glVertexAttribPointer — define an array of generic vertex attribute data
void glVertexAttribPointer( | GLuint | index, |
GLint | size, | |
GLenum | type, | |
GLboolean | normalized, | |
GLsizei | stride, | |
const GLvoid * | pointer) ; |
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.
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.
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.
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.
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
glArrayElement, glBindAttribLocation, glBindBuffer, glColorPointer, glDisableVertexAttribArray, glDrawArrays, glDrawElements, glDrawRangeElements, glEnableVertexAttribArray, glEdgeFlagPointer, glFogCoordPointer, glIndexPointer, glInterleavedArrays, glMultiDrawArrays, glMultiDrawElements, glNormalPointer, glPopClientAttrib, glPushClientAttrib, glSecondaryColorPointer, glTexCoordPointer, glVertexAttrib, glVertexPointer
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/.