Need simple sound

[FoxyBrown via Digitalmars-d-learn]

Heres a better version that automatically generates a class 
wrapping the portaudio.dll. Need portaudio.di(possibly renamed to 
portaudio.d and imported). Still same problem as original though.



import portaudio;
import std.conv, std.stdio;
import core.stdc.stdio;

alias BOOL = ubyte;
alias DWORD = uint;

auto BuildDLLClassFromCHeader(alias modulename, string name)()
{
	import std.traits, std.algorithm, std.meta;
	auto s = "extern (C) class " ~name~"\n{\n\timport ___import = 
"~moduleName!modulename~";\n";
	mixin("import "~moduleName!modulename~";");
	foreach(m; AliasSeq!(__traits(allMembers, modulename)))
	{		
		mixin("alias member = " ~ fullyQualifiedName!(modulename) ~ "." 
~ m ~ ";");		
		static if (is(typeof(member) == function))
			static if (functionLinkage!member != "C")
				continue;
			else
				s ~= "\tpublic static typeof(___import."~__traits(identifier, 
member)~")* "~__traits(identifier, member)~";\n";
	}
	
	return s ~ "}";
}

void DllImport(alias T)(string dllName)
{
	import core.sys.windows.windows, std.conv, std.meta;
	auto dll = LoadLibrary(to!wstring(dllName~"\0").ptr);
	if (dll == null)
		assert(0, "Cannot load DLL `"~dllName~"'");

	foreach(fname; __traits(derivedMembers, T))
	{		
		auto func = GetProcAddress(dll, fname);
		enum s = "auto p = cast(void**)&"~T.stringof~"."~fname~"; *p = 
cast(typeof(p))func;";				
		mixin(s);
	}
}


mixin(BuildDLLClassFromCHeader!(portaudio, "PortAudioDLL")());








struct Phase
{
     float left=0, right=0;
}

bool test = false;
extern(C) int sawtooth(const(void)* inputBuffer, void* 
outputBuffer, size_t framesPerBuffer, 
const(PaStreamCallbackTimeInfo)* timeInfo, PaStreamCallbackFlags 
statusFlags, void *userData)
{
	test = true;
     auto phase = cast(Phase*)userData;
     auto pout = cast(float*)outputBuffer;
     enum vol = 0.2f;
     foreach(i; 0 .. framesPerBuffer)
     {
         *pout++ = vol * phase.left;
         *pout++ = vol * phase.right;

         phase.left += 0.01f;
         if (phase.left >= 1.0f) phase.left -= 2.0f;

         phase.right += 0.03f;
         if (phase.right >= 1.0f) phase.right -= 2.0f;
     }
     return 0;
}

int main()
{
	DllImport!PortAudioDLL("portaudio_x86.dll");
	with(PortAudioDLL)
	{
		enum NUM_SECONDS = 5;

		PaStream* stream;
		PaError err;
		Phase phase_data;
	
		

		if ((err = Pa_Initialize()) == paNoError)
		{
			writeln("---------------------------------------------------------------------------");

			auto numDevices = Pa_GetDeviceCount();
			if(numDevices < 0)
			{
				printf("ERROR: Pa_CountDevices returned 0x%x\n", numDevices);
				err = numDevices;
				goto Lerror;
			}

		
			for(auto i = 0; i < numDevices; i++ )
			{	
				auto deviceInfo = Pa_GetDeviceInfo(i);
				writeln("Device "~to!string(i)~" > 
"~to!string(deviceInfo.name)~", 
"~to!string(deviceInfo.maxInputChannels)~", 
"~to!string(deviceInfo.maxOutputChannels)~", 
"~to!string(deviceInfo.defaultLowOutputLatency)~","~to!string(deviceInfo.defaultHighOutputLatency)~", "~to!string(deviceInfo.defaultSampleRate)~", "~to!string(deviceInfo.hostApi));
			}

			double sampleRate = 44100;
			PaStreamParameters* input;
			if (input != null)
			{
				input.device = 0;
				auto id = Pa_GetDeviceInfo(input.device);
				input.hostApiSpecificStreamInfo = null;
				input.channelCount = id.maxInputChannels;
				input.sampleFormat = paFloat32;
				input.suggestedLatency = (id.defaultLowInputLatency + 
id.defaultHighInputLatency)/2;
				sampleRate = id.defaultSampleRate;
			}
			PaStreamParameters* output = new PaStreamParameters();
			if (output != null)
			{
				output.device = 9;
				auto od = Pa_GetDeviceInfo(output.device);
				output.hostApiSpecificStreamInfo = null;
				output.channelCount = od.maxOutputChannels;
				output.sampleFormat = paFloat32;
				output.suggestedLatency = (od.defaultLowOutputLatency + 
od.defaultHighOutputLatency)/2;
				sampleRate = od.defaultSampleRate;
			}
			if ((err =          Pa_OpenStream(&stream, input, output,      
             sampleRate, paFramesPerBufferUnspecified, paNoFlag, 
&sawtooth, &phase_data)) != paNoError) goto Lerror;



			if ((err = Pa_StartStream(stream)) != paNoError) goto Lerror;

			Pa_Sleep(NUM_SECONDS * 1000);

			writeln(test);
			if ((err = Pa_StopStream(stream)) != paNoError) goto Lerror;
			if ((err = Pa_CloseStream(stream)) != paNoError) goto Lerror;
			if ((err = Pa_Terminate()) != paNoError) goto Lerror;

			writeln("DONE");
			getchar();
			return 0;
		} else
		{
			Lerror:
				writeln(to!string(Pa_GetErrorText(err)));
				getchar();
				return 1;
		}
	}
	return 0;
}