glNormalPointer

GLNORMALPOINTER(3G)					  GLNORMALPOINTER(3G)



NAME
       glNormalPointer - define an array of normals


C SPECIFICATION
       void glNormalPointer( GLenum type,
			     GLsizei stride,
			     const GLvoid *ptr )


PARAMETERS
       type    Specifies the data type of each coordinate in the array.	 Sym-
	       bolic  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.	The initial value is 0.

       ptr     Specifies  a pointer to the first coordinate of the first nor-
	       mal in the array.  The initial value is 0.

DESCRIPTION
       glNormalPointer specifies the location and data	of an array  of	 nor-
       mals  to use when rendering.  type specifies the data type of the nor-
       mal coordinates and stride gives the byte stride from  one  normal  to
       the  next, allowing vertices 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 ptr 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 vertices  and  vertex
       attributes and glDrawElements to construct a sequence of primitives by
       indexing vertices 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(3G),	 glColorPointer(3G),	    glDrawArrays(3G),
       glDrawElements(3G),	  glEdgeFlagPointer(3G),	glEnable(3G),
       glGetPointerv(3G),    glIndexPointer(3G),     glInterleavedArrays(3G),
       glPopClientAttrib(3G),  glPushClientAttrib(3G), glTexCoordPointer(3G),
       glVertexPointer(3G)



							  GLNORMALPOINTER(3G)