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Ipelib
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The library libipelua implements Lua bindings for many classes in Ipelib. The bindings are available in Lua ipelets, as well as in Lua scripts executed using the ipescript program.
These pages document the Lua bindings to Ipelib:
When writing Ipelets in Lua, you have access to additional methods provided by the Ipe program itself:
Here is a Lua script that reads an Ipe document and then recenters each page on the paper. You can run this script as "ipescript recenter".
-- recenter.lua
-- center objects on each page of the document
if #argv ~= 2 then
io.stderr:write("Usage: ipescript recenter <inputfile> <outputfile>\n")
return
end
inname = argv[1]
outname = argv[2]
doc = assert(ipe.Document(inname))
-- make sure we have size information for text
assert(doc:runLatex())
layout = doc:sheets():find("layout")
fs = layout.framesize
for i,p in doc:pages() do
box = ipe.Rect()
for j = 1,#p do
box:add(p:bbox(j))
end
nx = (fs.x - box:width()) / 2
ny = (fs.y - box:height()) / 2
trans = ipe.Vector(nx, ny) - box:bottomLeft()
m = ipe.Translation(trans)
for j = 1,#p do
p:transform(j, m)
end
end
doc:save(outname)
The following script prints out all the gradients defined in a document:
-- -*- lua -*-
function printTable(t, indent)
for k in pairs(t) do
local v = t[k]
if type(v) == "table" then
print(indent .. k .. ":")
printTable(v, " " .. indent)
else
print(indent .. k .. ": " .. tostring(v))
end
end
end
if #argv ~= 1 then
io.stderr:write("Usage: ipescript show-gradients <ipe-document>\n")
return
end
local figname = argv[1]
local doc = assert(ipe.Document(figname))
local s = doc:sheets()
for _,w in ipairs(s:allNames("gradient")) do
print("Gradient: ", w)
local g = s:find("gradient", w)
printTable(g, " ")
end
And here is a script that shows how to add a gradient to a document (the same technique works for tilings and effects):
-- -*- lua -*-
if #argv ~= 1 then
io.stderr:write("Usage: ipescript add-gradient <ipe-document>\n")
return
end
local figname = argv[1]
local doc = assert(ipe.Document(figname))
local sheet = [[<ipestyle>
<gradient name="ball" type="radial" coords="-4 10 2 0 0 18">
<stop offset="0" color="1 1 0"/>
<stop offset="1" color="0 1 0"/>
</gradient>
</ipestyle>]]
local ts = ipe.Sheet(nil, sheet)
local s = doc:sheets()
for i = 1,s:count() do
print(s:sheet(i):name())
end
-- add the gradient to the sheet on top of the stack
-- in general it is not a good idea to change the "basic" sheet,
-- better verify if a custom sheet for gradients exists already
-- and create it if not.
s:sheet(1):addFrom(ts, "gradient", "ball")
assert(doc:runLatex())
doc:save(figname .. ".new.ipe")
For more examples, have a look at the scripts in your Ipe installation, such as add-style.lua or update-styles.lua.