GLAPI/glBufferData

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glBufferData
Core in version 4.4
Core since version 1.5

glBufferData: creates and initializes a buffer object's data store

Function Definition

 void glBufferData(GLenum target​, GLsizeiptr size​, const GLvoid * data​, GLenum usage​);
target
Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER​, GL_ATOMIC_COUNTER_BUFFER​, GL_COPY_READ_BUFFER​, GL_COPY_WRITE_BUFFER​, GL_DRAW_INDIRECT_BUFFER​, GL_DISPATCH_INDIRECT_BUFFER​, GL_ELEMENT_ARRAY_BUFFER​, GL_PIXEL_PACK_BUFFER​, GL_PIXEL_UNPACK_BUFFER​, GL_QUERY_BUFFER​, GL_SHADER_STORAGE_BUFFER​, GL_TEXTURE_BUFFER​, GL_TRANSFORM_FEEDBACK_BUFFER​, or GL_UNIFORM_BUFFER​.
size
Specifies the size in bytes of the buffer object's new data store.
data
Specifies a pointer to data that will be copied into the data store for initialization, or NULL​ if no data is to be copied.
usage
Specifies the expected usage pattern of the data store. The symbolic constant must be GL_STREAM_DRAW​, GL_STREAM_READ​, GL_STREAM_COPY​, GL_STATIC_DRAW​, GL_STATIC_READ​, GL_STATIC_COPY​, GL_DYNAMIC_DRAW​, GL_DYNAMIC_READ​, or GL_DYNAMIC_COPY​.

Description

glBufferData creates a new data store for the buffer object currently bound to target​. Any pre-existing data store is deleted. The new data store is created with the specified size​ in bytes and usage​. If data​ is not NULL​, the data store is initialized with data from this pointer. In its initial state, the new data store is not mapped, it has a NULL​ mapped pointer, and its mapped access is GL_READ_WRITE​.

usage​ is a hint to the GL implementation as to how a buffer object's data store will be accessed. This enables the GL implementation to make more intelligent decisions that may significantly impact buffer object performance. It does not, however, constrain the actual usage of the data store. usage​ can be broken down into two parts: first, the frequency of access (modification and usage), and second, the nature of that access. The frequency of access may be one of these:

STREAM
The data store contents will be modified once and used at most a few times.
STATIC
The data store contents will be modified once and used many times.
DYNAMIC
The data store contents will be modified repeatedly and used many times.

The nature of access may be one of these:

DRAW
The data store contents are modified by the application, and used as the source for GL drawing and image specification commands.
READ
The data store contents are modified by reading data from the GL, and used to return that data when queried by the application.
COPY
The data store contents are modified by reading data from the GL, and used as the source for GL drawing and image specification commands.

Notes

If data​ is NULL​, a data store of the specified size is still created, but its contents remain uninitialized and thus undefined.

Clients must align data elements consistent with the requirements of the client platform, with an additional base-level requirement that an offset within a buffer to a datum comprising N bytes be a multiple of N.

The GL_ATOMIC_COUNTER_BUFFER​ target is available only if the GL version is 4.2 or greater.

The GL_DISPATCH_INDIRECT_BUFFER​ and GL_SHADER_STORAGE_BUFFER​ targets are available only if the GL version is 4.3 or greater.

The GL_QUERY_BUFFER​ target is available only if the GL version is 4.4 or greater.

Errors

GL_INVALID_ENUM​ is generated if target​ is not one of the accepted buffer targets.

GL_INVALID_ENUM​ is generated if usage​ is not GL_STREAM_DRAW​, GL_STREAM_READ​, GL_STREAM_COPY​, GL_STATIC_DRAW​, GL_STATIC_READ​, GL_STATIC_COPY​, GL_DYNAMIC_DRAW​, GL_DYNAMIC_READ​, or GL_DYNAMIC_COPY​.

GL_INVALID_VALUE​ is generated if size​ is negative.

GL_INVALID_OPERATION​ is generated if the reserved buffer object name 0 is bound to target​.

GL_OUT_OF_MEMORY​ is generated if the GL is unable to create a data store with the specified size​.

Associated Gets

glGetBufferSubData

glGetBufferParameter with argument GL_BUFFER_SIZE​ or GL_BUFFER_USAGE​

See Also

glBufferStorage, glBindBuffer, glBufferSubData, glInvalidateBufferData, glInvalidateBufferSubData, glClearBufferData, glClearBufferSubData, glMapBufferRange, glUnmapBuffer

Copyright

Copyright © 2005 Addison-Wesley. Copyright © 2011-2012 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/.