GLROTATE() MachTen Programmer’s Manual GLROTATE()

NAME
glRotated, glRotatef - multiply the current matrix by a
rotation matrix

C SPECIFICATION
void glRotated( GLdouble angle,
GLdouble x,
GLdouble y,
GLdouble z )
void glRotatef( GLfloat angle,
GLfloat x,
GLfloat y,
GLfloat z )

delim $$

PARAMETERS
angle Specifies the angle of rotation, in degrees.

x, y, z
Specify the x, y, and z coordinates of a vector,
respectively.

DESCRIPTION
glRotate produces a rotation of angle degrees around the
vector $("x", "y", "z")$. The current matrix (see glMa-
trixMode) is multiplied by a rotation matrix with the
product replacing the current matrix, as if glMultMatrix
were called with the following matrix as its argument:

left ( ~ down 20 matrix {
ccol { "x" "x" (1 - c)+ c above "y" "x" (1 - c)+ "z" s
above "x" "z" (1 - c)-"y" s above ~0 }
ccol {"x" "y" (1 - c)-"z" s above "y" "y" (1 - c)+ c
above "y" "z" (1 - c)+ "x" s above ~0 }
ccol { "x" "z" (1 - c)+ "y" s above "y" "z" (1 - c)-
"x" s above "z" "z" (1 - c) + c above ~0 }
ccol { ~0 above ~0 above ~0 above ~1} } ~~ right )

Where $c ~=~ cos("angle")$, $s ~=~ sine("angle")$, and
$||(~"x", "y", "z"~)|| ~=~ 1$ (if not, the GL will normal-
ize this vector).

If the matrix mode is either GL_MODELVIEW or
GL_PROJECTION, all objects drawn after glRotate is called
are rotated. Use glPushMatrix and glPopMatrix to save and
restore the unrotated coordinate system.

NOTES
This rotation follows the right-hand rule, so if the vec-
tor $("x", "y", "z")$ points toward the user, the rotation
will be counterclockwise.

ERRORS
GL_INVALID_OPERATION is generated if glRotate is executed
between the execution of glBegin and the corresponding
execution of glEnd.

ASSOCIATED GETS
glGet with argument GL_MATRIX_MODE
glGet with argument GL_MODELVIEW_MATRIX
glGet with argument GL_PROJECTION_MATRIX
glGet with argument GL_TEXTURE_MATRIX

SEE ALSO
glMatrixMode, glMultMatrix, glPushMatrix, glScale,
glTranslate

MachTen 2