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   1 Embedded Templates
   2 ~~~~~~~~~~~~~~~~~~
   3
   4 For small programs, it's irritating to have a separate templates file
   5 hanging around.  Separate files aren't necessary for sprites or messages,
   6 so templates become rather annoying.  An `embedded template' is a
   7 position-independent in-memory representation of a window template which
   8 has had some extra information added to make it particularly easy to
   9 construct a real window definition.  (The idea of adding relocation
  10 offsets is admittedly based on the Toolbox resource format.)  This
  11 trivial library unpacks embedded templates.
  12
  13 The format of an embedded template is (I think) as follows:
  14
  15 Offset    Size          Value
  16
  17    0        4           Offset to window definition ($w$)
  18    4        4           Offset to indirected data ($i$)
  19    8        4           Offset to limit of the template ($l$)
  20   12    $w - 12$        Relocation directives
  21
  22  $w$     $i - w$        Template window definition (as in template files)
  23
  24  $i$     $l - i$        Initialisation strings for indirected icons and
  25                         window titles.  This will be copied literally
  26                         into the application's indirected data space.
  27
  28 Each relocation directive consists of a single word; the top four bits of
  29 a relocation directive determine the `type'; the bottom twenty-eight bits
  30 give the `offset'.
  31
  32 Currently defined types are:
  33
  34 Type    Meaning
  35
  36   0     Add the address of the indirected data area to the word at the
  37                 given offset into the window definition.
  38   1     Store the `window sprite area' in the word at the given offset
  39                 into the window definition.
  40   2     Store the `icon sprite area' in the word at the given offset
  41                 into the window definition.
  42
  43 Embedded templates are not meant to be built by hand.  Instead, the
  44 programs `templAOF' and `resGen' will build AOF files containing embedded
  45 template defintions from standard template files.  These can be linked
  46 into applications and modules.
  47
  48 --
  49 [mdw]