C言語／C++/waveloop - Sample is best!

開発環境	Microsoft Visual Studio Community 2017
実行環境	Microsoft Windows 10 Home (64-bit)
プロジェクトの種類	Visual C++ / 空のプロジェクト
プロジェクト名	waveloop

waveloop.cpp

// プロジェクトのプロパティ
// Unicode文字セット
 
#pragma comment(lib, "winmm")
 
#include <Windows.h>
#include <wchar.h>
#include "Resource.h"
 
#define SAMPLE_RATE 44100
#define BUF_LEN 22050
 
// 関数プロトタイプ宣言
void Trace(LPCWSTR format, ...);
INT_PTR CALLBACK MainDlg(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam);
void Play(HWND hDlg);
void Stop(HWND hDlg);
void GenerateWaveForm();
 
// グローバル変数
HWAVEOUT hwo = NULL;
WAVEHDR wh;
 
BYTE waveform[BUF_LEN];
int phase;
 
int APIENTRY wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPWSTR lpCmdLine, int nCmdShow)
{
	DialogBox(hInstance, MAKEINTRESOURCE(IDD_MAINDLG), NULL, MainDlg);
	return 0;
}
 
void Trace(LPCWSTR format, ...)
{
	va_list arg_ptr;
	WCHAR buffer[256];
 
	va_start(arg_ptr, format);
	int size = _vsnwprintf_s(buffer, _TRUNCATE, format, arg_ptr);
	va_end(arg_ptr);
	OutputDebugString(buffer);
}
 
INT_PTR CALLBACK MainDlg(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
	INT_PTR ret = TRUE;	// メッセージを処理した
 
	switch (message) {
	case MM_WOM_DONE:
		GenerateWaveForm();
		break;
	case MM_WOM_OPEN:
		Trace(L"MM_WOM_OPEN:\n");
		break;
	case MM_WOM_CLOSE:
		Trace(L"MM_WOM_CLOSE:\n");
		break;
	case WM_COMMAND:
		switch (LOWORD(wParam)) {
		case IDC_PLAY:
			Play(hDlg);
			break;
		case IDC_STOP:
			Stop(hDlg);
			break;
		case IDCANCEL:
			EndDialog(hDlg, IDCANCEL);
			break;
		}
		break;
	case WM_INITDIALOG:
		ret = TRUE;		// SetFocusでフォーカスを設定した場合はFALSE
		break;
	case WM_CLOSE:
		Stop(hDlg);
		ret = FALSE;
		break;
	default:
		ret = FALSE;	// メッセージを処理しなかった
	}
 
	return ret;
}
 
void Play(HWND hDlg)
{
	MMRESULT mmr;
 
	WAVEFORMATEX wfx;
	wfx.wFormatTag = WAVE_FORMAT_PCM;
	wfx.nChannels = 1;
	wfx.nSamplesPerSec = SAMPLE_RATE;
	wfx.nAvgBytesPerSec = SAMPLE_RATE;
	wfx.nBlockAlign = 1;
	wfx.wBitsPerSample = 8;
	wfx.cbSize = 0;
	mmr = waveOutOpen(&hwo, WAVE_MAPPER, &wfx, (DWORD_PTR)hDlg, NULL, CALLBACK_WINDOW);
	Trace(L"waveOutOpen: %u\n", mmr);
 
	wh.lpData = (LPSTR)waveform;
	wh.dwBufferLength = BUF_LEN;
	wh.dwFlags = 0;
	mmr = waveOutPrepareHeader(hwo, &wh, sizeof wh);
	Trace(L"waveOutPrepareHeader: %u\n", mmr);
 
	phase = 0;
	GenerateWaveForm();
 
	EnableWindow(GetDlgItem(hDlg, IDC_PLAY), FALSE);
}
 
void Stop(HWND hDlg)
{
	Trace(L"Stop()\n");
	if (hwo) {
		MMRESULT mmr;
		mmr = waveOutReset(hwo);
		Trace(L"waveOutReset: %u\n", mmr);
		mmr = waveOutUnprepareHeader(hwo, &wh, sizeof wh);
		Trace(L"waveOutUnprepareHeader: %u\n", mmr);
		mmr = waveOutClose(hwo);
		Trace(L"waveOutClose: %u\n", mmr);
		hwo = NULL;
	}
	EnableWindow(GetDlgItem(hDlg, IDC_PLAY), TRUE);
}
 
void GenerateWaveForm()
{
	for (int i = 0; i < BUF_LEN; i++) {
		phase += 440;
		if (SAMPLE_RATE <= phase) phase -= SAMPLE_RATE;
		double t = phase / (double)SAMPLE_RATE;
		waveform[i] = 128 + (t < 0.5 ? 1 : -1) * 10;
	}
 
	waveOutWrite(hwo, &wh, sizeof wh);
}
 

Resource.h

#define IDD_MAINDLG	100
 
#define IDC_STATIC	-1
#define IDC_PLAY	1000
#define IDC_STOP	1001
 

waveloop.rc

// resource script
#include <windows.h>
#include "resource.h"
 
IDD_MAINDLG DIALOGEX 100, 100, 320, 200
STYLE DS_SETFONT | DS_MODALFRAME | DS_FIXEDSYS | WS_POPUP | WS_CAPTION | WS_SYSMENU
EXSTYLE WS_EX_APPWINDOW
CAPTION "waveloop"
FONT 9, "MS UI Gothic"
BEGIN
	PUSHBUTTON		"Play(&P)",IDC_PLAY, 10, 10, 50, 15
	PUSHBUTTON		"Stop(&S)",IDC_STOP, 70, 10, 50, 15
END