[Mesa-dev] [Bug 108977] Reading back an EGL Pbuffer using the OpenGL API returns garbled output

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108977

            Bug ID: 108977
           Summary: Reading back an EGL Pbuffer using the OpenGL API
                    returns garbled output
           Product: Mesa
           Version: 18.2
          Hardware: Other
                OS: All
            Status: NEW
          Severity: normal
          Priority: medium
         Component: EGL
          Assignee: mesa-dev at lists.freedesktop.org
          Reporter: matthieu.bouron at gmail.com
        QA Contact: mesa-dev at lists.freedesktop.org

Created attachment 142750
  --> https://bugs.freedesktop.org/attachment.cgi?id=142750&action=edit
EGL pbuffer test

Hello,

I am currently facing an issue while reading back EGL Pbuffers using
glReadPixels() with the OpenGL API as the output is garbled. It properly works
with the OpenGL ES API though.

I can reproduce the issue on different machines running Arch Linux with mesa
18.2.5 on X using the following GPU: Intel HD 5500, Intel Iris 580 Pro, AMD RX
580.

I am not able to reproduce the issue on an NVDIA GTX 1070 running the
proprietary driver.

I have attached a sample code that reproduces the issue:

On OpenGL:
gcc `pkg-config --libs egl gl` -Wall egl-pbuffer.c -o egl-pbuffer
&&./egl-pbuffer
0xff69fc07 0xff69fc07 0xff69fc07 0xff69fc07 
0xff69fc07 0xff11a1e4 0xff000000 0xff000000 
0xff69fc07 0xff000000 0xff7fc700 0xff000000 
0xff69fc07 0xff000000 0xff000000 0xff3a4e3b 

On OpenGLES (adding the -es parameter to ./egl-pbuffer):
gcc `pkg-config --libs egl gl` -Wall egl-pbuffer.c -o egl-pbuffer
&&./egl-pbuffer -es
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff 
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff 
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff 
0xff0000ff 0xff0000ff 0xff0000ff 0xff0000ff

-- 
You are receiving this mail because:
You are the assignee for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/mesa-dev/attachments/20181208/7867302a/attachment.html>