libs/backends/wavesaudio/portmidi/src/porttime/ptwinmm.c

   1 /* ptwinmm.c -- portable timer implementation for win32 */
   2
   3
   4 #include "porttime.h"
   5
   6 #include <windows.h>
   7 #include <mmsystem.h>
   8 #include <time.h>
   9
  10 TIMECAPS caps;
  11
  12 static long time_offset = 0;
  13 static int time_started_flag = FALSE;
  14 static long time_resolution;
  15 static MMRESULT timer_id;
  16 static PtCallback *time_callback;
  17
  18 void CALLBACK winmm_time_callback(UINT uID, UINT uMsg, DWORD_PTR dwUser,
  19                                   DWORD_PTR dw1, DWORD_PTR dw2)
  20 {
  21     (*time_callback)(Pt_Time(), (void *) dwUser);
  22 }
  23
  24
  25 PMEXPORT PtError Pt_Start(int resolution, PtCallback *callback, void *userData)
  26 {
  27     if (time_started_flag) return ptAlreadyStarted;
  28     timeBeginPeriod(resolution);
  29     time_resolution = resolution;
  30     time_offset = timeGetTime();
  31     time_started_flag = TRUE;
  32     time_callback = callback;
  33     if (callback) {
  34         timer_id = timeSetEvent(resolution, 1, winmm_time_callback,
  35             (DWORD_PTR) userData, TIME_PERIODIC | TIME_CALLBACK_FUNCTION);
  36         if (!timer_id) return ptHostError;
  37     }
  38     return ptNoError;
  39 }
  40
  41
  42 PMEXPORT PtError Pt_Stop()
  43 {
  44     if (!time_started_flag) return ptAlreadyStopped;
  45     if (time_callback && timer_id) {
  46         timeKillEvent(timer_id);
  47         time_callback = NULL;
  48         timer_id = 0;
  49     }
  50     time_started_flag = FALSE;
  51     timeEndPeriod(time_resolution);
  52     return ptNoError;
  53 }
  54
  55
  56 PMEXPORT int Pt_Started()
  57 {
  58     return time_started_flag;
  59 }
  60
  61
  62 PMEXPORT PtTimestamp Pt_Time()
  63 {
  64     return timeGetTime() - time_offset;
  65 }
  66
  67
  68 PMEXPORT void Pt_Sleep(int32_t duration)
  69 {
  70     Sleep(duration);
  71 }