Provided by: libvolpack1-dev_1.0b3-10_amd64 
NAME
vpRotate - multiply the current transformation matrix by a rotation matrix
SYNOPSIS
#include <volpack.h>
vpResult
vpRotate(vpc, axis, degrees)
vpContext *vpc;
int axis;
double degrees;
ARGUMENTS
vpc VolPack context from vpCreateContext.
axis Rotation axis code (VP_X_AXIS, VP_Y_AXIS or VP_Z_AXIS).
degrees
Number of degrees to rotate.
DESCRIPTION
vpRotate is used to multiply the current transformation matrix by a 4-by-4 rotation matrix. The rotation
axis must be one of the three principal viewing axes and is specified with one of the following codes:
VP_X_AXIS X axis
VP_Y_AXIS Y axis
VP_Z_AXIS Z axis The rotation angle is specified in degrees. A positive angle indicates a clockwise
rotation when looking towards the positive direction along the axis. For an X-axis rotation, the
rotation matrix is: 1 0 0 0
0 cos(d) sin(d) 0
0 -sin(d) cos(d) 0
0 0 0 1 where d stands for the degrees argument. For a Y-axis rotation, the
rotation matrix is: cos(d) 0 -sin(d) 0
0 1 0 0
sin(d) 0 cos(d) 0
0 0 0 1 For a Z-axis rotation, the rotation matrix is:
cos(d) sin(d) 0 0
-sin(d) cos(d) 0 0
0 0 1 0
0 0 0 1
Use vpCurrentMatrix to set the current transformation matrix. By default, the rotation matrix is post-
multiplied (M = M*R where M is the current matrix and R is the rotation matrix). The VP_CONCAT_MODE
option to vpSeti can be used to select pre-multiplication.
STATE VARIABLES
The current matrix concatenation parameters can be retrieved with the following state variable codes (see
vpGeti(3)): VP_CURRENT_MATRIX, VP_CONCAT_MODE.
ERRORS
The normal return value is VP_OK. The following error return value is possible:
VPERROR_BAD_OPTION
The axis argument is invalid.
SEE ALSO
VolPack(3), vpCreateContext(3), vpCurrentMatrix(3)