윈도 API를 이용한 wav 사운드 파일 재생

package main

import (
	"syscall"
	"unsafe"
)

const (
	SND_SYNC      uint = 0x0000 /* play synchronously (default) /
	SND_ASYNC     uint = 0x0001 / play asynchronously /
	SND_NODEFAULT uint = 0x0002 / silence (!default) if sound not found /
	SND_MEMORY    uint = 0x0004 / pszSound points to a memory file /
	SND_LOOP      uint = 0x0008 / loop the sound until next sndPlaySound /
	SND_NOSTOP    uint = 0x0010 / don't stop any currently playing sound /

	SND_NOWAIT      uint = 0x00002000 / don't wait if the driver is busy /
	SND_ALIAS       uint = 0x00010000 / name is a registry alias /
	SND_ALIAS_ID    uint = 0x00110000 / alias is a predefined ID /
	SND_FILENAME    uint = 0x00020000 / name is file name /
	SND_RESOURCE    uint = 0x00040004 / name is resource name or atom /
	SND_PURGE       uint = 0x0040     / purge non-static events for task /
	SND_APPLICATION uint = 0x0080     / look for application specific association /
	SND_SENTRY      uint = 0x00080000 / Generate a SoundSentry event with this sound /
	SND_RING        uint = 0x00100000 / Treat this as a "ring" from a communications app - don't duck me /
	SND_SYSTEM      uint = 0x00200000 / Treat this as a system sound /

	SND_ALIAS_START uint = 0 / alias base */
)

var (
	mmsystem = syscall.MustLoadDLL("winmm.dll")

	playSound     = mmsystem.MustFindProc("PlaySound")
	sndPlaySoundA = mmsystem.MustFindProc("sndPlaySoundA")
	sndPlaySoundW = mmsystem.MustFindProc("sndPlaySoundW")
)

// PlaySound play sound in Windows
func PlaySound(sound string, hmod int, flags uint) {
	if playSound == nil {
		return
	}

	s16,  := syscall.UTF16PtrFromString(sound)
	playSound.Call(uintptr(unsafe.Pointer(s16)), uintptr(hmod), uintptr(flags))
}

// SndPlaySoundA play sound file in Windows
func SndPlaySoundA(sound string, flags uint) {
	if sndPlaySoundA == nil {
		return
	}

	b := append([]byte(sound), 0)
	sndPlaySoundA.Call(uintptr(unsafe.Pointer(&b[0])), uintptr(flags))
}

// SndPlaySoundW play sound file in Windows
func SndPlaySoundW(sound string, flags uint) {
	if SndPlaySoundW == nil {
		return
	}
	s16,  := syscall.UTF16PtrFromString(sound)
	sndPlaySoundW.Call(uintptr(unsafe.Pointer(s16)), uintptr(flags))
}