GFA Raytrace file format - Revision history

>Lp at 19:07, 8 February 2017

2017-02-08T19:07:18Z

← Older revision		Revision as of 15:07, 8 February 2017
Line 44:		Line 44:
	? compressed image data, uncompressed size = 32000/factor		? compressed image data, uncompressed size = 32000/factor

	~~Notes~~: Currently there is no description of the compression method.		Additional information:
	The layout of the rasters and how to calculate the color of a pixel at a		Images and animations use the same decompression method. Currently there is no
	given x/y coordinate is unknown.		description of the compression method. The layout of the rasters and how to
			calculate the color of a pixel at a given x/y coordinate is unknown.

	Note: 68K decompression code can be found here:		Note: 68K decompression code can be found here:

>Lp: add source code link

2017-02-08T19:05:10Z

add source code link

← Older revision		Revision as of 15:05, 8 February 2017
Line 47:		Line 47:
	The layout of the rasters and how to calculate the color of a pixel at a		The layout of the rasters and how to calculate the color of a pixel at a
	given x/y coordinate is unknown.		given x/y coordinate is unknown.

			Note: 68K decompression code can be found here:
			http://gfa.atari-users.net/gfx/
	</pre>		</pre>
	Back to [[ST Picture Formats]]		Back to [[ST Picture Formats]]

>Lp: updated info

2017-02-06T20:09:48Z

updated info

← Older revision		Revision as of 16:09, 6 February 2017
Line 22:		Line 22:
	4 12608		4 12608
	8 6308		8 6308

	~~Currently there is no description of the compression method.~~

	SUH details: (similar to Degas *.PI3)		SUH details: (similar to Degas *.PI3)
Line 46:		Line 44:
	? compressed image data, uncompressed size = 32000/factor		? compressed image data, uncompressed size = 32000/factor

	Currently there is no description of the compression method.		Notes: Currently there is no description of the compression method.
			The layout of the rasters and how to calculate the color of a pixel at a
			given x/y coordinate is unknown.
	</pre>		</pre>
	Back to [[ST Picture Formats]]		Back to [[ST Picture Formats]]

>Lp: New page

2017-02-06T20:06:54Z

New page

New page

<pre>
GFA Raytrace *.SUL *.SUH (st low/high resolution image uncompressed)
*.SCL *.SCH (st low/high resolution image compressed)
*.SAL *.SAH (st low/high resolution animation compressed)

SUL/SCL/SCH details:

6 bytes file id in plain ASCII text: "sul" or "scl" + cr/lf
"sul' = uncompressed, "scl" = compressed
3 bytes size factor in plain ASCII text: "1", "2", "4", or "8" + cr/lf
factor = ASC(factor) - 48
image height = image height/factor
? bytes palette (first scan line is always black, not included in the file)
palette size = 18400/factor
? bytes image data
bitmap size = 32000/factor

Uncompressed fixed image sizes:
Factor Size in bytes
1 50408
2 25208
4 12608
8 6308

Currently there is no description of the compression method.

SUH details: (similar to Degas *.PI3)

1 word resolution flag [always 2]
16 words palette (should be ignored, seems to contain bogus values)
32000 bytes image data
-----------
32034 bytes total file size

SAL/SAH detail: (up to 10 frames maximum)

6 bytes file id in plain ASCII text: "sal" or "sah" + cr/lf
"sal' = st low resolution, "sah" = st high resolution
1 long frame count - 1
1 long size factor [1, 2, 4, or 8]
image height = image height/factor
1 long image data size
10 longs offsets to all 10 frames from the start of the file [0 for unused entries]
Repeated for each frame:
? palette, size = 18400/factor
? compressed image data, uncompressed size = 32000/factor

Currently there is no description of the compression method.
</pre>
Back to [[ST Picture Formats]]