examples/timer1.c

/*
          __
         / /_______________  ____  ___
        / __/ ___/ ___/ __ \/ __ \/ _ \
       / /_(__  ) /__/ /_/ / /_/ /  __/
       \__/____/\___/\____/ .___/\___/
                         /_/

    timer1.c
    basic timing of stimulus onset and response
*/

#include <tscope.h>

// trial timing constants
// Tscope uses clock tics
// use mtt function to convert milliseconds to tics
#define FIXTM   mtt(500)
#define BLANKTM mtt(500)
#define MAXTM   mtt(0)

// structure for the data we're interested in
struct {
    int rt;                     // response time
    int re;                     // timing error
    int resp;                   // response value
} data;

// structure for temporary timing data
// use 64 bit integers to store tic values
struct {
    __int64 junk;               // junk variabele
    __int64 t1, e1;             // timestamp and error stimulus onset
    __int64 t2, e2;             // timestamp and error response onset
} tmp;

int main()
{
    // prepare the subject
    ts_printf_centre(0, 10, "press one of the mouse buttons");
    ts_printf_centre(0, -10, "when the stimulus appears");
    ts_button(XMAX - 20, -YMAX + 20);
    ts_clrscr();

    // define response buttons (left and right mouse key)
    ts_defkey(M1);              // the first defined key will have response
    ts_defkey(M2);              // value 1, the second 2, etc. 


    // fixation mark
    // we dont't use this timing mark for computation of
    // the reaction time -> put it in a junk variable
    ts_vsync(&tmp.junk, &tmp.junk);
    ts_printf_centre(0, 0, "+");
    ts_wait(FIXTM);

    // blank screen
    // we don't use this timing mark either
    ts_vsync(&tmp.junk, &tmp.junk);
    ts_clrscr();
    ts_wait(BLANKTM);

    // onset stimulus: this timing mark is the start of the rt
    ts_vsync(&tmp.t1, &tmp.e1);
    ts_printf_centre(0, 0, "stimulus");

    // wait for a response (maximum time 0 = wait forever)
    data.resp = ts_resp(&tmp.t2, &tmp.e2, MAXTM);
    ts_clrscr();

    // compute reaction time
    data.rt = ttm(tmp.t2 - tmp.t1); // reaction time=mark2-mark1, converted to ms
    data.re = ttmu(tmp.e1 + tmp.e2);    // error=error1+error2, converted to us

    // print some results on the screen
    ts_printf_centre(0, 0, "response: %d.", data.resp);
    ts_printf_centre(0, -20, "reaction time: %d milliseconds.", data.rt);
    ts_printf_centre(0, -40, "timing error: %d microseconds.", data.re);

    ts_button(-XMAX + 20, YMAX - 20);
    return 0;
}

END_OF_MAIN();
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