Parameters

Description

glVertexAttribPointer and glVertexAttribIPointer specify 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, 4, or GL_BGRA. 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.

For glVertexAttribPointer, if normalized is set to GL_TRUE, it 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.

For glVertexAttribIPointer, only the integer types GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_INT, GL_UNSIGNED_INT are accepted. Values are always left as integer values.

If pointer is not NULL, a non-zero named buffer object must be bound to the GL_ARRAY_BUFFER target (see glBindBuffer), otherwise an error is generated. pointer is treated as a byte offset into the buffer object's data store. The buffer object binding (GL_ARRAY_BUFFER_BINDING) is saved as generic vertex attribute array 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 vertex array 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 glDrawArrays, glMultiDrawArrays, glDrawElements, glMultiDrawElements, or glDrawRangeElements is called.

Notes

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

glVertexAttribIPointer is available only if the GL version is 3.0 or higher.

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, 4 or (for glVertexAttribPointer), GL_BGRA.

GL_INVALID_ENUM is generated if type is not an accepted value.

GL_INVALID_VALUE is generated if stride is negative.

GL_INVALID_OPERATION is generated if size is GL_BGRA and type is not GL_UNSIGNED_BYTE, GL_INT_2_10_10_10_REV or GL_UNSIGNED_INT_2_10_10_10_REV.

GL_INVALID_OPERATION is generated if type is GL_INT_2_10_10_10_REV or GL_UNSIGNED_INT_2_10_10_10_REV and size is not 4 or GL_BGRA.

GL_INVALID_OPERATION is generated by glVertexAttribPointer if size is GL_BGRA and noramlized is GL_FALSE.

GL_INVALID_OPERATION is generated if zero is bound to the GL_ARRAY_BUFFER buffer object binding point and the pointer argument is not NULL. (Note: In the core context, the old method of passing glVertexAttribPointer and glDrawArrays pointers to mesh data in main memory is no longer allowed. You must create a Vertex Buffer Object and fill it with your mesh data.)

GL_INVALID_OPERATION is generated in the core context if there is no Vertex Array Object bound.

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

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);

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

Learning Modern 3D Graphics Programming - Chapter 5. Objects in Depth [Vertex Array Objects, Indexed Drawing]
open.gl - Geometry Shaders
open.gl - Textures Objects and Parameters
open.gl - The Graphics Pipeline
open.gl - Transform Feedback
opengl-tutorial.org - Particles / Instancing
opengl-tutorial.org - Tutorial 13 : Normal Mapping
opengl-tutorial.org - Tutorial 2 : The first triangle
opengl-tutorial.org - Tutorial 4 : A Colored Cube
opengl-tutorial.org - Tutorial 8 : Basic shading

See Also

glBindAttribLocation, glBindBuffer, glDisableVertexAttribArray, glDrawArrays, glDrawElements, glDrawRangeElements, glEnableVertexAttribArray, glMultiDrawArrays, glMultiDrawElements, glVertexAttrib