lua-leap

Lua bindings for the Leap Motion Controller (version 2.3.1 on GNU/Linux) for lua 5.2 and later.

Installation

Build with luarocks

To build the library using the rockspec file do this:

luarocks

Build locally

This package comes with autotools, to build it locally simply do this:

./configure && make

Use Luarocks (not yet ready)

This package it's not published on luarocks yet for now you have to build it locally.

Examples

Basic example

local leap = require('leap')

local c = leap.Controller()
print(c)

local lastFrameID = -1

local on = true

print("Press Enter to quit...")

while on
do
   local f = c:frame()
   if lastFrameID ~= f.ID then
      lastFrameID = f.ID
      print("ID " .. f.ID, f.FPS .. " FPS")

      if f.hands then
         print("leftmost.palmPosition.x", f.hands.leftmost.palmPosition.x)
      end
   end
end

First include the library and then create a leap.Controller, then poll the controller for receiving frames by calling c:frame() to be sure that a new frame is polled control for the frame ID, like in the example above.

Example with Awesome-wm

local gears = require("gears")
local leap = require("leap")

local controller = leap.Controller()
local lastFrameID = -1

local leapPoller = gears.timer
{
    timeout = 0.0085, -- 115 FPS
    autostart = true, -- default is false
    callback = function ()
        local frame = controller.frame()

        if lastFrameID ~= frame.ID then
            lastFrameID = frame.ID

            print("ID " .. frame.ID, frame.FPS .. " FPS")
        end
    end
}

An example on how to use lua-leap with Awesome-wm, in this case gears allows to poll the controller 115 times each seconds which is the highest FPS the controller can get. In the example above we're just logging the ID of the frame and the FPS on the device for testing.

Notes

The actual implementation generates a lua table with the data extracted from the frame, the data structure is similare of the Websocket version without having the overhead of using websockets.

Table structure

This is the message structure for a Frame in lua:

{
    ID,
    TS,
    FPS,
    handCount,
    hands = {
        frontmost = {
            confidence,
            id,
            isValid,
            isLeft,
            isRight,
            tosting,
            direction = {
                x,
                y,
                z,
                pitch,
                yaw,
                roll
            },
            palmNormal = { ... },
            palmPosition = { ... },
            palmVelocity = { ... },
            sphereRadius
        },
        leftmost = { ... },
        rightmost = { ... }
    }
}

Versions

Working on 0.1.0

marcopompili/lua-leap