GLBUFFERSUBDATA(3G)

📦
version 1.1 · 7 versions
, in centos-stream 9

💅 GLBUFFERSUBDATA — the 3G manual page, bestie ✨

okay so this is GLBUFFERSUBDATA(3G), and the header literally has a [FIXME: manual] placeholder in it — unfinished draft energy, but we move. This page is all about updating just a little slice of a buffer object's data store, and the main characters are glBufferSubData and glNamedBufferSubData. Let's go 💖

🌸 NAME 🌸

glBufferSubData, glNamedBufferSubData — updates a subset of a buffer object's data store

🧚 C SPECIFICATION 🧚

void glBufferSubData(GLenum target, GLintptr offset, GLsizeiptr size,
                     const GLvoid * data);

void glNamedBufferSubData(GLuint buffer, GLintptr offset,
                          GLsizeiptr size, const void *data);

✨ PARAMETERS ✨

  • target — specifies the target to which the buffer object is bound for glBufferSubData, which must be one of the buffer binding targets in the following table:
    • GL_ARRAY_BUFFER — vertex attributes
    • GL_ATOMIC_COUNTER_BUFFER — atomic counter storage
    • GL_COPY_READ_BUFFER — buffer copy source
    • GL_COPY_WRITE_BUFFER — buffer copy destination
    • GL_DISPATCH_INDIRECT_BUFFER — indirect compute dispatch commands
    • GL_DRAW_INDIRECT_BUFFER — indirect command arguments
    • GL_ELEMENT_ARRAY_BUFFER — vertex array indices
    • GL_PIXEL_PACK_BUFFER — pixel read target
    • GL_PIXEL_UNPACK_BUFFER — texture data source
    • GL_QUERY_BUFFER — query result buffer
    • GL_SHADER_STORAGE_BUFFER — read-write storage for shaders
    • GL_TEXTURE_BUFFER — texture data buffer
    • GL_TRANSFORM_FEEDBACK_BUFFER — transform feedback buffer
    • GL_UNIFORM_BUFFER — uniform block storage
  • buffer — specifies the name of the buffer object for glNamedBufferSubData.
  • offset — specifies the offset into the buffer object's data store where data replacement will begin, measured in bytes.
  • size — specifies the size in bytes of the data store region being replaced.
  • data — specifies a pointer to the new data that will be copied into the data store.

🦋 DESCRIPTION 🦋

glBufferSubData and glNamedBufferSubData redefine some or all of the data store for the specified buffer object. Data starting at byte offset and extending for size bytes is copied to the data store from the memory pointed to by data. offset and size must define a range lying entirely within the buffer object's data store.

🎀 NOTES 🎀

When replacing the entire data store, consider using glBufferSubData rather than completely recreating the data store with glBufferData. This avoids the cost of reallocating the data store.

Consider using multiple buffer objects to avoid stalling the rendering pipeline during data store updates. If any rendering in the pipeline makes reference to data in the buffer object being updated by glBufferSubData, especially from the specific region being updated, that rendering must drain from the pipeline before the data store can be updated.

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 by glBufferSubData if target is not one of the accepted buffer targets.
  • GL_INVALID_OPERATION is generated by glBufferSubData if zero is bound to target.
  • GL_INVALID_OPERATION is generated by glNamedBufferSubData if buffer is not the name of an existing buffer object.
  • GL_INVALID_VALUE is generated if offset or size is negative, or if offset + size is greater than the value of GL_BUFFER_SIZE for the specified buffer object.
  • GL_INVALID_OPERATION is generated if any part of the specified range of the buffer object is mapped with glMapBufferRange() or glMapBuffer(), unless it was mapped with the GL_MAP_PERSISTENT_BIT bit set in the glMapBufferRange access flags.
  • GL_INVALID_OPERATION is generated if the value of the GL_BUFFER_IMMUTABLE_STORAGE flag of the buffer object is GL_TRUE and the value of GL_BUFFER_STORAGE_FLAGS for the buffer object does not have the GL_DYNAMIC_STORAGE_BIT bit set.

👑 ASSOCIATED GETS 👑

glGetBufferSubData()

🌈 VERSION SUPPORT 🌈

The version-support table has Function / Feature Name on one side and OpenGL Version across the top. Here's the whole vibe check:

  • glBufferSubData — supported (✔) in OpenGL 2.0, 2.1, 3.0, 3.1, 3.2, 3.3, 4.0, 4.1, 4.2, 4.3, 4.4, and 4.5.
  • glNamedBufferSubData — not supported (-) in OpenGL 2.0, 2.1, 3.0, 3.1, 3.2, 3.3, 4.0, 4.1, 4.2, 4.3, and 4.4; supported (✔) only in 4.5.

🔥 SEE ALSO 🔥

glBindBuffer(), glBufferData(), glMapBuffer(), 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/.

Copyright © 2005 Sams Publishing Copyright © 2010-2014 Khronos Group

okay bye bestie — this page is from [FIXME: source], dated 08/09/2021, and it's literally the GLBUFFERSUBDATA(3G) manual page 💖🫶

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