Specifies the expected usage pattern of the data store. The symbolic constant must be
GLES20.GL_STREAM_DRAW, GLES20.GL_STREAM_READ, GLES20.GL_STREAM_COPY, GLES20.GL_STATIC_DRAW,
GLES20.GL_STATIC_READ, GLES20.GL_STATIC_COPY, GLES20.GL_DYNAMIC_DRAW, GLES20.GL_DYNAMIC_READ,
or GLES20.GL_DYNAMIC_COPY.
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.