mkottman · December 22, 2011 21:19 · Dec 22, 2011
diff --git a/multitouch.lua b/multitouch.lua
@@ -0,0 +1,50 @@
+-- Apple Multitouch MacBook trackpad in Lua using LuaJIT FFI, 2011 Michal Kottman
+-- definitions from http://www.steike.com/code/multitouch/
+
+local ffi = require 'ffi'
+
+ffi.cdef [[
+typedef struct { float x,y; } mtPoint;
+typedef struct { mtPoint pos,vel; } mtReadout;
+
+typedef struct {
+  int frame;
+  double timestamp;
+  int identifier, state, foo3, foo4;
+  mtReadout normalized;
+  float size;
+  int zero1;
+  float angle, majorAxis, minorAxis; // ellipsoid
+  mtReadout mm;
+  int zero2[2];
+  float unk2;
+} Finger;
+
+typedef void *MTDeviceRef;
+typedef int (*MTContactCallbackFunction)(int,Finger*,int,double,int);
+
+MTDeviceRef MTDeviceCreateDefault();
+void        MTRegisterContactFrameCallback(MTDeviceRef, MTContactCallbackFunction);
+void        MTDeviceStart(MTDeviceRef, int);
+
+typedef int (*MTCallback)(int device, Finger *data, int nFingers, double timestamp, int frame);
+
+unsigned int sleep(unsigned int seconds);
+]]
+
+local mt = ffi.load('/System/Library/PrivateFrameworks/MultitouchSupport.framework/Versions/Current/MultitouchSupport')
+
+local callback = ffi.cast('MTCallback', function(device, data, nFingers, timestamp, frame)
+	print('=== '..frame..', '..nFingers..' fingers ===')
+	for i=0,nFingers-1 do
+		local finger = data[i]
+		local pos = finger.normalized.pos
+		print(i, finger.identifier, pos.x, pos.y, finger.size)
+	end
+	return 0
+end)
+
+local dev = mt.MTDeviceCreateDefault()
+mt.MTRegisterContactFrameCallback(dev, callback)
+mt.MTDeviceStart(dev, 0);
+ffi.C.sleep(0xFFFFFFFF)