tga.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE fileformat>
<fileformat>
    <!--
    *******************
    *** basic types ***
    *******************
    -->

    <basic name="ubyte">
        An unsigned 8-bit integer.
    </basic>

    <basic name="byte">
        A signed 8-bit integer.
    </basic>

    <basic name="ushort">
        An unsigned 16-bit integer.
    </basic>

    <basic name="short">
        A signed 16-bit integer.
    </basic>

    <basic name="uint">
        An unsigned 32-bit integer.
    </basic>

    <basic name="int">
        A signed 32-bit integer.
    </basic>

    <basic name="char">
        An 8-bit character.
    </basic>

    <basic name="float">
        A standard 32-bit floating point number.
    </basic>

    <!--
    *******************
    *** alias types ***
    *******************
    -->

    <alias name="bool" type="ubyte" />
    
    <!--
    ******************
    *** enum types ***
    ******************
    -->

    <enum name="ImageType" numbytes="1" default="2">
        An unsigned 8-bit integer, describing the image type.
        <option value="1" name="INDEXED" />
        <option value="2" name="RGB" />
        <option value="3" name="GREY" />
        <option value="9" name="RLE_INDEXED" />
        <option value="10" name="RLE_RGB" />
        <option value="11" name="RLE_GREY" />
    </enum>
    
    <enum name="ColorMapType" numbytes="1">
        An unsigned 8-bit integer, describing the color map type.
        <option value="0" name="ABSENT" />
        <option value="1" name="PRESENT" />
        <!-- TODO: add more -->
    </enum>

    <!--
    ******************
    *** bitstructs ***
    ******************
    -->

    <bitstruct name="TgaFlags" numbytes="1" >
        <bits name="Alpha Channel Depth" numbits="4" />
        <bits name="Origin Right" numbits="1" />
        <bits name="Origin Upper" numbits="1" />
        <bits name="Interleave 2 Way" numbits="1" />
        <bits name="Interleave 4 Way" numbits="1" />
    </bitstruct>

    <!--
    ***************
    *** structs ***
    ***************
    -->

    <struct name="ColorMapEntry">
        <add name="Data" type="ubyte" arr1="ARG / 8" />
    </struct>

    <struct name="Pixel">
        <add name="Data" type="ubyte" arr1="ARG / 8" />
    </struct>

    <struct name="Header">
        <add name="Image Id Length" type="ubyte">Length of the Image ID field.</add>
        <add name="Color Map Type" type="ColorMapType" />
        <add name="Image Type" type="ImageType" />
        <add name="Color Map Index" type="ushort">Offset to the color map table.</add>
        <add name="Color Map Length" type="ushort">Number of entries.</add>
        <add name="Color Map Size" type="ubyte">Number of bits per pixel in the color map.</add>
        <add name="X Origin" type="ushort" />
        <add name="Y Origin" type="ushort" />
        <add name="Width" type="ushort" />
        <add name="Height" type="ushort" />
        <add name="Pixel Size" type="ubyte">Number of bits per pixel in the image data.</add>
        <add name="Flags" type="TgaFlags" />
        <add name="Image Id" type="ubyte" arr1="Image Id Length">
             Image identification.
        </add>
        <add name="Color Map" type="ColorMapEntry" cond="Color Map Type != 0" arr1="Color Map Length" arg="Color Map Size">
            Color lookup table.
        </add>
        <add name="Image" arr1="Height" arr2="Width" arg="Pixel Size" type="Pixel">
             The actual image data.
        </add>
    </struct>
</fileformat>