[File] [PATCH] Add ColoRIX images.

[Eddy Jansson]

My attempt at adding support for this old MS-DOS-era image format.

I'm been maintaining this at https://github.com/eloj/rix-magic where there
are also a directory of (truncated) test files.

---
 magic/Magdir/images | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/magic/Magdir/images b/magic/Magdir/images
index 0506915..a0ff1ad 100644
--- a/magic/Magdir/images
+++ b/magic/Magdir/images
@@ -4159,3 +4159,39 @@
 #!:mime	application/octet-stream
 !:mime	image/x-idf
 !:ext	idf
+
+# Type: ColoRIX VGA Paint Image File (.rix/.sci/.scX)
+# From: Eddy Jansson <github.com/eloj>
+# Reference: https://www.fileformat.info/format/rix/spec/
+#
+0	name	rix-header
+>0	uleshort x \b, %u x
+>2	uleshort x %u
+# palette type:
+# .. if direct color, low bits encode bpp
+>4	ubyte&128 0
+>>4 ubyte&127 x \b %u bpp (direct color)
+# .. else palette
+>4	ubyte&128 128
+>>4 ubyte&7 0 \b x 2
+>>4 ubyte&7 1 \b x 4
+>>4 ubyte&7 2 \b x 8
+>>4 ubyte&7 3 \b x 16
+>>4 ubyte&7 4 \b x 32
+>>4 ubyte&7 5 \b x 64
+>>4 ubyte&7 6 \b x 128
+>>4 ubyte&7 7 \b x 256
+# storage type
+#>5  ubyte&15 0 \b, Linear
+>5  ubyte&15 1 \b, Planar (0213)
+>5  ubyte&15 2 \b, Planar
+>5  ubyte&15 3 \b, Text
+>5  ubyte&15 4 \b, Planar lines
+>5	ubyte&128 128 \b (compressed)
+>5	ubyte&64 64 \b (extension)
+>5	ubyte&32 32 \b (encrypted)
+
+0	string	RIX3	ColoRIX Image
+>4 use rix-header
+
+0	string	RIX7	ColoRIX Slideshow
-- 
2.34.1