1vpTranspose(3)             Library Functions Manual             vpTranspose(3)
2
3
4

NAME

6       vpTranspose - transpose a volume
7

SYNOPSIS

9       #include <volpack.h>
10
11       vpResult
12       vpTranspose(vpc, axis)
13           vpContext *vpc;
14           int axis;
15

ARGUMENTS

17       vpc    VolPack context from vpCreateContext.
18
19       axis   Axis  which  should  have  the smallest stride after transposing
20              (VP_X_AXIS, VP_Y_AXIS or VP_Z_AXIS).
21

DESCRIPTION

23       vpTranspose is used to transpose the 3D voxel  array  to  optimize  the
24       memory  stride  for  a particular principal viewing axis.  The intended
25       way to use this function is to set  the  viewing  transformation,  call
26       vpGeti with the VP_VIEW_AXIS argument to find the corresponding viewing
27       axis, and then call vpTranspose with that axis.  Transposing  the  data
28       changes  the arrangement of the data stored in the 3D voxel array.  The
29       voxel stride state variables are updated to reflect this change, so the
30       viewing  transformation  does not need to be changed after transposing.
31       If the volume is already transposed for  the  requested  axis  then  it
32       returns immediately without modifying the voxel array.
33
34       This function is useful only for rendering large 3D voxel arrays.  This
35       function has no affect on the preclassified volume data.
36

STATE VARIABLES

38       Relevant variables may be retrieved with the following  state  variable
39       codes      (see     vpGeti(3)):     VP_VIEW_AXIS,     VP_VOXEL_XSTRIDE,
40       VP_VOXEL_YSTRIDE, VP_VOXEL_ZSTRIDE.
41

ERRORS

43       The normal return value is VP_OK.  The following  error  return  values
44       are possible:
45
46       VPERROR_BAD_OPTION
47              The axis argument is invalid.
48
49       VPERROR_BAD_VOLUME
50              The 3D voxel array is missing or invalid.
51
52       VPERROR_BAD_VOXEL
53              The voxel fields are incorrectly specified.
54

SEE ALSO

56       VolPack(3), vpCreateContext(3)
57
58
59
60VolPack                                                         vpTranspose(3)
Impressum