GRASS GIS 7 Programmer's Manual  7.7.svn(2018)-r73378
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raster/raster.c
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1 /*!
2  * \file lib/raster/raster.c
3  *
4  * \brief Raster Library - Raster cell value routines.
5  *
6  * (C) 2001-2009 by the GRASS Development Team
7  *
8  * This program is free software under the GNU General Public License
9  * (>=v2). Read the file COPYING that comes with GRASS for details.
10  *
11  * \author Original author CERL
12  */
13 
14 #include <stdlib.h>
15 #include <string.h>
16 #include <grass/gis.h>
17 #include <grass/raster.h>
18 
19 /*!
20  * \brief Compares raster values.
21  *
22  * \param v1,v2 values to be compared
23  * \param data_type raster type (CELL, FCELL, DCELL)
24  *
25  * \return 1 if p > q or only q is null value
26  * \return -1 if p < q or only p is null value
27  * \return 0 if p == q or p==q==null value
28  */
29 int Rast_raster_cmp(const void *v1, const void *v2, RASTER_MAP_TYPE data_type)
30 {
31  if (Rast_is_null_value(v1, data_type)) {
32  if (Rast_is_null_value(v2, data_type))
33  return 0;
34  else
35  return -1;
36  }
37  else if (Rast_is_null_value(v2, data_type))
38  return 1;
39 
40  switch (data_type) {
41  case CELL_TYPE:
42  if (*((const CELL *)v1) > *((const CELL *)v2))
43  return 1;
44  else if (*((const CELL *)v1) == *((const CELL *)v2))
45  return 0;
46  else
47  return -1;
48  case FCELL_TYPE:
49  if (*((const FCELL *)v1) > *((const FCELL *)v2))
50  return 1;
51  else if (*((const FCELL *)v1) == *((const FCELL *)v2))
52  return 0;
53  else
54  return -1;
55  case DCELL_TYPE:
56  if (*((const DCELL *)v1) > *((const DCELL *)v2))
57  return 1;
58  else if (*((const DCELL *)v1) == *((const DCELL *)v2))
59  return 0;
60  else
61  return -1;
62  }
63 
64  return 0;
65 }
66 
67 /*!
68  * \brief Copies raster values.
69  *
70  * If \p v2 is null value, sets \p v2 to null value.
71  * \p n is typically size of the destination array
72  * and the source array is at least that large.
73  *
74  * \param v1 destination array for raster values
75  * \param v2 source array with raster values
76  * \param n number of values to copy
77  * \param data_type raster type (CELL, FCELL, DCELL)
78  */
79 void Rast_raster_cpy(void *v1, const void *v2, int n,
80  RASTER_MAP_TYPE data_type)
81 {
82  memcpy(v1, v2, n * Rast_cell_size(data_type));
83 }
84 
85 /*!
86  * \brief Places a CELL raster value
87  *
88  * If Rast_is_c_null_value() is true, sets p to null value. Converts CELL
89  * val to data_type (type of p) and stores result in p. Used for
90  * assigning CELL values to raster cells of any type.
91  *
92  * \param rast pointer to raster cell value
93  * \param cval value to set
94  * \param data_type raster type (CELL, FCELL, DCELL)
95  */
96 void Rast_set_c_value(void *rast, CELL cval, RASTER_MAP_TYPE data_type)
97 {
98  CELL c;
99 
100  c = cval;
101  if (Rast_is_c_null_value(&c)) {
102  Rast_set_null_value(rast, 1, data_type);
103  return;
104  }
105  switch (data_type) {
106  case CELL_TYPE:
107  *((CELL *) rast) = cval;
108  break;
109  case FCELL_TYPE:
110  *((FCELL *) rast) = (FCELL) cval;
111  break;
112  case DCELL_TYPE:
113  *((DCELL *) rast) = (DCELL) cval;
114  break;
115  }
116 }
117 
118 /*!
119  * \brief Places a FCELL raster value
120  *
121  * If Rast_is_f_null_value() is true, sets p to null value. Converts
122  * FCELL val to data_type (type of p) and stores result in p. Used for
123  * assigning FCELL values to raster cells of any type.
