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glNormalPointer — define an array of normals
void glNormalPointer( | GLenum | type, |
| GLsizei | stride, | |
| const GLvoid * | pointer); |
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.
pointerSpecifies a pointer to the first coordinate of the first normal in the array. The initial value is 0.
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.
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.
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if stride is negative.
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
glArrayElement, glBindBuffer, glColorPointer, glDisableClientState, glDrawArrays, glDrawElements, glDrawRangeElements, glEdgeFlagPointer, glEnableClientState, glFogCoordPointer, glIndexPointer, glInterleavedArrays, glMultiDrawArrays, glMultiDrawElements, glNormal, glPopClientAttrib, glPushClientAttrib, glSecondaryColorPointer, glTexCoordPointer, glVertexAttribPointer, glVertexPointer
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/.