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# docs.GL

OpenGL 4
OpenGL 3
OpenGL 2
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# glVertexAttribPointer

## Name

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`

## Examples

Render an indexed vertex array (not loaded into OpenGL) using texture UV and normal vertex attributes.

    glEnableVertexAttribArray(texcoord_attrib_index); // Attribute indexes were received from calls to glGetAttribLocation, or passed into glBindAttribLocation.
    glEnableVertexAttribArray(normal_attrib_index);
    glEnableVertexAttribArray(position_attrib_index);

    glVertexAttribPointer(texcoord_attrib_index, 2, GL_FLOAT, false, 0, texcoords_data); // texcoords_data is a float*, 2 per vertex, representing UV coordinates.
    glVertexAttribPointer(normal_attrib_index, 3, GL_FLOAT, false, 0, normals_data); // normals_data is a float*, 3 per vertex, representing normal vectors.
    glVertexAttribPointer(position_attrib_index, 3, GL_FLOAT, false, 0, vertex_data); // vertex_data is a float*, 3 per vertex, representing the position of each vertex

    // num_vertices is the number of verts in your vertex_data.
    // index_data is an array of unsigned int offsets into vertex_data.
    glDrawElements(GL_TRIANGLES, num_vertices, GL_UNSIGNED_INT, index_data);

    glDisableVertexAttribArray(position_attrib_index);
    glDisableVertexAttribArray(texcoord_attrib_index);
    glDisableVertexAttribArray(normal_attrib_index);

Render an indexed buffer object using texture UV and normal vertex attributes.

    glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer); // vertex_buffer is retrieved from glGenBuffers
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, index_buffer); // index_buffer is retrieved from glGenBuffers

    glEnableVertexAttribArray(texcoord_attrib_index); // Attribute indexes were received from calls to glGetAttribLocation, or passed into glBindAttribLocation.
    glEnableVertexAttribArray(normal_attrib_index);
    glEnableVertexAttribArray(position_attrib_index);

    // vertex_stride is the size of bytes of each vertex in the buffer object
    // vertex_position_offset and kin are the offset in bytes of the position data
    // in each vertex. For example if your vertex structure is
    // [ position, texcoord, normal ] then position vertex_position_offset will
    // have offset 0, vertex_texcoord_offset is 12 (position is 3 * sizeof(float)
    // bytes large, and texcoord comes just after) and vertex_normal_offset is
    // 20 = 5 * sizeof(float).
    GLintptr vertex_texcoord_offset = 3 * sizeof(float);
    GLintptr vertex_normal_offset = 5 * sizeof(float);
    GLintptr vertex_position_offset = 0 * sizeof(float);

    glVertexAttribPointer(texcoord_attrib_index, 2, GL_FLOAT, false, vertex_stride, (GLvoid*)vertex_texcoord_offset);
    glVertexAttribPointer(normal_attrib_index, 3, GL_FLOAT, false, vertex_stride, (GLvoid*)vertex_normal_offset);
    glVertexAttribPointer(position_attrib_index, 3, GL_FLOAT, false, vertex_stride, (GLvoid*)vertex_position_offset);

    // num_vertices is the number of verts in your vertex_data.
    // index_data is an array of unsigned int offsets into vertex_data.
    glDrawElements(GL_TRIANGLES, num_vertices, GL_UNSIGNED_INT, NULL);

    glDisableVertexAttribArray(position_attrib_index);
    glDisableVertexAttribArray(texcoord_attrib_index);
    glDisableVertexAttribArray(normal_attrib_index);

## Tutorials

open.gl - Textures Objects and Parameters
open.gl - The Graphics Pipeline

## 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. https://opencontent.org/openpub/.

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