Vanara/UnitTests/PInvoke/Multimedia/midiTests.cs

using NUnit.Framework;
using NUnit.Framework.Internal;
using System;
using System.Runtime.InteropServices;
using System.Threading;
using static Vanara.PInvoke.Gdi32;
using static Vanara.PInvoke.WinMm;

namespace Vanara.PInvoke.Tests
{
	[TestFixture]
	public class midiTests
	{
		public HMIDIOUT hOut;

		[OneTimeSetUp]
		public void _Setup()
		{
			midiOutOpen(out hOut, 0);
		}

		[OneTimeTearDown]
		public void _TearDown()
		{
			midiOutClose(hOut);
		}

		[StructLayout(LayoutKind.Sequential)]
		struct midiMsg
		{
			public uint dwData;

			public midiMsg(params byte[] a) => dwData = BitConverter.ToUInt32(a, 0);

			public static implicit operator uint(midiMsg m) => m.dwData;
		}

		[Test]
		public void TestPlayNote()
		{
			Assert.That(midiOutOpen(out var device, 0), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			bool playing = false;
			const byte velocity = 100;
			try
			{
				for (int i = 0; i < 6; i++)
				{
					var msg = new midiMsg(0x90, 60, playing ? velocity : (byte)0, 0);
					playing = !playing;
					Assert.That(midiOutShortMsg(device, msg), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
					Thread.Sleep(200);
				}
			}
			finally
			{
				// turn any MIDI notes currently playing:
				midiOutReset(device);

				// Remove any data in MIDI device and close the MIDI Output port
				Assert.That(midiOutClose(device), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			}
		}

		[Test]
		public void midiOutGetDevCapsTest()
		{
			Assert.That(midiOutGetDevCaps(0, out var mCap, MIDIOUTCAPS.NativeSize), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			mCap.WriteValues();
		}

		[Test]
		public void midiOutGetIDTest()
		{
			Assert.That(midiOutGetID(hOut, out var devId), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			TestContext.Write(devId);
		}

		[Test]
		public void midiOutGetNumDevsTest()
		{
			uint c = 0;
			Assert.That(c = midiOutGetNumDevs(), Is.GreaterThanOrEqualTo(0));
			TestContext.Write(c);
		}

		[Test]
		public void midiOutGetSetVolumeTest()
		{
			Assert.That(midiOutGetVolume(hOut, out var vol), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			TestContext.Write(vol);
			var nVol = vol + 100;
			Assert.That(midiOutSetVolume(hOut, nVol), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			Assert.That(midiOutSetVolume(hOut, vol), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
		}

		[Test]
		public void midiOutHeaderTest()
		{
			const uint bufLen = 32 * 1024;
			MIDIHDR mhdr = new() { dwBufferLength = bufLen, lpData = Marshal.AllocHGlobal((int)bufLen) };

			try
			{
				Assert.That(midiOutLongMsg(hOut, mhdr, MIDIHDR.NativeSize), Is.EqualTo(MMRESULT.MIDIERR_UNPREPARED));

				Assert.That(midiOutPrepareHeader(hOut, ref mhdr, MIDIHDR.NativeSize), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
				mhdr.WriteValues();
				Assert.That(midiOutLongMsg(hOut, mhdr, MIDIHDR.NativeSize), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
				Assert.That(midiOutUnprepareHeader(hOut, ref mhdr, MIDIHDR.NativeSize), Is.EqualTo(MMRESULT.MMSYSERR_NOERROR));
			}
			finally
			{
				Marshal.FreeHGlobal(mhdr.lpData);
			}
		}
	}
}