kc3-lang/angle/extensions/ANGLE_external_objects_fuchsia.txt

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• Author : Michael Spang
  Date : 2020-02-19 15:49:23
  Hash : 0941e653
  Message : Add external object extensions for Fuchsia to GL API Add extensions layered on top of GL_EXT_memory_object and GL_EXT_semaphore to support GL & Vulkan interoperation on Fuchsia. They are analagous to the file descriptor versions, except not quite as opaque. This is a draft; the underlying vulkan extensions have not been submitted to Khronos. Bug: angleproject:3492 Change-Id: Ic4723ded9fff752c4186eaa6a7f07d9ac51a3364 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1642332 Commit-Queue: Michael Spang <spang@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>

• extensions/ANGLE_external_objects_fuchsia.txt

• Name
  
      ANGLE_external_objects_fuchsia
  
  Name Strings
  
      GL_ANGLE_memory_object_fuchsia
      GL_ANGLE_semaphore_fuchsia
  
  Contributors
  
      Michael Spang, Google
  
  Contact
  
      Michael Spang, Google (spang 'at' google.com)
  
  Status
  
      Draft
  
  Version
  
      Last Modified Date: Feb 19, 2020
      Revision: 1
  
  Number
  
      TBD
  
  Dependencies
  
      Written against the OpenGL 4.5 and OpenGL ES 3.2 specifications
  
      GL_ANGLE_memory_object_fuchsia requires GL_EXT_memory_object
  
      GL_ANGLE_semaphore_fuchsia requires GL_EXT_semaphore
  
  Overview
  
      Building upon the OpenGL memory object and semaphore framework
      defined in EXT_external_objects, this extension enables an OpenGL
      application to import a memory object or semaphore from Zircon
      external handles.
  
  New Procedures and Functions
  
      If the GL_ANGLE_memory_object_fuchsia string is reported, the following
      commands are added:
  
      void ImportMemoryZirconHandleANGLE(uint memory,
                                         uint64 size,
                                         enum handleType,
                                         uint handle);
  
      If the GL_ANGLE_semaphore_fuchsia string is reported, the following commands
      are added:
  
      void ImportSemaphoreZirconHandleANGLE(uint semaphore,
                                            enum handleType,
                                            uint handle);
  
  
  New Tokens
  
      If the GL_ANGLE_memory_object_fuchsia string is reported, the following
      tokens are added:
  
      Accepted by the <handleType> parameter of ImportMemoryZirconHandleANGLE().
  
          HANDLE_TYPE_ZIRCON_VMO_ANGLE               0x93AE
  
      If the GL_ANGLE_semaphore_fuchsia string is reported, the following
      tokens are added:
  
      Accepted by the <handleType> parameter of ImportSemaphoreZirconHandleANGLE().
  
          HANDLE_TYPE_ZIRCON_EVENT_ANGLE             0x93AF
  
  Additions to Chapter 4 of the OpenGL 4.5 Specification (Event Model)
  
      Add the following entry to table 4.2 "Commands for importing
      external semaphore handles."
  
          | Handle Type                    | Import command                   |
          +--------------------------------+----------------------------------+
          | HANDLE_TYPE_ZIRCON_EVENT_ANGLE | ImportSemaphoreZirconHandleANGLE |
          +--------------------------------+----------------------------------+
  
      Replace the paragraph in section 4.2.1 beginning "External handles
      are often defined..." with the following
  
          The command
  
              ImportSemaphoreZirconHandleANGLE(uint semaphore,
                                               enum handleType,
                                               uint handle);
  
          imports a semaphore from the zircon handle <handle>.  What type of
          handle <handle> refers to is determined by <handleType>.  A successful
          import operation transfers ownership of <handle> to the GL
          implementation, and performing any operation on <handle> in the
          application after an import results in undefined behavior.
  
  Additions to Chapter 6 of the OpenGL 4.5 Specification (Memory Objects)
  
      Add the following entry to table 6.2 "Commands for importing
      external memory handles."
  
          | Handle Type                  | Import command                |
          +------------------------------+-------------------------------+
          | HANDLE_TYPE_ZIRCON_VMO_ANGLE | ImportMemoryZirconHandleANGLE |
          +------------------------------+-------------------------------+
  
      Replace the paragraph in section 6.1 beginning "External handles are
      often defined..." with the following
  
          The command
  
              void ImportMemoryZirconHandleANGLE(uint memory,
                                                 uint64 size,
                                                 enum handleType,
                                                 uint handle);
  
          imports a memory object of length <size> from the handle
          <handle>.  What type of object <handle> refers to is determined by
          <handleType>.  A successful import operation transfers ownership
          of <handle> to the GL implementation, and performing any operation on
          <handle> in the application after an import results in undefined
          behavior.
  
  Revision History
  
      Revision 1, 2019-02-19 (Michael Spang)
          - Initial draft based closely on EXT_external_objects_fd.