Signature
glVertexAttribPointer(
GLuint (
index
)
,
GLint (
size
)
,
GLenum (
type
)
,
GLboolean (
normalized
)
,
GLsizei (
stride
)
,
const void * (
pointer
)
)-> void
glVertexAttribPointer(
index
,
size
,
type
,
normalized
,
stride
,
pointer
)
Set an attribute pointer for a given shader (index) index -- the index of the generic vertex to bind, see glGetAttribLocation for retrieval of the value, note that index is a global variable, not per-shader size -- number of basic elements per record, 1,2,3, or 4 type -- enum constant for data-type normalized -- whether to perform int to float normalization on integer-type values stride -- stride in machine units (bytes) between consecutive records, normally used to create "interleaved" arrays pointer -- data-pointer which provides the data-values, normally a vertex-buffer-object or offset into the same. This implementation stores a copy of the data-pointer in the contextdata structure in order to prevent null- reference errors in the renderer.
Parameters
Variables | Description |
---|---|
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, 4. Additionally, the symbolic constant
GL_BGRA
is accepted by
glVertexAttribPointer
. The initial value is 4.
|
type |
Specifies the data type of each component in
the array. The symbolic constants
GL_BYTE
,
GL_UNSIGNED_BYTE
,
GL_SHORT
,
GL_UNSIGNED_SHORT
,
GL_INT
, and
GL_UNSIGNED_INT
are accepted by
glVertexAttribPointer
and
glVertexAttribIPointer
. Additionally
GL_HALF_FLOAT
,
GL_FLOAT
,
GL_DOUBLE
,
GL_FIXED
,
GL_INT_2_10_10_10_REV
,
GL_UNSIGNED_INT_2_10_10_10_REV
and
GL_UNSIGNED_INT_10F_11F_11F_REV
are accepted by
glVertexAttribPointer
.
GL_DOUBLE
is also accepted by
glVertexAttribLPointer
and is
the only token accepted by the
type
parameter for that function.
The initial value is
GL_FLOAT
.
|
normalized |
For
glVertexAttribPointer
, 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 offset of the first component of the first generic vertex attribute in the array in the data store of the
buffer currently bound to the
GL_ARRAY_BUFFER
target. The initial value is 0.
|
Description
glVertexAttribPointer
,
glVertexAttribIPointer
and
glVertexAttribLPointer
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.
glVertexAttribLPointer
specifies state for a generic vertex attribute array associated
with a shader attribute variable declared with 64-bit double precision components.
type
must be
GL_DOUBLE
.
index
,
size
, and
stride
behave as described for
glVertexAttribPointer
and
glVertexAttribIPointer
.
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.
GL_UNSIGNED_INT_10F_11F_11F_REV
is accepted for
type
only if the GL version is 4.4 or higher.
Errors
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
normalized
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
.
Associated Gets
glGet
with argument
GL_MAX_VERTEX_ATTRIBS
glGet
with argument
GL_ARRAY_BUFFER_BINDING
Version Support
glVertexAttribIPointer | |
glVertexAttribLPointer | |
glVertexAttribPointer |
See Also
Copyright
Copyright
2003-2005 3Dlabs Inc. Ltd.
Copyright
2010-2014 Khronos Group.
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/
.
Sample Code References
The following code samples have been found which appear to reference the functions described here. Take care that the code may be old, broken or not even use PyOpenGL.
glVertexAttribPointer