glVertexAttribPointer
3G

# glVertexAttribPointer

define an array of generic vertex attribute data

## C Specification

    		void glVertexAttribPointer
    		GLuint index
    		GLint size
    		GLenum type
    		GLboolean normalized
    		GLsizei stride
    		const GLvoid * pointer

## Parameters

`index`

  Specifies the index of the generic vertex attribute to be modified.

`size`

  Specifies the number of components per generic vertex attribute. Must be 1, 2, 3, or 4. The initial value is 4.

`type`

  Specifies the data type of each component in the array. Symbolic constants `GL_BYTE`, `GL_UNSIGNED_BYTE`, `GL_SHORT`, `GL_UNSIGNED_SHORT`, `GL_INT`, `GL_UNSIGNED_INT`, `GL_FLOAT`, or `GL_DOUBLE` are accepted. The initial value is `GL_FLOAT`.

`normalized`

  Specifies whether fixed-point data values should be normalized (`GL_TRUE`) or converted directly as fixed-point values (`GL_FALSE`) when they are accessed.

`stride`

  Specifies the byte offset between consecutive generic vertex attributes. If `stride` is 0, the generic vertex attributes are understood to be tightly packed in the array. The initial value is 0.

`pointer`

  Specifies a pointer to the first component of the first generic vertex attribute in the array. The initial value is 0.

## Description

`glVertexAttribPointer` specifies the location and data format of the array of generic vertex attributes at index `index` to use when rendering. `size` specifies the number of components per attribute and must be 1, 2, 3, or 4. `type` specifies the data type of each component, and `stride` specifies the byte stride from one attribute to the next, allowing vertices and attributes to be packed into a single array or stored in separate arrays. If set to `GL_TRUE`, `normalized` indicates that values stored in an integer format are to be mapped to the range [-1,1] (for signed values) or [0,1] (for unsigned values) when they are accessed and converted to floating point. Otherwise, values will be converted to floats directly without normalization.

If a non-zero named buffer object is bound to the `GL_ARRAY_BUFFER` target (see glBindBuffer) while a generic vertex attribute 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 generic vertex attribute array client-side state (`GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING`) for index `index`.

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

To enable and disable a generic vertex attribute array, call glEnableVertexAttribArray and glDisableVertexAttribArray with `index`. If enabled, the generic vertex attribute array is used when glArrayElement, glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, or glDrawRangeElements is called.

## Notes

`glVertexAttribPointer` is available only if the GL version is 2.0 or greater.

Each generic vertex attribute array is initially disabled and isn't accessed when glArrayElement, glDrawElements, glDrawRangeElements, glDrawArrays, glMultiDrawArrays, or glMultiDrawElements is called.

Execution of `glVertexAttribPointer` is not allowed between the execution of glBegin and the corresponding execution of glEnd, but an error may or may not be generated. If no error is generated, the operation is undefined.

`glVertexAttribPointer` is typically implemented on the client side.

Generic vertex attribute 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_VALUE` is generated if `index` is greater than or equal to `GL_MAX_VERTEX_ATTRIBS`.

`GL_INVALID_VALUE` is generated if `size` is not 1, 2, 3, or 4.

`GL_INVALID_ENUM` is generated if `type` is not an accepted value.

`GL_INVALID_VALUE` is generated if `stride` is negative.

## Associated Gets

glGet with argument `GL_MAX_VERTEX_ATTRIBS`

glGetVertexAttrib with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_ENABLED`

glGetVertexAttrib with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_SIZE`

glGetVertexAttrib with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_TYPE`

glGetVertexAttrib with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_NORMALIZED`

glGetVertexAttrib with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_STRIDE`

glGetVertexAttrib with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_BUFFER_BINDING`

glGet with argument `GL_ARRAY_BUFFER_BINDING`

glGetVertexAttribPointerv with arguments `index` and `GL_VERTEX_ATTRIB_ARRAY_POINTER`

## See Also

glArrayElement, glBindAttribLocation, glBindBuffer, glColorPointer, glDisableVertexAttribArray, glDrawArrays, glDrawElements, glDrawRangeElements, glEnableVertexAttribArray, glEdgeFlagPointer, glFogCoordPointer, glIndexPointer, glInterleavedArrays, glMultiDrawArrays, glMultiDrawElements, glNormalPointer, glPopClientAttrib, glPushClientAttrib, glSecondaryColorPointer, glTexCoordPointer, glVertexAttrib, glVertexPointer

## Copyright

Copyright 2003-2005 3Dlabs Inc. Ltd. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.