NAME
glNormalPointer - define an array of normals
C SPECIFICATION
void glNormalPointer( GLenum type,
GLsizei stride,
const GLvoid *pointer )
PARAMETERS
type Specifies the data type of each coordinate in the
array. Symbolic constants GL_BYTE, GL_SHORT,
GL_INT, GL_FLOAT, and GL_DOUBLE are accepted. The
initial value is GL_FLOAT.
stride Specifies the byte offset between consecutive
normals. If stride is 0- the initial value-the
normals are understood to be tightly packed in the
array.
pointer Specifies a pointer to the first coordinate of the
first normal in the array.
DESCRIPTION
glNormalPointer specifies the location and data format of an
array of normals to use when rendering. type specifies the
data type of the normal coordinates and stride gives the
byte stride from one normal to the next, allowing vertexes
and attributes to be packed into a single array or stored in
separate arrays. (Single-array storage may be more
efficient on some implementations; see glInterleavedArrays.)
When a normal array is specified, type, stride, and pointer
are saved as client-side state.
To enable and disable the normal array, call
glEnableClientState and glDisableClientState with the
argument GL_NORMAL_ARRAY. If enabled, the normal array is
used when glDrawArrays, glDrawElements, or glArrayElement is
called.
Use glDrawArrays to construct a sequence of primitives (all
of the same type) from prespecified vertex and vertex
attribute arrays. Use glArrayElement to specify primitives
by indexing vertexes and vertex attributes and
glDrawElements to construct a sequence of primitives by
indexing vertexes and vertex attributes.
NOTES
glNormalPointer is available only if the GL version is 1.1
or greater.
The normal array is initially disabled and isn't accessed
when glArrayElement, glDrawElements, or glDrawArrays is
called.
Execution of glNormalPointer is not allowed between glBegin
and the corresponding glEnd, but an error may or may not be
generated. If an error is not generated, the operation is
undefined.
glNormalPointer is typically implemented on the client side.
Since the normal array parameters are client-side state,
they are not saved or restored by glPushAttrib and
glPopAttrib. Use glPushClientAttrib and glPopClientAttrib
instead.
ERRORS
GL_INVALID_ENUM is generated if type is not an accepted
value.
GL_INVALID_VALUE is generated if stride is negative.
ASSOCIATED GETS
glIsEnabled with argument GL_NORMAL_ARRAY
glGet with argument GL_NORMAL_ARRAY_TYPE
glGet with argument GL_NORMAL_ARRAY_STRIDE
glGetPointerv with argument GL_NORMAL_ARRAY_POINTER
SEE ALSO
glArrayElement, glColorPointer, glDrawArrays,
glDrawElements, glEdgeFlagPointer, glEnable, glGetPointerv,
glIndexPointer, glInterleavedArrays, glPopClientAttrib,
glPushClientAttrib, glTexCoordPointer, glVertexPointer