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