124  *
125  * \param rast pointer to raster cell value
126  * \param fval value to set
127  * \param data_type raster type (CELL, FCELL, DCELL)
128  */
129 void Rast_set_f_value(void *rast, FCELL fval, RASTER_MAP_TYPE data_type)
130 {
131  FCELL f;
132 
133  f = fval;
134  if (Rast_is_f_null_value(&f)) {
135  Rast_set_null_value(rast, 1, data_type);
136  return;
137  }
138  switch (data_type) {
139  case CELL_TYPE:
140  *((CELL *) rast) = (CELL) fval;
141  break;
142  case FCELL_TYPE:
143  *((FCELL *) rast) = fval;
144  break;
145  case DCELL_TYPE:
146  *((DCELL *) rast) = (DCELL) fval;
147  break;
148  }
149 }
150 
151 
152 /*!
153  * \brief Places a DCELL raster value
154  *
155  * If Rast_is_d_null_value() is true, sets p to null value. Converts
156  * DCELL val to data_type (type of p) and stores result in p. Used for
157  * assigning DCELL values to raster cells of any type.
158  *
159  * \param rast pointer to raster cell value
160  * \param fval value to set
161  * \param data_type raster type (CELL, FCELL, DCELL)
162  */
163 void Rast_set_d_value(void *rast, DCELL dval, RASTER_MAP_TYPE data_type)
164 {
165  DCELL d;
166 
167  d = dval;
168  if (Rast_is_d_null_value(&d)) {
169  Rast_set_null_value(rast, 1, data_type);
170  return;
171  }
172  switch (data_type) {
173  case CELL_TYPE:
174  *((CELL *) rast) = (CELL) dval;
175  break;
176  case FCELL_TYPE:
177  *((FCELL *) rast) = (FCELL) dval;
178  break;
179  case DCELL_TYPE:
180  *((DCELL *) rast) = dval;
181  break;
182  }
183 }
184 
185 /*!
186  * \brief Retrieves the value of give type from pointer p
187  *
188  * Retrieves the value of type data_type from pointer p, converts it
189  * to CELL type and returns the result. If null value is stored in p,
190  * returns CELL null value.
191  *
192  * Used for retrieving CELL values from raster cells of any type.
193  *
194  * Note: when data_type != CELL_TYPE, no quantization is used, only
195  * type conversion.
196  *
197  * \param rast pointer to raster cell value
198  * \param data_type raster type (CELL, FCELL, DCELL)
199  *
200  * \return raster value
201  */
202 CELL Rast_get_c_value(const void *rast, RASTER_MAP_TYPE data_type)
203 {
204  CELL c;
205 
206  if (Rast_is_null_value(rast, data_type)) {
207  Rast_set_c_null_value(&c, 1);
208  return c;
209  }
210  switch (data_type) {
211  case CELL_TYPE:
212  return *((const CELL *)rast);
213  case FCELL_TYPE:
214  return (CELL) * ((const FCELL *)rast);
215  case DCELL_TYPE:
216  return (CELL) * ((const DCELL *)rast);
217  }
218 
219  return 0;
220 }
221 
222 /*!
223  * \brief Retrieves the value of given raster type from pointer p (FCELL)
224  *
225  * Retrieves the value of type data_type from pointer p, converts it
226  * to FCELL type and returns the result. If null value is stored in p,
227  * returns FCELL null value.
228  *
229  * Used for retrieving FCELL values from raster cells of any type.
230  *
231  * \param rast pointer to raster cell value
232  * \param data_type raster type (CELL, FCELL, DCELL)
233  *
234  * \return raster value
235  */
236 FCELL Rast_get_f_value(const void *rast, RASTER_MAP_TYPE data_type)
237 {
238  FCELL f;
239 
240  if (Rast_is_null_value(rast, data_type)) {
241  Rast_set_f_null_value(&f, 1);
242  return f;
243  }
244  switch (data_type) {
245  case CELL_TYPE:
246  return (FCELL) * ((const CELL *)rast);
247  case FCELL_TYPE:
248  return *((const FCELL *)rast);
249  case DCELL_TYPE:
250  return (FCELL) * ((const DCELL *)rast);
251  }
252 
253  return 0;
254 }
255 
256 
257 /*!
