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GLBUFFERDATA(3G)                                 OpenGL 3.3                                 GLBUFFERDATA(3G)



NAME
       glBufferData - creates and initializes a buffer object's data store

C SPECIFICATION
       void glBufferData(GLenum target, GLsizeiptr size, const GLvoid * data, GLenum usage);

PARAMETERS
       target
           Specifies the target buffer object. The symbolic constant must be GL_ARRAY_BUFFER,
           GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, GL_ELEMENT_ARRAY_BUFFER, GL_PIXEL_PACK_BUFFER,
           GL_PIXEL_UNPACK_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.

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
       glBindBuffer(), glBufferSubData(), glMapBuffer(), glUnmapBuffer()


COPYRIGHT
       Copyright (C) 2005 Addison-Wesley. 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/.



OpenGL 3.3                                       03/08/2011                                 GLBUFFERDATA(3G)