if not modules then modules = { } end modules ['grph-inc'] = {
version = 1.001,
comment = "companion to grph-inc.mkiv",
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
local xpcall, pcall = xpcall, pcall
local bpfactor = number.dimenfactors.bp
local report = logs.reporter("graphics")
local report_inclusion = logs.reporter("graphics","inclusion")
local report_bitmap = logs.reporter("graphics","bitmap")
local report_pdf = logs.reporter("graphics","pdf")
local trace_pdf = false trackers.register("graphics.pdf", function(v) trace_pdf = v end)
local checkers = figures.checkers
local genericchecker = checkers.generic
local placeholder = graphics.bitmaps.placeholder
-- This is an experiment. The following method uses Lua to handle the embedding
-- using the epdf library. This feature will be used when we make the transition
-- from the pre 1.10 epdf library (using an unsuported low level poppler api) to a
-- new (lightweight, small and statically compiled) library. More on that later.
--
-- The method implemented below has the same performance as the hard coded inclusion
-- but opens up some possibilities (like merging fonts) that I will look into some
-- day.
function checkers.pdf(data)
local request = data.request
local used = data.used
if request and used and not request.scanimage then
local image = lpdf.epdf.image
local openpdf = image.open
local closepdf = image.close
local querypdf = image.query
local copypage = image.copy
local pdfdoc = nil
local filename = nil
request.scanimage = function(t)
if pdfdoc then
if trace_pdf then
report_pdf("scan image %a",filename)
end
if not filename then
filename = pdfdoc.filename
end
else
filename = t.filename
if trace_pdf then
report_pdf("open and scan image %a",filename)
end
pdfdoc = openpdf(filename,request.userpassword,request.ownerpassword)
end
if pdfdoc then
--
local info = querypdf(pdfdoc,request.page,request.size)
if info then
local bbox = info and info.boundingbox or { 0, 0, 0, 0 }
local height = bbox[4] - bbox[2]
local width = bbox[3] - bbox[1]
local rotation = info.rotation or 0
if rotation == 90 then
rotation, height, width = 3, width, height
elseif rotation == 180 then
rotation = 2
elseif rotation == 270 then
rotation, height, width = 1, width, height
elseif rotation == 1 or rotation == 3 then
height, width = width, height
else
rotation = 0
end
return {
filename = filename,
-- page = 1,
pages = pdfdoc.nofpages,
width = width,
height = height,
depth = 0,
colordepth = 0,
xres = 0,
yres = 0,
xsize = width,
ysize = height,
rotation = rotation,
pdfdoc = pdfdoc,
}
end
end
end
request.copyimage = function(t)
if not pdfdoc then
pdfdoc = t.pdfdoc
end
if pdfdoc then
local page = request.page
local copied = pdfdoc.nofcopied or 0
if not pdfdoc.copied[page] then
pdfdoc.copied[page] = true
copied = copied + 1
end
pdfdoc.nofcopied = copied
if trace_pdf then
report_pdf("copy page %i from image %a, %i pages copied",page,filename,copied)
end
local result = copypage(pdfdoc,page,nil,request.compact,request.width,request.height,request.attr)
if pdfdoc.nofcopied >= pdfdoc.nofpages then
if trace_pdf then
report_pdf("closing image %a, %i pages copied",filename,copied)
end
closepdf(pdfdoc)
pdfdoc = nil
t.pdfdoc = nil
end
return result
else
-- message, should not happen as we always first scan so that reopens
end
end
end
return genericchecker(data)
end
local function wrappedidentify(identify,filename)
local wrapup = function() report_inclusion("fatal error reading %a",filename) end
local _, result = xpcall(identify,wrapup,filename)
if result then
local xsize = result.xsize or 0
local ysize = result.ysize or 0
local xres = result.xres or 0
local yres = result.yres or 0
if xres == 0 or yres == 0 then
xres = 300
yres = 300
end
result.xsize = xsize
result.ysize = ysize
result.xres = xres
result.yres = yres
result.width = result.width or ((72/xres) * xsize / bpfactor)
result.height = result.height or ((72/yres) * ysize / bpfactor)
result.depth = result.depth or 0
result.filename = filename
result.colordepth = result.colordepth or 0
result.colorspace = result.colorspace or 0
result.rotation = result.rotation or 0
result.orientation = result.orientation or 0
result.transform = result.transform or 0
return result
else
return { error = "fatal error" }
end
end
function checkers.jpg(data)
local request = data.request
local used = data.used
if request and used and not request.scanimage then
local identify = graphics.identify
local inject = lpdf.injectors.jpg
local found = false
request.scanimage = function(t)
local result = wrappedidentify(identify,t.filename)
found = not result.error
return {
filename = result.filename,
width = result.width,
height = result.height,
depth = result.depth,
colordepth = result.colordepth,
xres = result.xres,
yres = result.yres,
xsize = result.xsize,
ysize = result.ysize,
colorspace = result.colorspace,
rotation = result.rotation,
orientation = result.orientation,
transform = result.transform,
}
end
request.copyimage = function(t)
if found then
found = false
return inject(t)
end
end
end
return genericchecker(data)
end
function checkers.jp2(data) -- idem as jpg
local request = data.request
local used = data.used
if request and used and not request.scanimage then
local identify = graphics.identify
local inject = lpdf.injectors.jp2
local found = false
request.scanimage = function(t)
local result = wrappedidentify(identify,t.filename)
found = not result.error
return {
filename = result.filename,
width = result.width,
height = result.height,
depth = result.depth,
colordepth = result.colordepth,
xres = result.xres,
yres = result.yres,
xsize = result.xsize,
ysize = result.ysize,
rotation = result.rotation,
colorspace = result.colorspace,
orientation = result.orientation,
transform = result.transform,
}
end
request.copyimage = function(t)
if found then
found = false
return inject(t)
end
end
end
return genericchecker(data)
end
function checkers.png(data) -- same as jpg (for now)
local request = data.request
local used = data.used
if request and used and not request.scanimage then
local identify = graphics.identify
local inject = lpdf.injectors.png -- currently pdf specific
local found = false
request.scanimage = function(t)
local result = wrappedidentify(identify,t.filename)
found = not result.error
return {
filename = result.filename,
width = result.width,
height = result.height,
depth = result.depth,
colordepth = result.colordepth,
xres = result.xres,
yres = result.yres,
xsize = result.xsize,
ysize = result.ysize,
rotation = result.rotation,
colorspace = result.colorspace,
tables = result.tables,
interlace = result.interlace,
filter = result.filter,
orientation = result.orientation,
transform = result.transform,
}
end
request.copyimage = function(t)
t.colorref = used.colorref -- this is a bit of a hack
if found then
found = false
local ok, result = pcall(inject,t)
if ok then
return result
else
report_inclusion("bad bitmap image")
return placeholder()
end
end
end
end
return genericchecker(data)
end
