+
+ #ifdef __DOS__
+ // Under DOS the MGL timer has a 24hr period, so consider the 12 hours
+ // before y to be 'less' and the the 12 hours after 'greater' modulo
+ // 24 hours.
+ inline bool wxTickGreaterEqual(wxTimerTick_t x, wxTimerTick_t y)
+ {
+ // _EVT_getTicks wraps at 1573040 * 55
+ const wxTimerTick_t modulus = 1573040 * 55;
+ return (2 * modulus + x - y) % modulus < modulus / 2;
+ }
+ #else
+ // If wxTimerTick_t is 32-bits then it'll wrap in around 50 days. So
+ // let the 25 days before y be 'less' and 25 days after be 'greater'.
+ inline bool wxTickGreaterEqual(wxTimerTick_t x, wxTimerTick_t y)
+ {
+ // This code assumes wxTimerTick_t is an unsigned type.
+ // Set half_modulus with top bit set and the rest zeros.
+ const wxTimerTick_t half_modulus = ~((~(wxTimerTick_t)0) >> 1);
+ return x - y < half_modulus;
+ }
+ #endif