marcan / blitzloop

Open source karaoke software
GNU General Public License v2.0
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alpha problems on libmpv #7

Closed yacoob closed 8 years ago

yacoob commented 8 years ago

There seem to be some alpha problems with lyrics line textures on Samsung Chromebox XE300M22. Each character features black bounding rectangle. See the attached screenshot. This problem doesn't manifest on master branch. It is also present on libmpv as of 6efd28dc7bc015c503953efd98bcc1e710a76d1b, so it shouldn't be a side effect of that osx fix.

$ lspci | grep -i vga
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
$ dpkg -l | grep -i 'open ?gl'
ii  freeglut3:amd64                             2.8.1-2                                   amd64        OpenGL Utility Toolkit
ii  libepoxy0:amd64                             1.3.1-1                                   amd64        OpenGL function pointer management library
ii  libgl1-mesa-dev:amd64                       11.2.0-1ubuntu2.2                         amd64        free implementation of the OpenGL API -- GLX development files
ii  libgl1-mesa-dri:amd64                       11.2.0-1ubuntu2.2                         amd64        free implementation of the OpenGL API -- DRI modules
ii  libgl1-mesa-glx:amd64                       11.2.0-1ubuntu2.2                         amd64        free implementation of the OpenGL API -- GLX runtime
ii  libglu1-mesa:amd64                          9.0.0-2.1                                 amd64        Mesa OpenGL utility library (GLU)
ii  libgtkglext1:amd64                          1.2.0-3.2fakesync1ubuntu1                 amd64        OpenGL Extension to GTK+ (shared libraries)
ii  python-opengl                               3.0.2-1                                   all          Python bindings to OpenGL (Python 2)
ii  x11proto-gl-dev                             1.4.17-1                                  all          X11 OpenGL extension wire protocol

2016-11-11-225119_1280x1024_scrot

marcan commented 8 years ago

This again. I know what this is. That card/driver really doesn't like NaN pixel values, even when alpha=0, and 1ea67de210e (which fixed a subtle alpha problem) re-introduced NaNs due to a divide by zero on fully transparent pixels.