Parameters

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

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

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