[Mesa-dev] [Bug 47166] New: Bad datatype in interpolate_int_colors

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=47166

             Bug #: 47166
           Summary: Bad datatype in interpolate_int_colors
    Classification: Unclassified
           Product: Mesa
           Version: 8.0
          Platform: x86-64 (AMD64)
        OS/Version: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: Mesa core
        AssignedTo: mesa-dev at lists.freedesktop.org
        ReportedBy: hdewey2 at gmail.com


I have a program that uses Mesa for calculation of radiosity view factors. 
During drawing/reading I get the following errors:

Mesa 8.0.1 implementation error: bad datatype 0x1010101 in
interpolate_int_colors
Please report at bugs.freedesktop.org
Mesa 8.0.1 implementation error: Invalid datatype in _mesa_convert_colors
Please report at bugs.freedesktop.org

I have tried Mesa 8.0.1, 7.11.2, and 7.8.1 and they all have the same issue.

The errors seem to be related to the near clipping plane distance.  Due to the
geometry that is being rendered, the global near clipping plane that is
required is 7.178571e-08 (compared to a global far clipping plane value of
1.195193e+02).  A total of 108 stacked frustums are used to avoid Z-buffer
precision issues stemming from this small value, so the nearest frustum has
near and far clipping plane distances of 7.178571e-08 and 3.263309e-05,
respectively.  If I manually change the nearest near clipping plane distance by
+/- 10%, I do not get the Mesa errors.  Manually changing this value by a
smaller amount, +/- 5%, still produces errors.

After the Mesa errors appear, some of the pixel data read using glReadPixels
contains junk data (RGBA = 0x01010101) ... the same value as the invalid
datatype mentioned in the error message.

The program runs just fine on ATI and NVIDIA hardware (Windows desktops without
Mesa), but not when using OSMesa without graphics hardware (on a SUSE Linux
HPC).

Here's some additional information in case any of it matters:
The scene consists of ~270,000 GL_QUADS that are drawn from ~1,000,000
different eye locations.
The drawing is done into a hemicube (drawing is done 5 times using different
orientations and viewports for each eye location).
The program is using 2 PBOs to asynchronously draw and read the framebuffer
data.
The PBOs are read using glReadPixels with a type of GL_UNSIGNED_BYTE and a hint
of GL_STATIC_READ.
The drawing is done into a FBO with RBOs that are using GL_RGBA for color and
GL_DEPTH24_STENCIL8_EXT for depth and stencil data.
The drawing is done with multiple VBOs that are limited to 4.8 MBytes in size
each (for performance reasons).
The VBOs consist of interleaved color (4 x GL_UNSIGNED_BYTE) and location (3 x
GL_FLOAT) data for each vertex.

-- 
Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.