hex/plugins/xcursor.lua
Přemysl Eric Janouch 9489358c92
xcursor.lua: fix file version decoding
The Xcursor header file contains more documentation than there is
in the actual documentation.
2021-11-17 12:18:37 +01:00

55 lines
1.9 KiB
Lua

--
-- xcursor.lua: X11 cursors
--
-- Copyright (c) 2021, Přemysl Eric Janouch <p@janouch.name>
--
-- Permission to use, copy, modify, and/or distribute this software for any
-- purpose with or without fee is hereby granted.
--
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--
local detect = function (c)
return c:read (4) == "Xcur"
end
-- https://www.x.org/releases/current/doc/man/man3/Xcursor.3.xhtml
local decode = function (c)
if not detect (c) then error ("not an Xcursor file") end
-- libXcursor shows that they are always little-endian
c (1, 4):mark ("Xcursor magic")
c.endianity = "le"
local size = c:u32 ("header size: %d")
-- TODO: check the version, although it is essentially set in stone
-- as 1.0, with X.org being a nearly abandoned project
local version = c:u32 ("file version: %s", function (u32)
return "%d.%d", u32 >> 16, u32 & 0xffff
end)
local ntoc = c:u32 ("number of ToC entries: %d")
local i
for i = 1, ntoc do
local start = c.position
local type = c:u32 ("entry type: %s", function (u32)
if u32 == 0xfffe0001 then return "comment" end
if u32 == 0xfffd0002 then return "image" end
return "unknown: %d", u32
end)
local subtype = c:u32 ("entry subtype: %d")
local position = c:u32 ("chunk position: %d")
c (start, c.position - 1):mark (("ToC entry %d"):format (i))
end
-- TODO: decode all entries as well
end
hex.register { type="xcursor", detect=detect, decode=decode }