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Member "mesa-20.1.8/docs/specs/EGL_MESA_drm_image_formats.txt" (16 Sep 2020, 2689 Bytes) of package /linux/misc/mesa-20.1.8.tar.xz:


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    1 Name
    2 
    3     MESA_drm_image_formats
    4 
    5 Name Strings
    6 
    7     EGL_MESA_drm_image_formats
    8 
    9 Contributors
   10 
   11     Nicolai Hähnle <Nicolai.Haehnle@amd.com>
   12     Qiang Yu <Qiang.Yu@amd.com>
   13 
   14 Contact
   15 
   16     Nicolai Hähnle <Nicolai.Haehnle@amd.com>
   17 
   18 Status
   19 
   20     Proposal
   21 
   22 Version
   23 
   24     Version 1, January 26, 2017
   25 
   26 Number
   27 
   28     EGL Extension #??
   29 
   30 Dependencies
   31 
   32     This extension requires the EGL_MESA_drm_image extension.
   33 
   34     This extension is written against the wording of EGL_MESA_drm_image
   35     specification.
   36 
   37 Overview
   38 
   39     This extension extends the functionality of EGL_MESA_drm_image by adding
   40     additional formats required by Glamor for use with DRM buffers.
   41 
   42 IP Status
   43 
   44     Open-source; freely implementable.
   45 
   46 New Procedures and Functions
   47 
   48     None
   49 
   50 New Tokens
   51 
   52     Accepted as values for the EGL_IMAGE_FORMAT_MESA attribute:
   53 
   54         EGL_DRM_BUFFER_FORMAT_ARGB2101010_MESA  0x3290
   55         EGL_DRM_BUFFER_FORMAT_ARGB1555_MESA     0x3291
   56         EGL_DRM_BUFFER_FORMAT_RGB565_MESA       0x3292
   57 
   58 Additions to the EGL_MESA_drm_image Specification:
   59 
   60     Remove the sentence "The only format specified ..." from the paragraph
   61     describing eglCreateDRMImageMESA and add the following paragraph:
   62 
   63         The formats specified for use with EGL_DRM_BUFFER_FORMAT_MESA are:
   64 
   65       * EGL_DRM_BUFFER_FORMAT_ARGB32_MESA, where each pixel is a CPU-endian
   66         32-bit quantity, with alpha in the upper 8 bits, then red, then green,
   67         then blue,
   68 
   69       * EGL_DRM_BUFFER_FORMAT_ARGB2101010_MESA, where each pixel is a CPU-
   70         endian, 32-bit quantity, with alpha in the most significant 2 bits,
   71         followed by 10 bits each for red, green, and blue,
   72 
   73       * EGL_DRM_BUFFER_FORMAT_ARGB1555_MESA, where each pixel is a CPU-endian
   74         16-bit quantity, with alpha in the most significant bit, followed by
   75         5 bits each for red, green, and blue, and
   76 
   77       * EGL_DRM_BUFFER_FORMAT_RGB565_MESA, where each pixel is a CPU-endian
   78         16-bit quantity, with red in the 5 most significant bits, followed by
   79         6 bits of green and 5 bits of blue.
   80 
   81 Issues
   82 
   83     1. Should we expose the full set of channel permutations for the formats,
   84        e.g. ABGR2101010, RGBA1010102, and BGRA1010102 in addition to
   85        ARGB2101010?
   86 
   87        RESOLVED: No.
   88 
   89        DISCUSSION: The original extension sets a precedent of only exposing one
   90        of the possible permutations of 8-bit channel formats. It is also not
   91        clear where the additional permutations would be used. For example,
   92        Glamor has a fixed mapping from pixmap/screen depth to format that
   93        doesn't allow for the other permutations.
   94 
   95 Revision History
   96 
   97     Version 1, January, 2017
   98         Initial draft (Nicolai Hähnle)