glNormalPointer

glNormalPointer: man2/glNormalPointer.xml

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.