GLNORMALPOINTER(3G)

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 normals are understood to be tightly packed in the array. The initial value is 0.

pointer
    Specifies a pointer to the first coordinate of the first normal in the array. The initial value is 0.

DESCRIPTION

glNormalPointer specifies the location and data format of an array of normals to use when rendering. type specifies the data type of each normal coordinate, and stride specifies 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().)

If a non-zero named buffer object is bound to the GL_ARRAY_BUFFER target (see glBindBuffer()) while a normal array is specified, pointer is treated as a byte offset into the buffer object's data store. Also, the buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as normal vertex array client-side state (GL_NORMAL_ARRAY_BUFFER_BINDING).

When a normal array is specified, type, stride, and pointer are saved as client-side state, in addition to the current vertex array buffer object binding.

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(), glMultiDrawArrays(), glDrawElements(), glMultiDrawElements(), glDrawRangeElements(), or glArrayElement() is called.

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(), glDrawRangeElements(), glDrawArrays(), glMultiDrawArrays(), or glMultiDrawElements() 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.

Normal array parameters are client-side state and are therefore 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

glGet() with argument GL_NORMAL_ARRAY_BUFFER_BINDING

glGet() with argument GL_ARRAY_BUFFER_BINDING

glGetPointerv() with argument GL_NORMAL_ARRAY_POINTER

SEE ALSO

glArrayElement(), glBindBuffer(), glColorPointer(), glDisableClientState(), glDrawArrays(), glDrawElements(), glDrawRangeElements(), glEdgeFlagPointer(), glEnableClientState(), glFogCoordPointer(), glIndexPointer(), glInterleavedArrays(), glMultiDrawArrays(), glMultiDrawElements(), glNormal(), glPopClientAttrib(), glPushClientAttrib(), glSecondaryColorPointer(), glTexCoordPointer(), glVertexAttribPointer(), glVertexPointer()

COPYRIGHT

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.