Added more detail about the DDS file format:

- Indicate compression, alpha-only, YUV, and luminance.
  Previously, all DDS textures were assumed to be compressed.
- For uncompressed RGB, attempt to decode the format using the channel masks.
(David Korth)

diff --git a/magic/Magdir/images b/magic/Magdir/images
index 6ca1956875266c8ff617a4df96a5006e22ef19ee..89f10b4910c4f205344ae6d06aeada3e4a60f1c1 100644 (file)
--- a/magic/Magdir/images
+++ b/magic/Magdir/images
@@ -1,6 +1,6 @@
 
 #------------------------------------------------------------------------------
-# $File: images,v 1.142 2018/06/23 16:41:10 christos Exp $
+# $File: images,v 1.143 2018/06/23 16:41:47 christos Exp $
 # images:  file(1) magic for image formats (see also "iff", and "c-lang" for
 # XPM bitmaps)
 #
@@ -1402,9 +1402,102 @@
 # URL: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/directx9_c/directx/graphics/reference/DDSFileReference/ddsfileformat.asp
 # From: Morten Hustveit <morten@debian.org>
 0      string/b        DDS\040\174\000\000\000 Microsoft DirectDraw Surface (DDS),
->16    lelong  >0                      %d x
->12    lelong  >0                      %d,
->84    string  x                       %.4s
+>0x10  ulelong >0                      %u x
+>0x0C  ulelong >0                      %u
+# Color depth.
+>0x58  ulelong >0                      \b, %u-bit color
+# Determine the pixel format.
+>0x50  ulelong&0x4     4
+# FIXME: Handle DX10 and XBOX formats.
+>>0x54 string  x                       \b, compressed using %.4s
+>0x50  ulelong&0x2     0x2             \b, alpha only
+>0x50  ulelong&0x200   0x200           \b, YUV
+>0x50  ulelong&0x20000 0x20000         \b, luminance
+# RGB pixel format
+>0x50  ulelong&0x40    0x40
+
+# Determine the RGB format using the color masks.
+# ulequad order: 0xGGGGGGGGRRRRRRRR, 0xAAAAAAAABBBBBBBB
+
+>>0x58         ulelong 16
+
+# NOTE: 15-bit color formats usually have 16-bit listed as the color depth.
+>>>0x5C                ulequad 0x000003E000007C00
+>>>>0x64       ulequad 0x000000000000001F      \b, RGB555
+>>>0x5C                ulequad 0x000003E000001F00
+>>>>0x64       ulequad 0x000000000000007C      \b, BGR555
+
+>>>0x5C                ulequad 0x000007E00000F800
+>>>>0x64       ulequad 0x000000000000001F      \b, RGB565
+>>>0x5C                ulequad 0x000007E000001F00
+>>>>0x64       ulequad 0x00000000000000F8      \b, BGR565
+
+>>>0x5C                ulequad 0x000000F000000F00
+>>>>0x64       ulequad 0x0000F0000000000F      \b, ARGB4444
+>>>0x5C                ulequad 0x000000F00000000F
+>>>>0x64       ulequad 0x0000F00000000F00      \b, ABGR4444
+
+>>>0x5C                ulequad 0x00000F000000F000
+>>>>0x64       ulequad 0x0000000F000000F0      \b, RGBA4444
+>>>0x5C                ulequad 0x00000F00000000F0
+>>>>0x64       ulequad 0x0000000F0000F000      \b, BGRA4444
+
+>>>0x5C                ulequad 0x000000F000000F00
+>>>>0x64       ulequad 0x000000000000000F      \b, xRGB4444
+>>>0x5C                ulequad 0x000000F00000000F
+>>>>0x64       ulequad 0x0000000000000F00      \b, xBGR4444
+
+>>>0x5C                ulequad 0x00000F000000F000
+>>>>0x64       ulequad 0x00000000000000F0      \b, RGBx4444
+>>>0x5C                ulequad 0x00000F00000000F0
+>>>>0x64       ulequad 0x000000000000F000      \b, BGRx4444
+
+>>>0x5C                ulequad 0x000003E000007C00
+>>>>0x64       ulequad 0x000080000000001F      \b, ARGB1555
+>>>0x5C                ulequad 0x000003E000001F00
+>>>>0x64       ulequad 0x000080000000007C      \b, ABGR1555
+>>>0x5C                ulequad 0x000007C00000F800
+>>>>0x64       ulequad 0x000000010000003E      \b, RGBA5551
+>>>0x5C                ulequad 0x000007C00000003E
+>>>>0x64       ulequad 0x000000010000F800      \b, BGRA5551
+
+>>88           ulelong 24
+>>>0x5C                ulequad 0x0000FF0000FF0000
+>>>>0x64       ulequad 0x00000000000000FF      \b, RGB888
+>>>0x5C                ulequad 0x0000FF00000000FF
+>>>>0x64       ulequad 0x0000000000FF0000      \b, BGR888
+
+>>88           ulelong 32
+>>>0x5C                ulequad 0x0000FF0000FF0000
+>>>>0x64       ulequad 0xFF000000000000FF      \b, ARGB8888
+>>>0x5C                ulequad 0x0000FF00000000FF
+>>>>0x64       ulequad 0xFF00000000FF0000      \b, ABGR8888
+
+>>>0x5C                ulequad 0x00FF0000FF000000
+>>>>0x64       ulequad 0x000000FF0000FF00      \b, RGBA8888
+>>>0x5C                ulequad 0x00FF00000000FF00
+>>>>0x64       ulequad 0x000000FFFF000000      \b, BGBA8888
+
+>>>0x5C                ulequad 0x0000FF0000FF0000
+>>>>0x64       ulequad 0x00000000000000FF      \b, xRGB8888
+>>>0x5C                ulequad 0x0000FF00000000FF
+>>>>0x64       ulequad 0x0000000000FF0000      \b, xBGR8888
+
+>>>0x5C                ulequad 0x00FF0000FF000000
+>>>>0x64       ulequad 0x000000000000FF00      \b, RGBx8888
+>>>0x5C                ulequad 0x00FF00000000FF00
+>>>>0x64       ulequad 0x00000000FF000000      \b, BGBx8888
+
+# Less common 32-bit color formats.
+>>>0x5C                ulequad 0xFFFF00000000FFFF
+>>>>0x64       ulequad 0x0000000000000000      \b, G16R16
+>>>0x5C                ulequad 0x0000FFFFFFFF0000
+>>>>0x64       ulequad 0x0000000000000000      \b, R16G16
+
+>>>0x5C                ulequad 0x000FFC003FF00000
+>>>>0x64       ulequad 0xC0000000000003FF      \b, A2R10G10B10
+>>>0x5C                ulequad 0x000FFC00000003FF
+>>>>0x64       ulequad 0xC00000003FF00000      \b, A2B10G10R10
 
 # Type: Sega PVR image.
 # From: David Korth <gerbilsoft@gerbilsoft.com>