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Lua libcurl

This thread is a few years old. Some details may refer to an earlier version of Visionaire Studio. Current tutorials

  • #1, by darren-beckett 10 years ago Quote
    Are you able to give an example of how to display an image loaded into memory using the new Libcurl functions?

    This example from the forum is incomplete:
    function draw()

if sprite2 ~= nil then

sprite.position = {x = posx, y = 0}

graphics.drawSprite(sprite2)

end

if sprite ~= nil then

graphics.drawSprite(sprite)

end

-- Font switch

-- graphics.font = Fonts.blocked

graphics.drawFont(" Test\nTest", 10, 10)

end



graphics.setDrawFunc("draw()")



startTween("posx", posx, 300, 3000, easeQuadInOut, true, true)
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  • #2, by darren-beckett 10 years ago Quote
    Also:
    1) Is is possible to display the HTML returned from a libcurl Get statement?
    2) Can the object be clickable? - Can it open a webpage?
  • #3, by SimonS 10 years ago Quote
    At best use this script:
    --[[
Lua-Curl script for Visionaire
(c) 13/6/2015
]]

curl_multi = curl.new_multi()
curls = {}
handles_count = 1
loadcount = 0
max_loadcount = 10
loadlist = {}

function GET(url, func,param, buf, startoffset, endoffset)
 if buf~=nil then
  table.insert(curls,{curl.new(),buf, func,param})
 else
  table.insert(curls,{curl.new(),{}, func,param})
 end
    c = curls[#curls][1]
    c:setopt(curl.OPT_URL, url)
 if startoffset ~= nil then
  c:setopt(curl.OPT_RANGE, startoffset.."-"..endoffset)
 end
    c:setopt(curl.OPT_FOLLOWLOCATION, true)
    c:setopt(curl.OPT_TIMEOUT, 300)
    c:setopt(curl.OPT_IOCTLFUNCTION, function (param, buf) return #buf end)
    c:setopt(curl.OPT_HEADERFUNCTION, function (param, buf) return #buf end)
    c:setopt(curl.OPT_WRITEDATA, {curls[#curls]})
    c:setopt(curl.OPT_WRITEFUNCTION, function (param, buf)
        table.insert(param[1][2], buf) -- store a chunk of data received
        return #buf
    end)
    c:setopt(curl.OPT_PROGRESSDATA, {curls[#curls]})
    c:setopt(curl.OPT_PROGRESSFUNCTION, function(param, dltotal, dlnow)
        if param[1][4][2]~=nil then
            param[1][4][2](dtotal, dnow)
        end
    end)
    c:setopt(curl.OPT_NOPROGRESS, false) -- use this to activate progress
    curl_multi:add(c)
    curl_multi:perform()
end

function POST(url,data,func,param, buf, startoffset, endoffset, userPassword)
    if buf~=nil then
        table.insert(curls,{curl.new(),buf, func,param})
    else
        table.insert(curls,{curl.new(),{}, func,param})
    end
    c = curls[#curls][1]
    c:setopt(curl.OPT_URL, url)
    if startoffset ~= nil then
        c:setopt(curl.OPT_RANGE, startoffset.."-"..endoffset)
    end
    c:setopt(curl.OPT_FOLLOWLOCATION, true)
    c:setopt(curl.OPT_TIMEOUT, 300)
    c:setopt(curl.OPT_WRITEDATA, {curls[#curls]})
    c:setopt(curl.OPT_WRITEFUNCTION, function (param, buf)
        table.insert(param[1][2], buf) -- store a chunk of data received
        return #buf
    end)
 c:setopt(curl.OPT_POST, true)
    c:setopt(curl.OPT_POSTFIELDS, data)
    c:setopt(curl.OPT_NOPROGRESS, false) -- use this to activate progress
 c:setopt(curl.OPT_HTTPHEADER, "Content-Type: application/json")
 if userPassword ~= nil then
  c:setopt(curl.OPT_USERPWD, userPassword)
 end
    curl_multi:add(c)
    curl_multi:perform()
end

function postRequest(httpurl, data, onFinish, onProgress, userPassword)
    POST(httpurl, data, onFinish, {nil, onProgress}, nil, nil, nil, userPassword)
end

function downloadFile(httpurl, file, onFinish, onProgress)
    GET(httpurl, function(s, param) 
        local file = io.open(param[1], "wb");file:write(s);file:close() 
        onFinish() 
    end, {file, onProgress})
end

function downloadMemory(httpurl, onFinish, onProgress)
    GET(httpurl, onFinish, {nil, onProgress})
end

function update_curl()
    while loadcount < max_loadcount and #loadlist > 0 do
        loadcount = loadcount + 1 
        GET(loadlist[1][1], function(s,param) loadcount = loadcount - 1; param[2](s,param[3]) end, loadlist[1])
        table.remove(loadlist, 1)
    end
    local handles = curl_multi:perform()
    local result = curl_multi:info()
    if result ~= -1 then
        for k,v in pairs(curls) do
            if tostring(v[1]) == tostring(result) then
                local size = v[1]:getinfo(curl.INFO_CONTENT_LENGTH_DOWNLOAD)
                local downsize = v[1]:getinfo(curl.INFO_SIZE_DOWNLOAD)
                if(size~=-1 and size~=downsize)then
                    print("not complete")
                    local element = table.remove(curls, k)
                else
                    v[3](table.concat(v[2]),v[4])
                    table.remove(curls, k)
                end
                break
            end
        end
    end
end

registerEventHandler("mainLoop", "update_curl")

    You can then do something like this:

    downloadMemory("http://url...", function(s,code,param) 
  sprite = graphics.loadMemoryJPG(s)
-- sprite = graphics.loadMemoryPNG(s)
-- sprite = graphics.loadMemoryWEBP(s)
end)

downloadMemory("http://url...", function(s,code,param) 
  print(s) -- html
end) 

    If you want to open a webpage, use startDefaultBrowser, may not work everywhere.

  • #4, by darren-beckett 10 years ago Quote
    Thanks Simon
  • #5, by darren-beckett 10 years ago Quote
    Are you able to provide a link to some documentation relating to the specific implementation of libcurl?
  • #6, by SimonS 10 years ago Quote
    We're using this implementation: http://luacurl.luaforge.net/
    It's modified for curl_multi, so I'd recommend sticking to the script, I already did all the heavy lifting there. Also because curl is not very easy.
  • #7, by darren-beckett 10 years ago Quote
    This is great, we shouldn't need to bug you guys so much now :-)
    Thanks again.
  • #8, by darren-beckett 10 years ago Quote
    I can't see how to assign the downloaded picture to an objects sprite, is there no SetSprite method?



    Also, The script isn't showing correctly, the LessThan "<" sign makes it show wrongly:
    function update_curl()
   <i>--while loadcount 0 do</i>
   while loadcount < max_loadcount and #loadlist > 0 do
      loadcount = loadcount + 1
  • #9, by SimonS 10 years ago Quote
    You need to draw the sprite yourself like you did in the initial code:
    graphics.drawSprite(sprite)
  • #10, by sebastian 10 years ago Quote
    I hope there will be a tutorial for these lua lib curl stuff some time after VS5 release. 
    It seems very weird if you guys tell "you need to ..." and all the above code is a level to high for me grin 
    I could assume now that the "sprite" was the previousely fetched png/jpg/webp image from the downloadMemory() function, right?

    Often it sounds like:

    "you need to program to get a game" .... yeah... but how do i start here? razz


  • #11, by darren-beckett 10 years ago Quote
    Don't worry Seb, you don't need to do any of this stuff to make an awesome game.