diff options
Diffstat (limited to 'tex/context/base/mkiv/util-fil.lua')
| -rw-r--r-- | tex/context/base/mkiv/util-fil.lua | 218 |
1 files changed, 189 insertions, 29 deletions
diff --git a/tex/context/base/mkiv/util-fil.lua b/tex/context/base/mkiv/util-fil.lua index 28c92c7c3..01bcd571e 100644 --- a/tex/context/base/mkiv/util-fil.lua +++ b/tex/context/base/mkiv/util-fil.lua @@ -6,8 +6,10 @@ if not modules then modules = { } end modules ['util-fil'] = { license = "see context related readme files" } -local byte = string.byte -local extract = bit32.extract +local byte = string.byte +local char = string.char +local extract = bit32 and bit32.extract +local floor = math.floor -- Here are a few helpers (the starting point were old ones I used for parsing -- flac files). In Lua 5.3 we can probably do this better. Some code will move @@ -36,6 +38,8 @@ function files.size(f) return f:seek("end") end +files.getsize = files.size + function files.setposition(f,n) if zerobased[f] then f:seek("set",n) @@ -79,6 +83,12 @@ function files.readbytes(f,n) return byte(f:read(n),1,n) end +function files.readbytetable(f,n) + -- return { byte(f:read(n),1,n) } + local s = f:read(n or 1) + return { byte(s,1,#s) } -- best use the real length +end + function files.readchar(f) return f:read(1) end @@ -89,29 +99,43 @@ end function files.readinteger1(f) -- one byte local n = byte(f:read(1)) - if n >= 0x80 then - return n - 0xFF - 1 + if n >= 0x80 then + return n - 0x100 else return n end end -files.readcardinal1 = files.readbyte -- one byte -files.readcardinal = files.readcardinal1 -files.readinteger = files.readinteger1 +files.readcardinal1 = files.readbyte -- one byte +files.readcardinal = files.readcardinal1 +files.readinteger = files.readinteger1 +files.readsignedbyte = files.readinteger1 function files.readcardinal2(f) local a, b = byte(f:read(2),1,2) return 0x100 * a + b end +function files.readcardinal2le(f) + local b, a = byte(f:read(2),1,2) + return 0x100 * a + b +end + function files.readinteger2(f) local a, b = byte(f:read(2),1,2) - local n = 0x100 * a + b - if n >= 0x8000 then - return n - 0xFFFF - 1 + if a >= 0x80 then + return 0x100 * a + b - 0x10000 else - return n + return 0x100 * a + b + end +end + +function files.readinteger2le(f) + local b, a = byte(f:read(2),1,2) + if a >= 0x80 then + return 0x100 * a + b - 0x10000 + else + return 0x100 * a + b end end @@ -120,44 +144,115 @@ function files.readcardinal3(f) return 0x10000 * a + 0x100 * b + c end +function files.readcardinal3le(f) + local c, b, a = byte(f:read(3),1,3) + return 0x10000 * a + 0x100 * b + c +end + +function files.readinteger3(f) + local a, b, c = byte(f:read(3),1,3) + if a >= 0x80 then + return 0x10000 * a + 0x100 * b + c - 0x1000000 + else + return 0x10000 * a + 0x100 * b + c + end +end + +function files.readinteger3le(f) + local c, b, a = byte(f:read(3),1,3) + if a >= 0x80 then + return 0x10000 * a + 0x100 * b + c - 0x1000000 + else + return 0x10000 * a + 0x100 * b + c + end +end + function files.readcardinal4(f) local a, b, c, d = byte(f:read(4),1,4) return 0x1000000 * a + 0x10000 * b + 0x100 * c + d end +function files.readcardinal4le(f) + local d, c, b, a = byte(f:read(4),1,4) + return 0x1000000 * a + 0x10000 * b + 0x100 * c + d +end + function files.readinteger4(f) local a, b, c, d = byte(f:read(4),1,4) - local n = 0x1000000 * a + 0x10000 * b + 0x100 * c + d - if n >= 0x8000000 then - return n - 0xFFFFFFFF - 1 + if a >= 0x80 then + return 0x1000000 * a + 0x10000 * b + 0x100 * c + d - 0x100000000 else - return n + return 0x1000000 * a + 0x10000 * b + 0x100 * c + d end end -function