[Mesa-dev] [Bug 100151] Front buffer drawing mode shows black window

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=100151

            Bug ID: 100151
           Summary: Front buffer drawing mode shows black window
           Product: Mesa
           Version: 13.0
          Hardware: x86-64 (AMD64)
                OS: Linux (All)
            Status: NEW
          Severity: major
          Priority: medium
         Component: Drivers/Gallium/swr
          Assignee: mesa-dev at lists.freedesktop.org
          Reporter: pradeep.yadav at ansys.com
        QA Contact: mesa-dev at lists.freedesktop.org

Created attachment 130157
  --> https://bugs.freedesktop.org/attachment.cgi?id=130157&action=edit
Standalone OpenGL program for reproducing this issue

When front buffer drawing mode is enabled using glDrawBuffer(GL_FRONT); the
window becomes black after glFlush() call.

Attached program OpenGLXORApp.cpp demonstrates it.

Follow these steps to reproduce:
1. Compile the program using: g++ -I/usr/include -lglut -lGLU -lGL
OpenGLXORApp.cpp -o OpenGLXORApp
2. Run the program: ./OpenGLXORApp
3. Using mouse start drawing a rectangle, i.e., click left mouse button
anywhere inside the window and drag the mouse while the left mouse button is
depressed.

Expected Result: A blue triangle on the white background is seen while a green
rectangle is being drawn over it.

Actual Result: A black window with green rectangle being drawn over it.

Tried with:
1. GALLIUM_DRIVER=softpipe <-- Black window on Mesa 10.x.x BUT not on Mesa 11+
releases. But in our complex application where rotation is involved, after
front buffer drawing, when we switch to double buffer drawing, the background
remains static. The attached program cannot be used to reproduce this last
issue because it doesn't have rotation functionality.
2. GALLIUM_DRIVER=llvmpipe <-- Black window on Mesa 10.x.x, 11.2.2 and Mesa
13.0.5
3. Mesa classic software rasterizer <-- NO ISSUES!
4. LIBGL_DEBUG=verbose and MESA_DEBUG=1 didn't print out any errors or
warnings, except this warning: Mesa warning: couldn't open libtxc_dxtn.so,
software DXTn compression/decompression unavailable.

Note: Specific Mesa versions were mentioned above because those are the
versions I have built and tested against.

-- 
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/20170310/cee72892/attachment.html>