diff options
Diffstat (limited to 'tex/context/base/mkxl/lpdf-img.lmt')
| -rw-r--r-- | tex/context/base/mkxl/lpdf-img.lmt | 113 |
1 files changed, 68 insertions, 45 deletions
diff --git a/tex/context/base/mkxl/lpdf-img.lmt b/tex/context/base/mkxl/lpdf-img.lmt index e1b822210..6914b2b29 100644 --- a/tex/context/base/mkxl/lpdf-img.lmt +++ b/tex/context/base/mkxl/lpdf-img.lmt @@ -18,6 +18,15 @@ if not modules then modules = { } end modules ['lpdf-img'] = { -- wanted but best gain a little. The idea is that we collect striped (in stages) so -- that we can play with substitutions. We keep this variant commented but not -- embedding it saves some 14K bytecode in the format. +-- +-- We keep the \LUA\ code commented because it is what I started with from the \PNG\ +-- specification. It was one fo the first things needed for dropping the backend so +-- actually this was part of the first \LUA\ based \PDF\ backend, the one that for a +-- while was part of \MKIV. That bit of development was not widely advertized and +-- just for me to make the transition and prove that it could be done. At some point +-- I decided to not provide a generic backend so that cdoe went away. Reminder: +-- there ended up some code here that was needed for font related png too (and I'd +-- already forgotten about: I need to document that). local type = type local concat, move = table.concat, table.move @@ -198,6 +207,7 @@ do local pnginterlace = pngdecode.interlace local pngexpand = pngdecode.expand local pngtocmyk = pngdecode.tocmyk + local pngtomask = pngdecode.tomask local filtermask, decodemask, decodestrip, transpose, expand, tocmyk @@ -206,7 +216,7 @@ do local function newoutput(size) if newindex then - return newindex(size,0) + return newindex(size,char(0)) end local t = newtable and newtable(size,0) or { } for i=1,size do @@ -806,52 +816,65 @@ do -- end -- end + -- We had this for a while (the reference now): + -- + -- local function createmask_c(content,palette,transparent,xsize,ysize,colordepth,colorspace) + -- if palette then + -- local r = expandvector(transparent) + -- local size = xsize*ysize + -- local len = ceil(xsize*colordepth/8) + -- local o = newoutput(size) + -- content = zlibdecompress(content) + -- content = pngapplyfilter(content,len,ysize,1) -- nostrip (saves copy) + -- content = openstring(content) + -- for i=0,ysize-1 do + -- local t = readbytetable(content,len) + -- local k = i * xsize + -- if colordepth == 8 then + -- for j=1,len do + -- local v = t[j] + -- k = k + 1 ; o[k] = r[v] + -- end + -- elseif colordepth == 4 then + -- for j=1,len do + -- local v = t[j] + -- k = k + 1 ; o[k] = r[(v >> 4) & 0x0F] -- r[extract4(v,4)] + -- k = k + 1 ; o[k] = r[(v >> 0) & 0x0F] -- r[extract4(v,0)] + -- end + -- elseif colordepth == 2 then + -- for j=1,len do + -- local v = t[j] + -- k = k + 1 ; o[k] = r[(v >> 6) & 0x03] -- r[extract2(v,6)] + -- k = k + 1 ; o[k] = r[(v >> 4) & 0x03] -- r[extract2(v,4)] + -- k = k + 1 ; o[k] = r[(v >> 2) & 0x03] -- r[extract2(v,2)] + -- k = k + 1 ; o[k] = r[(v >> 0) & 0x03] -- r[extract2(v,0)] + -- end + -- else + -- for j=1,len do + -- local v = t[j] + -- k = k + 1 ; o[k] = r[(v >> 7) & 0x01] -- r[extract1(v,7)] + -- k = k + 1 ; o[k] = r[(v >> 6) & 0x01] -- r[extract1(v,6)] + -- k = k + 1 ; o[k] = r[(v >> 5) & 0x01] -- r[extract1(v,5)] + -- k = k + 1 ; o[k] = r[(v >> 4) & 0x01] -- r[extract1(v,4)] + -- k = k + 1 ; o[k] = r[(v >> 3) & 0x01] -- r[extract1(v,3)] + -- k = k + 1 ; o[k] = r[(v >> 2) & 0x01] -- r[extract1(v,2)] + -- k = k + 1 ; o[k] = r[(v >> 1) & 0x01] -- r[extract1(v,1)] + -- k = k + 1 ; o[k] = r[(v >> 0) & 0x01] -- r[extract1(v,0)] + -- end + -- end + -- end + -- return concat(o,"",1,size) + -- end + -- end + -- + -- But this is nicer for memory usage: + local function createmask_c(content,palette,transparent,xsize,ysize,colordepth,colorspace) if palette then - local r = expandvector(transparent) - local size = xsize*ysize - local len = ceil(xsize*colordepth/8) - local o = newoutput(size) - content = zlibdecompress(content) - content = pngapplyfilter(content,len,ysize,1) -- nostrip (saves copy) - content = openstring(content) - for i=0,ysize-1 do - local t = readbytetable(content,len) - local k = i * xsize - if colordepth == 8 then - for j=1,len do - local v = t[j] - k = k + 1 ; o[k] = r[v] - end - elseif colordepth == 4 then - for j=1,len do - local v = t[j] - k = k + 1 ; o[k] = r[(v >> 4) & 0x0F] -- r[extract4(v,4)] - k = k + 1 ; o[k] = r[(v >> 0) & 0x0F] -- r[extract4(v,0)] - end - elseif colordepth == 2 then - for j=1,len do - local v = t[j] - k = k + 1 ; o[k] = r[(v >> 6) & 0x03] -- r[extract2(v,6)] - k = k + 1 ; o[k] = r[(v >> 4) & 0x03] -- r[extract2(v,4)] - k = k + 1 ; o[k] = r[(v >> 2) & 0x03] -- r[extract2(v,2)] - k = k + 1 ; o[k] = r[(v >> 0) & 0x03] -- r[extract2(v,0)] - end - else - for j=1,len do - local v = t[j] - k = k + 1 ; o[k] = r[(v >> 7) & 0x01] -- r[extract1(v,7)] - k = k + 1 ; o[k] = r[(v >> 6) & 0x01] -- r[extract1(v,6)] - k = k + 1 ; o[k] = r[(v >> 5) & 0x01] -- r[extract1(v,5)] - k = k + 1 ; o[k] = r[(v >> 4) & 0x01] -- r[extract1(v,4)] - k = k + 1 ; o[k] = r[(v >> 3) & 0x01] -- r[extract1(v,3)] - k = k + 1 ; o[k] = r[(v >> 2) & 0x01] -- r[extract1(v,2)] - k = k + 1 ; o[k] = r[(v >> 1) & 0x01] -- r[extract1(v,1)] - k = k + 1 ; o[k] = r[(v >> 0) & 0x01] -- r[extract1(v,0)] - end - end - end - return concat(o,"",1,size) + local len = ceil(xsize*colordepth/8) + content = zlibdecompress(content) + content = pngapplyfilter(content,len,ysize,1) -- nostrip (saves copy) + return pngtomask(content,transparent,xsize,ysize,colordepth) end end |