%mathent; ]> 2005 Sams Publishing 2010-2014 Khronos Group glBufferData 3G glBufferData creates and initializes a buffer object's data store 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_SHADER_STORAGE_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. 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. 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 consistently 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_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER, GL_PIXEL_PACK_BUFFER,GL_PIXEL_UNPACK_READ_BUFFER, GL_TRANSFORM_FEEDBACK_BUFFER and GL_UNIFORM_BUFFER targets are available only if the GL ES version is 3.0 or greater. The GL_ATOMIC_COUNTER_BUFFER, GL_DISPATCH_INDIRECT_BUFFER, GL_DRAW_INDIRECT_BUFFER and GL_SHADER_STORAGE_BUFFER targets are available only if the GL ES version is 3.1 or greater. 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. glGetBufferParameter with argument GL_BUFFER_SIZE or GL_BUFFER_USAGE glBufferData glBindBuffer, glBufferSubData, glMapBufferRange, glUnmapBuffer Copyright 2005 Addison-Wesley. 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/.