if (count > key->gk_count) count = key->gk_count;
164 5050 : size = key->gk_size;
165 5050 : type = key->gk_type;
166 :
167 5050 : if (count==1 && type==TYPE_SHORT) data = (char *)&key->gk_data;
168 1207 : else data = key->gk_data;
169 :
170 5050 : _GTIFmemcpy( val, data + index*size, count*size );
171 :
172 5050 : if (type==TYPE_ASCII)
173 23 : ((char *)val)[count-1] = '\0'; /* replace last char with NULL */
174 :
175 5050 : return count;
176 : }
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