GRASS GIS 8 Programmer's Manual  8.5.0dev(2024)-d6dec75dd4
gsget.h
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1 #ifndef _GSGET_H
2 #define _GSGET_H
3 
4 #include <grass/ogsf.h>
5 
6 #define GET_MAPATT1(buff, offset, att) \
7  att = (buff->ib ? (float)buff->ib[offset] \
8  : buff->sb ? (float)buff->sb[offset] \
9  : buff->cb ? (float)buff->cb[offset] \
10  : buff->fb ? (float)buff->fb[offset] \
11  : 0.0)
12 
13 #define GET_MAPATT2(buff, offset, att) \
14  att = (buff->ib ? (float)buff->ib[offset] \
15  : buff->sb ? (float)buff->sb[offset] \
16  : buff->cb ? (float)buff->cb[offset] \
17  : buff->fb ? (float)buff->fb[offset] \
18  : buff->k); \
19  if (buff->tfunc) \
20  att = (buff->tfunc)(att, offset);
21 
22 /* cast to float, otherwise doesn't seem to handle neg. values */
23 
24 #define SCALE_ATT(att, val, low, high) \
25  ((val) <= att->max_nz && (val) >= att->min_nz && att->range_nz \
26  ? (((val) - att->min_nz) / att->range_nz) * ((high) - (low)) + (low) \
27  : 0)
28 
29 #define GET_MAPATT(buff, offset, att) (get_mapatt(buff, offset, &(att)))
30 
31 #define BM_GET_BYOFFSET(bm, off) \
32  (bm ? BM_get(bm, (off % bm->cols), (off / bm->cols)) : 0)
33 
34 #define XYMAXPOS 0x3ff /* 1023 */
35 #define ZMAXPOS 0x3ff /* 1023 */
36 
37 #define NXMASK 0xffe00000 /* top 11 bits */
38 #define NYMASK 0x1ffc00 /* middle 11 bits of packed int */
39 #define NZMASK 0x3ff /* lowest 10 bits */
40 
41 #define NZUP 0x000003ff
42 
43 /* Fetch Normal vector from packed int */
44 /*
45  #define FNORM(i,nv) \
46  nv[X] = ((int)(((i) & NXMASK) >> 21) - XYMAXPOS)/(float)XYMAXPOS; \
47  nv[Y] = ((int)(((i) & NYMASK) >> 10) - XYMAXPOS)/(float)XYMAXPOS; \
48  nv[Z] = (int)((i) & NZMASK) * GS_global_exag()/(float)ZMAXPOS
49  */
50 
51 #define FNORM(i, nv) \
52  nv[X] = ((int)(((i) & NXMASK) >> 21) - XYMAXPOS) / (float)XYMAXPOS; \
53  nv[Y] = ((int)(((i) & NYMASK) >> 10) - XYMAXPOS) / (float)XYMAXPOS; \
54  nv[Z] = (int)((i) & NZMASK) / (float)ZMAXPOS
55 
56 /* Pack Normal vector into int */
57 #define PNORM(i, nv) \
58  i = ((unsigned int)((nv[X] * XYMAXPOS) + XYMAXPOS) << 21) | \
59  ((unsigned int)((nv[Y] * XYMAXPOS) + XYMAXPOS) << 10) | \
60  (unsigned int)(nv[Z] * ZMAXPOS)
61 
62 #endif /* _GSGET_H */