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[Robert Ancell <robert.ancell@xxxxxxxxxxxxx>]

Public bug reported:

When Glamor generates textures it does so with format=GL_RGBA and
type=GL_UNSIGNED_BYTE using glTexImage2D. However when it writes to
these images it does it with format=GL_BGRA and type =
GL_UNSIGNED_INT_8_8_8_8_REV using glTexSubImage2D.

This works fine on a desktop (Intel) but when running on a Nexus 4 a
GL_INVALID_OPERATION is generated when calling glTexSubImage2D.

There seems to be a couple of problems:
- The format is originally GL_RGBA and then changed to GL_BGRA. glTexSubImage2D says "GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D or glCopyTexImage2D operation  whose internalformat matches the format of glTexSubImage2D."
- type GL_UNSIGNED_INT_8_8_8_8_REV is an extension and doesn't seem to be supported on the Nexus 4.

By changing the original format to GL_RGBA (in glamor/glamor_utils.h)
and the glTexSubImage2D to use format=GL_RGBA type=GL_UNSIGNED_BYTE
(glamor/glamor_transfer.c) we can get this to work.

The question is - is the current Glamor code to aggressive in using
extensions or should it be able to better detect which method is
appropriate for each driver? Are there other issues with the X format
the pixmap data is in?

** Affects: xorg-server (Ubuntu)
     Importance: High
     Assignee: Robert Ancell (robert-ancell)
         Status: Triaged


** Tags: xmir

** Tags added: xmir

** Changed in: xorg-server (Ubuntu)
       Status: New => Triaged

** Changed in: xorg-server (Ubuntu)
   Importance: Undecided => High

** Changed in: xorg-server (Ubuntu)
     Assignee: (unassigned) => Robert Ancell (robert-ancell)

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https://bugs.launchpad.net/bugs/1493596

Title:
  Glamor chooses texture format that don't work on Nexus 4

Status in xorg-server package in Ubuntu:
  Triaged

Bug description:
  When Glamor generates textures it does so with format=GL_RGBA and
  type=GL_UNSIGNED_BYTE using glTexImage2D. However when it writes to
  these images it does it with format=GL_BGRA and type =
  GL_UNSIGNED_INT_8_8_8_8_REV using glTexSubImage2D.

  This works fine on a desktop (Intel) but when running on a Nexus 4 a
  GL_INVALID_OPERATION is generated when calling glTexSubImage2D.

  There seems to be a couple of problems:
  - The format is originally GL_RGBA and then changed to GL_BGRA. glTexSubImage2D says "GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage2D or glCopyTexImage2D operation  whose internalformat matches the format of glTexSubImage2D."
  - type GL_UNSIGNED_INT_8_8_8_8_REV is an extension and doesn't seem to be supported on the Nexus 4.

  By changing the original format to GL_RGBA (in glamor/glamor_utils.h)
  and the glTexSubImage2D to use format=GL_RGBA type=GL_UNSIGNED_BYTE
  (glamor/glamor_transfer.c) we can get this to work.

  The question is - is the current Glamor code to aggressive in using
  extensions or should it be able to better detect which method is
  appropriate for each driver? Are there other issues with the X format
  the pixmap data is in?

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