pgfplots (26oct12)

git-svn-id: svn://tug.org/texlive/trunk@28094 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 30 insertions, 0 deletions

diff --git a/Master/texmf-dist/tex/generic/pgfplots/lua/pgfplots.lua b/Master/texmf-dist/tex/generic/pgfplots/lua/pgfplots.lua
new file mode 100644
index 00000000000..8242222e8d6
--- /dev/null
+++ b/Master/texmf-dist/tex/generic/pgfplots/lua/pgfplots.lua
@@ -0,0 +1,30 @@
+
+pgfplotsGetLuaBinaryStringFromCharIndicesChunkSize = 7000;
+
+-- Takes a table containing an arbitrary number of integers in the range 0..255 and converts it 
+-- into a binary stream of the corresponding binary chars.
+--
+-- @param charIndices a table containing 0...N arguments; each in the range 0..255
+--
+-- @return a string containing binary content, one byte for each input integer.
+function pgfplotsGetLuaBinaryStringFromCharIndices(charIndices)
+	-- unpack extracts only the indices (we can't provide a table to string.char).
+	-- note that pdf.immediateobj has been designed to avoid sanity checking for invalid UTF strings -
+	-- in other words: it accepts binary strings.
+	--
+	-- unfortunately, this here fails for huge input tables:
+	--   pgfplotsretval=string.char(unpack(charIndices));
+	-- we have to create it incrementally using chunks:
+	local len = #charIndices;
+	local chunkSize = pgfplotsGetLuaBinaryStringFromCharIndicesChunkSize;
+	local buf = {};
+	-- ok, append all full chunks of chunkSize first:
+	local numFullChunks = math.floor(len/chunkSize);
+	for i = 0, numFullChunks-1, 1 do
+		table.insert(buf, string.char(unpack(charIndices, 1+i*chunkSize, (i+1)*chunkSize)));
+	end
+	-- append the rest:
+	table.insert(buf, string.char(unpack(charIndices, 1+numFullChunks*chunkSize)));
+	return table.concat(buf);
+end
+