ARB_indirect_parameters

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Overview

Numbers ARB Extension #154

Requires OpenGL 4.2

Since OpenGL 4.6 Core Profile Specification

和它相关的OpenGL概念是Indirect Draw, 相关的扩展是GL_ARB_draw_indirect(since OpenGL 3.2 Compatible Profile and since OpenGL 4.0 Core Profile)和GL_ARB_multi_draw_indirect(since OpenGL 4.1 Core Profile). 这个扩展引入了"parameter buffer"的概念，可以让indirect draw的大量的参数集合存储在buffer object, 然后用一个API调用分发整个indirect draw列表，从而提高OpenGL管线的执行效率。

更确切地说，这个扩展新增了一个buffer target，专门用来存放某个indirect drawing command的参数。

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PARAMETER_BUFFER_ARB    0x80EE

它可以作为下列命令的参数

  • BindBuffer
  • BufferData
  • BufferSubData
  • MapBuffer
  • UnmapBuffer
  • GetBufferSubData
  • GetBufferPointerv
  • MapBufferRange
  • FlushMappedBufferRange
  • GetBufferParameteriv
  • CopyBufferSubData

新增的MultiDraw*Indirect命令的变种是

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MultiDrawArraysIndirectCountARB
MultiDrawElementsIndirectCountARB