files.readfixed4(f) - local a, b, c, d = byte(f:read(4),1,4) - local n = 0x100 * a + b - if n >= 0x8000 then - return n - 0xFFFF - 1 + (0x100 * c + d)/0xFFFF +function files.readinteger4le(f) + local d, c, b, a = byte(f:read(4),1,4) + if a >= 0x80 then + return 0x1000000 * a + 0x10000 * b + 0x100 * c + d - 0x100000000 else - return n + (0x100 * c + d)/0xFFFF + return 0x1000000 * a + 0x10000 * b + 0x100 * c + d end end -function files.read2dot14(f) +-- function files.readfixed2(f) +-- local a, b = byte(f:read(2),1,2) +-- if a >= 0x80 then +-- return (0x100 * a + b - 0x10000)/256.0 +-- else +-- return (0x100 * a + b)/256.0 +-- end +-- end + +function files.readfixed2(f) local a, b = byte(f:read(2),1,2) - local n = 0x100 * a + b - local m = extract(n,0,30) - if n > 0x7FFF then - n = extract(n,30,2) - return m/0x4000 - 4 + if a >= 0x80 then + return (a - 0x100) + b/0x100 else - n = extract(n,30,2) - return n + m/0x4000 + return (a ) + b/0x100 end end +-- (real) (n>>16) + ((n&0xffff)/65536.0)) + +-- function files.readfixed4(f) +-- local a, b, c, d = byte(f:read(4),1,4) +-- if a >= 0x80 then +-- return (0x1000000 * a + 0x10000 * b + 0x100 * c + d - 0x100000000)/65536.0 +-- else +-- return (0x1000000 * a + 0x10000 * b + 0x100 * c + d)/65536.0 +-- end +-- end + +function files.readfixed4(f) + local a, b, c, d = byte(f:read(4),1,4) + if a >= 0x80 then + return (0x100 * a + b - 0x10000) + (0x100 * c + d)/0x10000 + else + return (0x100 * a + b ) + (0x100 * c + d)/0x10000 + end +end + +if extract then + + local extract = bit32.extract + local band = bit32.band + + -- (real) ((n<<16)>>(16+14)) + ((n&0x3fff)/16384.0)) + + function files.read2dot14(f) + local a, b = byte(f:read(2),1,2) + if a >= 0x80 then + local n = -(0x100 * a + b) + return - (extract(n,14,2) + (band(n,0x3FFF) / 16384.0)) + else + local n = 0x100 * a + b + return (extract(n,14,2) + (band(n,0x3FFF) / 16384.0)) + end + end + +end + function files.skipshort(f,n) f:read(2*(n or 1)) end @@ -165,3 +260,68 @@ end function files.skiplong(f,n) f:read(4*(n or 1)) end + +-- writers (kind of slow) + +function files.writecardinal2(f,n) + local a = char(n % 256) + n = floor(n/256) + local b = char(n % 256) + f:write(b,a) +end + +function files.writecardinal4(f,n) + local a = char(n % 256) + n = floor(n/256) + local b = char(n % 256) + n = floor(n/256) + local c = char(n % 256) + n = floor(n/256) + local d = char(n % 256) + f:write(d,c,b,a) +end + +function files.writestring(f,s) + f:write(char(byte(s,1,#s))) +end + +function files.writebyte(f,b) + f:write(char(b)) +end + +if fio and fio.readcardinal1 then + + files.readcardinal1 = fio.readcardinal1 + files.readcardinal2 = fio.readcardinal2 + files.readcardinal3 = fio.readcardinal3 + files.readcardinal4 = fio.readcardinal4 + files.readinteger1 = fio.readinteger1 + files.readinteger2 = fio.readinteger2 + files.readinteger3 = fio.readinteger3 + files.readinteger4 = fio.readinteger4 + -- files.readfixed2 = fio.readfixed2 -- needs recent luatex + -- files.readfixed4 = fio.readfixed4 -- needs recent luatex + files.read2dot14 = fio.read2dot14 + files.setposition = fio.setposition + files.getposition = fio.getposition + + files.readbyte = files.readcardinal1 + files.readsignedbyte = files.readinteger1 + files.readcardinal = files.readcardinal1 + files.readinteger = files.readinteger1 + + local skipposition = fio.skipposition + files.skipposition = skipposition + + files.readbytes = fio.readbytes + files.readbytetable = fio.readbytetable + + function files.skipshort(f,n) + skipposition(f,2*(n or 1)) + end + + function files.skiplong(f,n) + skipposition(f,4*(n or 1)) + end + +end |