SMT Library (Sensible UI's Multi-Touch) Library.

1.0

File

• smt.h/smt.cpp

Date

• 2011/01/26

Author

• Wook Chang(wook.chang@seneibleui.com)
• YoungSeok Ahn(david.ahn@seneibleui.com)

Developer

• Sensible UI (http://www.sensibleui.com)

All rights reserved.

• Copyright (c) 2010 Sensible UI (http://www.sensibleui.com)

Summary

SMT Library is a part of OpenMT project.

SMT (Sensibleui's Multi Touch) Library is an ANSI C-based multi-touch algorithm, so to be easily ported to microcontrollers.

With multitouch data provided, it processes the data and outputs touch position, touch ID, and gesture recognition results.

• Input: int mt_sensor_data[MAXCOL*MAXROW]
  • Note: SMT library uses a 1-dimensional array to store 2D multi-touch data. It doesn't concern if data storage is based on row-wise or column-wise.
• Output: TOUCHEVENT EVENTLIST[MAX_EVENT]
  • Note: SMT library allows multiple touch events for a single touch frame. That is, for kth time instant, SMT library will give you N touch events. This design policy can be justified as follows.

Imagine that you are control a photo with multi-touch. In this case you want to simultaneously rotate and rersize the size of the photo. And your action will produce rotation and resize (scaling) events at a same time instant. This is why SMT sends out multiple events at a single time instant.

Example

This tutorial shows example usage of SMT library. In using SMT, the most important functions are initsmt() and runsmt().

        #include <smt.h>
        
        void main(void)
        {
                // Set and initialize parameters of multi-touch algorithms
                initsmt();

                do
                {
                        // You should provide a data acquisition code
                        // Touch data SHOULD be stored at mt_sensor_data[] variable
                        your_data_acquisition_routine(mt_sensor_data);

                        // Call SMT for every single frame.
                        runsmt();

                        // All computing results of SMT library is stored in
                        // TOUCHEVENT EVENTLIST[] variable.
                        // You can directly access it or make your own reporting routine
                        // as follows:
                        your_report_routine(EVENTLIST);
                } while (1);
        }

____________________________________________________________________________________

File

• SMTG.h/SMTG.cpp

Date

• 2011/01/26

Author

• Wook Chang(wook.chang@seneibleui.com)
• YoungSeok Ahn(david.ahn@seneibleui.com)

Developer

• Sensible UI (http://www.sensibleui.com)

All rights reserved.

• Copyright (c) 2010 Sensible UI (http://www.sensibleui.com)

Development Goal

• SMTG is designed to recognize multi-touch gestures from the OpenMT multi-touch hardware.

Summary

SMTG Library is a part of OpenMT project.

SMTG Library include gesture recognition and interpreter.

Example

• Input: TUIO Message received by UDP communication.
• Output: gesture recognition & gesture interpreter.

        void main(void)
        {
                do
                {
                        // Set and initialize parameters of SMTG algorithm when the number of touch is zero.
                        if(the number of touch == 0) InitializeSMTG();

                        // Call ProcessSMTG for every single frame.
                        ProcessSMTG();
                
                } while (1);
        }

Example

• Input: Touch information received by touch variables.
• Output: gesture recognition & gesture interpreter.

        void main(void)
        {
                do
                {
                        // Set and initialize parameters of SMTG algorithm when the number of touch is zero.
                        if(the number of touch == 0) InitializeSMTG();

                        // assign variable to save touch values from 
                        int id[SG_MAX_TOUCH];           // TUIO compatible monotonically increasing touch ID
                        float fx[SG_MAX_TOUCH];         // x value of touch point.
                        float fy[SG_MAX_TOUCH];         // y value of touch point.
                        float fdx[SG_MAX_TOUCH];        // displacement between current x value of touch point and old x value of it.
                        float fdy[SG_MAX_TOUCH];        // displacement between current y value of touch point and old y value of it.

                        int nBlobsSize = 0;
                        for(int i=0;i<num_touch;i++) // num_touch is the number of current touch.
                        {
                                id[nBlobsSize] = cur_touch->getCursorID();
                                fx[nBlobsSize] = cur_touch->getX();
                                fy[nBlobsSize] = cur_touch->getY();
                                fdx[nBlobsSize] = cur_touch->getXSpeed();
                                fdy[nBlobsSize] = cur_touch->getYSpeed();

                                nBlobsSize++;
                        }

                        sgRecognizeGesture(nBlobsSize, id, fx, fy, fdx, fdy);  // recognize gesture from touch information.
                        sgInterpreteGesture(MAGIC_MT_TRACKPAD_INTERPRETER);    // interpret meaning of gesture from recgnized gesture results.

                } while (1);

        }