Artifacts

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ggg
2006-06-27
2013-04-17
  • ggg
    ggg
    2006-06-27

    HI HMM

    I have run the tutorial4-light in the following URL with vincent libarary.
    http://www.typhoonlabs.com/index.php?option=com_content&task=view&id=19&Itemid=33

    But found some artifacts(white dots) in the display.
    And what make me suprised is that when I EGL_LOG_RASTER_BLOCK_SIZE define in OGLES to 4,
    more artifacts were found,
    #define EGL_LOG_RASTER_BLOCK_SIZE    4

    When I change  EGL_LOG_RASTER_BLOCK_SIZE to 0:
    #define EGL_LOG_RASTER_BLOCK_SIZE    0

    It seems that there is no artifacts in the display!
    I really do not know what's the reason of that.
    The larger EGL_LOG_RASTER_BLOCK_SIZE is, more artifacts were found.
    Would you like give me a explain or correct it.Thanks.

    Regards

     
    • ggg
      ggg
      2006-06-27

      Also,I test the following fog example and met the same problem!
      http://www.zeuscmd.com/tutorials/opengles/22-Fog.php

       
    • Can you attach a screen shot for EGL_LOG_RASTER_BLOCK_SIZE = 0 and EGL_LOG_RASTER_BLOCK_SIZE = 3?

      (I don't think a block size > 3 will work, because you will need more than a byte to represent the pixel mask).

      Thanks,
      HM

       
    • ggg
      ggg
      2006-07-05

      HI
      I was out of office for a week.
      I have port vincent to vc6.The artifacts were found in the vc6 applicaions.
      I have trace the code.I found the artifacts when varying0[m_VaryingInfo.colorIndex][0] is negtive in RasterBlockColorAlpha function.So the negtive number is clamp to zero and the display is black(artifacts)!
      I try to trace the code now.

      And In Rasterizer.h:

      #if EGL_RASTER_BLOCK_SIZE <= 8
          typedef U8 PixelMask;
      #elif EGL_RASTER_BLOCK_SIZE <= 16
          typedef U16 PixelMask;
      #else
          typedef U32 PixelMask;
      #endif

      So I think a block size = 4 or 5 will work with U16 and U32.
      I do not know how to post the screen shot picture here.

      Regards

       
    • When you submit a bug or support request, you can attach one or more files.

      - HM