touch_input_win.cpp

#include <Windows.h>

BOOL TouchInput(POINTER_FLAGS pointerFlags, int x, int y)
{
    POINTER_TOUCH_INFO contact = { 0 };
    contact.pointerInfo.pointerType = PT_TOUCH;
    contact.pointerInfo.pointerFlags = pointerFlags;
    contact.pointerInfo.ptPixelLocation.x = x;
    contact.pointerInfo.ptPixelLocation.y = y;
    contact.pointerInfo.pointerId = 0;
    return InjectTouchInput(1, &contact);
}

BOOL TouchInputDown(int x, int y) 
{
    return TouchInput(POINTER_FLAG_INRANGE | POINTER_FLAG_INCONTACT | POINTER_FLAG_DOWN, x, y);
}

BOOL TouchInputDrag(int x, int y)
{
    return TouchInput(POINTER_FLAG_INRANGE | POINTER_FLAG_INCONTACT | POINTER_FLAG_UPDATE, x, y);
}

BOOL TouchInputUp(int x, int y)
{
    return TouchInput(POINTER_FLAG_INRANGE | POINTER_FLAG_UP, x, y);
}

// Left to right swipe simulation (app switch in Win8/8.1)
void SimulateTouchSwipe()
{
    InitializeTouchInjection(1, TOUCH_FEEDBACK_NONE);
    
    int x = 0, y = 10;
    
    TouchInputDown(0, 10);
    
    for (int itr = 0; itr < 100; ++itr) {
        x = (itr * 10);
        TouchInputDrag(x, y);
    }
    
    TouchInputUp(x, y);
}