258  * \brief Retrieves the value of given type from pointer p (DCELL)
259  *
260  * Retrieves the value of type data_type from pointer p, converts it
261  * to DCELL type and returns the result. If null value is stored in p,
262  * returns DCELL null value.
263 
264  * Used for retrieving DCELL values from raster cells of any type.
265  *
266  * \param rast pointer to raster cell value
267  * \param data_type raster type (CELL, FCELL, DCELL)
268  *
269  * \return raster value
270  */
271 DCELL Rast_get_d_value(const void *rast, RASTER_MAP_TYPE data_type)
272 {
273  DCELL d;
274 
275  if (Rast_is_null_value(rast, data_type)) {
276  Rast_set_d_null_value(&d, 1);
277  return d;
278  }
279  switch (data_type) {
280  case CELL_TYPE:
281  return (DCELL) * ((const CELL *)rast);
282  case FCELL_TYPE:
283  return (DCELL) * ((const FCELL *)rast);
284  case DCELL_TYPE:
285  return *((const DCELL *)rast);
286  }
287 
288  return 0;
289 }
void Rast_set_f_value(void *rast, FCELL fval, RASTER_MAP_TYPE data_type)
Places a FCELL raster value.
#define CELL_TYPE
Definition: raster.h:11
int Rast_is_f_null_value(const FCELL *fcellVal)
To check if a FCELL raster value is set to NULL.
Definition: null_val.c:242
void Rast_set_d_value(void *rast, DCELL dval, RASTER_MAP_TYPE data_type)
Places a DCELL raster value.
double DCELL
Definition: gis.h:581
int Rast_raster_cmp(const void *v1, const void *v2, RASTER_MAP_TYPE data_type)
Compares raster values.
Definition: raster/raster.c:29
int Rast_is_c_null_value(const CELL *cellVal)
To check if a CELL raster value is set to NULL.
Definition: null_val.c:209
void Rast_set_null_value(void *buf, int numVals, RASTER_MAP_TYPE data_type)
To set one or more raster values to null.
Definition: null_val.c:98
#define DCELL_TYPE
Definition: raster.h:13
size_t Rast_cell_size(RASTER_MAP_TYPE data_type)
Returns size of a raster cell in bytes.
Definition: alloc_cell.c:39
void Rast_set_c_null_value(CELL *cellVals, int numVals)
To set a number of CELL raster values to NULL.
Definition: null_val.c:124
int Rast_is_null_value(const void *rast, RASTER_MAP_TYPE data_type)
To check if a raster value is set to NULL.
Definition: null_val.c:179
void Rast_set_f_null_value(FCELL *fcellVals, int numVals)
To set a number of FCELL raster values to NULL.
Definition: null_val.c:138
void Rast_raster_cpy(void *v1, const void *v2, int n, RASTER_MAP_TYPE data_type)
Copies raster values.
Definition: raster/raster.c:79
CELL Rast_get_c_value(const void *rast, RASTER_MAP_TYPE data_type)
Retrieves the value of give type from pointer p.
void Rast_set_d_null_value(DCELL *dcellVals, int numVals)
To set a number of DCELL raster values to NULL.
Definition: null_val.c:155
float FCELL
Definition: gis.h:582
void Rast_set_c_value(void *rast, CELL cval, RASTER_MAP_TYPE data_type)
Places a CELL raster value.
Definition: raster/raster.c:96
int CELL
Definition: gis.h:580
int RASTER_MAP_TYPE
Definition: raster.h:25
#define FCELL_TYPE
Definition: raster.h:12
FCELL Rast_get_f_value(const void *rast, RASTER_MAP_TYPE data_type)
Retrieves the value of given raster type from pointer p (FCELL)
DCELL Rast_get_d_value(const void *rast, RASTER_MAP_TYPE data_type)
Retrieves the value of given type from pointer p (DCELL)
int Rast_is_d_null_value(const DCELL *dcellVal)
To check if a DCELL raster value is set to NULL.
Definition: null_val.c:261