81 lines
1.5 KiB
Forth
Executable file
81 lines
1.5 KiB
Forth
Executable file
#!/usr/bin/env retro
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This is a quick tool to generate an `image.js` from the ngaImage
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for use with the JavaScript and Typescript implementations of
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the VM.
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First up, I need to load the image to a buffer, so I allocate
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space for this now.
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~~~
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#65535 #4 * 'IMAGE-SIZE const
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'Image d:create
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IMAGE-SIZE allot
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~~~
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Next is reading in the file. This is slightly complicated by
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the need to pack the individual bytes into the memory cells.
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So, a variable to track the open file ID.
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~~~
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'FID var
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~~~
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Then read in a byte.
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~~~
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:read-byte (n-) @FID file:read #255 and ;
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~~~
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Reading in four bytes, I can shift and merge them back into
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a single cell.
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~~~
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:read-cell (-n)
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read-byte read-byte read-byte read-byte
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#-8 shift + #-8 shift + #-8 shift + ;
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~~~
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The next step is a word to return the size of the file in
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cells.
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~~~
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:size (-n) @FID file:size #4 / ;
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~~~
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And then, using the above, read in the data from the file
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to the image buffer.
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~~~
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:load-image (s-)
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file:R file:open !FID
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&Image size [ read-cell over store n:inc ] times drop
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@FID file:close ;
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~~~
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Read in the file.
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~~~
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'ngaImage load-image
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~~~
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The final part is to export the image as a C array. To keep
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line length to a reasonible length, I have a counter and add
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a newline after 18 values.
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~~~
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'Count var
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:EOL? &Count v:inc @Count #18 eq? [ nl #0 !Count ] if ;
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~~~
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The rest is easy. Display the relevant header bits, then
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the cells, then the needed footer.
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~~~
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'var_ngaImage_=_[ s:put nl
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&Image dup #3 + fetch [ fetch-next n:put $, c:put EOL? ] times nl drop
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']; s:put nl
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~~~
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