Re: A86: Libraries and Loaders


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Re: A86: Libraries and Loaders



On Tue, 5 Aug 1997, B. Nagel wrote:

> These library/function vars wouldn't need any special formatting or
> tables, but we better play it safe and use a version # at the beginning:
> 
> .dw $0000
> .dw pFixupTable

Looks okay.

> I was thinking that the import table could be like:
> 
> .db $0B,$06,"sprite"
> .db $0B,$07,"findpix"

I agree.  Very nice, but how about a byte that tells which function
within the library to call.  I know you want to have one function per
library, but let me pose this situation:

	You have a library, Lsprite (or something) that has a function to
	do the logical OR of a bitmap to the screen.  If you sometime want
	to to XOR, it would be convenient if you could just call a second
	function within that same library, since all the code except for a
	few lines is the same.

To simplify things, could we compromise by saying that when a library is
used, the entire thing is loaded, but also that up to 256 entry points may
be specified?

> Now about pointers in the table,
> Why be relative when you can be absolute? :)

When I wrote up the standard I was thinking of the export tables in the
libraries and thought it would be easier to have relative pointers there
(since the vars could be anywhere in memory).  You're 100% correct, 
though.  The programs should definitely use absolute pointers.

--------
Dan Eble (mailto:eble@cis.ohio-state.edu)
         (http://www.cis.ohio-state.edu/~eble)


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